Refine
Year of publication
- 2024 (7)
- 2023 (8)
- 2022 (49)
- 2021 (68)
- 2020 (84)
- 2019 (89)
- 2018 (92)
- 2017 (84)
- 2016 (84)
- 2015 (75)
- 2014 (58)
- 2013 (40)
- 2012 (61)
- 2011 (52)
- 2010 (28)
- 2009 (39)
- 2008 (13)
- 2007 (14)
- 2006 (32)
- 2005 (42)
- 2004 (39)
- 2003 (31)
- 2002 (17)
- 2001 (25)
- 2000 (27)
- 1999 (21)
- 1998 (13)
- 1997 (14)
- 1996 (5)
- 1995 (18)
- 1994 (17)
- 1993 (4)
- 1992 (1)
- 1991 (2)
- 1989 (1)
- 1988 (1)
- 1987 (1)
- 1982 (1)
Document Type
- Article (759)
- Doctoral Thesis (278)
- Postprint (106)
- Conference Proceeding (36)
- Review (34)
- Other (31)
- Monograph/Edited Volume (9)
- Habilitation Thesis (5)
- Preprint (2)
- Master's Thesis (1)
Keywords
- inflammation (23)
- obesity (18)
- oxidative stress (15)
- insulin (14)
- type 2 diabetes (14)
- Biomarker (13)
- LC-MS/MS (13)
- cancer (12)
- carotenoids (12)
- insulin resistance (12)
- FGF21 (10)
- selenium (10)
- sphingolipids (10)
- α-amylase/trypsin inhibitors (10)
- acid sphingomyelinase (9)
- ceramide (9)
- cytokines (9)
- Adipositas (8)
- Caenorhabditis elegans (8)
- Insulin resistance (8)
- Manganese (8)
- Selen (8)
- metabolic syndrome (8)
- protein (8)
- Oxidative stress (7)
- adipose tissue (7)
- metabolism (7)
- retinol (7)
- Geschmack (6)
- Mitochondria (6)
- NASH (6)
- Obesity (6)
- Pregnancy (6)
- Prunus avium L. (6)
- SDS-PAGE (6)
- Solanaceae (6)
- Vitamin A (6)
- aging (6)
- cholesterol (6)
- diet (6)
- disease (6)
- epigenetics (6)
- polyphenols (6)
- pregnancy (6)
- probiotics (6)
- retinol-binding protein 4 (6)
- taste (6)
- vitamin A (6)
- zinc (6)
- Aging (5)
- Arsenolipids (5)
- C. elegans (5)
- DNA methylation (5)
- Dexamethasone (5)
- Energiestoffwechsel (5)
- Entzündung (5)
- Epigenetics (5)
- Fetal programming (5)
- HPLC (5)
- Inflammation (5)
- LC–MS/MS (5)
- NAFLD (5)
- Sphingolipids (5)
- Sphingosine 1-phosphate (5)
- Type 2 diabetes (5)
- adiponectin (5)
- biomarker (5)
- cardiovascular disease (5)
- coffee by-products (5)
- diabetes (5)
- genes (5)
- linagliptin (5)
- liver (5)
- mass spectrometry (5)
- mitochondria (5)
- plasma (5)
- type 2 diabetes mellitus (5)
- wheat (5)
- Adipose tissue (4)
- Arsenic-containing fatty acids (4)
- Arsenic-containing hydrocarbons (4)
- C-reactive protein (4)
- Cardiovascular diseases (4)
- Carotenoids (4)
- DNA damage (4)
- Emulsion (4)
- Endothelin (4)
- Flower buds (4)
- GDF15 (4)
- Hypertension (4)
- Insulin (4)
- Mass spectrometry (4)
- Metabolisches Syndrom (4)
- PUFA (4)
- Placenta (4)
- SDS PAGE (4)
- Sphingosine-1-phosphate (4)
- Typ-2-Diabetes (4)
- Vitamin E (4)
- Zinc (4)
- adipogenesis (4)
- brain (4)
- cell-based assay (4)
- cells (4)
- chronic kidney disease (4)
- copper (4)
- database (4)
- electrochemistry (4)
- epidemiology (4)
- glutathione peroxidase (4)
- gut microbiota (4)
- lipid metabolism (4)
- lutein (4)
- macrophages (4)
- malnutrition (4)
- manganese (4)
- metabolomics (4)
- micronutrients (4)
- neurodegeneration (4)
- protein modification (4)
- proteinuria (4)
- resistin (4)
- transcriptomics (4)
- weight loss (4)
- Abscisic acid (3)
- Acid sphingomyelinase (3)
- African indigenous vegetables (3)
- Alterung (3)
- Arabica coffee beans (3)
- Bilophila wadsworthia (3)
- Bioavailability (3)
- Bittergeschmack (3)
- Boron exposure (3)
- Diabetes (3)
- Diabetic nephropathy (3)
- Doehlert design (3)
- Dormancy (3)
- Drug delivery (3)
- Ernährung (3)
- Fettstoffwechsel (3)
- GCN2 (3)
- Glucagon (3)
- Glucosinolates (3)
- Hepatocytes (3)
- Insulinresistenz (3)
- Kidney (3)
- MALDI-TOF-MS (3)
- Mendelian randomization (3)
- Meta-analysis (3)
- Methylmercury (3)
- Mitochondrien (3)
- NZO (3)
- Neurotoxicity (3)
- Nrf2 (3)
- Nutrition (3)
- Proteom (3)
- Selenium (3)
- Skeletal muscle (3)
- Sphingosine kinase (3)
- Stability (3)
- Toxicity (3)
- Verhalten (3)
- acid ceramidase (3)
- activated carbon (3)
- adiposity (3)
- age (3)
- antioxidants (3)
- bioavailability (3)
- biofortification (3)
- bitter taste (3)
- chronic diseases (3)
- coffee processing (3)
- colorectal cancer (3)
- diabetic nephropathy (3)
- differentiation (3)
- elevated plus-maze (3)
- energy metabolism (3)
- fatty acid metabolism (3)
- fatty acids (3)
- fibrosis (3)
- food choice (3)
- gallbladder cancer (3)
- glucocorticoid receptor (3)
- goblet cells (3)
- heart (3)
- high-sodium (3)
- homeostasis (3)
- iCheck (3)
- infection (3)
- kidney transplantation (3)
- lifestyle (3)
- liver metabolism (3)
- mitochondrial dysfunction (3)
- model (3)
- mortality (3)
- non-alcoholic fatty liver disease (3)
- nutrition (3)
- omega-3 fatty acids (3)
- open-field (3)
- p53 (3)
- plant volatiles (3)
- polymorphism (3)
- post-natal (3)
- pre-natal (3)
- prevention (3)
- prostaglandin E2 (3)
- protein restriction (3)
- proteome (3)
- red meat (3)
- redox state (3)
- refinement (3)
- saliva (3)
- sample preparation (3)
- sarcopenia (3)
- selenoprotein P (3)
- sphingomyelin (3)
- sphingosine (3)
- sphingosine-1-phosphate (3)
- sulfotransferase (3)
- survival (3)
- tocopherols (3)
- transformation products (3)
- transthyretin (3)
- type 2 (3)
- vascular calcification (3)
- vegetables (3)
- 1-Hydroxymethylpyren (2)
- 1-aminodecylidene bis-phosphonic acid (2)
- AMD (2)
- Ageing (2)
- Akt pathway (2)
- Amino acids (2)
- Amylase (2)
- Anemia (2)
- Apoptosis (2)
- Arabica coffee (2)
- Arabidopsis (2)
- Arsenic (2)
- BMI (2)
- BMI change (2)
- Beer (2)
- Birth weight (2)
- Blood (2)
- Blood pressure (2)
- BoNT (2)
- BoNT/B uptake (2)
- Boric acid (2)
- Botulinum neurotoxin (2)
- COVID 19 (2)
- CRISPR editing validation (2)
- Caco-2 (2)
- Caco-2 intestinal barrier model (2)
- Caco-2/HT-29-MTX-model (2)
- Caenorhabitis elegans (2)
- Camellia sinensis (2)
- Carotenoid (2)
- Carotinoide (2)
- Cattle (2)
- Ceramide (2)
- Ceramides (2)
- Cereals (2)
- Christentum (2)
- Chrysopidae (2)
- Circadian rhythm (2)
- Clinical (2)
- Cohort studies (2)
- Copper (2)
- Cow-side assay (2)
- Curcumin (2)
- Cytotoxicity (2)
- DNA adducts (2)
- DNA damage response (2)
- DPP-4 inhibitors (2)
- Development (2)
- Differenzierung (2)
- Donors (2)
- Dopamine (2)
- E-2 (2)
- ET-1 (2)
- Endothelial cells (2)
- Endothelin-1 (2)
- Energy metabolism (2)
- Epidemiologie (2)
- Ernährungsfaktoren (2)
- Ernährungsgewohnheit (2)
- Ethanol (2)
- FTY720 (2)
- Ferritin (2)
- Fettgewebe (2)
- Fettsäuren (2)
- Flavonoid (2)
- Fluorescence (2)
- Food labeling (2)
- Foxp3 (2)
- GI-GPx (2)
- GPx activity (2)
- Genotoxicity (2)
- Genregulation (2)
- Gestational diabetes (2)
- Gestational diabetes mellitus (2)
- Global DNA methylation (2)
- Glucose homeostasis (2)
- Glutathionperoxidase (2)
- HEK293 (2)
- HRMS (2)
- Hemoglobin (2)
- HepG2 (2)
- Hypermethylation (2)
- IGF-1 (2)
- IL-8 transcription (2)
- In vitro blood-brain barrier model (2)
- Inflammatory bowel disease (2)
- Insulin secretion (2)
- Iron deficiency anemia (2)
- Islam (2)
- Isoflavone (2)
- Judentum (2)
- Jurkat cells (2)
- Kaffee (2)
- Körperzusammensetzung (2)
- LC-MRM-MS (2)
- LC/HRMS (2)
- Labile zinc (2)
- Lebensstil (2)
- Leber (2)
- Linagliptin (2)
- Lipid metabolism (2)
- Lipidomics (2)
- Lymphocytes (2)
- M1/M2 differentiation (2)
- MALDI-TOF/MS (2)
- MRSA (2)
- Makrophagen (2)
- Maus (2)
- Meat (2)
- Mediterranean diet (2)
- Mercaptursäure (2)
- Mercuric mercury (2)
- Metabolomics (2)
- Method comparison (2)
- Microarray (2)
- Modified mycotoxins (2)
- Mortality (2)
- Mycotoxins (2)
- NAFLD/MAFLD (2)
- Nahrungssulfonate (2)
- Neutrophils (2)
- Nitric oxide (2)
- PTH (2)
- PXR (2)
- Pak choi (2)
- Palmitate (2)
- Parkinson disease (2)
- Pesticides (2)
- Phenole (2)
- Phenological modelling (2)
- Phenylpropanoids (2)
- Plackett–Burman design (2)
- Polymorphismus (2)
- Polyphenole (2)
- Post mortem chemistry (2)
- Prediabetes (2)
- Prostaglandin E2 (2)
- Proteasome (2)
- Protein oxidation (2)
- Protein restriction (2)
- RBP4 (2)
- RRR (2)
- Rats (2)
- Redoxregulation (2)
- Religiöses Leben (2)
- Renal failure (2)
- Reticulocytes (2)
- Review (2)
- S-XRF (2)
- SCFA (2)
- SFA (2)
- SIMS techniques (2)
- Sarcopenia (2)
- Se (2)
- Selenoproteine (2)
- Skeletal muscle cells (2)
- Skin nanocarrier (2)
- Skin penetration (2)
- Small for gestational age (2)
- Smpd1 (2)
- Solanum lycopersicum (2)
- Speisegebot (2)
- Stoffwechsel (2)
- Stress response (2)
- Sulforaphan (2)
- Sulfotransferase (2)
- TAS2R (2)
- TEM (2)
- TLR signaling (2)
- Tandem mass spectrometry (2)
- Technical enzymes (2)
- Tenebrio molitor larvae (2)
- Thiomersal (2)
- Thioredoxin (2)
- Tight Junction (2)
- Trace elements (2)
- Typ-2-Diabetes mellitus (2)
- VGCC (2)
- Vitamin K (2)
- Vollkorn (2)
- Whey protein (2)
- Xylanase (2)
- Zinc homeostasis (2)
- accumulation (2)
- activation (2)
- acute kidney injury (2)
- adipose tissue dysregulation (2)
- aflatoxin B1 (2)
- ageing (2)
- albuminuria (2)
- alkylierte polyzyklische aromatische Kohlenwasserstoffe (2)
- all-cause mortality (2)
- angiotensin receptor blockers (2)
- anorexia (2)
- anthropometric measures (2)
- anti-genotoxicity (2)
- anti-inflammatory nutrition (2)
- anti-oxidant activity (2)
- anti-oxidative capacity (2)
- anxiety-like behavior (2)
- apoptosis (2)
- appetite (2)
- ascorbate (2)
- atherosclerosis (2)
- autophagy (2)
- base excision repair (incision activity) (2)
- batch process (2)
- behavior (2)
- benzylic alcohol (2)
- benzylischer Alkohol (2)
- beta-cell (2)
- binding (2)
- biological pest control (2)
- birth weight (2)
- bisphosphonates (2)
- bitter (2)
- bitter taste receptors (2)
- body weight gain (2)
- botulinum toxin (2)
- bound phenolic compounds (2)
- brain insulin signaling (2)
- c. elegans (2)
- calcination (2)
- calcium (2)
- cancer cachexia (2)
- cancer chemoprevention (2)
- cancer epidemiology (2)
- cardiovascular diseases (2)
- carotenoid (2)
- carotenoid biosynthesis (2)
- cellular bioimaging (2)
- cerami-des (2)
- ceramides (2)
- cereal meals (2)
- chaperones (2)
- chronic fatigue (2)
- chronic psychosocial stress (2)
- chronic subordinate colony housing (CSC) (2)
- chronisch-entzündliche Darmerkrankungen (2)
- circadian clock (2)
- clusterin (2)
- coenzyme-a (2)
- coffee (2)
- colon carcinogenesis (2)
- continuous process (2)
- copper-related disorders (2)
- copy number analyses (2)
- coronary heart disease (2)
- cortisol (2)
- cyclooxygenase (2)
- cysteine alkylation (2)
- cytokine (2)
- depressive-like behavior (2)
- design of experiment (2)
- diabetes mellitus (2)
- dietary patterns (2)
- dietary restriction (2)
- digestive enzymes quantification (2)
- dogs (2)
- dormancy (2)
- drug delivery (2)
- eicosanoids (2)
- endothelin (2)
- endurance exercise (2)
- energy homeostasis (2)
- energy-metabolism (2)
- enzymology (2)
- equine (2)
- erythropoiesis (2)
- ethanol (2)
- exercise (2)
- exposome (2)
- exposome‐ wide association study (2)
- expression (2)
- extraction (2)
- fatigue reduction diet (2)
- fatty liver (2)
- feeding (2)
- fetal origins hypothesis (2)
- fetal programming (2)
- flavonoid (2)
- flavonoids (2)
- flower buds (2)
- food frequency questionnaire (2)
- force-field (2)
- forebrain (2)
- fractionation (2)
- fruit (2)
- functional inhibitors of acid sphin-gomyelinase (2)
- gene expression (2)
- genetically modified BoNT (2)
- glomerular filtration rate (2)
- glucagon (2)
- glucose (2)
- glucose intolerance (2)
- glucosinolates (2)
- glutathione (2)
- glycaemic control (2)
- growth behavior (2)
- growth restriction (2)
- gwas (2)
- hallervorden-spatz-syndrome (2)
- halophytes (2)
- hepatic steatosis (2)
- high protein diet (2)
- homologous recombination deficiency (2)
- homology-directed repair (2)
- hsp-70 (2)
- human excised skin (2)
- hydrolysis (2)
- hypertension (2)
- immunology (2)
- in vitro intestinal model (2)
- insulin signaling (2)
- insulin-resistance (2)
- interleukin-8 (2)
- intestinal microbiota (2)
- intestinal mucins (2)
- intestinal zinc resorption (2)
- ion-exchange chromatography (2)
- keratinocytes (2)
- kidney (2)
- kupffer cells (2)
- laminitis (2)
- later health (2)
- legumes (2)
- leptin (2)
- life-span (2)
- lipid peroxidation (2)
- lipidomics (2)
- liver fibrosis (2)
- loci (2)
- low birth weight (2)
- lung infection (2)
- lymphoma (2)
- lysosomal hydrolases (2)
- lysosome (2)
- maintenance of genomic integrity (2)
- mass index (2)
- meal timing (2)
- melatonin (2)
- membrane fusion (2)
- menadione (2)
- mercapturic acid (2)
- meta-analysis (2)
- metabolic disorders (2)
- metabolic stress (2)
- metabolic syndrom (2)
- method comparison (2)
- mice lacking (2)
- microarray (2)
- microcomputed tomography (2)
- microvascular complications (2)
- microwave assisted digestion (2)
- middle adulthood (2)
- mitochondria homeostasis (2)
- mitochondrial function (2)
- mobility-mass spectrometry (2)
- monensin (2)
- monitoring (2)
- mouse (2)
- mucus layer (2)
- multiple-pest infestation (2)
- muscarinic acetylcholine receptor (2)
- myalgic encephalomyelitis (2)
- myocardial infarction (2)
- myopathy (2)
- n-acetyl-cysteine (2)
- nanogels (2)
- nanoparticles (2)
- nanotoxicology (2)
- native American ancestry (2)
- neurodegenerative diseases (2)
- neurotoxicity (2)
- neurotoxins (2)
- nitric oxide (2)
- non-alcoholic fatty liver disease (NAFLD) (2)
- nonalcoholic steatohepatthis (2)
- nut allergenic proteins (2)
- nutrient transport (2)
- nutrients (2)
- nutritional characteristics (2)
- nuts (2)
- odd chain fatty acids (2)
- offspring (2)
- older persons (2)
- organic compounds adsorption (2)
- overweight (2)
- parchment (2)
- particle characterization (2)
- patterns (2)
- pea (2)
- peptide biomarkers (2)
- peptides markers (2)
- phagocytosis (2)
- phenolics (2)
- physical activity (2)
- pink1 (2)
- plasma measurements (2)
- platelets (2)
- pneumonia (2)
- poly(ADP-ribosyl)ation (2)
- polyenoic fatty acids (2)
- population-specific risk marker (2)
- prediction (2)
- proliferation (2)
- prospective study (2)
- prostaglandins (2)
- proteasome (2)
- protein extraction (2)
- proteomic analysis (2)
- proteomics (2)
- proteostasis (2)
- provitamin A (2)
- purification (2)
- rapid test kit (2)
- rat (2)
- rat hepatocytes (2)
- redox regulation (2)
- redox-metabolites (2)
- reducing agents (2)
- relative quantification (2)
- reliability (2)
- renal disease (2)
- repetitive elements (2)
- replacement (2)
- reversed-phase chromatography (2)
- risk (2)
- rotes Fleisch (2)
- s-glutathionylation (2)
- saline agriculture (2)
- salt (2)
- secondary plant metabolites (2)
- seeds (2)
- selenite (2)
- selenoneine (2)
- selenoproteins (2)
- serine palmitoyltransferase (2)
- serum (2)
- sex (2)
- signal transduction (2)
- size (2)
- skeletal muscle (2)
- skin penetration (2)
- sorghum (2)
- soy protein (2)
- spent coffee grounds (2)
- sphingolipid de novo synthesis (2)
- sphingolipid metabolism (2)
- sphingosine kinase (2)
- stable-isotope labeling (2)
- status markers (2)
- stroke (2)
- suppress VLDL secretion (2)
- tacrolimus formulation (2)
- targeted proteomics (2)
- tetanus toxin (2)
- tight junction (2)
- tritrophic system (2)
- tryptic digestion (2)
- ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS) (2)
- ungeradkettige Fettsäuren (2)
- validity (2)
- valorization (2)
- variants (2)
- veterinary drugs (2)
- vicious cycle (2)
- visfatin (2)
- voltage-dependent calcium channels (2)
- weight gain (2)
- wheat cultivars (2)
- zinc binding (2)
- (2E)-Hexadecenal (1)
- (2E)-hexadecenal (1)
- (2E)-hexadecenoic acid (1)
- (9Z)-neoxanthin (1)
- 1-Methoxy-3-indolylmethyl glucosinolate (1)
- 1-Phenylethanol (1)
- 1-hydroxy methyl pyrene (1)
- 1-hydroxymethylpyrene (1)
- 1-phosphate (1)
- 11 beta-hydroxysteroid dehydrogenase 2 (1)
- 2-Phenylethanol (1)
- 20S (1)
- 20S proteasome (1)
- 25-OH vitamin D (1)
- 2D-LC-MS/MS (1)
- 2k1c renovascular hypertension (1)
- 3,4-didehydroretinol (1)
- 3,5-Dimethoxytoluene (1)
- 3-Methylhistidin (1)
- 3-methylhistidine (1)
- 3D breast cell model (1)
- 3D tissue model (1)
- 5-gliadin (1)
- 6-Shogaol (1)
- 6-shogaol (1)
- 7 macrophages (1)
- ACE I/D polymorphism (1)
- ACE inhibitors (1)
- ADPKD (1)
- AGE (1)
- AMPK (1)
- AOAC (1)
- APC (1)
- APOM protein (1)
- ARPE-19 cells (1)
- ASI-3 (1)
- Abrus precatorius (1)
- Acute coronary syndrome (1)
- Acute renal failure (1)
- Adioponectin (1)
- Adipocytes (1)
- Adipozyt (1)
- Adult height (1)
- Advanced fetal programming hypothesis (1)
- Advanced glycation end products (1)
- Advanced glycation end-products (1)
- Advanced glycation endproducts (1)
- Aflatoxin B1 (1)
- Age (1)
- Agonisteninteraktion (1)
- Akkermansia muciniphila (1)
- Akt (1)
- Akt signaling (1)
- Akt/PKB (1)
- Aktivkohle (1)
- Alcohol dependence (1)
- Aldehyddehydrogenase (1)
- Alkohol (1)
- Alkoholdehydrogenase (1)
- Alkoholkonsum (1)
- Allantoin (1)
- Allergenic food (1)
- Allicin (1)
- Alltagsbedingungen (1)
- Allyl isothiocyanate (1)
- Alpine metamorphism (1)
- Alternative to animal testing (1)
- Alternativmethoden (1)
- Alveolar epithelial cells (1)
- Amaranth (1)
- Amaranthaceae (1)
- Anaphylatoxin (1)
- Anaphylaxie (1)
- Anatomy (1)
- Angiotensin converting enzyme inhibitor (1)
- Animal (1)
- Ankle-brachial index (1)
- Anorexia (1)
- Antibeschlag-Additive (1)
- Antibiotics (1)
- Antibiotikaresistenz (1)
- Antimicrobial drugs (1)
- Antioxidant capacity (1)
- Antioxidants (1)
- Anxiety (1)
- Anxiety Sensitivity Index (1)
- Aortic valve (1)
- Apgar score (1)
- Apple polyphenoloxidase (1)
- Arabica Kaffeebohnen (1)
- Arbuscularmycorrhizal fungi (1)
- Arsenic speciation (1)
- Arsenite (1)
- Arsenolipid (1)
- Arsenosugar (1)
- Aryl-hydrocarbon receptor (1)
- Asian subjects (1)
- Aspergillus (1)
- Aspirin (1)
- Assay High-resolution mass spectrometry (1)
- Assay hochauflösende Massenspektrometrie (1)
- Assays (1)
- Astrocytes (1)
- Astrozyten (1)
- Atemwegserkrankungen (1)
- Atherosclerosis (1)
- Athletes (1)
- Augmentation (1)
- Ausdauerleistung (1)
- Autophagie Lysosomale System (1)
- Autotaxin (1)
- B cells (1)
- BALB/c-3T3 cells (1)
- BBsome (1)
- BIOCROSS (1)
- BMP4 (1)
- BPA (1)
- BRAF (1)
- Baked products (1)
- Ballaststoffe (1)
- Barriere (1)
- Bbs4 (1)
- Be-10 dating (1)
- Beef (1)
- Benzylisothiocyanat (1)
- Beryllium (1)
- Beta-Oxidation (1)
- Beta-Oxydation (1)
- Beta-Zelle (1)
- Beta-amylase (1)
- Beta-lactoglobulin (1)
- BfR MEAL Study (1)
- Bifidobacterium (1)
- Bile Acids (1)
- Bioaktivität (1)
- Biochemical analysis (1)
- Biocompatibility (1)
- Biological Assay (1)
- Biomarkers (1)
- Bioreactor (1)
- Biotransformation (1)
- Bioverfügbarkeit (1)
- Biparietal diameter (1)
- Birds of prey (1)
- Bisphenol A (1)
- Bitter (1)
- Bittergeschmacksrezeptoren (1)
- Bitterrezeptoren (1)
- Blood flow resistance (1)
- Blood platelets (1)
- Blood protein adducts (1)
- Blood-cerebrospinal fluid barrier (1)
- Blood-liquor barrier (1)
- Blut-Hirn-Schranke (1)
- Body composition (1)
- Body weight (1)
- Body-Mass-Index (1)
- Botulinumtoxine (1)
- Brain development (1)
- Brassica (1)
- Brassica carinata (1)
- Brassica oleracea var. sabellica (1)
- Brassica rapa ssp. chinensis (1)
- Brassica vegetables (1)
- Brassicaceae (1)
- Breast cancer (1)
- Brood size (1)
- Brown adipose tissue (1)
- Brustkrebs (1)
- CAR (1)
- CD, DLS (1)
- CEHC (1)
- CKD (1)
- COPD (1)
- CRC (1)
- CRISPR/Cas9 (1)
- CVD (1)
- CXCL10 (1)
- CXCR2 (1)
- CYP3A4 (1)
- Cachexia (1)
- Calculated free 25-hydroxyvitamin D (1)
- Calorimetry (1)
- Cameroon (1)
- Cancer prevention (1)
- Cannabidiol (CBD) (1)
- Cardiac function (1)
- Cardiac ischemia/reperfusion (1)
- Cardiac rehabilitation (1)
- Cardiovascular (1)
- Cardiovascular effects (1)
- Carobballaststoff (1)
- Carotene supplementation (1)
- Case-control study (1)
- Casein (1)
- Catabolism (1)
- Catechin (1)
- Catechins (1)
- Catecholamine (1)
- Cell culture materials (1)
- Cell proliferation (1)
- Cellular bioavailability (1)
- Cellular damage response (1)
- Cellular uptake (1)
- Cellulose acetate phthalate (1)
- Chad (1)
- Chaperone (1)
- Chemerin (1)
- Chemotherapy resistance (1)
- Childhood nephrotic syndrome (1)
- Chlorogensäure (1)
- Chlorophyllide a oxygenase (1)
- Chlorophylls (1)
- Chloroplast (1)
- Cholesterol (1)
- Chronic diseases (1)
- Chronic kidney disease (1)
- Chylomicron (1)
- Claudin-4 (1)
- Clinical study (1)
- Clinical trials (1)
- Clostridium difficile (1)
- Coagulation (1)
- Cognition (1)
- Colitis (1)
- Colitis ulcerosa (1)
- Collagen (1)
- Colon cancer (1)
- Colonic microbiota (1)
- Colonkanzerogenese (1)
- Colorectal cancer (1)
- Colorectal carcinomas (1)
- Comet assay (1)
- Complement system (1)
- Complications in diabetes (1)
- Confluence (1)
- Connective tissue growth factor (1)
- Contaminants (1)
- Contamination (1)
- Contrast induced acute kidney injury (1)
- Control region (1)
- Core-multishell nanocarriers (1)
- Coronary angiography (1)
- Corticotropin-Releasing Factor Receptor Type 1 (1)
- Corticotropin-Releasing Factor Rezeptor Typ 1 (1)
- Cortisol Maternal cortisol (1)
- Cortisol vertical bar metabolism (1)
- Costs (1)
- Covalent modification (1)
- Coxsackie and Adenovirus Receptor (1)
- Coxsackie- und Adenovirus Rezeptor (1)
- Crop quality (1)
- Cross-sectional studies (1)
- Cu NP-incorporated MI-dPG coating (1)
- Cyp2b1 (1)
- Cyp3a11 (1)
- CypP450 (1)
- Cystic fibrosis (1)
- Cytokines (1)
- D3 cells (1)
- D3-Zellen (1)
- DAF-16 (1)
- DAF-16 transcription factor (1)
- DAIH (1)
- DASH study (1)
- DASH-Studie (1)
- DDP-4 inhibition (1)
- DNA integrity (1)
- DNA repair (1)
- DNA-Addukte (1)
- DNMT inhibitor (1)
- DNMT1 (1)
- DPP-4 inhibition (1)
- DPP-4 inhibitor (1)
- DPP-IV inhibitor (1)
- DPP4 (1)
- DPP4 inhibition (1)
- Dairy biomarkers (1)
- Darmbakterien (1)
- Darmbakterium (1)
- Darmerkrankung (1)
- Darmkrebs (1)
- Darmkrebsdiagnostik (1)
- Darmlänge (1)
- Daucus (1)
- Decontamination (1)
- Delinquency (1)
- Demographic transitions (1)
- Dendritic cells (1)
- Dendritic core-multishell nanocarriers (1)
- Dengue (1)
- Depression (1)
- Derivatisation (1)
- Derivatization (1)
- Dermal delivery (1)
- Dermal drug delivery (1)
- Desensibilisierung (1)
- Determinants (1)
- Developmental programming (1)
- Diabetes incidence (1)
- Diabetes mellitus Typ 2 (1)
- Diabetic cardiomyopathy (1)
- Diacylglycerol (DAG) (1)
- Diagnostic (1)
- Diallyl disulfide (1)
- Diarrhoea (1)
- Dichlorofluorescein assay (1)
- Dickdarmkanzerogenese (1)
- Dickdarmkrebs (1)
- Dietary Fibre (1)
- Dietary compliance (1)
- Dietary fat composition (1)
- Dietary fat replacement (1)
- Dietary sulfonates (1)
- Differential Gene Expression (1)
- Differenzierungsassay (1)
- Dipeptidyl peptidase 4 inhibitor (1)
- Dipeptidyl peptidase IV (1)
- Dipeptidyl peptidase-4 inhibition (1)
- Dipeptidylpeptidase-4 (1)
- Disease (1)
- Distal tubules (1)
- Diät (1)
- Dog growth (1)
- Dogs (1)
- Dolichol lipids (1)
- Domestic cat (1)
- Domestic cooking (1)
- Dopaminergic neurons (1)
- Dopaminergic system (1)
- Drug delivery systems (1)
- Drug metabolism (1)
- E. coli (1)
- EBI3 (1)
- EDC (1)
- ENaC (1)
- EPIC-Potsdam study (1)
- ER stress (1)
- ER-stress (1)
- EST (1)
- ETA (1)
- ETB (1)
- ETB receptor-deficient mouse (1)
- Edible insects (1)
- Eicosanoid (1)
- Electrochemistry (1)
- Electron paramagnetic resonance spectroscopy (1)
- Elektrochemie (1)
- Elemental blood serum concentration (1)
- Ellagsäure (1)
- Embryonaler Stammzelltest (EST) (1)
- Emulsifying properties (1)
- Enantio-selective reduction (1)
- Endocannabinoide (1)
- Endocrine disruption (1)
- Endodormancy (1)
- Endosomal sorting (1)
- Endothelfunktion (1)
- Endothelial dysfunction (1)
- Endothelial nitric oxide synthase (1)
- Endothelin receptor antagonists (1)
- Endothelin-1 transgenic mice (1)
- Endothelzelle (1)
- Energiehaushalt (1)
- Energy expenditure (1)
- Energy intake (1)
- Energy requirement (1)
- Enteric polymer (1)
- Enterolignanen (1)
- Enterolignans (1)
- Environmental (1)
- Enzyme (1)
- Epigallocatechingallat (1)
- Epigenetic (1)
- Epigenetik (1)
- Epstein-Barr Virus-induziertes Gen 3 (1)
- Equine metabolic syndrome (1)
- Equines (1)
- Equol (1)
- Erdnussallergie (1)
- Ernährungsmuster (1)
- Erosion kinetics (1)
- Escherichia coli (1)
- Et-1 (1)
- Ethyl cellulose (1)
- Eudragit (R) (1)
- Eudragit (R) RS (1)
- Eudragit L 100 (1)
- Euphorbia mauritanica (1)
- Euphorbiaceae (1)
- Europe (1)
- Evaluation tool (1)
- Excretion (1)
- Exercise tests (1)
- Experimental autoimmune encephalomyelitis (EAE) (1)
- Experimental study (1)
- Exploration (1)
- Extraction (1)
- Extrudate (1)
- FASN (1)
- FISH (1)
- FOXO1 (1)
- FVB/NJ Maus (1)
- FVB/NJ mouse (1)
- Fabaceae (1)
- Factor-Xa (1)
- Faecal bacteria (1)
- Farber disease (1)
- Fast and slow fibers (1)
- Fat infiltration in muscle (1)
- Fat-free mass (1)
- Fattening pigs (1)
- Fatty acid hydroperoxides (1)
- Fetal development (1)
- Fettinfiltration im Muskel (1)
- Fettleibigkeit (1)
- Fettsucht (1)
- Fettwahrnehmung (1)
- Fettzelle (1)
- Fetuin-A (1)
- Fibroblast growth factor 21 (1)
- Fibrosis (1)
- Fingolimod (1)
- Firefly luciferase inhibition (1)
- First trimester (1)
- Flavonoid glycosides (1)
- Flavonoide (1)
- Flavonoids (1)
- Floral scent compound (1)
- Flowering (1)
- Fluorescence lifetime imaging microscopy (1)
- Fluorescence screening (1)
- Foal (1)
- Foaming properties (1)
- Folientunnel (1)
- Food (1)
- Food Chain (1)
- Food analysis (1)
- Food authentication (1)
- Food choice (1)
- Food composition (1)
- Food labelling (1)
- Food safety (1)
- Food-exchange model (1)
- Forensic science (1)
- Formyl-Peptid Rezeptor 2 (1)
- Forster resonance energy transfer (FRET) (1)
- Frailty (1)
- Frailty criteria (1)
- Frataxin (1)
- Free radicals (1)
- Free vitamin D (1)
- Freeze-fracturing (1)
- Fremdstoffmetabolismus (1)
- Fruits (1)
- Functionality (1)
- Furosemide (1)
- G protein-coupled receptors (1)
- G-Protein gekoppelte Rezeptoren (1)
- G-Protein-gekoppelte Rezeptoren (1)
- G-protein coupled receptors (1)
- GADD45A and GADD45G (1)
- GC gene (1)
- GC-MS (1)
- GC-globulin (1)
- GLP-1 (1)
- GLUT1 XbaI gene polymorphism (1)
- GLUT8 (1)
- GOAT (1)
- GPCR (1)
- GPX (1)
- GPx2 (1)
- Gallensäuren (1)
- Gallensäurenbindung (1)
- Garlic (1)
- Gastrointestinal tract (1)
- Gene Array (1)
- Gene Chip (1)
- Gene expression (1)
- Gene polymorphism (1)
- Genetics (1)
- Genetik (1)
- Genexpression (1)
- Genexpressionsanalysen (qRT-PCR) (1)
- Geriatric patients (1)
- Gerontologie (1)
- Geschlecht (1)
- Geschmacksrezeptor (1)
- Getränkeauswahl (1)
- Getränkeautomat (1)
- Gewicht (1)
- Gewichtserhalt (1)
- Gewichtsreduktion (1)
- Gewichtsverlust (1)
- Ghrelin (1)
- Gliadin and glutenin fractions (1)
- Global (1)
- Glp1r(-/-) mice (1)
- Glucose intolerance (1)
- Glucose metabolism disorders (1)
- Glucose tolerance (1)
- Glucosehomöostase (1)
- Glucosetransport (1)
- Glucosinolate breakdown product (1)
- Glukoseintoleranz (1)
- Glukosestoffwechselstörungen (1)
- Glukosinolaten (1)
- Glutathion-Peroxidase (1)
- Glutathione (1)
- Gluten (1)
- Glycation (1)
- Glycemia (1)
- Glycerophospholipids (1)
- Grave’s orbitopathy (1)
- Grüner Tee (1)
- Gut microbiota (1)
- HAMP (1)
- HNRNPA1 (1)
- HOG (1)
- HOMA (1)
- HPLC-ESI-QTOF (1)
- HPLC/HR-ESMS (1)
- HPLC/ICPMS (1)
- HPMCP (1)
- HSD11B2[CA]n polymorphism (1)
- HSP70 (1)
- HaCaT cells (1)
- Hafer (1)
- Halophyten (1)
- Hautmodell (1)
- Head circumference (1)
- Health care expenditure (1)
- Health-promoting compounds (1)
- Heart failure (1)
- Heart weight (1)
- Heat aggregation (1)
- Heat shock protein 90 (1)
- Heat shock proteins (1)
- Heavy metals (1)
- Heme (1)
- Hepatic artery (1)
- Hepatic glucose balance (1)
- Hepatic hemodynamics (1)
- Hepatic insulin resistance (1)
- Hepatic lactate balance (1)
- Hepatic nerve (1)
- Hepatic stellate cells (1)
- Hepatocyte (rat) (1)
- Hepatotoxicity (1)
- Hepatotoxizität (1)
- Herd size (1)
- Herd type (1)
- Heritabilität (1)
- Herzinfarkt (1)
- Herzkreislauferkrankungen (1)
- Heterocyclic aromatic amines (1)
- Heterogeneity (1)
- High pressure - low temperature treatments (1)
- High resolution microscopy (1)
- High-resolution mass spectrometry (1)
- Histologie (1)
- Hoch-Protein Diät (1)
- Hochfettdiät (1)
- Homocystein (1)
- Homologiemodellierung (1)
- Honey (1)
- Honeydew honey (1)
- Hormone (1)
- Hormonersatztherapie (1)
- Hormones (1)
- Horse (1)
- Host-plant suitability (1)
- Human (1)
- Human differentiated neurons (1)
- Human nutritional intervention (1)
- Hungerhormon (1)
- Hydroxycinnamic acids (1)
- Hydroxymethylfurfural (1)
- Hydroxymethylpyren (1)
- Hyperglycaemia (1)
- Hypertonie (1)
- Hyphenated techniques (1)
- Hypoxia (1)
- IBD (1)
- ICP-MS (1)
- ICP-QQQ-MS (1)
- IDH1 (1)
- IRAK (1)
- IgE (1)
- Imiquimod (1)
- Immediate-early-Gen (1)
- Immunhistochemie (1)
- Inactivation (1)
- Indigenous African leafy vegetables (1)
- Indole (1)
- Indoor farming (1)
- Induced pluripotent stem cells (1)
- Inductively (1)
- Inductively coupled plasma mass spectrometry (1)
- Infarct size (1)
- Inflammaging (1)
- Inflammatory skin disease (1)
- Influenza virus (1)
- Inhalation (1)
- Inorganic mercury (1)
- Insulin sensitivity (1)
- Insulin signaling (1)
- Insulin signalling (1)
- Insulin-induzierte Hypoglykämie (1)
- Insulinsekretion (1)
- Insulinsensitivität (1)
- Intergenerational effects (1)
- Interleukin-1 (1)
- Intestinal absorption (1)
- Intimahyperplasie (1)
- Intimal Hyperplasia (1)
- Intraperitoneal administration (1)
- Iodization (1)
- Ischemia/reperfusion (1)
- Isoprostane (1)
- Isotope ratios (1)
- Isotope-dilution (1)
- Isotope-dilution analysis (1)
- Ivy (1)
- IκB (1)
- Jod (1)
- K-RAS (1)
- K-ras (1)
- Kachexie (1)
- Kaede (1)
- Kaffeenebenprodukte (1)
- Kaffeeproteine (1)
- Kaffeeverarbeitung (1)
- Kalorienrestriktion (1)
- Kalzium (1)
- Kanzerogenese (1)
- Kardiovaskuläre Erkrankungen (1)
- Kardiovaskuläre Krankheit (1)
- Katalase (1)
- Kernrezeptor (1)
- Kidney weight (1)
- Kinetik (1)
- Knock-out (1)
- Kokultur (1)
- Kolokalisation (1)
- Kolonkrebs (1)
- Konsum (1)
- Kontaktallergie (1)
- Kontrollierte klinische Studie (1)
- Kopfsalat (1)
- Kosakonia radicincitans (1)
- Krebs (1)
- Kunststoff-Additive (1)
- Kupfer (1)
- Kupfferzellen (1)
- Kurzkettige Fettsäuren (1)
- Kynurenine (1)
- Körperfett (1)
- Körpergewichsterhalt (1)
- Körpergewicht (1)
- Körpergewichtsregulation (1)
- Körpergewichtsverlust (1)
- Körpermasse (1)
- LC (1)
- LC-MS (1)
- LC-MS-MS (1)
- LC/MS/MS (1)
- LC/MS/MS; Quantification of allergenic plant traces (1)
- LEDs (1)
- LNA- clamp-PCR (1)
- LNA-clamp-PCR (1)
- LPA(3) receptor subtype (1)
- LRP8 (1)
- Labormäuse (1)
- Langerhans Zellen (1)
- Langerhans cells (1)
- Lebensmittelkette (1)
- Leg length (1)
- Legume (1)
- Lemna paucicostata (1)
- Life science (1)
- Light quality (1)
- Lignan-converting bacteria (1)
- Lignan-umwandelnde Bakterien (1)
- Lipase (1)
- Lipasen (1)
- Lipid (1)
- Lipid droplet proteome (1)
- Lipidstoffwechsel (1)
- Lipolysis (1)
- Liquid chromatography-tandem mass spectrometry (1)
- Liquid-liquid extraction (1)
- Lithiumion battery (LIB) (1)
- Liver fat (1)
- Liver fibrosis (1)
- Liver injury (1)
- Long term health (1)
- Long-term cellular toxicity (1)
- Loop diuretics (1)
- Low birth weight (1)
- Low lean mass (1)
- Low muscle mass (1)
- Lu-Hf geochronology (1)
- Lupin (1)
- Lutein (1)
- Lutein ester (1)
- Luteinester (1)
- Lysophosphatidic acid (1)
- Lysophosphatidylcholines (1)
- MCHR-1 (1)
- MCT oil (1)
- MMF (1)
- MS quantification of leguminous additives (1)
- MSCs (1)
- MUFA (1)
- Macrovascular (1)
- Major adverse kidney event (1)
- Major royal jelly proteins (1)
- Mangan (1)
- Manganese . C. elegans (1)
- Manganism (1)
- Marker (1)
- Marker peptides (1)
- Massenspektrometrie (1)
- Mauritanicain (1)
- Measured free 25-hydroxyvitamin D (1)
- Meat peptide biomarker (1)
- Mediationsanalyse (1)
- Mediterranean Diet (1)
- Medizinprodukt (1)
- Membrane (1)
- Menderes Massif (1)
- Mesoangioblasts (1)
- Meta-analyses (1)
- Metabolically benign (1)
- Metabolism (1)
- Metabolismus (1)
- Metabolom (1)
- Metabolome analysis (1)
- Metals (1)
- Methicillin resistant Staphylococcus aureus (1)
- Methylation (1)
- Methylglyoxal (1)
- MiSpEx* (1)
- Mice (1)
- Micellar caseins (1)
- MicroRNAs (1)
- Microbial degradation (1)
- Microbiome (1)
- Microdialysis (1)
- Microelements (1)
- Microsatellite instability (1)
- Microsomal (1)
- Microvascular complications (1)
- Migration (1)
- Mikrobiologie (1)
- Mikrobiota (1)
- Mikronährstoffe (1)
- Mikrosomal (1)
- Milcheinnahme (1)
- Mitochondrial respiration (1)
- Mitohormesis (1)
- Mixed lymphocyte culture (MLC) (1)
- Model (1)
- Modell (1)
- Modelling (1)
- Molecular cloning and expression (1)
- Molecular structure (1)
- Molkenproteine (1)
- Monocyte (1)
- Moringa oleifera (1)
- Morphogenesis (1)
- Mortalität (1)
- Motor coordination (1)
- Motor neurons (1)
- Motorneurone (1)
- Multi-Methods (1)
- Multi-method (1)
- Multi-mycotoxin analysis (1)
- Multiple herbivory (1)
- Multiple sclerosis (1)
- Multiplex platforms (1)
- Muskelproteinumsatz (1)
- Muskelschwund (1)
- Mycobacterium tuberculosis (1)
- Myoblasts (1)
- Myocardial infarction (1)
- Myocardial ischemia (1)
- Myofibroblasten (1)
- Myogenic differentiation (1)
- Myoglobin (1)
- Myrrhe (1)
- Myzus persicae (1)
- NF-?B (1)
- NF-kB (1)
- NF-kappa B (1)
- NF-κB (1)
- NF1 (1)
- NMR-based metabolomics (1)
- NR3C1 gene (1)
- Nachkommen (1)
- Nahrung der Zukunft (1)
- Nahrungsbestandteile (1)
- Nahrungsfette (1)
- Nahrungsmittelallergie (1)
- Nahrunsgergänzungsmittel (1)
- Nanoparticle uptake (1)
- Nanoparticles (1)
- Nanotoxicology (1)
- Natriuretic peptides (1)
- Neisseria gonorrhoeae (1)
- Neoglucobrassicin (1)
- Neointima (1)
- Nephropathie (1)
- Netzwerke (1)
- Neurodegeneration (1)
- Neurodevelopmental toxicity (1)
- Neurone (1)
- Neuronen (1)
- Neurons (1)
- Neuropathie (1)
- Neuropeptides (1)
- Neutral lipids (1)
- New World camelids (1)
- Nif2 (1)
- Non-esterified fatty acids (NEFA) (1)
- Nordic diet (1)
- Novelose (1)
- Nuclear receptor (1)
- Nucleus tractus solitarii (1)
- Nukleosidaddukt (1)
- NutriAct family study (1)
- Nutritional counseling (1)
- Nährstoffe (1)
- OCFA (1)
- Oats (1)
- Occurrence data (1)
- Ocular delivery (1)
- Odorant compounds (1)
- Offending (1)
- Offspring (1)
- Oligomere (1)
- Olivenöl (1)
- Omega-3 Fettsäuren (1)
- Omega-Hydroxylation (1)
- Omega-Hydroxylierung (1)
- Oncogenes (1)
- Ontogenetic development (1)
- Ontogeny (1)
- Optogenetik (1)
- Organic and conventional type of production (1)
- Organic arsenic (1)
- Organic carbonates (1)
- Organic mercury (1)
- Other livestock (1)
- Outcome (1)
- Oxidativer Stress (1)
- Oxidized proteins (1)
- OxyR (1)
- Oxylipin (1)
- Oxylipins (1)
- PBCEC (1)
- PBPK (1)
- PBTK (1)
- PCR-DHPLC (1)
- PCaaC38:6 (1)
- PGC1 alpha (1)
- PHGPx (1)
- PKM2 (1)
- PPARalpha (1)
- PRM/Alf Maus (1)
- PRM/Alf mouse (1)
- PTEN (1)
- Pancreatic cells (1)
- Pannexin 1 (1)
- Parenthood (1)
- Paternal exposure (1)
- Paternal, maternal, sex differences (1)
- Pea flour (1)
- Pea protein isolate (1)
- Peptides (1)
- Perfusion (1)
- Permeability (1)
- Peroxidatic and resolving cysteine (1)
- Peroxiredoxin (1)
- Peroxynitrite (1)
- Personalised medicine (1)
- Pest infestation (1)
- Pest-pest interaction (1)
- Pflanzliches Lignan (1)
- PhIP (1)
- Pharbitis nil cv. Violet (1)
- Pharmacokinetics (1)
- Phase II Enzyme (1)
- Phenol-amino-adducts (1)
- Phosphatidylcholines (1)
- Phosphatidylinositols (1)
- Phosphoenolpyruvate carboxykinase (1)
- Phospholipids (1)
- Photosynthesis (1)
- Physical activity (1)
- Physicochemical properties (1)
- Physiologie (1)
- Pig (1)
- Pilot-Studie (1)
- PlGF (1)
- Plant allergen (soy, sesame, lupine) (1)
- Plant authentication (1)
- Plant growth promoting bacteria (1)
- Plant lignan (1)
- Plasma (1)
- Plasma concentration (1)
- Plasmalogens (1)
- Platelets (1)
- Polyamine (1)
- Polymeric nanoparticle (1)
- Polymeric nanoparticles (1)
- Polyphenols (1)
- Polyubiquitination (1)
- Ponderostat (1)
- Pooling analysis (1)
- Portal vein (1)
- Post-translational modifications (1)
- Post-translational protein modification (1)
- Postharvest processing (1)
- Preadipozyt (1)
- Precision medicine (1)
- Precision prognostics (1)
- Preeclampsia (1)
- Pregnane X Receptor (1)
- Preinterventional biomarker (1)
- Presystemic metabolism (1)
- Preterm birth (1)
- Preterm delivery (1)
- Prevention (1)
- Primary care (1)
- Principal component analysis (1)
- Probiotika (1)
- Procyanidins (1)
- Proliferation (1)
- Prostaglandin (1)
- Prostaglandin E₂ (1)
- Prostaglandin receptor (1)
- Prostaglandin receptor EP4 (1)
- Prostaglandine (1)
- Proteasomal system (1)
- Proteasome and lysosome (1)
- Protein (1)
- Protein Modifizierung (1)
- Protein aggregates (1)
- Protein functionality and modification (1)
- Protein-Wechselwirkungen (1)
- Proteine (1)
- Proteinmodifizierung (1)
- Proteolysis (1)
- Proteome (1)
- Proteostase (1)
- Proteostasis (1)
- Prävention (1)
- Pseudomonas aeruginosa (1)
- Psoriasis (1)
- Pulmonary arterial hypertension (1)
- Pulse wave velocity (1)
- Punktmutation (1)
- Purification (1)
- Pyrrolizidine alkaloids (1)
- QSAR (1)
- QTL (1)
- Quality appraisal (1)
- Quantification of peptides (1)
- Quercetin (1)
- RAW 264 (1)
- RBP (1)
- RNA Sequencing (1)
- RNA Sequenzierung (1)
- RNAseq (1)
- ROS (1)
- Radiocontrast media-induced nephropathy (1)
- Raman spectroscopy (1)
- Rat (1)
- Ratte (1)
- Rauchen (1)
- Reactive Oxygen Species (1)
- Reaktive Sauerstoffspezies (1)
- Recycling (1)
- Redox (1)
- Redox control (1)
- Redox homeostasis (1)
- Redox regulation (1)
- Reduktase (1)
- Reference intervals (1)
- Refinement (1)
- Regionality (1)
- Regulatory T cells (Treg) (1)
- Reh (1)
- Relaxin (1)
- Reliability (1)
- Renin-angiotensin system (1)
- Renin-angiotensin-aldosterone system (1)
- Reportergen-Assay (1)
- Resistance (1)
- Resistant starch (1)
- Retinoblastoma (1)
- Retinol (1)
- Retinol-Bindungsprotein 4 (1)
- Retinol-binding protein 4 (1)
- Retinopathie (1)
- Rezeptoren (1)
- Rezeptorscreening (1)
- Rheologie (1)
- Risikobewertungen (1)
- Risikoeinschätzung (1)
- Risk (1)
- Risk factor (1)
- Risk prediction (1)
- Risk prediction model (1)
- Risk score (1)
- Root exudates (1)
- Rosa x level (1)
- Rye (1)
- S1P receptors (1)
- S1P(3) receptor (1)
- SCID mice (1)
- SEC-HPLC (1)
- SELENOH (1)
- SGK-1 (1)
- SNARE proteins (1)
- SREBP-1c (1)
- SSCP (1)
- ST-1071 (1)
- ST-1893 (1)
- ST-1894 (1)
- ST-968 (1)
- SU5416 (1)
- SULT1A1 (1)
- SULT1A2 (1)
- SVM (1)
- Saccharomyces boulardii (1)
- Safety (1)
- Salicin (1)
- Saline Landwirtschaft (1)
- Salzgeschmack (1)
- Sarkopenie (1)
- Schilddrüse (1)
- Schilddrüsenautoimmunerkrankungen (1)
- Schlaganfall (1)
- Schwerkraft (1)
- Se-methylselenoneine (1)
- Seafood (1)
- Seasonality (1)
- Secondary metabolites (1)
- Selenonein (1)
- Selenoneine (1)
- Selenoprotein (1)
- Selenosugar 1 (1)
- Senescence (1)
- Sensorik (1)
- Serine and trypsin protease (1)
- Serotonin (1)
- Set-Point (1)
- Sex ratio at birth (1)
- Sexual dimorphism (1)
- Shan He Jian Fei Granules (SHJFG) (1)
- Short chain dehydrogenase (1)
- Short stature (1)
- Side effects (1)
- Signal transduction (1)
- Signaling pathways (1)
- Signalübertragung (1)
- Single nucleotide polymorphism (1)
- Skelettmuskel (1)
- Skelettmuskelalterung (1)
- Skin (1)
- Skin barrier disruption (1)
- Skin model (1)
- Slatted floor (1)
- Small molecules (1)
- Small selenium species (1)
- Smooth muscle cells (1)
- Sojabohne (1)
- Solanum scabrum (1)
- Speciation (1)
- Species differences (1)
- Spectrophotometry (1)
- Speichel (1)
- Spelt (1)
- Spermienmotilität (1)
- Sphingomyelin (1)
- Sphingosine 1-phosphate (S1P) (1)
- Sphingosine 1phosphate (1)
- Sphingosine kinase-1 (1)
- Sphingosine-1-phosphate lyase (1)
- Spirulina (1)
- Sport (1)
- Spurenelement (1)
- Stammzelle (1)
- Stereotypien (1)
- Stickstoffmonoxid (1)
- Stillbirth (1)
- Stoffwechselkäfig (1)
- Stroke (1)
- Stromal cell-derived factor-1 (1)
- Structural changes (1)
- Study protocol (1)
- Styrol (1)
- Substratverwertung (1)
- Sucrose (1)
- Sulfid (1)
- Sulfonate (1)
- Sulfoquinovose (1)
- Superoxiddismutase (1)
- Susceptibility-genes (1)
- Suszeptibilitätsgene (1)
- Swine (1)
- Synbiotika (1)
- Synthesis (1)
- Säugetiere ; Fettgewebe ; Zelldifferenzierung ; Genexpression (1)
- Säuglingsnahrung (1)
- Süßgeschmack (1)
- Süßrezeptor (1)
- Süßstoff (1)
- T helper 17 cells (1)
- TAVI (1)
- TEAC (1)
- TET (1)
- TFA (1)
- TGF-beta (1)
- TGF-beta 1 (1)
- TNF alpha (1)
- TRPV5 (1)
- TRPV6 (1)
- TTC (1)
- TTR (1)
- Tagetes (1)
- Tas1r1 (1)
- Tas2r (1)
- Tas2rs (1)
- Taurocholate (1)
- Tea leaves (1)
- Technique (1)
- Technofunctional properties (1)
- Teecatechin (1)
- Testicle (1)
- Tetranychus urticae (1)
- Th17 (1)
- Thai population (1)
- Thermal and nonthermal treatment (1)
- Thermal processing (1)
- Thin layer chromatography (1)
- Thio-arsenosugar-glycerol (1)
- Thio-dimethylarsinic acid (1)
- Thiol (1)
- Thiol-dependent peroxidase (1)
- Thiolmodifikation (1)
- Thioredoxin reductase (1)
- Three phase partitioning (1)
- Thrifty phenotype (1)
- Thyroid hormone (1)
- Tierarzneimittel (1)
- Tierschutz (1)
- Tight Junctions (1)
- ToF-SIMS (1)
- ToF-SIMS imaging (1)
- Tocopherol (1)
- Tocotrienol (1)
- Tocotrienols (1)
- Total arsenic (1)
- Total diet study (1)
- Toxicokinetics (1)
- Toxikokinetik (1)
- TraceAge (1)
- Trans-Fettsäuren (1)
- Trans-epoxy-fatty acid (1)
- Transactivation assay (1)
- Transcatheter Aortic Valve Implantation (1)
- Transcriptomics (1)
- Transformation product (1)
- Transformationsprodukt (1)
- Transforming Growth Factor beta (1)
- Transforming growth factor beta (1)
- Transkriptionsfaktor (1)
- Transkriptom (1)
- Transmembrane asymmetry (1)
- Transmission (1)
- Transplantation (1)
- Triglyceride secretion (1)
- Trunk length (1)
- Tumor (1)
- Tumor necrosis factor alpha (1)
- Tumour suppressor genes (1)
- Tween40 micelles (1)
- Twister (TM) (1)
- Twister TM (1)
- Typ 2 Diabetes (1)
- Type-2-diabetes (1)
- UDP-glucuronosyltransferase (1)
- UV light (1)
- Ubiquitin Proteasom System (1)
- Ulcerative colitis (1)
- Umbilical artery Doppler (1)
- Umbrella review (1)
- Uncoupling proteins (1)
- Unprepared and (1)
- Urate (1)
- Urinary ET-1 (1)
- Urine excretion (1)
- Uruguay River (1)
- VCAM-1 (1)
- VOC (1)
- Validation (1)
- Vascular stiffness (1)
- Vegan (1)
- Verhaltensstudien (1)
- Versuchstierkunde (1)
- Very low birth weight infant (1)
- Veterinary drugs (1)
- Vineatrol (R) 30 (1)
- Vitamin A supplementation (1)
- Vitamin C (1)
- Vitamin D (1)
- Vitamin D binding protein (1)
- Vitamin D deficiency (1)
- Vitamin D insufficiency (1)
- Vitamin D-binding protein (1)
- Vitellogenin (1)
- Volatile compound (1)
- WAT (1)
- Warburg effect (1)
- Water and salt retention (1)
- Wheat (1)
- Whey proteins (1)
- Wiederkäuer (1)
- Wnt pathway (1)
- Wnt-Signalweg (1)
- World Cancer Research Fund/American Institute for Cancer Research Recommendations (1)
- Xenobesity (1)
- Y:X chromosome ratio (1)
- YB-1 (1)
- Yolk (1)
- Zellkulturen (1)
- Zelllinien (1)
- Zellproliferation (1)
- Zink (1)
- Zinypr-1 (1)
- Zirkadianer Rhythmus (1)
- Zoonoses (1)
- Zwillingsstudie (1)
- Zytokine (1)
- Zytotoxizitätsassay (1)
- [N-15]Anthranilic acid (1)
- [N-15]Indole (1)
- a-tocopherol (1)
- absorption (1)
- accretionary wedge (1)
- acetate (1)
- activity-regulated cytoskeleton-associated protein (1)
- acute inflammation (1)
- ad libitum consumption (1)
- ad libitum-Verzehr (1)
- adenylate-cyclase (1)
- adipocyte (1)
- advanced glycation endproducts (1)
- aggregated immunoglobulin-g (1)
- agonists interaction (1)
- air pollution (1)
- air-dried (1)
- air-fried (1)
- akute Entzündung (1)
- alcohol (1)
- alcohol dehydrogenase (1)
- alcohol intake (1)
- alcylated polycyclic aromatic hydrocarbons (1)
- aldehyde dehydrogenase (1)
- alkylated polycyclic aromatic hydrocarbons (1)
- allometric model (1)
- alpha-Catenin (1)
- alpha-SMA (1)
- alpha-Tocopherol (1)
- alpha-tocopherol (1)
- alpha-tocopherol transfer protein (Ttpa) (1)
- alternative zu Tierversuchen (1)
- amaranth (1)
- amino acid score (1)
- amino acids (1)
- amitriptyline (1)
- amylase activity (1)
- analytical methods (1)
- anaphylaxis (1)
- and nutrition (1)
- angiotensin (1-7) (1)
- angiotensin II (1)
- animal welfare (1)
- anti-inflammatory therapy (1)
- antibacterial aerosol (1)
- antibacterial effect (1)
- antibakterielles Aerosol (1)
- anticancer (1)
- antidiabetic drug (1)
- antifogging additives (1)
- antioxidant activity (1)
- antioxidant defense systems (1)
- antioxidant potential (1)
- antioxidative capacity (1)
- antioxidative phenolic ingredients (1)
- anxiety sensitivity (1)
- aphids (1)
- appetite regulation (1)
- arabinoxylan (1)
- arachidonic-acid (1)
- aroma quality (1)
- aromatic amines; sulfotransferases; mutagenicity; bioactivation (1)
- aromatische Amine; Sulfotransferasen; Mutagenität; Bioaktivierung (1)
- arsenic (1)
- arsenolipids (1)
- artificial (1)
- astrocytes (1)
- asymmetric dimethylarginine (1)
- asymmetric dimethylarginine (ADMA) (1)
- asymmetrisches Dimethylarginin (1)
- atmospheric deposition (1)
- auditory neurons (1)
- autofluorescence (1)
- autoimmunity (1)
- autophagy flux (1)
- autophagy lysosomal system (1)
- b-Catenin (1)
- barrier (1)
- behavioral experiments (1)
- behaviour (1)
- benzylic sulfate (1)
- benzylic sulfuric acid ester (1)
- benzylischer Schwefelsäureester (1)
- benzylisches Sulfat (1)
- benzylisothiocyanate (1)
- beta-Lactoglobulin (1)
- beta-carotene (1)
- beta-carotene hydroxylase (1)
- beta-cell loss (1)
- beta-cells (1)
- beverage (1)
- bifidobacterium (1)
- bile acids (1)
- bioactive peptides (1)
- bioactivity (1)
- biomarkers (1)
- biomarkers of renal failure (1)
- biotransformation (1)
- birds of prey (1)
- birthweight (1)
- bladder cancer cells (1)
- blood banking (1)
- blood biomarker (1)
- blood pressure (1)
- blood-brain barrier (1)
- blood– brain barrier (1)
- blood– cerebrospinal fluid barrier (1)
- body composition (1)
- body mass (1)
- body weight (1)
- body weight loss (1)
- body weight maintenance (1)
- bone (1)
- bone mineral density (1)
- brain-gut axis (1)
- branched chain amino acids (1)
- braunes Fettgewebe (1)
- breast cancer (1)
- broiler chicks (1)
- brown adipose tissue (1)
- browning (1)
- burn injury (1)
- c-Fos (1)
- cachexia (1)
- caenorhabditis elegans (1)
- caffeic acid derivatives (1)
- calbindin D9k (1)
- calcitriol (1)
- calcium imaging (1)
- calcium transport (1)
- caloric restriction (1)
- cancer cells (1)
- cancer stem cells (1)
- canine osteoarthritis (1)
- cannabidiol (CBD) (1)
- capillary blood (1)
- caquexia (1)
- carbon sequestration (1)
- carcinogenesis (1)
- cardiac progenitor migration and differentiation (1)
- cardiokine (1)
- cardiometabolic diseases (1)
- cardiovascular risk (1)
- carob fibre (1)
- carota L (1)
- carotene (1)
- carotenoids bioavailability (1)
- catFISH (1)
- catalase (1)
- cell cuture (1)
- cell cycle (1)
- cell line (1)
- cell migration (1)
- cell transformation assay (1)
- cell wall deficient mutant (1)
- cell-based in vitro assay (1)
- cellular uptake (1)
- central nervous system (1)
- chemokines (1)
- chick embryo (1)
- children (1)
- chimpanzee (1)
- chlorbenzol (1)
- chlorogenic acid (1)
- chlorophylls (1)
- chronic and acute inflammation (1)
- chronic disease (1)
- chronic renal failure (1)
- chronic renal failure in children (1)
- cilium (1)
- circulation (1)
- classification (1)
- claudin-4 (1)
- click chemistry (1)
- clinical prediction rule (1)
- clinical sample (1)
- clinical studies (1)
- clinical trial (1)
- cocoa processing (1)
- cocoa proteins (1)
- coffee proteins (1)
- cold atmospheric pressure plasma (1)
- collagen I (1)
- colocalisation study (1)
- colon cancer (1)
- colon cancer diagnosis (1)
- color (1)
- color preference (1)
- color vision (1)
- colorectal carcinoma (1)
- colorectal neoplasm (1)
- colostrum (1)
- colour (1)
- commensal (1)
- comparison (1)
- complement (1)
- complication (1)
- complications (1)
- constitutive androstane receptor (1)
- construct validity (1)
- contrast-induced nephropathy (1)
- core (1)
- cost-effectiveness analysis (1)
- coupled plasma mass spectrometry (1)
- cow-side assay (1)
- crop (1)
- curcumin (1)
- cystic fibrosis (1)
- cytotoxicity (1)
- cytotoxicity assay (1)
- d-Loop (1)
- dairy intake (1)
- decision tree (1)
- decitabine (1)
- deep-fried (1)
- dendritic cell (1)
- dendritic polyglycerol (1)
- depression (1)
- desensitization (1)
- determinants (1)
- diatoms (1)
- dichlorbenzol (1)
- dichlorobenzene (1)
- diet score (1)
- diet selection (1)
- diet-disease association (1)
- dietary antioxidants (1)
- dietary citric acid (1)
- dietary factors (1)
- dietary fibre (1)
- dietary guidelines (1)
- dietary lipids (1)
- dietary sulfonates (1)
- dietary supplements (1)
- differentiation assay (1)
- disproportional intrauterine growth retardation (1)
- distal convoluted tubule (1)
- distress (1)
- diurnal rhythm (1)
- diätetische Antioxidantien (1)
- dog (1)
- domestic cooking (1)
- dosage recommendation (1)
- drug design (1)
- drug metabolism (1)
- drug-resistant bacteria (1)
- dysfunction (1)
- e-Zigarette (1)
- e-cigarette (1)
- eNOS (1)
- eating (1)
- echocardiography (1)
- egg yolk (1)
- electronic drug delivery system (EDDS) (1)
- electronic nicotin delivery system (ENDS) (1)
- ellagic acid (1)
- embryonic stem cell test (EST) (1)
- emotionality (1)
- emulsion (1)
- endocannabinoids (1)
- endocrine disruption (1)
- endothelabhängige flussinduzierte Vasodilatation (1)
- endothelial cell (1)
- endothelial function (1)
- endothelin-converting enzyme (1)
- energy (1)
- energy expenditure (1)
- energy harvest (1)
- environmental DNA (1)
- enzyme assays (1)
- enzyme induction (1)
- enzymes (1)
- epigallocatechin gallate (1)
- equol (1)
- essential oils (1)
- etanercept (1)
- etiology (1)
- exercise performance (1)
- experimental antigen-induced encephalomyelitis (1)
- expression analysis (1)
- extinction (1)
- extra-cellular matrix (1)
- extracellular matrix (1)
- extraction and characterization methods (1)
- extrazelluläre Matrix (1)
- factor structure (1)
- fasting blood glucose (1)
- fat metabolism (1)
- fat perception (1)
- fat-soluble vitamin (1)
- fatigue (1)
- fatty acid synthesis (1)
- fatty pancreas (1)
- female (1)
- fermentation (1)
- fermentation-related enzymes (1)
- fetal programing (1)
- fetal sex (1)
- fiber (1)
- filter paper (1)
- fingolimod (1)
- first trimester (1)
- flow (1)
- fluorescent probe (1)
- fluvial terraces (1)
- foal (1)
- food (1)
- food allergy (1)
- food groups (1)
- food safety (1)
- foot and mouth disease (HFMD) (1)
- formyl peptide receptor 2 (1)
- fortification (1)
- frailty (1)
- frataxin (1)
- free radicals (1)
- free zinc (1)
- fruit metabolites (1)
- functional diversity (1)
- functional properties (1)
- funktionelle Variabilität (1)
- future food (1)
- fígado (1)
- garnet (1)
- gender (1)
- gene (1)
- gene expression analysis (qRT-PCR) (1)
- gene regulation (1)
- gene-lifestyle interaction (1)
- genetic variants (1)
- genetics (1)
- genomics (1)
- gerontology (1)
- geschützter Anbau (1)
- gestational diabetes mellitus (GDM) (1)
- girths and breadths (1)
- glasswort (1)
- gliptins (1)
- glomerular arterioles (1)
- glucose homeostasis (1)
- glucose transport (1)
- glycation (1)
- glycemic control (1)
- glycemic control during pregnancy (1)
- glycogen synthase kinase-3 (1)
- gold nanostars (1)
- grafische Modelle (1)
- graphical models (1)
- gravity (1)
- green tea (1)
- green tea phenols (1)
- groEL (1)
- growth (1)
- gut length (1)
- hTAS2R10 (1)
- haemodialysis (1)
- hand (1)
- haplotype (1)
- health (1)
- health span (1)
- healthy subjects (1)
- heart tube (1)
- heart-type fatty acid binding protein (1)
- heat shock proteins (1)
- heath potentials (1)
- heme (1)
- hemodialysis (1)
- hepatic impairment (1)
- hepatocellular carcinoma (1)
- hepatotoxicity (1)
- heptadecanoic acid (C17:0) (1)
- heritability (1)
- heterocyclic aromatic amine (1)
- heterocyclic aromatic amines (1)
- heterocyclisches aromatisches Amin (1)
- heterologe Expression (1)
- heterologous expression (1)
- heterozyklische aromatische Amine (1)
- high fat diet (1)
- high salt (1)
- high-density lipoprotein (HDL) (1)
- high-fat diet (1)
- high-resolution imaging (1)
- hippocampus (1)
- homocysteine (1)
- homology modelling (1)
- hormones (1)
- human body composition (1)
- human diet (1)
- human follicular fluid (1)
- human health (1)
- human liver microsomes (1)
- human milk (1)
- hunger hormone (1)
- hydroxymethylfurfural (1)
- hydroxymethylpyrene (1)
- hyperglycemia (1)
- hypotension (1)
- hypoxic pulmonary vasoconstriction (1)
- hypoxische pulmonale Vasokonstriktion (1)
- immediate early gene (1)
- immune (1)
- immune response (1)
- immune system (1)
- immune-inflammatory biomarkers (1)
- immunoblot (1)
- immunohistochemistry (1)
- immunomodulator (1)
- impaired glucose tolerance (1)
- in silico (1)
- in situ chemical reduction (1)
- in vitro blood-brain barrier model (1)
- in vivo (1)
- incident type 2 diabetes (1)
- increases (1)
- index (1)
- indigenous leafy vegetables (1)
- indoor farming (1)
- induced pluripotent stem cells (1)
- induction (1)
- induzierte pluripotente Stammzellen (1)
- inflamação (1)
- inflammatory bowel disease (1)
- inhalative Applikation (1)
- inhibitory cytokines (1)
- inorganic mercury (1)
- insect proteins (1)
- insulin signalling (1)
- insulin-induced hypoglycemia (1)
- insulina (1)
- insulinresistance (1)
- integrated stress response (1)
- integrins (1)
- intercellular communication (1)
- intercropping (1)
- interleukin-1 (1)
- interleukin-35 (1)
- interventions (1)
- intesinal disease (1)
- intestinal (1)
- intestinal epithelial cells (1)
- intestinal inflammation (1)
- intestinal model (1)
- intestinale Epithelzellen (1)
- intestinale Mikrobiota (1)
- intrauterine (1)
- intrauterine fetal growth (1)
- inulin (1)
- invasion (1)
- involuntary weight loss (1)
- iodine (1)
- ion chromatography (1)
- ion quantification (1)
- ionophore antibiotics (1)
- iron (1)
- ischemia reperfusion injury (1)
- isoflavones (1)
- isothiocyanate (1)
- kale (1)
- kardiovaskuläres Risiko (1)
- ki-ras (1)
- kidney dysfunction (1)
- kidney injury molecule 1 (1)
- kinetics (1)
- knock-out (1)
- kolorektales Karzinom (1)
- kurzkettige Fettsäuren (1)
- körperliche Aktivität (1)
- laboratory animal sciences (1)
- laboratory mice (1)
- lactate output (1)
- lactobacillus (1)
- lake sediments (1)
- land-based aquaculture (1)
- langsame und schnelle Fasertypen (1)
- large for gestational age fetus (LGA) (1)
- large sample size studies (1)
- latex (1)
- lettuce (1)
- leucine (1)
- leukocyte-endothelial interaction (1)
- life style (1)
- lifestyle risk reduction (1)
- limb lengths (1)
- lineage commitment (1)
- linear gemischte Modelle (1)
- linear mixed models (1)
- lipases (1)
- lipid (1)
- lipid analysis (1)
- lipids (1)
- liposomes (1)
- litter decomposition (1)
- liver disease (1)
- liver regeneration (1)
- liver toxicity (1)
- long chain base (1)
- longevity (1)
- longitudinal analysis (1)
- low birth weight (LBW) (1)
- low molecular weight selenium species (1)
- low temperature (1)
- low-grade inflammation (1)
- lower nephron (1)
- lower respiratory tract infections (LRTIs) (1)
- lung cancer (1)
- lung inflammation (1)
- lupin (1)
- lutein ester (1)
- lutein esters (1)
- lycopene (1)
- lymphopenia (1)
- lysosomal storage disorders (1)
- lysozyme (1)
- lysozyme activity (1)
- mPGES (1)
- mRNA degradation (1)
- machine learning (1)
- macroarray (1)
- macrophage (1)
- macrovascular complications (1)
- macrófagos (1)
- macular pigment density (1)
- makrovaskuläre Komplikationen (1)
- male (1)
- malignant transformation (1)
- maligne Transformation (1)
- mare (1)
- maternal diet (1)
- maternale Ernährung (1)
- matrix metalloproteinases (1)
- maturity (1)
- mealworm (1)
- measles virus (1)
- mediation analysis (1)
- mediterrane Ernährung (1)
- membrane analysis (1)
- membrane lipids (1)
- membrane-lipid therapy (1)
- menschliche Ernährung (1)
- mercuric mercury (1)
- metablism (1)
- metabolic cage (1)
- metabolic response (1)
- metabolischer Stress (1)
- metabolisches Syndrom (1)
- methionine restriction (1)
- method development (1)
- method validation (1)
- methyl jasmonate (1)
- methylmercury (1)
- miRNAs (1)
- microRNAs (1)
- microbial mining (1)
- microbiology (1)
- microbiomics (1)
- microbiota (1)
- microgreen (1)
- micronutrient (1)
- micronutrient deficiencies (1)
- microorganisms (1)
- microparticle (1)
- microplastics (1)
- microscope (1)
- migration (1)
- mikrovaskuläre Komplikationen (1)
- mitochondria, (1)
- mixtures (1)
- molecular dynamics (1)
- molecular modeling (1)
- molecular pathways (1)
- monochlorobenzene (1)
- morpholino analogues of fingolimod (1)
- motor neurons (1)
- mouse models (1)
- moxidectin (1)
- mtDNA (1)
- mucus (1)
- multiple sclerosis (1)
- muscle (1)
- muscle atrophy (1)
- muscle fibre composition (1)
- muscle fibre type (1)
- muscle metabolism (1)
- muscle protein turnover (1)
- muscle wasting (1)
- myofibroblast (1)
- myoglobin (1)
- myokine (1)
- myrrh (1)
- n-3 fatty acid (1)
- n-6 fatty acid (1)
- n-oxPTH (1)
- narrow-banded UVB (1)
- natural compounds (1)
- nephrin (1)
- nephropathy (1)
- network (1)
- networks (1)
- neurofibromatosis (1)
- neuron (1)
- neurons (1)
- neuropathy (1)
- neuropeptides (1)
- neutral endopeptidase (1)
- neutrophil chemotaxis (1)
- neutrophil gelatinase-associated lipocalin (1)
- new analysis method (1)
- nomadic pastoralist (1)
- non-alcoholic steatohepatitis (1)
- nonlinear microscopy (1)
- nuclear receptor (1)
- nucleosidadduct (1)
- nucleus of the solitary tract (1)
- nukleärer Rezeptor (1)
- nutrition security (1)
- nutritional factors (1)
- nutritional supplements (1)
- old adults (1)
- oligomers (1)
- omega-3 fatty acid (1)
- one dot two development signals (ODTDS) dot blot (1)
- ontogeny (1)
- operant behavior (1)
- optogenetic (1)
- oral immunotherapy (1)
- orale Immuntherapie (1)
- orangutan (1)
- organ failure (1)
- organic mercury (1)
- orphan crops (1)
- osteoblast (1)
- osteopontin (1)
- osteoporosis (1)
- osterix (1)
- outcome (1)
- ovarian cancer (1)
- oxidation (1)
- oxidativer Stress (1)
- p-AKT (1)
- p-mTOR (1)
- pH-sensitive nanoparticle (1)
- pH-sensitive nanoparticles (1)
- palm oil (1)
- paternal programming (1)
- pathogen (1)
- peanut allergy (1)
- pentadecanoic acid (C15:0) (1)
- peptide (1)
- performance (1)
- perfused-rat-liver (1)
- peripheral nervous system (1)
- peripheres Nervensystem (1)
- perturbation (1)
- pflanzliche Sekundär Metabolite (1)
- phase II enzymes (1)
- phenol nitration (1)
- phenol oxidation (1)
- phenols (1)
- phosphorus (1)
- photochemistry (1)
- photosynthesis (1)
- photothermal therapy (1)
- phthalates (1)
- physiology (1)
- phytochemicals (1)
- pilot study (1)
- placenta (1)
- plant growth-promoting bacteria (1)
- plant phenolic compounds (1)
- plant protease (1)
- plant secondary metabolites (1)
- plant-based diets (1)
- plasma process indicators (1)
- plastic additives (1)
- point mutation (1)
- pollution (1)
- poly ungesättigte Fettsäuren (1)
- polyamines (1)
- polycystic kidney disease (1)
- polycystic ovary syndrome (1)
- polytunnel (1)
- polyunsaturated fatty acids (1)
- ponderostat (1)
- positional cloning (1)
- post-hospital syndrome (1)
- post-menopausal Thai women (1)
- postmenopausal (1)
- postprandial response (1)
- postprandial study (1)
- potassium iodate (1)
- potency assessment (1)
- preadipocyte (1)
- prebiotics (1)
- pregnancy induced diabetes (1)
- pregnane X-receptor (1)
- prepared foods (1)
- presystemic metabolism (1)
- preterm delivery (1)
- preterm infant (1)
- preventive measures (1)
- primary immunodeficiencies (1)
- priming effect (1)
- principal component analysis (1)
- proinsulin (1)
- proline rich proteins (1)
- prolinreiche Proteine (1)
- propionate (1)
- prostaglandin receptor (1)
- prostaglandin-f2-alpha (1)
- prostaglandine (1)
- prostate cancer (1)
- protected cultivation (1)
- protein derivatization (1)
- protein digestibility (1)
- protein interactions (1)
- protein microheterogeneity (1)
- protein pattern (1)
- protein quantification (1)
- protein-phenol binding (1)
- protein-phenol interactions (1)
- proteomix analysis (1)
- pulmonalarterielle glatte Muskelzellen (1)
- pulmonary artery smooth muscle cells (1)
- qPCR-based gene expression screening (1)
- quality control (1)
- quantitativ (1)
- quantitative (1)
- quercetin (1)
- ramipril (1)
- randomisierte Studie (1)
- randomized controlled intervention study (1)
- randomized controlled trial (1)
- rapeseed protein (1)
- rapid detection method (1)
- reactive oxygen and nitrogen species (1)
- reactive oxygen species (1)
- real life context (1)
- receptor (1)
- red wine (1)
- redox (1)
- redox homeostasis (1)
- reductase (1)
- reflection spectroscopy (1)
- regional diets (1)
- regulatory T cells (1)
- regulatory monitoring (1)
- relative dose response test (1)
- reliability; (1)
- renal dysfunction (1)
- renal function (1)
- renal haemodynamics (1)
- repeated measures design (1)
- replication (1)
- reporter gene assay (1)
- reproducibility (1)
- resistência à insulina (1)
- respiratory diseases (1)
- resveratrol (1)
- resveratrol oligomers (1)
- retinoic acid (1)
- retinol (ROH) (1)
- retinol binding protein 4 (1)
- retinol-binding protein (1)
- retinopathy (1)
- retinyl esters (1)
- retinyl palmitate (1)
- risk assessment (1)
- risk factors (1)
- risk score (1)
- risk scores (1)
- roe deer (1)
- ruminant (1)
- ruminants (1)
- sFlt-1 (1)
- safety efficacy (1)
- salinomycin (1)
- saliva proteins (1)
- salivary proteins (1)
- salmon fish (1)
- salt composition (1)
- salt taste perception (1)
- scores (1)
- screening (1)
- scrub typhus (1)
- seawater (1)
- sekundäre Pflanzenstoffe (1)
- selenium transport (1)
- selenoprotein (1)
- sensory analysis (1)
- sepsis (1)
- serine protease (1)
- serum amyloid A (SAA) (1)
- serum retinol binding protein (RBP4) (1)
- set-point (1)
- short chain fatty acids (1)
- shortening rate (1)
- single nucleotide polymorphism (1)
- single-cell analysis (1)
- situation (1)
- skeletal muscle aging (1)
- skeletal-muscle (1)
- skin (1)
- skin equivalents (1)
- slow and fast fiber types (1)
- smartphone (1)
- smoking (1)
- sodium (1)
- soy (1)
- soy isoflavones (1)
- spectrophotometry (1)
- sperm motility (1)
- spermatogenesis (1)
- sphingomyelin phosphodiesterase 1 (1)
- sphingosine kinase-1 (1)
- sphingosine kinases (1)
- sphingosine-1-phosphate (S1P) (1)
- spider mites (1)
- starter formula (1)
- stem cell (1)
- stereotypy (1)
- stomach model (1)
- storage (1)
- styrene (1)
- suPAR (1)
- substrate utilisation (1)
- succession (1)
- sudden death (1)
- sulfide (1)
- sulforaphan (1)
- sulforaphane (1)
- superoxide dismutase (1)
- suppressor of cytokine signaling (SOCS) (1)
- sweet taste (1)
- sweet taste receptor (1)
- sweetener (1)
- synbiotics (1)
- synovial fluid (1)
- systematischer Review (1)
- systemic response (1)
- systolic function (1)
- síndrome metabólica (1)
- tannin binding salivary proteins (1)
- tannin-protein interaction (1)
- tanninbindende Speichelproteine (1)
- targeted metabolomics (1)
- taste receptor (1)
- taste receptor screening (1)
- tea catechin (1)
- tea processing (1)
- telbivudine (1)
- telmisartan (1)
- terpenoids (1)
- therapy (1)
- thermal processing (1)
- thermal processing of food (1)
- thermogenesis (1)
- thermoresponsive-nanogel (1)
- thiol modification (1)
- thiomersal (1)
- thioredoxin-interacting protein (1)
- thymosin beta 4 (1)
- tight junctions (1)
- tissue inhibitior of metalloproteinases 1 (1)
- tocopherol (1)
- topical (1)
- total body fat (1)
- total glycated hemoglobin (1)
- total glycosylated hemoglobin (1)
- total phenol content (1)
- toxicology (1)
- trace element (1)
- training intervention (1)
- trans fatty acids (1)
- trans-Golgi (1)
- trans-migration (1)
- transcription factor (1)
- transformation product (1)
- transforming growth factor beta (1)
- transfusion-related acute lung injury (1)
- transgenerational effects (1)
- transgenes Mausmodell (1)
- transgenic mousemodel (1)
- transient receptor potential (1)
- transmission of hepatitis B virus (HBV) (1)
- transport proteins (1)
- transthyretin (TTR) (1)
- triazole fungicides (1)
- tryptophan quenching (1)
- tumor (1)
- tumor-metastasis (1)
- twin study (1)
- type 2 diabetes (T2DM) (1)
- type II diabetes (T2DM) (1)
- type-2-diabetes (1)
- ubiquitin proteasomal system (1)
- ultra heat treatment (1)
- ultrasound (1)
- umami (1)
- underutilized species (1)
- universal coating (1)
- urban (1)
- urinary biomarker (1)
- urine (1)
- valine (1)
- vascular disease; (1)
- vascular smooth muscle cells (1)
- vegan diet (1)
- vending machine (1)
- verzweigtkettige Aminosäuren (1)
- vesicular trafficking (1)
- vesicular transport (1)
- vesikulärer Transport (1)
- veterinary drug (1)
- vitamin (1)
- vitamin A deficiency (1)
- vitamin D binding protein (1)
- vitamin D-binding protein (1)
- vitamin E (1)
- vitamins (1)
- volatile compounds (1)
- weight loss intervention (1)
- weight maintenance (1)
- weight reduction (1)
- weight regulation (1)
- western blot (1)
- whey proteins (1)
- white adipose tissue (1)
- whole grains (1)
- whole-grain (1)
- yield enhancement (1)
- yolk (1)
- zeaxanthin (1)
- zentrales Nervensystem (1)
- zinc/iron supplementation (1)
- Östrogene (1)
- Übertragung (1)
- ß-Glucan (1)
- ätherische Öle (1)
- α-Tocopheroltransferprotein (Ttpa) (1)
- α-tocophero (1)
Institute
- Institut für Ernährungswissenschaft (1261) (remove)
Protected cultivation in greenhouses or polytunnels offers the potential for sustainable production of high-yield, high-quality vegetables. This is related to the ability to produce more on less land and to use resources responsibly and efficiently. Crop yield has long been considered the most important factor. However, as plant-based diets have been proposed for a sustainable food system, the targeted enrichment of health-promoting plant secondary metabolites should be addressed. These metabolites include carotenoids and flavonoids, which are associated with several health benefits, such as cardiovascular health and cancer protection.
Cover materials generally have an influence on the climatic conditions, which in turn can affect the levels of secondary metabolites in vegetables grown underneath. Plastic materials are cost-effective and their properties can be modified by incorporating additives, making them the first choice. However, these additives can migrate and leach from the material, resulting in reduced service life, increased waste and possible environmental release. Antifogging additives are used in agricultural films to prevent the formation of droplets on the film surface, thereby increasing light transmission and preventing microbiological contamination.
This thesis focuses on LDPE/EVA covers and incorporated antifogging additives for sustainable protected cultivation, following two different approaches. The first addressed the direct effects of leached antifogging additives using simulation studies on lettuce leaves (Lactuca sativa var capitata L). The second determined the effect of antifog polytunnel covers on lettuce quality. Lettuce is usually grown under protective cover and can provide high nutritional value due to its carotenoid and flavonoid content, depending on the cultivar.
To study the influence of simulated leached antifogging additives on lettuce leaves, a GC-MS method was first developed to analyze these additives based on their fatty acid moieties. Three structurally different antifogging additives (reference material) were characterized outside of a polymer matrix for the first time. All of them contained more than the main fatty acid specified by the manufacturer. Furthermore, they were found to adhere to the leaf surface and could not be removed by water or partially by hexane.
The incorporation of these additives into polytunnel covers affects carotenoid levels in lettuce, but not flavonoids, caffeic acid derivatives and chlorophylls. Specifically, carotenoids were higher in lettuce grown under polytunnels without antifog than with antifog. This has been linked to their effect on the light regime and was suggested to be related to carotenoid function in photosynthesis.
In terms of protected cultivation, the use of LDPE/EVA polytunnels affected light and temperature, and both are closely related. The carotenoid and flavonoid contents of lettuce grown under polytunnels was reversed, with higher carotenoid and lower flavonoid levels. At the individual level, the flavonoids detected in lettuce did not differ however, lettuce carotenoids adapted specifically depending on the time of cultivation. Flavonoid reduction was shown to be transcriptionally regulated (CHS) in response to UV light (UVR8). In contrast, carotenoids are thought to be regulated post-transcriptionally, as indicated by the lack of correlation between carotenoid levels and transcripts of the first enzyme in carotenoid biosynthesis (PSY) and a carotenoid degrading enzyme (CCD4), as well as the increased carotenoid metabolic flux. Understanding the regulatory mechanisms and metabolite adaptation strategies could further advance the strategic development and selection of cover materials.
Du sollst nicht essen
(2024)
Zwar sind Menschen biologisch gesehen Allesesser, dennoch gibt es keine Gemeinschaft, die alle ihr zur Verfügung stehenden Nahrungsmittel voll ausschöpft. Immer wird etwas nicht gegessen. Warum wir nicht essen, was wir nicht essen – das beleuchtet dieser Sammelband aus neuro-, ernährungs-, gesellschafts- und religionswissenschaftlicher Perspektive. Ein „religiöser Nutriscore“ gibt Auskunft über die wichtigsten Verzichtsregeln in Judentum, Christentum und Islam. Eine Fotostrecke veranschaulicht, wie bestimmte Speisen zu Festen und Feiertagen zu einem heiligen Essen werden. Nicht zuletzt werden Wege aufgezeigt, wie Menschen, die verschiedene Speiseregeln befolgen, dennoch zusammen essen können – inklusive Praxistest in der Unimensa.
Hässlich aber gut
(2024)
With the many challenges facing the agricultural system, such as water scarcity, loss of arable land due to climate change, population growth, urbanization or trade disruptions, new agri-food systems are needed to ensure food security in the future. In addition, healthy diets are needed to combat non-communicable diseases. Therefore, plant-based diets rich in health-promoting plant secondary metabolites are desirable. A saline indoor farming system is representing a sustainable and resilient new agrifood system and can preserve valuable fresh water. Since indoor farming relies on artificial lighting, assessment of lighting conditions is essential. In this thesis, the cultivation of halophytes in a saline indoor farming system was evaluated and the influence of cultivation conditions were assessed in favor of improving the nutritional quality of halophytes for human consumption. Therefore, five selected edible halophyte species (Brassica oleracea var. palmifolia, Cochlearia officinalis, Atriplex hortensis, Chenopodium quinoa, and Salicornia europaea) were cultivated in saline indoor farming. The halophyte species were selected for to their salt tolerance levels and mechanisms. First, the suitability of halophytes for saline indoor farming and the influence of salinity on their nutritional properties, e.g. plant secondary metabolites and minerals, were investigated. Changes in plant performance and nutritional properties were observed as a function of salinity. The response to salinity was found to be species-specific and related to the salt tolerance mechanism of the halophytes. At their optimal salinity levels, the halophytes showed improved carotenoid content. In addition, a negative correlation was found between the nitrate and chloride content of halophytes as a function of salinity. Since chloride and nitrate can be antinutrient compounds, depending on their content, monitoring is essential, especially in halophytes. Second, regional brine water was introduced as an alternative saline water resource in the saline indoor farming system. Brine water was shown to be feasible for saline indoor farming
of halophytes, as there was no adverse effect on growth or nutritional properties, e.g. carotenoids. Carotenoids were shown to be less affected by salt composition than by salt concentration. In addition, the interaction between the salinity and the light regime in indoor farming and greenhouse cultivation has been studied. There it was shown that interacting light regime and salinity alters the content of carotenoids and chlorophylls. Further, glucosinolate and nitrate content were also shown to be influenced by light regime. Finally, the influence of UVB light on halophytes was investigated using supplemental narrow-band UVB LEDs. It was shown that UVB light affects the growth, phenotype and metabolite profile of halophytes and that the UVB response is species specific. Furthermore, a modulation of carotenoid content in S. europaea could be achieved to enhance health-promoting properties and thus improve nutritional quality. This was shown to be dose-dependent and the underlying mechanisms of carotenoid accumulation were also investigated. Here it was revealed that carotenoid accumulation is related to oxidative stress.
In conclusion, this work demonstrated the potential of halophytes as alternative vegetables produced in a saline indoor farming system for future diets that could contribute to ensuring food security in the future. To improve the sustainability of the saline indoor farming system, LED lamps and regional brine water could be integrated into the system. Since the nutritional properties have been shown to be influenced by salt, light regime and UVB light, these abiotic stressors must be taken into account when considering halophytes as alternative vegetables for human nutrition.
Du sollst nicht essen
(2024)
Zwar sind Menschen biologisch gesehen Allesesser, dennoch gibt es keine Gemeinschaft, die alle ihr zur Verfügung stehenden Nahrungsmittel voll ausschöpft. Immer wird etwas nicht gegessen. Warum wir nicht essen, was wir nicht essen – das beleuchtet dieser Sammelband aus neuro-, ernährungs-, gesellschafts- und religionswissenschaftlicher Perspektive. Ein „religiöser Nutriscore“ gibt Auskunft über die wichtigsten Verzichtsregeln in Judentum, Christentum und Islam. Eine Fotostrecke veranschaulicht, wie bestimmte Speisen zu Festen und Feiertagen zu einem heiligen Essen werden. Nicht zuletzt werden Wege aufgezeigt, wie Menschen, die verschiedene Speiseregeln befolgen, dennoch zusammen essen können – inklusive Praxistest in der Unimensa.
Aging is associated with bone loss, which can lead to osteoporosis and high fracture risk. This coincides with the enhanced formation of bone marrow adipose tissue (BMAT), suggesting a negative effect of bone marrow adipocytes on skeletal health. Increased BMAT formation is also observed in pathologies such as obesity, type 2 diabetes and osteoporosis. However, a subset of bone marrow adipocytes forming the constitutive BMAT (cBMAT), arise early in life in the distal skeleton, contain high levels of unsaturated fatty acids and are thought to provide a physiological function. Regulated BMAT (rBMAT) forms during aging and obesity in proximal regions of the bone and contain a large proportion of saturated fatty acids. Paradoxically, BMAT accumulation is also enhanced during caloric restriction (CR), a life-span extending dietary intervention. This indicates, that different types of BMAT can form in response to opposing nutritional stimuli with potentially different functions.
To this end, two types of nutritional interventions, CR and high fat diet (HFD), that are both described to induce BMAT accumulation were carried out. CR markedly increased BMAT formation in the proximal tibia and led to a higher proportion of unsaturated fatty acids, making it similar to the physiological cBMAT. Additionally, proximal and diaphyseal tibia regions displayed higher adiponectin expression. In aged mice, CR was associated with an improved trabecular bone structure. Taken together, these findings demonstrate, that the type of BMAT that forms during CR might provide beneficial effects for local bone stem/progenitor cells and metabolic health. The HFD intervention performed in this thesis showed no effect on BMAT accumulation and bone microstructure. RNA Seq analysis revealed alterations in the composition of the collagen-containing extracellular matrix (ECM).
In order to investigate the effects of glucose homeostasis on osteogenesis, differentiation capacity of immortalized multipotent mesenchymal stromal cells (MSCs) and osteochondrogenic progenitor cells (OPCs) was analyzed. Insulin improved differentiation in both cell types, however, combination of with a high glucose concentration led to an impaired mineralization of the ECM. In the MSCs, this was accompanied by the formation of adipocytes, indicating negative effects of the adipocytes formed during hyperglycemic conditions on mineralization processes. However, the altered mineralization pattern and structure of the ECM was also observed in OPCs, which did not form any adipocytes, suggesting further negative effects of a hyperglycemic environment on osteogenic differentiation.
In summary, the work provided in this thesis demonstrated that differentiation commitment of bone-resident stem cells can be altered through nutrient availability, specifically glucose. Surprisingly, both high nutrient supply, e.g. the hyperglycemic cell culture conditions, and low nutrient supply, e.g. CR, can induce adipogenic differentiation. However, while CR-induced adipocyte formation was associated with improved trabecular bone structure, adipocyte formation in a hyperglycemic cell-culture environment hampered mineralization. This thesis provides further evidence for the existence of different types of BMAT with specific functions.
Cross-sectional associations of dietary biomarker patterns with health and nutritional status
(2024)
Selenium (Se) is an essential trace element that is ubiquitously present in the environment in small concentrations. Essential functions of Se in the human body are manifested through the wide range of proteins, containing selenocysteine as their active center. Such proteins are called selenoproteins which are found in multiple physiological processes like antioxidative defense and the regulation of thyroid hormone functions. Therefore, Se deficiency is known to cause a broad spectrum of physiological impairments, especially in endemic regions with low Se content. Nevertheless, being an essential trace element, Se could exhibit toxic effects, if its intake exceeds tolerable levels. Accordingly, this range between deficiency and overexposure represents optimal Se supply. However, this range was found to be narrower than for any other essential trace element. Together with significantly varying Se concentrations in soil and the presence of specific bioaccumulation factors, this represents a noticeable difficulty in the assessment of Se
epidemiological status. While Se is acting in the body through multiple selenoproteins, its intake occurs mainly in form of small organic or inorganic molecular mass species. Thus, Se exposure not only depends on daily intake but also on the respective chemical form, in which it is present.
The essential functions of selenium have been known for a long time and its primary forms in different food sources have been described. Nevertheless, analytical capabilities for a comprehensive investigation of Se species and their derivatives have been introduced only in the last decades. A new Se compound was identified in 2010 in the blood and tissues of bluefin tuna. It was called selenoneine (SeN) since it is an isologue of naturally occurring antioxidant ergothioneine (ET), where Se replaces sulfur. In the following years, SeN was identified in a number of edible fish species and attracted attention as a new dietary Se source and potentially strong antioxidant. Studies in populations whose diet largely relies on fish revealed that SeN
represents the main non-protein bound Se pool in their blood. First studies, conducted with enriched fish extracts, already demonstrated the high antioxidative potential of SeN and its possible function in the detoxification of methylmercury in fish. Cell culture studies demonstrated, that SeN can utilize the same transporter as ergothioneine, and SeN metabolite was found in human urine.
Until recently, studies on SeN properties were severely limited due to the lack of ways to obtain the pure compound. As a predisposition to this work was firstly a successful approach to SeN synthesis in the University of Graz, utilizing genetically modified yeasts. In the current study, by use of HepG2 liver carcinoma cells, it was demonstrated, that SeN does not cause toxic effectsup to 100 μM concentration in hepatocytes. Uptake experiments showed that SeN is not bioavailable to the used liver cells.
In the next part a blood-brain barrier (BBB) model, based on capillary endothelial cells from the porcine brain, was used to describe the possible transfer of SeN into the central nervous system (CNS). The assessment of toxicity markers in these endothelial cells and monitoring of barrier conditions during transfer experiments demonstrated the absence of toxic effects from SeN on the BBB endothelium up to 100 μM concentration. Transfer data for SeN showed slow but substantial transfer. A statistically significant increase was observed after 48 hours following SeN incubation from the blood-facing side of the barrier. However, an increase in Se content was clearly visible already after 6 hours of incubation with 1 μM of SeN. While the transfer rate of SeN after application of 0.1 μM dose was very close to that for 1 μM, incubation with 10 μM of SeN resulted in a significantly decreased transfer rate. Double-sided application of SeN caused no side-specific transfer of SeN, thus suggesting a passive diffusion mechanism of SeN across the BBB. This data is in accordance with animal studies, where ET accumulation was observed in the rat brain, even though rat BBB does not have the primary ET transporter – OCTN1. Investigation of capillary endothelial cell monolayers after incubation with SeN and reference selenium compounds showed no significant increase of intracellular selenium concentration. Speciesspecific Se measurements in medium samples from apical and basolateral compartments, as good as in cell lysates, showed no SeN metabolization. Therefore, it can be concluded that SeN may reach the brain without significant transformation.
As the third part of this work, the assessment of SeN antioxidant properties was performed in Caco-2 human colorectal adenocarcinoma cells. Previous studies demonstrated that the intestinal epithelium is able to actively transport SeN from the intestinal lumen to the blood side and accumulate SeN. Further investigation within current work showed a much higher antioxidant potential of SeN compared to ET. The radical scavenging activity after incubation with SeN was close to the one observed for selenite and selenomethionine. However, the SeN effect on the viability of intestinal cells under oxidative conditions was close to the one caused by ET. To answer the question if SeN is able to be used as a dietary Se source and induce the activity of selenoproteins, the activity of glutathione peroxidase (GPx) and the secretion of selenoprotein P (SelenoP) were measured in Caco-2 cells, additionally. As expected, reference selenium compounds selenite and selenomethionine caused efficient induction of GPx activity. In contrast to those SeN had no effect on GPx activity. To examine the possibility of SeN being embedded into the selenoproteome, SelenoP was measured in a culture medium. Even though Caco-2 cells effectively take up SeN in quantities much higher than selenite or selenomethionine, no secretion of SelenoP was observed after SeN incubation.
Summarizing, we can conclude that SeN can hardly serve as a Se source for selenoprotein synthesis. However, SeN exhibit strong antioxidative properties, which appear when sulfur in ET is exchanged by Se. Therefore, SeN is of particular interest for research not as part of Se metabolism, but important endemic dietary antioxidant.
Mit dem Alter kann eine Zunahme leichtgradiger Entzündungsprozesse beobachtet werden, von denen angenommen wird, dass sie den typischen, altersbedingten Verlust an Muskelmasse, -kraft und -funktion „befeuern“. Diese als Inflammaging bezeichneten Prozesse können auf ein komplexes Zusammenspiel aus einem dysfunktionalen (viszeralen) Fettgewebe, einer Dysbiose und damit einhergehender mikrobiellen Translokation und geringeren Abwehrfähigkeit sowie einer insgesamt zunehmenden Immunseneszenz zurückgeführt werden. In Summa begünstigt ein pro-inflammatorisches Milieu metabolische Störungen und chronische, altersassoziierte Erkrankungen, die das Entzündungsgeschehen aufrechterhalten oder vorantreiben. Neben einem essenziellen Bewegungsmangel trägt auch eine westlich geprägte, industrialisierte Ernährungsweise zum Entzündungsgeschehen und zur Entwicklung chronischer Erkrankungen bei. Daher liegt die Vermutung nahe, dem Entzündungsgeschehen mit ausreichend Bewegung und einer anti-inflammatorischen Ernährung entgegenzuwirken. In dieser Hinsicht werden insbesondere Omega-3-Fettsäuren (Omega-3) mit anti-inflammatorischen Eigenschaften verbunden. Obwohl ein Zusammenhang zwischen dem ernährungsbedingten Inflammationspotenzial bzw. der Zufuhr von Omega-3 und dem Inflammationsprofil bereits untersucht wurde, fehlen bislang Untersuchungen insbesondere bei älteren Erwachsenen, die den Link zwischen dem Inflammationspotenzial der Ernährung und Sarkopenie-relevanten Muskelparametern herstellen.
Aufgrund des Proteinmehrbedarfs zum Erhalt der funktionellen Muskulatur im Alter wurde bereits eine Vielzahl an Sport- und Ernährungsinterventionen durchgeführt, die eine Verbesserung des Muskelstatus mit Hilfe von strukturiertem Krafttraining und einer proteinreichen Ernährung zeigen. Es gibt zudem Hinweise, dass Omega-3 auch die Proteinsynthese verstärken könnten. Unklar ist jedoch, inwiefern eine anti-inflammatorische Ernährung mit Fokus auf Omega-3 sowohl die Entzündungsprozesse als auch den Muskelproteinmetabolismus und die neuromuskuläre Funktionalität im Alter günstig unterstützen kann. Dies vor allem im Hinblick auf die Muskelleistung, die eng mit der Sturzneigung und der Autonomie im Alltag verknüpft ist, aber in Interventionsstudien mit älteren Erwachsenen bisher wenig Berücksichtigung erhielt. Darüber hinaus werden häufig progressive Trainingselemente genutzt, die nach Studienabschluss oftmals wenig Anschluss im Lebensalltag der Betroffenen finden und somit wenig nachhaltig sind. Ziel dieser Arbeit war demnach die Evaluierung einer proteinreichen und zusätzlich mit Omega-3 supplementierten Ernährung in Kombination mit einem wöchentlichen Vibrationstraining und altersgemäßen Bewegungsprogramm auf Inflammation und neuromuskuläre Funktion bei älteren, selbständig lebenden Erwachsenen.
Hierzu wurden zunächst mögliche Zusammenhänge zwischen dem ernährungsbedingten Inflammationspotenzial, ermittelt anhand des Dietary Inflammatory Index, und dem Muskelstatus sowie dem Inflammationsprofil im Alter eruiert. Dazu dienten die Ausgangswerte von älteren, selbständig lebenden Erwachsenen einer postprandialen Interventionsstudie (POST-Studie), die im Querschnitt analysiert wurden. Die Ergebnisse bestätigten, dass eine pro-inflammatorische Ernährung sich einerseits in einem stärkeren Entzündungsgeschehen widerspiegelt und andererseits mit Sarkopenie-relevanten Parametern, wie einer geringeren Muskelmasse und Gehgeschwindigkeit, ungünstig assoziiert ist. Darüber hinaus zeigten sich diese Zusammenhänge auch in Bezug auf die Handgreifkraft bei den inaktiven, älteren Erwachsenen der Studie.
Anschließend wurde in einer explorativ ausgerichteten Pilot-Interventionsstudie (AIDA-Studie) in einem dreiarmigen Design untersucht, inwieweit sich eine Supplementierung mit Omega-3 unter Voraussetzung einer optimierten Proteinzufuhr und altersgemäßen Sportintervention mit Vibrationstraining auf die neuromuskuläre Funktion und Inflammation bei selbständig lebenden, älteren Erwachsenen auswirkt. Nach acht Wochen Intervention zeigte sich, dass eine mit Omega-3 supplementierte, proteinreiche Ernährung die Muskelleistung insbesondere bei den älteren Männern steigerte. Während sich die Kontrollgruppe nach acht Wochen Sportintervention nicht verbesserte, bestätigte sich zusätzlich eine Verbesserung der Beinkraft und der Testzeit beim Stuhl-Aufsteh-Test der älteren Erwachsenen mit einer proteinreichen Ernährung in Kombination mit der Sportintervention.
Darüber hinaus wurde deutlich, dass die zusätzliche Omega-3-Supplementierung insbesondere bei den Männern eine Reduktion der pro-inflammatorischen Zytokine im Serum zur Folge hatte. Allerdings spiegelten sich diese Beobachtungen nicht auf Genexpressionsebene in mononukleären Immunzellen oder in der LPS-induzierten Sekretion der Zytokine und Chemokine in Vollblutzellkulturen wider. Dies erfordert weitere Untersuchungen.
Housing in metabolic cages can induce a pronounced stress response. Metabolic cage systems imply housing mice on metal wire mesh for the collection of urine and feces in addition to monitoring food and water intake. Moreover, mice are single-housed, and no nesting, bedding, or enrichment material is provided, which is often argued to have a not negligible impact on animal welfare due to cold stress. We therefore attempted to reduce stress during metabolic cage housing for mice by comparing an innovative metabolic cage (IMC) with a commercially available metabolic cage from Tecniplast GmbH (TMC) and a control cage. Substantial refinement measures were incorporated into the IMC cage design. In the frame of a multifactorial approach for severity assessment, parameters such as body weight, body composition, food intake, cage and body surface temperature (thermal imaging), mRNA expression of uncoupling protein 1 (Ucp1) in brown adipose tissue (BAT), fur score, and fecal corticosterone metabolites (CMs) were included. Female and male C57BL/6J mice were single-housed for 24 h in either conventional Macrolon cages (control), IMC, or TMC for two sessions. Body weight decreased less in the IMC (females—1st restraint: 6.94%; 2nd restraint: 6.89%; males—1st restraint: 8.08%; 2nd restraint: 5.82%) compared to the TMC (females—1st restraint: 13.2%; 2nd restraint: 15.0%; males—1st restraint: 13.1%; 2nd restraint: 14.9%) and the IMC possessed a higher cage temperature (females—1st restraint: 23.7°C; 2nd restraint: 23.5 °C; males—1st restraint: 23.3 °C; 2nd restraint: 23.5 °C) compared with the TMC (females—1st restraint: 22.4 °C; 2nd restraint: 22.5 °C; males—1st restraint: 22.6 °C; 2nd restraint: 22.4 °C). The concentration of fecal corticosterone metabolites in the TMC (females—1st restraint: 1376 ng/g dry weight (DW); 2nd restraint: 2098 ng/g DW; males—1st restraint: 1030 ng/g DW; 2nd restraint: 1163 ng/g DW) was higher compared to control cage housing (females—1st restraint:
640 ng/g DW; 2nd restraint: 941 ng/g DW; males—1st restraint: 504 ng/g DW; 2nd restraint: 537 ng/g DW). Our results show the stress potential induced by metabolic cage restraint that is markedly influenced by the lower housing temperature. The IMC represents a first attempt to target cold stress reduction during metabolic cage application thereby producing more animal welfare friendly data.
Over the last decades, interest in the impact of the intestinal microbiota on host health has steadily increased. Diet is a major factor that influences the gut microbiota and thereby indirectly affects human health. For example, a high fat diet rich in saturated fatty acids led to an intestinal proliferation of the colitogenic bacterium Bilophila (B.) wadsworthia by stimulating the release of the bile acid taurocholate (TC). TC contains the sulfonated head group taurine, which undergoes conversion to sulfide (H2S) by B. wadsworthia. In a colitis prone murine animal model (IL10 / mice), the bloom of B. wadsworthia was accompanied by an exacerbation of intestinal inflammation. B. wadsworthia is able to convert taurine and also other sulfonates to H2S, indicating the potential association of sulfonate utilization and the stimulation of colitogenic bacteria.
This potential link raised the question, whether dietary sulfonates or their sulfonated metabolites stimulate the growth of colitogenic bacteria such as B. wadsworthia and whether these bacteria convert sulfonates to H2S. Besides taurine, which is present in meat, fish and life-style beverages, other dietary sulfonates are part of daily human nutrition. Sulfolipids such as sulfoquinovosyldiacylglycerols (SQDG) are highly abundant in salad, parsley and the cyanobacterium Arthrospira platensis (Spirulina). Based on previous findings, Escherichia (E.) coli releases the polar headgroup sulfoquinovose (SQ) from SQDG. Moreover, E. coli is able to convert SQ to 2,3 dihydroxypropane 1 sulfonate (DHPS) under anoxic conditions. DHPS is also converted to H2S by B. wadsworthia or by other potentially harmful gut bacteria such as members of the genus Desulfovibrio. However, only few studies report the conversion of sulfonates to H2S by bacteria directly isolated from the human intestinal tract. Most sulfonate utilizing bacteria were obtained from environmental sources such as soil or lake sediment or from potentially intestinal sources such as sewage.
In the present study, fecal slurries from healthy human subjects were incubated with sulfonates under strictly anoxic conditions, using formate and lactate as electron donors. Fecal slurries that converted sulfonates to H2S, were used as a source for the isolation of H2S forming bacteria. Isolates were identified based on their 16S ribosomal RNA (16S rRNA) gene sequence. In addition, conventional C57BL/6 mice were fed a semisynthetic diet supplemented with the SQDG rich Spirulina (SD) or a Spirulina free control diet (CD). During the intervention, body weight, water and food intake were monitored and fecal samples were collected. After three weeks, mice were killed and organ weight and size were measured, intestinal sulfonate concentrations were quantified, gut microbiota composition was determined and parameters of intestinal and hepatic fat metabolism were analyzed.
Human fecal slurries converted taurine, isethionate, cysteate, 3 sulfolacate, SQ and DHPS to H2S. However, inter individual differences in the degradation of these sulfonates were observed. Taurine, isethionate, and 3 sulfolactate were utilized by fecal microbiota of all donors, while SQ, DHPS and cysteate were converted to H2S only by microbiota from certain individuals. Bacterial isolates from human feces able to convert sulfonates to H2S were identified as taurine-utilizing Desulfovibrio strains, taurine- and isethionate-utilizing B. wadsworthia, or as SQ- and 3-sulfolactate- utilizing E. coli. In addition, a co culture of E. coli and B. wadsworthia led to complete degradation of SQ to H2S, with DHPS as an intermediate. Of the human fecal isolates, B. wadsworthia and Desulfovibrio are potentially harmful. E. coli strains might be also pathogenic, but isolated E. coli strains from human feces were identified as commensal gut bacteria.
Feeding SD to mice increased the cecal and fecal SQ concentration and altered the microbiota composition, but the relative abundance of SQDG or SQ converting bacteria and colitogenic bacteria was not enriched in mice fed SD for 21 days. SD did not affect the relative abundance of Enterobacteriaceae, to which the SQDG- and SQ-utilizing E. coli strain belong to. Furthermore, the abundance of B. wadsworthia decreased from day 2 to day 9 in feces, but recovered afterwards in the same mice. In cecum, the family Desulfovibrionaceae, to which B. wadsworthia and Desulfovibrio belong to, were reduced. No changes in the number of B. wadsworthia in cecal contents or of Desulfovibrionaceae in feces were observed. SD led to a mild activation of the immune system, which was not observed in control mice fed CD. Mice fed SD had an increased body weight, a higher adipose tissue weight, and a decreased liver weight compared to the control mice, suggesting an impact of Spirulina supplementation on fat metabolism. However, expression levels of genes involved in intestinal and hepatic intracellular lipid uptake and availability were reduced. Further investigations on the lipid metabolism at protein level could help to clarify these discrepancies.
In summary, humans differ in the ability of their fecal microbiota to utilize dietary sulfonates. While sulfonates stimulated the proliferation of potentially colitogenic isolates from human fecal slurries, the increased availability of SQ in Spirulina fed conventional mice did not lead to an enrichment of such bacteria. Presence or absence of these bacteria may explain the inter individual differences in sulfonate conversion observed for fecal slurries. This work provides new insights in the ability of intestinal bacteria to utilize sulfonates and thus, contributes to a better understanding of microbiota-mediated effects on dietary sulfonate utilization. Interestingly, feeding of the Spirulina-supplemented diet led to body-weight gain in mice in the first two days of intervention, the reasons for which are unknown.
Aging is a complex process characterized by several factors, including loss of genetic and epigenetic information, accumulation of chronic oxidative stress, protein damage and aggregates and it is becoming an emergent drug target. Therefore, it is the utmost importance to study aging and agerelated diseases, to provide treatments to develop a healthy aging process. Skeletal muscle is one of the earliest tissues affected by age-related changes with progressive loss of muscle mass and function from 30 years old, effect known as sarcopenia. Several studies have shown the accumulation of protein aggregates in different animal models, as well as in humans, suggesting impaired proteostasis, a hallmark of aging, especially regarding degradation systems. Thus, different publications have explored the role of the main proteolytic systems in skeletal muscle from rodents and humans, like ubiquitin proteasomal system (UPS) and autophagy lysosomal system (ALS), however with contradictory results. Yet, most of the published studies are performed in muscles that comprise more than one fiber type, that means, muscles composed by slow and fast fibers. These fiber types, exhibit different metabolism and contraction speed; the slow fibers or type I display an oxidative metabolism, while fast fibers function towards a glycolytic metabolism ranging from fast oxidative to fast glycolytic fibers. To this extent, the aim of this thesis sought to understand on how aging impacts both fiber types not only regarding proteostasis but also at a metabolome and transcriptome network levels. Therefore, the first part of this thesis, presents the differences between slow oxidative (from Soleus muscle) and fast glycolytic fibers (Extensor digitorum longus, EDL) in terms of degradation systems and how they cope with oxidative stress during aging, while the second part explores the differences between young and old EDL muscle transcriptome and metabolome, unraveling molecular features. More specifically, the results from the present work show that slow oxidative muscle performs better at maintaining the function of UPS and ALS during aging than EDL muscle, which is clearly affected, accounting for the decline in the catalytic activity rates and accumulation of autophagy-related proteins. Strinkingly, transcriptome and metabolome analyses reveal that fast glycolytic muscle evidences significant downregulation of mitochondrial related processes and damaged mitochondria morphology during aging, despite of having a lower oxidative metabolism compared to oxidative fibers. Moreover, predictive analyses reveal a negative association between aged EDL gene signature and lifespan extending interventions such as caloric restriction (CR). Although, CR intervention does not alter the levels of mitochondrial markers in aged EDL muscle, it can reverse the higher mRNA levels of muscle damage markers. Together, the results from this thesis give new insights about how different metabolic muscle fibers cope with age-related changes and why fast glycolytic fibers are more susceptible to aging than slow oxidative fibers.
Background: The role of fatty acid (FA) intake and metabolism in type 2 diabetes (T2D) incidence is controversial. Some FAs are not synthesised endogenously and, therefore, these circulating FAs reflect dietary intake, for example, the trans fatty acids (TFAs), saturated odd chain fatty acids (OCFAs), and linoleic acid, an n-6 polyunsaturated fatty acids (PUFA). It remains unclear if intake of TFA influence T2D risk and whether industrial TFAs (iTFAs) and ruminant TFAs (rTFAs) exert the same effect. Unlike even chain saturated FAs, the OCFAs have been inversely associated with T2D risk, but this association is poorly understood. Furthermore, the associations of n-6 PUFAs intake with T2D risk are still debated, while delta-5 desaturase (D5D), a key enzyme in the metabolism of PUFAs, has been consistently related to T2D risk. To better understand these relationships, the FA composition in circulating lipid fractions can be used as biomarkers of dietary intake and metabolism. The exploration of TFAs subtypes in plasma phospholipids and OCFAs and n-6 PUFAs within a wide range of lipid classes may give insights into the pathophysiology of T2D.
Aim: This thesis aimed mainly to analyse the association of TFAs, OCFAs and n-6 PUFAs with self-reported dietary intake and prospective T2D risk, using seven types of TFAs in plasma phospholipids and deep lipidomics profiling data from fifteen lipid classes.
Methods: A prospective case-cohort study was designed within the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam study, including all the participants who developed T2D (median follow-up 6.5 years) and a random subsample of the full cohort (subcohort: n=1248; T2D cases: n=820). The main analyses included two lipid profiles. The first was an assessment of seven TFA in plasma phospholipids, with a modified method for analysis of FA with very low abundances. The second lipid profile was derived from a high-throughout lipid profiling technology, which identified 940 distinct molecular species and allowed to quantify OCFAs and PUFAs composition across 15 lipid classes. Delta-5 desaturase (D5D) activity was estimated as 20:4/20:3-ratio. Using multivariable Cox regression models, we examined the associations of TFA subtypes with incident T2D and class-specific associations of OCFA and n-6 PUFAs with T2D risk.
Results: 16:1n-7t, 18:1n-7t, and c9t11-CLA were positively correlated with the intake of fat-rich dairy foods. iTFA 18:1 isomers were positively correlated with margarine. After adjustment for confounders and other TFAs, higher plasma phospholipid concentrations of two rTFAs were associated with a lower incidence of T2D: 18:1n-7t and t10c12-CLA. In contrast, the rTFA c9t11-CLA was associated with a higher incidence of T2D. rTFA 16:1n-7t and iTFAs (18:1n-6t, 18:1n-9t, 18:2n-6,9t) were not statistically significantly associated with T2D risk.
We observed heterogeneous integration of OCFA in different lipid classes, and the contribution of 15:0 versus 17:0 to the total OCFA abundance differed across lipid classes. Consumption of fat-rich dairy and fiber-rich foods were positively and red meat inversely correlated to OCFA abundance in plasma phospholipid classes. In women only, higher abundances of 15:0 in phosphatidylcholines (PC) and diacylglycerols (DG), and 17:0 in PC, lysophosphatidylcholines (LPC), and cholesterol esters (CE) were inversely associated with T2D risk. In men and women, a higher abundance of 15:0 in monoacylglycerols (MG) was also inversely associated with T2D. Conversely, a higher 15:0 concentration in LPC and triacylglycerols (TG) was associated with higher T2D risk in men. Women with a higher concentration of 17:0 as free fatty acids (FFA) also had higher T2D incidence.
The integration of n-6 PUFAs in lipid classes was also heterogeneous. 18:2 was highly abundant in phospholipids (particularly PC), CE, and TG; 20:3 represented a small fraction of FA in most lipid classes, and 20:4 accounted for a large proportion of circulating phosphatidylinositol (PI) and phosphatidylethanolamines (PE). Higher concentrations of 18:2 were inversely associated with T2D risk, especially within DG, TG, and LPC. However, 18:2 as part of MG was positively associated with T2D risk. Higher concentrations of 20:3 in phospholipids (PC, PE, PI), FFA, CE, and MG were linked to higher T2D incidence. 20:4 was unrelated to risk in most lipid classes, except positive associations were observed for 20:4 enriched in FFA and PE. The estimated D5D activities in PC, PE, PI, LPC, and CE were inversely associated with T2D and explained variance of estimated D5D activity by genomic variation in the FADS locus was only substantial in those lipid classes.
Conclusion: The TFAs' conformation is essential in their relationship to diabetes risk, as indicated by plasma rTFA subtypes concentrations having opposite directions of associations with diabetes risk. Plasma OCFA concentration is linked to T2D risk in a lipid class and sex-specific manner. Plasma n-6 PUFA concentrations are associated differently with T2D incidence depending on the specific FA and the lipid class. Overall, these results highlight the complexity of circulating FAs and their heterogeneous association with T2D risk depending on the specific FA structure, lipid class, and sex. My results extend the evidence of the relationship between diet, lipid metabolism, and subsequent T2D risk. In addition, my work generated several potential new biomarkers of dietary intake and prospective T2D risk.
The trace elements, selenium (Se) and copper (Cu) play an important role in maintaining normal brain function. Since they have essential functions as cofactors of enzymes or structural components of proteins, an optimal supply as well as a well-defined homeostatic regulation are crucial. Disturbances in trace element homeostasis affect the health status and contribute to the incidence and severity of various diseases. The brain in particular is vulnerable to oxidative stress due to its extensive oxygen consumption and high energy turnover, among other factors. As components of a number of antioxidant enzymes, both elements are involved in redox homeostasis. However, high concentrations are also associated with the occurrence of oxidative stress, which can induce cellular damage. Especially high Cu concentrations in some brain areas are associated with the development and progression of neurodegenerative diseases such as Alzheimer's disease (AD). In contrast, reduced Se levels were measured in brains of AD patients. The opposing behavior of Cu and Se renders the study of these two trace elements as well as the interactions between them being particularly relevant and addressed in this work.
The intake of high-fat diets (HFDs) containing large amounts of saturated long-chain fatty acids leads to obesity, oxidative stress, inflammation, and insulin resistance. The trace element selenium, as a crucial part of antioxidative selenoproteins, can protect against the development of diet-induced insulin resistance in white adipose tissue (WAT) by increasing glutathione peroxidase 3 (GPx3) and insulin receptor (IR) expression. Whether selenite (Se) can attenuate insulin resistance in established lipotoxic and obese conditions is unclear. We confirm that GPX3 mRNA expression in adipose tissue correlates with BMI in humans. Cultivating 3T3-L1 pre-adipocytes in palmitate-containing medium followed by Se treatment attenuates insulin resistance with enhanced GPx3 and IR expression and adipocyte differentiation. However, feeding obese mice a selenium-enriched high-fat diet (SRHFD) only resulted in a modest increase in overall selenoprotein gene expression in WAT in mice with unaltered body weight development, glucose tolerance, and insulin resistance. While Se supplementation improved adipocyte morphology, it did not alter WAT insulin sensitivity. However, mice fed a SRHFD exhibited increased insulin content in the pancreas. Overall, while selenite protects against palmitate-induced insulin resistance in vitro, obesity impedes the effect of selenite on insulin action and adipose tissue metabolism in vivo.
Die allergische Kontaktdermatitis ist eine immunologisch bedingte Hauterkrankung mit insbesondere in den westlichen Industrienationen hoher und weiter ansteigender Prävalenz. Es handelt sich hierbei um eine Hypersensitivitätsreaktion vom Typ IV, die sich nach Allergenkontakt durch Juckreiz, Rötung, Bläschenbildung und Abschälung der Haut äußert. Zahlreiche Xenobiotika besitzen das Potenzial, Kontaktallergien auszulösen, darunter Konservierungsstoffe, Medikamente, Duftstoffe und Chemikalien. Die wirksamste Maßnahme zur Eindämmung der Erkrankung ist die Expositionsprophylaxe, also die Vermeidung des Kontakts mit den entsprechenden Substanzen. Dies wiederum setzt die Kenntnis des jeweiligen sensibilisierenden Potenzials einer Substanz voraus, dessen Bestimmung aus diesem Grund eine hohe toxikologische Relevanz besitzt. Zu diesem Zweck existieren von der OECD veröffentlichte Testleitlinien, welche auf entsprechend validierten Testmethoden basieren. Goldstandard bei der Prüfung auf hautsensibilisierendes Potenzial war über lange Zeit der murine Lokale Lymphknotentest. Seit der 7. Änderung der EU-Kosmetikrichtlinie, welche Tierversuche für Kosmetika und deren Inhaltsstoffe untersagt, wurden vermehrt Alternativmethoden in die OECD-Testleitlinien implementiert.. Die bestehenden in vitro Methoden sind jedoch alleinstehend nur begrenzt aussagekräftig, da sie lediglich singuläre Mechanismen bei der Entstehung einer Kontaktallergie abbilden. Die Entwicklung von Testmethoden, welche mehrere dieser Schlüsselereignisse berücksichtigen, erscheint daher richtungsweisend. Einen vielversprechenden Ansatz liefert hierbei der Loose-fit coculture-based sensitisation assay (LCSA), welcher eine Kokultur aus primären Keratinozyten und PBMC darstellt. Bei der Kokultivierung von Immunzellen mit anderen Zelltypen stellt sich allerdings die Frage, inwiefern die Nutzung von Zellen derselben Spender*innen (autologe Kokultur) bzw. verschiedener Spender*innen (allogene Kokultur) einen Einfluss nimmt. Zu diesem Zweck wurden im Rahmen dieser Arbeit Hautzellen spenderspezifisch aus gezupften Haarfollikeln isoliert und der LCSA mit den generierten HFDK in autologen und allogenen Ansätzen verglichen. Zusätzlich wurde auch ein Vergleich zwischen der Nutzung von HFDK und NHK, welche aus humaner Vorhaut isoliert wurden, im LCSA durchgeführt. Dabei ergaben sich keine signifikanten Unterschiede zwischen autologen und allogenen Kokulturen bzw. zwischen der Verwendung von HFDK und NHK. Die Verwendung allogener Zellen aus anonymem Spendermaterial sowie die Nutzung von Keratinozyten aus unterschiedlichen Quellen scheint im Rahmen des LCSA problemlos möglich. Einige der getesteten Kontaktallergene, darunter DNCB und NiCl2, erwiesen sich im LCSA jedoch als problematisch und konnten nicht zufriedenstellend als sensibilisierend detektiert werden. Daher wurde eine Optimierung der Kokultur durch Verwendung ex vivo differenzierter Langerhans Zellen (MoLC) angestrebt, welche ein besseres Modell primärer epidermaler Langerhans Zellen darstellen als die dendritischen Zellen aus dem LCSA. Zusätzlich wurden weitere, den Erfolg der Kokultur beeinflussende Faktoren, wie die Art und Zusammensetzung des Mediums und die Kokultivierungsdauer, untersucht und angepasst. Das schlussendlich etablierte Kokultivierungsprotokoll führte zu einer maßgeblich verstärkten Expression von CD207 (Langerin) auf den MoLC, was auf eine wirkungsvolle Interaktion zwischen Haut- und Immunzellen in der Kokultur hindeutete. Des Weiteren konnten DNCB und NiCl2 im Gegensatz zum LCSA durch Verwendung des kostimulatorischen Moleküls CD86 sowie des Reifungsmarkers CD83 als Ausleseparameter eindeutig als Kontaktallergene identifiziert werden. Die Untersuchungen zur Kokultur von MoLC und HFDK wurden jeweils vergleichend in autologen und allogenen Ansätzen durchgeführt. Ähnlich wie beim LCSA kam es aber auch hier zu keinen signifikanten Unterschieden, weder hinsichtlich der Expression von Charakterisierungs- und Aktivierungsmarkern auf MoLC noch hinsichtlich der Zytokinsekretion in den Zellkulturüberstand. Die Hinweise aus zahlreichen Studien im Mausmodell, dass Zellen des angeborenen Immunsystems zur Erkennung von und Aktivierung durch allogene Zellen bzw. Gewebe in der Lage sind, bestätigten sich im Rahmen dieser Arbeit dementsprechend nicht. Aus diesem Grund wurden abschließend CD4+ T-Lymphozyten, die Effektorzellen des adaptiven Immunsystems, in die Kokultur aus MoLC und autologen bzw. allogenen HFDK integriert. Überraschenderweise traten auch hier keine verstärkten Aktivierungen in allogener Kokultur im Vergleich zur autologen Kokultur auf. Die Nutzung autologer Primärzellen scheint im Rahmen der hier getesteten Methoden nicht notwendig zu sein, was die Validierung von Kokulturen und deren Implementierung in die OECD-Testleitlinien erleichtern dürfte. Zuletzt wurde eine Kokultivierung primärer Haut- und Immunzellen auch im 3D-Vollhautmodell durchgeführt, wobei autologe MoLC in die Epidermisäquivalente entsprechender Modelle integriert werden sollten. Obwohl die erstellten Hautmodelle unter Verwendung autologer Haarfollikel-generierter Keratinozyten und Fibroblasten eine zufriedenstellende Differenzierung und Stratifizierung aufwiesen, gestaltete sich die Inkorporation der MoLC als problematisch und konnte im Rahmen dieser Arbeit nicht erreicht werden.
The prevalence of depression and anxiety is increased in obese patients compared to healthy humans, which is partially due to a shared pathogenesis, including insulin resistance and inflammation. These factors are also linked to intestinal dysbiosis. Additionally, the chronic consumption of diets rich in saturated fats results in body weight gain, hormonal resistances and unfavorable changes in the microbiome composition. The intake of Lactobacilli has already been shown to improve dysbiosis along with metabolism and mood. Yet, the beneficial role and the underlying mechanism of Lactobacillus rhamnosus GG (LGG) to improve emotional behavior in established diet-induced obese conditions are, so far, unknown. To characterize the role of LGG in diet-induced obesity, female and male C57BL/6N mice were fed a semi-synthetic low-fat diet (LFD, 10 % kcal from fat) or a conventional high-fat diet (HFD, 45 % kcal from fat) for initial 6 weeks, which was followed by daily oral gavage of vehicle or 1x10^8 CFU of LGG until the end of the experiment. Mice were subjected to basic metabolic and extensive behavioral phenotyping, with a focus on emotional behavior. Moreover, composition of cecal gut microbiome, metabolomic profile in plasma and cerebrospinal fluid was investigated and followed by molecular analyses. Both HFD-feeding and LGG application resulted in sex-specific differences. While LGG prevented the increase of plasma insulin, adrenal gland weight and hyperactivity in diet-induced obese female mice, there was no regulation of anxiodepressive-like behavior. In contrast, metabolism of male mice did not benefit from LGG application, but strikingly, LGG decreased specifically depressive-like behavior in the Mousetail Suspension Test which was confirmed by the Splash Test characterizing motivation for ’self-care’. The microbiome analysis in male mice revealed that HFD-feeding, but not LGG application, altered cecal microbiome composition, indicating a direct effect of LGG on behavioral regulation. However, in female mice, both HFD-feeding and LGG application resulted in changes of microbiome composition, which presumably affected metabolism. Moreover, as diet-induced obese female mice unexpectedly did not exhibit anxiodepressive-like behavior, follow-up analyses were conducted in male mice. Here, HFD-feeding significantly altered abundance of plasma lipids whereas LGG decreased branched chain amino acids which associated with improved emotional behavior. In nucleus accumbens (NAcc) and VTA/SN, which belong to the dopaminergic system, LGG restored HFD-induced decrease of tyrosine hydroxylase, the rate-limiting enzyme in dopamine synthesis, on gene expression level. Lastly, transcriptome analysis in the NAcc identified gene expression of cholecystokinin as a potential mediator of the effect of LGG on HFD-induced emotional alterations. In summary, this thesis revealed the beneficial effects of LGG application on emotional alterations in established diet-induced obesity. Furthermore, both HFD-feeding and LGG treatment exhibited sex-specific effects, resulting in metabolic improvements in female mice while LGG application mitigated depressive-like behavior in obese male mice along with a molecular signature of restored dopamine synthesis and neuropeptide signaling.
Botulinum neurotoxin (BoNT) is used for the treatment of a number of ailments. The activity of the toxin that is isolated from bacterial cultures is frequently tested in the mouse lethality assay. Apart from the ethical concerns inherent to this assay, species-specific differences in the affinity for different BoNT serotypes give rise to activity results that differ from the activity in humans. Thus, BoNT/B is more active in mice than in humans. The current study shows that the stimulus-dependent release of a luciferase from a differentiated human neuroblastoma–based reporter cell line (SIMA-hPOMC1-26-Gluc) was inhibited by clostridial and recombinant BoNT/A to the same extent, whereas both clostridial and recombinant BoNT/B inhibited the release to a lesser extent and only at much higher concentrations, reflecting the low activity of BoNT/B in humans. By contrast, the genetically modified BoNT/B-MY, which has increased affinity for human synaptotagmin, and the BoNT/B protein receptor inhibited luciferase release effectively and with an EC50 comparable to recombinant BoNT/A. This was due to an enhanced uptake into the reporter cells of BoNT/B-MY in comparison to the recombinant wild-type toxin. Thus, the SIMA-hPOMC1-26-Gluc cell assay is a versatile tool to determine the activity of different BoNT serotypes providing human-relevant dose-response data.
Epigenetische Mechanismen spielen eine entscheidende Rolle bei der Pathogenese von Colitis ulcerosa (CU). Ihr Einfluss auf das beobachtete Ungleichgewicht zwischen pro- und anti-inflammatorischen Cytokinen ist hingegen weitgehend unerforscht. Einige der wichtigsten immunmodulatorischen Cytokine sind die Mitglieder der heterodimeren Interleukin- (IL-) 12-Familie, die durch das Kombinieren einer der drei α-Ketten (IL-12p35, IL-27p28, IL-23p19) mit den ß-Untereinheiten IL-12p40 oder EBI3 (Epstein-Barr Virus-induziertes Gen 3) charakterisiert sind. IL-35 (IL-12p35/EBI3) spielt eine bedeutende anti-inflammatorische Rolle bei verschiedenen Erkrankungen, wohingegen seine Level bei chronischen Entzündungen erniedrigt sind. Eine mögliche Ursache könnte eine transkriptionelle Stilllegung über epigenetische Modifikationen sein. Tatsächlich konnte durch die Stimulation mit dem DNA-Methyltransferase-Inhibitor (DNMTi) Decitabin (DAC; Dacogen®) eine Induktion von EBI3 in humanen Epithelzellen aus gesundem Colon (HCEC) erreicht werden, die als Modell für ein lokales Entzündungsgeschehen dienten. Diese Regulation über DNA-Methylierung konnte in weiteren humanen Zellen unterschiedlichen Ursprungs sowie durch Stimulation von HCEC-Zellen mit zwei weiteren DNMTi, dem Cytosin-Analogon Azacytidin (AZA; Vidaza®) und dem natürlich vorkommenden, epigenetisch wirksamen Polyphenol Epigallocatechingallat (EGCG), verifiziert werden. Die kombinierte Inkubation mit Tumor-Nekrose-Faktor α (TNFα) resultierte jeweils in einer über-additiven Induktion von EBI3.
Weiterführende Untersuchungen zeigten, dass TNFα trotz Beeinflussung der epigenetischen DNMT- und Ten-eleven Translocation- (TET-) Enzyme keinen Einfluss auf die globalen Methylierungs- oder Hydroxymethylierungslevel hatte, jedoch eine genspezifische DNA-Hypomethylierung im EBI3-Promotor induzierte. Durch Nutzung verschiedener Inhibitoren konnte darüber hinaus nachgewiesen werden, dass der beobachtete synergistische Effekt der gemeinsamen DAC und TNFα-Stimulation hauptsächlich über NFκB (Nuclear factor “kappa-light-chain-enhancer” of activated B-cells) vermittelt wird. Ein Teil verläuft dabei über p38 MAPK (mitogen-activated protein kinases), während die JNK- (c-Jun N-terminale Kinasen-) und ERK- (extracellular-signal-regulated kinases) Signalwege keine Rolle spielen.
In der vorliegenden Arbeit wurde zudem gezeigt, dass die DNA-Hypomethylierung während eines entzündlichen Zustandes auch in einer erhöhten EBI3-Proteinexpression resultiert. Die Höhe der immunologisch detektierten Banden wies auf eine Dimerbildung sowohl im Zelllysat als auch im Überstand hin. Humane Colonepithelzellen sind demnach in der Lage, Cytokine zu bilden und zu sezernieren, was die Bedeutung von Nicht-Immunzellen bei der lokalen Immunantwort unterstreicht. Mittels Genexpressionsanalysen wurden IL-12p35 und IL-23p19 als mögliche Bindungspartner identifiziert. Aufgrund kreuzreaktiver Antikörper ist ein direkter Nachweis der EBI3-Dimere derzeit nicht möglich. Die stattdessen genutzte Kombination verschiedener Methoden dient als geeigneter Ersatz für die problematischen Antikörper-basierten Analysen wie Immunpräzipitation oder ELISA. Durch molekularbiologische, immunologische und massenspektrometrische Methoden konnte IL-35 identifiziert werden, während IL-39 (IL-23p19/EBI3) nicht detektiert wurde. Dies ist in Einklang mit den Erkenntnissen mehrerer Forschungsgruppen, die eine Bildung des nativen humanen Dimers aus IL-23p19 und EBI3 bezweifeln. Des Weiteren wurde die biologische Aktivität des behandlungsinduzierten IL 35-Proteins durch einen Funktionsassay nachgewiesen.
Neben einer DNMTi-bedingten transkriptionellen Aktivierung konnte eine Regulation von EBI3 über Histonacetylierungen gezeigt werden. Der EBI3-induzierende Effekt des Histondeacetylasen-Inhibitors (HDACi) Trichostatin A (TSA) wurde durch SAHA (suberoylanilide hydroxamic acid (Vorinostat; Zolinza®)) verifiziert. Ähnlich zu der Stimulation mit den hypomethylierenden Substanzen wurde ein synergistischer Effekt bei paralleler Inkubation mit TNFα beobachtet, der in einer gesteigerten Bildung des EBI3-Proteins resultierte.
Um die Befunde in einem komplexeren in vivo-Modell zu untersuchen, wurde eine chronische Colitis in Ebi3-defizienten Mäusen und dem dazugehörigen Wildtypstamm C57BL/6 durch zyklische Applikation von Natriumdextransulfat (Dextran sodium sulfate (DSS)) induziert. Der Vergleich klinischer Parameter wie Mortalitätsrate und Körper- sowie Milzgewicht wies bei Abwesenheit von Ebi3 signifikant stärkere colitische Symptome auf. Dies bestätigte die zentrale Rolle von Ebi3 in der Colitisentwicklung und deutete auf eine bevorzugte Bildung des anti-inflammatorisch wirkenden IL-35 statt des pro-inflammatorischen IL-39 in den Wildtyptieren hin. Durch zusätzliche therapeutische Behandlung der C57BL/6-Mäuse nach der DSS-Gabe konnte die in der Literatur beschriebene positive Wirkung von SAHA auf die Colitismanifestation bestätigt werden. Im Gegensatz dazu war der HDACi in den Ebi3-defizienten Tieren nicht in der Lage, die colitischen Parameter zu verbessern beziehungsweise verschlimmerte den Krankheitsphänotyp. Expressionsanalysen von Up- und Downstream-Target-Genen lieferten weitere Hinweise darauf, dass bei Anwesenheit von Ebi3 IL-35 statt IL-39 gebildet wird, was in Einklang mit den in vitro-Untersuchungen steht.
Die vorliegende Arbeit konnte durch den Vergleich der C57BL/6-Mäuse mit den Ebi3-defizienten Tieren neue Erkenntnisse über die Wirkungsweise von SAHA erbringen. Histonacetylierende Bedingungen verbessern colitische Symptome über einen Mechanismus, der die epigenetische Induktion von Ebi3 mit nachfolgender IL-35-Bildung involviert. Durch Kooperation der epigenetischen Mechanismen Hypomethylierung und Histonacetylierung wurde der stärkste Effekt auf die EBI3-Induktion bewirkt.
Insgesamt konnte in der vorliegenden Arbeit durch in vitro- und in vivo-Analysen die epigenetische und NFκB-vermittelte Induktion von EBI3 über DNA-Demethylierung und Histonacetylierung mit nachfolgender IL-35-Bildung und –Sezernierung nachgewiesen werden. Da IL-35 in der Lage ist, colitische Symptome zu mildern, stellt die epigenetische Reaktivierbarkeit von EBI3 durch DNMTi und HDACi eine vielversprechende Alternative für die derzeit genutzten, oft nicht oder nur kurzfristig wirksamen Therapien bei der Behandlung einer CU dar. Einer übermäßigen Immunantwort während schubweiser entzündlicher Phasen könnte entgegengewirkt und Komplikationen wie die Bildung Colitis-assoziierter Karzinome verhindert werden.
Botulinum neurotoxin (BoNT) is used for the treatment of a number of ailments. The activity of the toxin that is isolated from bacterial cultures is frequently tested in the mouse lethality assay. Apart from the ethical concerns inherent to this assay, species-specific differences in the affinity for different BoNT serotypes give rise to activity results that differ from the activity in humans. Thus, BoNT/B is more active in mice than in humans. The current study shows that the stimulus-dependent release of a luciferase from a differentiated human neuroblastoma–based reporter cell line (SIMA-hPOMC1-26-Gluc) was inhibited by clostridial and recombinant BoNT/A to the same extent, whereas both clostridial and recombinant BoNT/B inhibited the release to a lesser extent and only at much higher concentrations, reflecting the low activity of BoNT/B in humans. By contrast, the genetically modified BoNT/B-MY, which has increased affinity for human synaptotagmin, and the BoNT/B protein receptor inhibited luciferase release effectively and with an EC50 comparable to recombinant BoNT/A. This was due to an enhanced uptake into the reporter cells of BoNT/B-MY in comparison to the recombinant wild-type toxin. Thus, the SIMA-hPOMC1-26-Gluc cell assay is a versatile tool to determine the activity of different BoNT serotypes providing human-relevant dose-response data.
In order to improve a recently established cell-based assay to assess the potency of botulinum neurotoxin, neuroblastoma-derived SiMa cells and induced pluripotent stem-cells (iPSC) were modified to incorporate the coding sequence of a reporter luciferase into a genetic safe harbor utilizing CRISPR/Cas9. A novel method, the double-control quantitative copy number PCR (dc-qcnPCR), was developed to detect off-target integrations of donor DNA. The donor DNA insertion success rate and targeted insertion success rate were analyzed in clones of each cell type. The dc-qcnPCR reliably quantified the copy number in both cell lines. The probability of incorrect donor DNA integration was significantly increased in SiMa cells in comparison to the iPSCs. This can possibly be explained by the lower bundled relative gene expression of a number of double-strand repair genes (BRCA1, DNA2, EXO1, MCPH1, MRE11, and RAD51) in SiMa clones than in iPSC clones. The dc-qcnPCR offers an efficient and cost-effective method to detect off-target CRISPR/Cas9-induced donor DNA integrations.
Respiratorische Erkrankungen stellen zunehmend eine relevante globale Problematik dar. Die Erweiterung bzw. Modifizierung von Applikationswegen möglicher Arzneimittel für gezielte topische Anwendungen ist dabei von größter Bedeutung. Die Variation eines bekannten Applikationsweges durch unterschiedliche technologische Umsetzungen kann die Vielfalt der Anwendungsmöglichkeiten, aber auch die Patienten-Compliance erhöhen. Die einfache und flexible Verfahrensweise durch schnelle Verfügbarkeit und eine handliche Technologie sind heutzutage wichtige Eigenschaften im Entwicklungsprozess eines Produktes. Eine direkte topische Behandlung von Atemwegserkrankungen am Wirkort in Form einer inhalativen Applikation bietet dabei viele Vorteile gegenüber einer systemischen Therapie. Die medizinische Inhalation von Wirkstoffen über die Lunge ist jedoch eine komplexe Herausforderung. Inhalatoren gehören zu den erklärungsbedürftigen Applikationsformen, die zur Erhöhung der konsequenten Einhaltung der Verordnung so einfach, wie möglich gestaltet werden müssen. Parallel besitzen und nutzen weltweit annähernd 68 Millionen Menschen die Technologie eines inhalativen Applikators zur bewussten Schädigung ihrer Gesundheit in Form einer elektronischen Zigarette. Diese bekannte Anwendung bietet die potentielle Möglichkeit einer verfügbaren, kostengünstigen und qualitätsgeprüften Gesundheitsmaßnahme zur Kontrolle, Prävention und Heilung von Atemwegserkrankungen. Sie erzeugt ein Aerosol durch elektrothermische Erwärmung eines sogenannten Liquids, das durch Kapillarkräfte eines Trägermaterials an ein Heizelement gelangt und verdampft. Ihr Bekanntheitsgrad zeigt, dass eine beabsichtigte Wirkung in den Atemwegen eintritt. Diese Wirkung könnte jedoch auch auf potentielle pharmazeutische Einsatzgebiete übertragbar sein. Die Vorteile der pulmonalen Verabreichung sind dabei vielfältig. Im Vergleich zur peroralen Applikation gelangt der Wirkstoff gezielt zum Wirkort. Wenn eine systemische Applikation zu Arzneimittelkonzentrationen unterhalb der therapeutischen Wirksamkeit in der Lunge führt, könnte eine inhalative Darreichung bereits bei niedriger Dosierung die gewünschten höheren Konzentrationen am Wirkort hervorrufen. Aufgrund der großen Resorptionsfläche der Lunge sind eine höhere Bioverfügbarkeit und ein schnellerer Wirkungseintritt infolge des fehlenden First-Pass-Effektes möglich. Es kommt ebenfalls zu minimalen systemischen Nebenwirkungen. Die elektronische Zigarette erzeugt wie die medizinischen Inhalatoren lungengängige Partikel. Die atemzuggesteuerte Technik ermöglicht eine unkomplizierte und intuitive Anwendung. Der prinzipielle Aufbau besteht aus einer elektrisch beheizten Wendel und einem Akku. Die Heizwendel ist von einem sogenannten Liquid in einem Tank umgeben und erzeugt das Aerosol. Das Liquid beinhaltet eine Basismischung bestehend aus Propylenglycol, Glycerin und reinem Wasser in unterschiedlichen prozentualen Anteilen. Es besteht die Annahme, dass das Basisliquid auch mit pharmazeutischen Wirkstoffen für die pulmonale Applikation beladen werden kann. Aufgrund der thermischen Belastung durch die e-Zigarette müssen potentielle Wirkstoffe sowie das Vehikel eine thermische Stabilität aufweisen.
Die potentielle medizinische Anwendung der Technologie einer handelsüblichen e-Zigarette wurde anhand von drei Schwerpunkten an vier Wirkstoffen untersucht. Die drei ätherischen Öle Eucalyptusöl, Minzöl und Nelkenöl wurden aufgrund ihrer leichten Flüchtigkeit und der historischen pharmazeutischen Anwendung anhand von Inhalationen bei Erkältungssymptomen bzw. im zahnmedizinischen Bereich gewählt. Das eingesetzte Cannabinoid Cannabidiol (CBD) hat einen aktuellen Bezug zu dem pharmazeutischen Markt Deutschlands zur Legalisierung von cannabishaltigen Produkten und der medizinischen Forschung zum inhalativen Konsum. Es wurden relevante wirkstoffhaltige Flüssigformulierungen entwickelt und hinsichtlich ihrer Verdampfbarkeit zu Aerosolen bewertet. In den quantitativen und qualitativen chromatographischen Untersuchungen konnten spezifische Verdampfungsprofile der Wirkstoffe erfasst und bewertet werden. Dabei stieg die verdampfte Masse der Leitsubstanzen 1,8-Cineol (Eucalyptusöl), Menthol (Minzöl) und Eugenol (Nelkenöl) zwischen 33,6 µg und 156,2 µg pro Zug proportional zur Konzentration im Liquid im Bereich zwischen 0,5% und 1,5% bei einer Leistung von 20 Watt. Die Freisetzungsrate von Cannabidiol hingegen schien unabhängig von der Konzentration im Liquid im Mittelwert bei 13,3 µg pro Zug zu liegen. Dieses konnte an fünf CBD-haltigen Liquids im Konzentrationsbereich zwischen 31 µg/g und 5120 µg/g Liquid gezeigt werden. Außerdem konnte eine Steigerung der verdampften Massen mit Zunahme der Leistung der e-Zigarette festgestellt werden. Die Interaktion der Liquids bzw. Aerosole mit den Bestandteilen des Speichels sowie weiterer gastrointestinaler Flüssigkeiten wurde über die Anwendung von zugehörigen in vitro Modellen und Einsatz von Enzymaktivitäts-Assays geprüft. In den Untersuchungen wurden Änderungen von Enzymaktivitäten anhand des oralen Schlüsselenzyms α-Amylase sowie von Proteasen ermittelt. Damit sollte exemplarisch ein möglicher Einfluss auf physiologische bzw. metabolische Prozesse im humanen Organismus geprüft werden. Das Bedampfen von biologischen Suspensionen führte bei niedriger Leistung der e-Zigarette (20 Watt) zu keiner bzw. einer leichten Änderung der Enzymaktivität. Die Anwendung einer hohen Leistung (80 Watt) bewirkte tendenziell das Herabsetzen der Enzymaktivitäten. Die Erhöhung der Enzymaktivitäten könnte zu einem enzymatischen Abbau von Schleimstoffen wie Mucinen führen, was wiederum die effektive, mechanische Abwehr gegenüber bakteriellen Infektionen zur Folge hätte. Da eine Anwendung der Applikation insbesondere bei bakteriellen Atemwegserkrankungen denkbar wäre, folgten abschließend Untersuchungen der antibakteriellen Eigenschaften der Liquids bzw. Aerosole in vitro. Es wurden sechs klinisch relevante bakterielle Krankheitserreger ausgewählt, die nach zwei Charakteristika gruppiert werden können. Die drei multiresistenten Bakterien Pseudomonas aeruginosa, Klebsiella pneumoniae und Methicillin-resistenter Staphylococcus aureus können mithilfe von üblichen Therapien mit Antibiotika nicht abgetötet werden und haben vor allem eine nosokomiale Relevanz. Die zweite Gruppe weist Eigenschaften auf, die vordergründig assoziiert sind mit respiratorischen Erkrankungen. Die Bakterien Streptococcus pneumoniae, Moraxella catarrhalis und Haemophilus influenzae sind repräsentativ beteiligt an Atemwegserkrankungen mit diverser Symptomatik. Die Bakterienarten wurden mit den jeweiligen Liquids behandelt bzw. bedampft und deren grundlegende Dosis-Wirkungsbeziehung charakterisiert. Dabei konnte eine antibakterielle Aktivität der Formulierungen ermittelt werden, die durch Zugabe eines Wirkstoffes die bereits antibakterielle Wirkung der Bestandteile Glycerin und Propylenglycol verstärkte. Die hygroskopischen Eigenschaften dieser Substanzen sind vermutlich für eine Wirkung in aerosolierter Form verantwortlich. Sie entziehen die Feuchtigkeit aus der Luft und haben einen austrocknenden Effekt auf die Bakterien. Das Bedampfen der Bakterienarten Streptococcus pneumoniae, Moraxella catarrhalis und Haemophilus influenzae hatte einen antibakteriellen Effekt, der zeitlich abhängig von der Leistung der e-Zigarette war.
Die Ergebnisse der Untersuchungen führen zu dem Schluss, dass jeder Wirkstoff bzw. jede Substanzklasse individuell zu bewerten ist und somit Inhalator und Formulierung aufeinander abgestimmt werden müssen. Der Einsatz der e-Zigarette als Medizinprodukt zur Applikation von Arzneimitteln setzt stets Prüfungen nach Europäischem Arzneibuch voraus. Durch Modifizierungen könnte eine Dosierung gut kontrollierbar gemacht werden, aber auch die Partikelgrößenverteilung kann insoweit reguliert werden, dass die Wirkstoffe je nach Partikelgröße zu einem geeigneten Applikationsort wie Mund, Rachen oder Bronchien transportiert werden. Der Vergleich mit den Eigenschaften anderer medizinischer Inhalatoren führt zu dem Schluss, dass die Technologie der e-Zigarette durchaus eine gleichartige oder bessere Performance für thermisch stabile Wirkstoffe bieten könnte. Dieses fiktive Medizinprodukt könnte aus einer hersteller-unspezifisch produzierten, wieder aufladbaren Energiequelle mit Universalgewinde zum mehrfachen Gebrauch und einer hersteller- und wirkstoffspezifisch produzierten Einheit aus Verdampfer und Arzneimittel bestehen. Das Arzneimittel, ein medizinisches Liquid (Vehikel und Wirkstoff) kann in dem Tank des Verdampfers mit konstanten, nicht variablen Parametern patientenindividuell produziert werden. Inhalative Anwendungen werden perspektivisch wohl nicht zuletzt aufgrund der aktuellen COVID-19-Pandemie eine zunehmende Rolle spielen. Der Bedarf nach alternativen Therapieoptionen wird weiter ansteigen. Diese Arbeit liefert einen Beitrag zum Einsatz der Technologie der elektronischen Zigarette als electronic nicotin delivery system (ENDS) nach Modifizierung zu einem potentiellen pulmonalen Applikationssystem als electronic drug delivery system (EDDS) von inhalativen, thermisch stabilen Arzneimitteln in Form eines Medizinproduktes.
As of late, epidemiological studies have highlighted a strong association of dairy intake with lower disease risk, and similarly with an increased amount of odd-chain fatty acids (OCFA). While the OCFA also demonstrate inverse associations with disease incidence, the direct dietary sources and mode of action of the OCFA remain poorly understood.
The overall aim of this thesis was to determine the impact of two main fractions of dairy, milk fat and milk protein, on OCFA levels and their influence on health outcomes under high-fat (HF) diet conditions. Both fractions represent viable sources of OCFA, as milk fats contain a significant amount of OCFA and milk proteins are high in branched chain amino acids (BCAA), namely valine (Val) and isoleucine (Ile), which can produce propionyl-CoA (Pr-CoA), a precursor for endogenous OCFA synthesis, while leucine (Leu) does not. Additionally, this project sought to clarify the specific metabolic effects of the OCFA heptadecanoic acid (C17:0).
Both short-term and long-term feeding studies were performed using male C57BL/6JRj mice fed HF diets supplemented with milk fat or C17:0, as well as milk protein or individual BCAA (Val; Leu) to determine their influences on OCFA and metabolic health. Short-term feeding revealed that both milk fractions induce OCFA in vivo, and the increases elicited by milk protein could be, in part, explained by Val intake. In vitro studies using primary hepatocytes further showed an induction of OCFA after Val treatment via de novo lipogenesis and increased α-oxidation. In the long-term studies, both milk fat and milk protein increased hepatic and circulating OCFA levels; however, only milk protein elicited protective effects on adiposity and hepatic fat accumulation—likely mediated by the anti-obesogenic effects of an increased Leu intake. In contrast, Val feeding did not increase OCFA levels nor improve obesity, but rather resulted in glucotoxicity-induced insulin resistance in skeletal muscle mediated by its metabolite 3-hydroxyisobutyrate (3-HIB). Finally, while OCFA levels correlated with improved health outcomes, C17:0 produced negligible effects in preventing HF-diet induced health impairments.
The results presented herein demonstrate that the beneficial health outcomes associated with dairy intake are likely mediated through the effects of milk protein, while OCFA levels are likely a mere association and do not play a significant causal role in metabolic health under HF conditions. Furthermore, the highly divergent metabolic effects of the two BCAA, Leu and Val, unraveled herein highlight the importance of protein quality.
The intake of high-fat diets (HFDs) containing large amounts of saturated long-chain fatty acids leads to obesity, oxidative stress, inflammation, and insulin resistance. The trace element selenium, as a crucial part of antioxidative selenoproteins, can protect against the development of diet-induced insulin resistance in white adipose tissue (WAT) by increasing glutathione peroxidase 3 (GPx3) and insulin receptor (IR) expression. Whether selenite (Se) can attenuate insulin resistance in established lipotoxic and obese conditions is unclear. We confirm that GPX3 mRNA expression in adipose tissue correlates with BMI in humans. Cultivating 3T3-L1 pre-adipocytes in palmitate-containing medium followed by Se treatment attenuates insulin resistance with enhanced GPx3 and IR expression and adipocyte differentiation. However, feeding obese mice a selenium-enriched high-fat diet (SRHFD) only resulted in a modest increase in overall selenoprotein gene expression in WAT in mice with unaltered body weight development, glucose tolerance, and insulin resistance. While Se supplementation improved adipocyte morphology, it did not alter WAT insulin sensitivity. However, mice fed a SRHFD exhibited increased insulin content in the pancreas. Overall, while selenite protects against palmitate-induced insulin resistance in vitro, obesity impedes the effect of selenite on insulin action and adipose tissue metabolism in vivo.
Metabolic derangement with poor glycemic control accompanying overweight and obesity is associated with chronic low-grade inflammation and hyperinsulinemia. Macrophages, which present a very heterogeneous population of cells, play a key role in the maintenance of normal tissue homeostasis, but functional alterations in the resident macrophage pool as well as newly recruited monocyte-derived macrophages are important drivers in the development of low-grade inflammation. While metabolic dysfunction, insulin resistance and tissue damage may trigger or advance pro-inflammatory responses in macrophages, the inflammation itself contributes to the development of insulin resistance and the resulting hyperinsulinemia. Macrophages express insulin receptors whose downstream signaling networks share a number of knots with the signaling pathways of pattern recognition and cytokine receptors, which shape macrophage polarity. The shared knots allow insulin to enhance or attenuate both pro-inflammatory and anti-inflammatory macrophage responses. This supposedly physiological function may be impaired by hyperinsulinemia or insulin resistance in macrophages. This review discusses the mutual ambiguous relationship of low-grade inflammation, insulin resistance, hyperinsulinemia and the insulin-dependent modulation of macrophage activity with a focus on adipose tissue and liver.
Background
Coronavirus disease (COVID-19) has a severe impact on all aspects of patient care. Among the numerous biomarkers of potential validity for diagnostic and clinical management of COVID-19 are biomarkers at the interface of iron metabolism and inflammation.
Methods
The follow-up study included 54 hospitalized patients with laboratory-confirmed COVID-19 with a moderate and severe/critical form of the disease. Iron deficiency specific biomarkers such as iron, ferritin, transferrin receptor, hepcidin, and zinc protoporphyrin (ZnPP) as well as relevant markers of inflammation were evaluated twice: in the first five days when the patient was admitted to the hospital and during five to 15 days; and their validity to diagnose iron deficiency was further assessed. The regression and Receiver Operating Characteristics (ROC) analyses were performed to evaluate the prognosis and determine the probability for predicting the severity of the disease in the first five days of COVID-19.
Results
Based on hemoglobin values, anemia was observed in 21 of 54 patients. Of all iron deficiency anemia-related markers, only ZnPP was significantly elevated (P<0.001) in the anemic group. When patients were grouped according to the severity of disease, slight differences in hemoglobin or other anemia-related parameters could be observed. However, the levels of ZnPP were significantly increased in the severely ill group of patients. The ratio of ZnPP to lymphocyte count (ZnPP/L) had a discrimination power stronger than the neutrophil to lymphocyte count ratio (N/L) to determine disease severity. Additionally, only two markers were independently associated with the severity of COVID-19 in logistic regression analysis; D-dimer (OR (5.606)(95% CI 1.019–30.867)) and ZnPP/L ratio (OR (74.313) (95% CI 1.081–5108.103)).
Conclusions
For the first time ZnPP in COVID-19 patients were reported in this study. Among all iron-related markers tested, ZnPP was the only one that was associated with anemia as based on hemoglobin. The increase in ZnPP might indicate that the underlying cause of anemia in COVID-19 patients is not only due to the inflammation but also of nutritional origin. Additionally, the ZnPP/L ratio might be a valid prognostic marker for the severity of COVID-19.
Objective
Insulin regulates mitochondrial function, thereby propagating an efficient metabolism. Conversely, diabetes and insulin resistance are linked to mitochondrial dysfunction with a decreased expression of the mitochondrial chaperone HSP60. The aim of this investigation was to determine the effect of a reduced HSP60 expression on the development of obesity and insulin resistance.
Methods
Control and heterozygous whole-body HSP60 knockout (Hsp60+/−) mice were fed a high-fat diet (HFD, 60% calories from fat) for 16 weeks and subjected to extensive metabolic phenotyping. To understand the effect of HSP60 on white adipose tissue, microarray analysis of gonadal WAT was performed, ex vivo experiments were performed, and a lentiviral knockdown of HSP60 in 3T3-L1 cells was conducted to gain detailed insights into the effect of reduced HSP60 levels on adipocyte homeostasis.
Results
Male Hsp60+/− mice exhibited lower body weight with lower fat mass. These mice exhibited improved insulin sensitivity compared to control, as assessed by Matsuda Index and HOMA-IR. Accordingly, insulin levels were significantly reduced in Hsp60+/− mice in a glucose tolerance test. However, Hsp60+/− mice exhibited an altered adipose tissue metabolism with elevated insulin-independent glucose uptake, adipocyte hyperplasia in the presence of mitochondrial dysfunction, altered autophagy, and local insulin resistance.
Conclusions
We discovered that the reduction of HSP60 in mice predominantly affects adipose tissue homeostasis, leading to beneficial alterations in body weight, body composition, and adipocyte morphology, albeit exhibiting local insulin resistance.
The BfR MEAL Study provides representative levels of substances in foods consumed in Germany. Mercury, cadmium, lead, and nickel are contaminants present in foods introduced by environmental and industrial processes. Levels of these elements were investigated in 356 foods. Foods were purchased representatively, prepared as consumed and pooled with similar foods before analysis. Highest mean levels of mercury were determined in fish and seafood, while high levels of cadmium, lead, and nickel were present in cocoa products and legumes, nuts, oilseeds, and spices. The sampling by region, season, and production type showed minor differences in element levels for specific foods, however no tendency over all foods or for some food groups was apparent. The data on mercury, cadmium, lead, and nickel provide a comprehensive basis for chronic dietary exposure assessment of the population in Germany. All levels found were below regulated maximum levels.
Analysis of electrochemical and liver microsomal transformation products of lasalocid by LC/HRMS
(2022)
Rationale:
Lasalocid (LAS), an ionophore, is used in cattle and poultry farming as feed additive for its antibiotic and growth-promoting properties. Literature on transformation products (TP) resulting from LAS degradation is limited. So far, only hydroxylation is found to occur as the metabolic reaction during the LAS degradation. To investigate potential TPs of LAS, we used electrochemistry (EC) and liver microsome (LM) assays to synthesize TPs, which were identified using liquid chromatography high-resolution mass spectrometry (LC/HRMS).
Methods:
Electrochemically produced TPs were analyzed online by direct coupling of the electrochemical cell to the electrospray ionization (ESI) source of a Sciex Triple-TOF high resolution mass spectrometer. Then, EC-treated LAS solution was collected and analyzed offline using LC/HRMS to confirm stable TPs and improve their annotation with a chemical structure due to informative MS/MS spectra. In a complementary approach, TPs formed by rat and human microsomal incubation were investigated using LC/HRMS. The resulting data were used to investigate LAS modification reactions and elucidate the chemical structure of obtained TPs.
Results:
The online measurements identified a broad variety of TPs, resulting from modification reactions like (de-)hydrogenation, hydration, methylation, oxidation as well as adduct formation with methanol. We consistently observed different ion complexations of LAS and LAS-TPs (Na+; 2Na(+) K+; NaNH4+; KNH4+). Two stable methylated EC-TPs were found, structurally annotated, and assigned to a likely modification reaction. Using LM incubation, seven TPs were formed, mostly by oxidation/hydroxylation. After the identification of LM-TPs as Na+-complexes, we identified LM-TPs as K+-complexes.
Conclusion:
We identified and characterized TPs of LAS using EC- and LM-based methods. Moreover, we found different ion complexes of LAS-based TPs. This knowledge, especially the different ion complexes, may help elucidate the metabolic and environmental degradation pathways of LAS.
The drug salinomycin (SAL) is a polyether antibiotic and used in veterinary medicine as coccidiostat and growth promoter. Recently, SAL was suggested as a potential anticancer drug. However, transformation products (TPs) resulting from metabolic and environmental degradation of SAL are incompletely known and structural information is missing. In this study, we therefore systematically investigated the formation and identification of SAL derived TPs using electrochemistry (EC) in an electrochemical reactor and rat and human liver microsome incubation (RLM and HLM) as TP generating methods. Liquid chromatography (LC) coupled to high-resolution mass spectrometry (HRMS) was applied to determine accurate masses in a suspected target analysis to identify TPs and to deduce occurring modification reactions of derived TPs. A total of 14 new, structurally different TPs were found (two EC-TPs, five RLM-TPs, and 11 HLM-TPs). The main modification reactions are decarbonylation for EC-TPs and oxidation (hydroxylation) for RLM/HLM-TPs. Of particular interest are potassium-based TPs identified after liver microsome incubation because these might have been overlooked or declared as oxidated sodium adducts in previous, non-HRMS-based studies due to the small mass difference between K and O + Na of 21 mDa. The MS fragmentation pattern of TPs was used to predict the position of identified modifications in the SAL molecule. The obtained knowledge regarding transformation reactions and novel TPs of SAL will contribute to elucidate SAL-metabolites with regards to structural prediction.
Pancreatic steatosis associates with beta-cell failure and may participate in the development of type-2-diabetes. Our previous studies have shown that diabetes-susceptible mice accumulate more adipocytes in the pancreas than diabetes-resistant mice. In addition, we have demonstrated that the co-culture of pancreatic islets and adipocytes affect insulin secretion. The aim of this current study was to elucidate if and to what extent pancreas-resident mesenchymal stromal cells (MSCs) with adipogenic progenitor potential differ from the corresponding stromal-type cells of the inguinal white adipose tissue (iWAT). miRNA (miRNome) and mRNA expression (transcriptome) analyses of MSCs isolated by flow cytometry of both tissues revealed 121 differentially expressed miRNAs and 1227 differentially expressed genes (DEGs). Target prediction analysis estimated 510 DEGs to be regulated by 58 differentially expressed miRNAs. Pathway analyses of DEGs and miRNA target genes showed unique transcriptional and miRNA signatures in pancreas (pMSCs) and iWAT MSCs (iwatMSCs), for instance fibrogenic and adipogenic differentiation, respectively. Accordingly, iwatMSCs revealed a higher adipogenic lineage commitment, whereas pMSCs showed an elevated fibrogenesis. As a low degree of adipogenesis was also observed in pMSCs of diabetes-susceptible mice, we conclude that the development of pancreatic steatosis has to be induced by other factors not related to cell-autonomous transcriptomic changes and miRNA-based signals.
Wheat alpha-amylase/trypsin inhibitors remain a subject of interest considering the latest findings showing their implication in wheat-related non-celiac sensitivity (NCWS). Understanding their functions in such a disorder is still unclear and for further study, the need for pure ATI molecules is one of the limiting problems. In this work, a simplified approach based on the successive fractionation of ATI extracts by reverse phase and ion exchange chromatography was developed. ATIs were first extracted from wheat flour using a combination of Tris buffer and chloroform/methanol methods. The separation of the extracts on a C18 column generated two main fractions of interest F1 and F2. The response surface methodology with the Doehlert design allowed optimizing the operating parameters of the strong anion exchange chromatography. Finally, the seven major wheat ATIs namely P01083, P17314, P16850, P01085, P16851, P16159, and P83207 were recovered with purity levels (according to the targeted LC-MS/MS analysis) of 98.2 ± 0.7; 98.1 ± 0.8; 97.9 ± 0.5; 95.1 ± 0.8; 98.3 ± 0.4; 96.9 ± 0.5, and 96.2 ± 0.4%, respectively. MALDI-TOF-MS analysis revealed single peaks in each of the pure fractions and the mass analysis yielded deviations of 0.4, 1.9, 0.1, 0.2, 0.2, 0.9, and 0.1% between the theoretical and the determined masses of P01083, P17314, P16850, P01085, P16851, P16159, and P83207, respectively. Overall, the study allowed establishing an efficient purification process of the most important wheat ATIs. This paves the way for further in-depth investigation of the ATIs to gain more knowledge related to their involvement in NCWS disease and to allow the absolute quantification in wheat samples.
Wheat alpha-amylase/trypsin inhibitors remain a subject of interest considering the latest findings showing their implication in wheat-related non-celiac sensitivity (NCWS). Understanding their functions in such a disorder is still unclear and for further study, the need for pure ATI molecules is one of the limiting problems. In this work, a simplified approach based on the successive fractionation of ATI extracts by reverse phase and ion exchange chromatography was developed. ATIs were first extracted from wheat flour using a combination of Tris buffer and chloroform/methanol methods. The separation of the extracts on a C18 column generated two main fractions of interest F1 and F2. The response surface methodology with the Doehlert design allowed optimizing the operating parameters of the strong anion exchange chromatography. Finally, the seven major wheat ATIs namely P01083, P17314, P16850, P01085, P16851, P16159, and P83207 were recovered with purity levels (according to the targeted LC-MS/MS analysis) of 98.2 ± 0.7; 98.1 ± 0.8; 97.9 ± 0.5; 95.1 ± 0.8; 98.3 ± 0.4; 96.9 ± 0.5, and 96.2 ± 0.4%, respectively. MALDI-TOF-MS analysis revealed single peaks in each of the pure fractions and the mass analysis yielded deviations of 0.4, 1.9, 0.1, 0.2, 0.2, 0.9, and 0.1% between the theoretical and the determined masses of P01083, P17314, P16850, P01085, P16851, P16159, and P83207, respectively. Overall, the study allowed establishing an efficient purification process of the most important wheat ATIs. This paves the way for further in-depth investigation of the ATIs to gain more knowledge related to their involvement in NCWS disease and to allow the absolute quantification in wheat samples.
High-salt (HS) diets have recently been linked to oxidative stress in the brain, a fact that may be a precursor to behavioral changes, such as those involving anxiety-like behavior. However, to the best of our knowledge, no study has evaluated the amygdala redox status after consuming a HS diet in the pre- or postweaning periods. This study aimed to evaluate the amygdala redox status and anxiety-like behaviors in adulthood, after inclusion of HS diet in two periods: preconception, gestation, and lactation (preweaning); and only after weaning (postweaning). Initially, 18 females and 9 male Wistar rats received a standard (n = 9 females and 4 males) or a HS diet (n = 9 females and 5 males) for 120 days. After mating, females continued to receive the aforementioned diets during gestation and lactation. Weaning occurred at 21-day-old Wistar rats and the male offspring were subdivided: control-control (C-C)-offspring of standard diet fed dams who received a standard diet after weaning (n = 9-11), control-HS (C-HS)-offspring of standard diet fed dams who received a HS diet after weaning (n = 9-11), HS-C-offspring of HS diet fed dams who received a standard diet after weaning (n = 9-11), and HS-HS-offspring of HS diet fed dams who received a HS diet after weaning (n = 9-11). At adulthood, the male offspring performed the elevated plus maze and open field tests. At 152-day-old Wistar rats, the offspring were euthanized and the amygdala was removed for redox state analysis. The HS-HS group showed higher locomotion and rearing frequency in the open field test. These results indicate that this group developed hyperactivity. The C-HS group had a higher ratio of entries and time spent in the open arms of the elevated plus maze test in addition to a higher head-dipping frequency. These results suggest less anxiety-like behaviors. In the analysis of the redox state, less activity of antioxidant enzymes and higher levels of the thiobarbituric acid reactive substances (TBARS) in the amygdala were shown in the amygdala of animals that received a high-salt diet regardless of the period (pre- or postweaning). In conclusion, the high-salt diet promoted hyperactivity when administered in the pre- and postweaning periods. In animals that received only in the postweaning period, the addition of salt induced a reduction in anxiety-like behaviors. Also, regardless of the period, salt provided amygdala oxidative stress, which may be linked to the observed behaviors.
Growth differentiation factor 15 (GDF15) is a stress-induced cytokine secreted into the circulation by a number of tissues under different pathological conditions such as cardiovascular disease, cancer or mitochondrial dysfunction, among others. While GDF15 signaling through its recently identified hindbrain-specific receptor GDNF family receptor alpha-like (GFRAL) has been proposed to be involved in the metabolic stress response, its endocrine role under chronic stress conditions is still poorly understood. Mitochondrial dysfunction is characterized by the impairment of oxidative phosphorylation (OXPHOS), leading to inefficient functioning of mitochondria and consequently, to mitochondrial stress. Importantly, mitochondrial dysfunction is among the pathologies to most robustly induce GDF15 as a cytokine in the circulation.
The overall aim of this thesis was to elucidate the role of the GDF15-GFRAL pathway under mitochondrial stress conditions. For this purpose, a mouse model of skeletal muscle-specific mitochondrial stress achieved by ectopic expression of uncoupling protein 1 (UCP1), the HSA-Ucp1-transgenic (TG) mouse, was employed. As a consequence of mitochondrial stress, TG mice display a metabolic remodeling consisting of a lean phenotype, an improved glucose metabolism, an increased metabolic flexibility and a metabolic activation of white adipose tissue.
Making use of TG mice crossed with whole body Gdf15-knockout (GdKO) and Gfral-knockout (GfKO) mouse models, this thesis demonstrates that skeletal muscle mitochondrial stress induces the integrated stress response (ISR) and GDF15 in skeletal muscle, which is released into the circulation as a myokine (muscle-induced cytokine) in a circadian manner. Further, this work identifies GDF15-GFRAL signaling to be responsible for the systemic metabolic remodeling elicited by mitochondrial stress in TG mice. Moreover, this study reveals a daytime-restricted anorexia induced by the GDF15-GFRAL axis under muscle mitochondrial stress, which is, mechanistically, mediated through the induction of hypothalamic corticotropin releasing hormone (CRH). Finally, this work elucidates a so far unknown physiological outcome of the GDF15-GFRAL pathway: the induction of anxiety-like behavior.
In conclusion, this study uncovers a muscle-brain crosstalk under skeletal muscle mitochondrial stress conditions through the induction of GDF15 as a myokine that signals through the hindbrain-specific GFRAL receptor to elicit a stress response leading to metabolic remodeling and modulation of ingestive- and anxiety-like behavior.
Chronic stress is a major cause of neuropsychiatric conditions such as depression. Stress vulnerability varies individually in mice and humans, measured by behavioral changes. In contrast to affective symptoms, motor retardation as a consequence of stress is not well understood. We repeatedly imaged dendritic spines of the motor cortex in Thy1-GFP M mice before and after chronic social defeat stress. Susceptible and resilient phenotypes were discriminated by symptom load and their motor learning abilities were assessed by a gross and fine motor task. Stress phenotypes presented individual short- and long-term changes in the hypothalamic-pituitary-adrenal axis as well as distinct patterns of altered motor learning. Importantly, stress was generally accompanied by a marked reduction of spine density in the motor cortex and spine dynamics depended on the stress phenotype. We found astrogliosis and altered microglia morphology along with increased microglia-neuron interaction in the motor cortex of susceptible mice. In cerebrospinal fluid, proteomic fingerprints link the behavioral changes and structural alterations in the brain to neurodegenerative disorders and dysregulated synaptic homeostasis. Our work emphasizes the importance of synaptic integrity and the risk of neurodegeneration within depression as a threat to brain health.
The protein fraction, important for coffee cup quality, is modified during post-harvest treatment prior to roasting. Proteins may interact with phenolic compounds, which constitute the major metabolites of coffee, where the processing affects these interactions. This allows the hypothesis that the proteins are denatured and modified via enzymatic and/or redox activation steps. The present study was initiated to encompass changes in the protein fraction. The investigations were limited to major storage protein of green coffee beans. Fourteen Coffea arabica samples from various processing methods and countries were used. Different extraction protocols were compared to maintain the status quo of the protein modification. The extracts contained about 4–8 µg of chlorogenic acid derivatives per mg of extracted protein. High-resolution chromatography with multiple reaction monitoring was used to detect lysine modifications in the coffee protein. Marker peptides were allocated for the storage protein of the coffee beans. Among these, the modified peptides K.FFLANGPQQGGK.E and R.LGGK.T of the α-chain and R.ITTVNSQK.I and K.VFDDEVK.Q of β-chain were detected. Results showed a significant increase (p < 0.05) of modified peptides from wet processed green beans as compared to the dry ones. The present study contributes to a better understanding of the influence of the different processing methods on protein quality and its role in the scope of coffee cup quality and aroma. View Full-Text
Epidemiological data suggest that consuming diets rich in carotenoids can reduce the risk of developing several non-communicable diseases. Thus, we investigated the extent to which carotenoid contents of foods can be increased by the choice of food matrices with naturally high carotenoid contents and thermal processing methods that maintain their stability. For this purpose, carotenoids of 15 carrot (Daucus carota L.) cultivars of different colors were assessed with UHPLC-DAD-ToF-MS. Additionally, the processing effects of air drying, air frying, and deep frying on carotenoid stability were applied. Cultivar selection accounted for up to 12.9-fold differences in total carotenoid content in differently colored carrots and a 2.2-fold difference between orange carrot cultivars. Air frying for 18 and 25 min and deep frying for 10 min led to a significant decrease in total carotenoid contents. TEAC assay of lipophilic extracts showed a correlation between carotenoid content and antioxidant capacity in untreated carrots.
Countries processing raw coffee beans are burdened with low economical incomes to fight the serious environmental problems caused by the by-products and wastewater that is generated during the wet-coffee processing. The aim of this work was to develop alternative methods of improving the waste by-product quality and thus making the process economically more attractive with valorization options that can be brought to the coffee producers.
The type of processing influences not only the constitution of green coffee but also of by-products and wastewater. Therefore, coffee bean samples as well as by-products and wastewater collected at different production steps of were analyzed. Results show that the composition of wastewater is dependent on how much and how often the wastewater is recycled in the processing. Considering the coffee beans, results indicate that the proteins might be affected during processing and a positive effect of the fermentation on the solubility and accessibility of proteins seems to be probable. The steps of coffee processing influence the different constituents of green coffee beans which, during roasting, give rise to aroma compounds and express the characteristics of roasted coffee beans. Knowing that this group of compounds is involved in the Maillard reaction during roasting, this possibility could be utilized for the coffee producers to improve the quality of green coffee beans and finally the coffee cup quality.
The valorization of coffee wastes through modification to activated carbon has been considered as a low-cost option creating an adsorbent with prospective to compete with commercial carbons. Activation protocol using spent coffee and parchment was developed and prepared to assess their adsorption capacity for organic compounds. Spent coffee grounds and parchment proved to have similar adsorption efficiency to commercial activated carbon.
The results of this study document a significant information originating from the processing of the de-pulped to green coffee beans. Furthermore, it showed that coffee parchment and spent coffee grounds can be valorized as low-cost option to produce activated carbons. Further work needs to be directed to the optimization of the activation methods to improve the quality of the materials produced and the viability of applying such experiments in-situ to bring the coffee producer further valorization opportunities with environmental perspectives.
Coffee producers would profit in establishing appropriate simple technologies to improve green coffee quality, re-use coffee by-products, and wastewater valorization.
The protein fraction, important for coffee cup quality, is modified during post-harvest treatment prior to roasting. Proteins may interact with phenolic compounds, which constitute the major metabolites of coffee, where the processing affects these interactions. This allows the hypothesis that the proteins are denatured and modified via enzymatic and/or redox activation steps. The present study was initiated to encompass changes in the protein fraction. The investigations were limited to major storage protein of green coffee beans. Fourteen Coffea arabica samples from various processing methods and countries were used. Different extraction protocols were compared to maintain the status quo of the protein modification. The extracts contained about 4–8 µg of chlorogenic acid derivatives per mg of extracted protein. High-resolution chromatography with multiple reaction monitoring was used to detect lysine modifications in the coffee protein. Marker peptides were allocated for the storage protein of the coffee beans. Among these, the modified peptides K.FFLANGPQQGGK.E and R.LGGK.T of the α-chain and R.ITTVNSQK.I and K.VFDDEVK.Q of β-chain were detected. Results showed a significant increase (p < 0.05) of modified peptides from wet processed green beans as compared to the dry ones. The present study contributes to a better understanding of the influence of the different processing methods on protein quality and its role in the scope of coffee cup quality and aroma. View Full-Text
Current attempts to prevent and manage type 2 diabetes have been moderately effective, and a better understanding of the molecular roots of this complex disease is important to develop more successful and precise treatment options.
Recently, we initiated the collective diabetes cross, where four mouse inbred strains differing in their diabetes susceptibility were crossed with the obese and diabetes-prone NZO strain and identified the quantitative trait loci (QTL) Nidd13/NZO, a genomic region on chromosome 13 that correlates with hyperglycemia in NZO allele carriers compared to B6 controls.
Subsequent analysis of the critical region, harboring 644 genes, included expression studies in pancreatic islets of congenic Nidd13/NZO mice, integration of single-cell data from parental NZO and B6 islets as well as haplotype analysis.
Finally, of the five genes (Acot12, S100z, Ankrd55, Rnf180, and Iqgap2) within the polymorphic haplotype block that are differently expressed in islets of B6 compared to NZO mice, we identified the calcium-binding protein S100z gene to affect islet cell proliferation as well as apoptosis when overexpressed in MINE cells. In summary, we define S100z as the most striking gene to be causal for the diabetes QTL Nidd13/NZO by affecting beta-cell proliferation and apoptosis. Thus, S100z is an entirely novel diabetes gene regulating islet cell function.
Background
Coronavirus disease (COVID-19) has a severe impact on all aspects of patient care. Among the numerous biomarkers of potential validity for diagnostic and clinical management of COVID-19 are biomarkers at the interface of iron metabolism and inflammation.
Methods
The follow-up study included 54 hospitalized patients with laboratory-confirmed COVID-19 with a moderate and severe/critical form of the disease. Iron deficiency specific biomarkers such as iron, ferritin, transferrin receptor, hepcidin, and zinc protoporphyrin (ZnPP) as well as relevant markers of inflammation were evaluated twice: in the first five days when the patient was admitted to the hospital and during five to 15 days; and their validity to diagnose iron deficiency was further assessed. The regression and Receiver Operating Characteristics (ROC) analyses were performed to evaluate the prognosis and determine the probability for predicting the severity of the disease in the first five days of COVID-19.
Results
Based on hemoglobin values, anemia was observed in 21 of 54 patients. Of all iron deficiency anemia-related markers, only ZnPP was significantly elevated (P<0.001) in the anemic group. When patients were grouped according to the severity of disease, slight differences in hemoglobin or other anemia-related parameters could be observed. However, the levels of ZnPP were significantly increased in the severely ill group of patients. The ratio of ZnPP to lymphocyte count (ZnPP/L) had a discrimination power stronger than the neutrophil to lymphocyte count ratio (N/L) to determine disease severity. Additionally, only two markers were independently associated with the severity of COVID-19 in logistic regression analysis; D-dimer (OR (5.606)(95% CI 1.019–30.867)) and ZnPP/L ratio (OR (74.313) (95% CI 1.081–5108.103)).
Conclusions
For the first time ZnPP in COVID-19 patients were reported in this study. Among all iron-related markers tested, ZnPP was the only one that was associated with anemia as based on hemoglobin. The increase in ZnPP might indicate that the underlying cause of anemia in COVID-19 patients is not only due to the inflammation but also of nutritional origin. Additionally, the ZnPP/L ratio might be a valid prognostic marker for the severity of COVID-19.
In order to improve a recently established cell-based assay to assess the potency of botulinum neurotoxin, neuroblastoma-derived SiMa cells and induced pluripotent stem-cells (iPSC) were modified to incorporate the coding sequence of a reporter luciferase into a genetic safe harbor utilizing CRISPR/Cas9. A novel method, the double-control quantitative copy number PCR (dc-qcnPCR), was developed to detect off-target integrations of donor DNA. The donor DNA insertion success rate and targeted insertion success rate were analyzed in clones of each cell type. The dc-qcnPCR reliably quantified the copy number in both cell lines. The probability of incorrect donor DNA integration was significantly increased in SiMa cells in comparison to the iPSCs. This can possibly be explained by the lower bundled relative gene expression of a number of double-strand repair genes (BRCA1, DNA2, EXO1, MCPH1, MRE11, and RAD51) in SiMa clones than in iPSC clones. The dc-qcnPCR offers an efficient and cost-effective method to detect off-target CRISPR/Cas9-induced donor DNA integrations.
Mammalian arachidonic acid lipoxygenases (ALOXs) have been implicated in cell differentiation and in the pathogenesis of inflammation. The mouse genome involves seven functional Alox genes and the encoded enzymes share a high degree of amino acid conservation with their human orthologs. There are, however, functional differences between mouse and human ALOX orthologs. Human ALOX15B oxygenates arachidonic acid exclusively to its 15-hydroperoxy derivative (15S-HpETE), whereas 8S-HpETE is dominantly formed by mouse Alox15b. The structural basis for this functional difference has been explored and in vitro mutagenesis humanized the reaction specificity of the mouse enzyme. To explore whether this mutagenesis strategy may also humanize the reaction specificity of mouse Alox15b in vivo, we created Alox15b knock-in mice expressing the arachidonic acid 15-lipoxygenating Tyr603Asp+His604Val double mutant instead of the 8-lipoxygenating wildtype enzyme. These mice are fertile, display slightly modified plasma oxylipidomes and develop normally up to an age of 24 weeks. At later developmental stages, male Alox15b-KI mice gain significantly less body weight than outbred wildtype controls, but this effect was not observed for female individuals. To explore the possible reasons for the observed gender-specific growth arrest, we determined the basic hematological parameters and found that aged male Alox15b-KI mice exhibited significantly attenuated red blood cell parameters (erythrocyte counts, hematocrit, hemoglobin). Here again, these differences were not observed in female individuals. These data suggest that humanization of the reaction specificity of mouse Alox15b impairs the functionality of the hematopoietic system in males, which is paralleled by a premature growth arrest.
Mammalian arachidonic acid lipoxygenases (ALOXs) have been implicated in cell differentiation and in the pathogenesis of inflammation. The mouse genome involves seven functional Alox genes and the encoded enzymes share a high degree of amino acid conservation with their human orthologs. There are, however, functional differences between mouse and human ALOX orthologs. Human ALOX15B oxygenates arachidonic acid exclusively to its 15-hydroperoxy derivative (15S-HpETE), whereas 8S-HpETE is dominantly formed by mouse Alox15b. The structural basis for this functional difference has been explored and in vitro mutagenesis humanized the reaction specificity of the mouse enzyme. To explore whether this mutagenesis strategy may also humanize the reaction specificity of mouse Alox15b in vivo, we created Alox15b knock-in mice expressing the arachidonic acid 15-lipoxygenating Tyr603Asp+His604Val double mutant instead of the 8-lipoxygenating wildtype enzyme. These mice are fertile, display slightly modified plasma oxylipidomes and develop normally up to an age of 24 weeks. At later developmental stages, male Alox15b-KI mice gain significantly less body weight than outbred wildtype controls, but this effect was not observed for female individuals. To explore the possible reasons for the observed gender-specific growth arrest, we determined the basic hematological parameters and found that aged male Alox15b-KI mice exhibited significantly attenuated red blood cell parameters (erythrocyte counts, hematocrit, hemoglobin). Here again, these differences were not observed in female individuals. These data suggest that humanization of the reaction specificity of mouse Alox15b impairs the functionality of the hematopoietic system in males, which is paralleled by a premature growth arrest.
The Caenorhabditis elegans (C. elegans) is a model organism that has been increasingly used in health and environmental toxicity assessments. The quantification of such elements in vivo can assist in studies that seek to relate the exposure concentration to possible biological effects.
Therefore, this study is the first to propose a method of quantitative analysis of 21 ions by ion chromatography (IC), which can be applied in different toxicity studies in C. elegans.
The developed method was validated for 12 anionic species (fluoride, acetate, chloride, nitrite, bromide, nitrate, sulfate, oxalate, molybdate, dichromate, phosphate, and perchlorate), and 9 cationic species (lithium, sodium, ammonium, thallium, potassium, magnesium, manganese, calcium, and barium).
The method did not present the presence of interfering species, with R2 varying between 0.9991 and 0.9999, with a linear range from 1 to 100 mu g L-1.
Limits of detection (LOD) and limits of quantification (LOQ) values ranged from 0.2319 mu g L-1 to 1.7160 mu g L-1 and 0.7028 mu g L-1 to 5.1999 mu g L-1, respectively.
The intraday and interday precision tests showed an Relative Standard Deviation (RSD) below 10.0 % and recovery ranging from 71.0 % to 118.0 % with a maximum RSD of 5.5 %.
The method was applied to real samples of C. elegans treated with 200 uM of thallium acetate solution, determining the uptake and bioaccumulated Tl+ content during acute exposure.
Background The Berlin Fat Mouse Inbred line (BFMI) is a model for obesity and the metabolic syndrome. This study aimed to identify genetic variants associated with impaired glucose metabolism using the obese lines BFMI861-S1 and BFMI861-S2, which are genetically closely related, but differ in several traits. BFMI861-S1 is insulin resistant and stores ectopic fat in the liver, whereas BFMI861-S2 is insulin sensitive. Methods In generation 10, 397 males of an advanced intercross line (AIL) BFMI861-S1 x BFMI861-S2 were challenged with a high-fat, high-carbohydrate diet and phenotyped over 25 weeks. QTL-analysis was performed after selective genotyping of 200 mice using the GigaMUGA Genotyping Array. Additional 197 males were genotyped for 7 top SNPs in QTL regions. For the prioritization of positional candidate genes whole genome sequencing and gene expression data of the parental lines were used. Results Overlapping QTL for gonadal adipose tissue weight and blood glucose concentration were detected on chromosome (Chr) 3 (95.8-100.1 Mb), and for gonadal adipose tissue weight, liver weight, and blood glucose concentration on Chr 17 (9.5-26.1 Mb). Causal modeling suggested for Chr 3-QTL direct effects on adipose tissue weight, but indirect effects on blood glucose concentration. Direct effects on adipose tissue weight, liver weight, and blood glucose concentration were suggested for Chr 17-QTL. Prioritized positional candidate genes for the identified QTL were Notch2 and Fmo5 (Chr 3) and Plg and Acat2 (Chr 17). Two additional QTL were detected for gonadal adipose tissue weight on Chr 15 (67.9-74.6 Mb) and for body weight on Chr 16 (3.9-21.4 Mb). Conclusions QTL mapping together with a detailed prioritization approach allowed us to identify candidate genes associated with traits of the metabolic syndrome. In addition, we provided evidence for direct and indirect genetic effects on blood glucose concentration in the insulin-resistant mouse line BFMI861-S1.
Mechanistic studies on the adverse effects of manganese overexposure in differentiated LUHMES cells
(2022)
Manganese (Mn) is an essential trace element, but overexposure is associated with toxicity and neurological dysfunction. Accumulation of Mn can be observed in dopamine-rich regions of the brain in vivo and Mn-induced oxidative stress has been discussed extensively. Nevertheless, Mn-induced DNA damage, adverse effects of DNA repair, and possible resulting consequences for the neurite network are not yet characterized. For this, LUHMES cells were used, as they differentiate into dopaminergic-like neurons and form extensive neurite networks. Experiments were conducted to analyze Mn bioavailability and cytotoxicity of MnCl2, indicating a dose-dependent uptake and substantial cytotoxic effects. DNA damage, analyzed by means of 8-oxo-7,8-dihydro-2'-guanine (8oxodG) and single DNA strand break formation, showed significant dose- and time-dependent increase of DNA damage upon 48 h Mn exposure. Furthermore, the DNA damage response was increased which was assessed by analytical quantification of poly(ADP-ribosyl)ation (PARylation). Gene expression of the respective DNA repair genes was not significantly affected. Degradation of the neuronal network is significantly altered by 48 h Mn exposure. Altogether, this study contributes to the characterization of Mn-induced neurotoxicity, by analyzing the adverse effects of Mn on genome integrity in dopaminergic-like neurons and respective outcomes.
Manganese (Mn), although important for multiple cellular processes, has posed environmental health concerns due to its neurotoxic effects. In recent years, there have been extensive studies on the mechanism of Mn-induced neuropathology, as well as the sex-dependent vulnerability to its neurotoxic effects. Nonetheless, cellular mechanisms influenced by sex differences in susceptibility to Mn have yet to be adequately characterized. Since oxidative stress is a key mechanism of Mn neurotoxicity, here, we have probed Hsp70 and Nrf2 proteins to investigate the sex-dependent changes following exposure to Mn. Male and female rats were administered intraperitoneal injections of MnCl2 (10 mg/kg and 25 mg/kg) 48 hourly for a total of eight injections (15 days). We evaluated changes in body weight, as well as Mn accumulation, Nrf2 and Hsp70 expression across four brain regions; striatum, cortex, hippocampus and cerebellum in both sexes. Our results showed sex-specific changes in body-weight, specifically in males but not in females. Additionally, we noted sex-dependent accumulation of Mn in the brain, as well as in expression levels of Nrf2 and Hsp70 proteins. These findings revealed sex-dependent susceptibility to Mn-induced neurotoxicity corresponding to differential Mn accumulation, and expression of Hsp70 and Nrf2 across several brain regions.
The knowledge of transformation pathways and transformation products of veterinary drugs is important for health, food and environmental matters. Residues, consisting of original veterinary drug and transformation products, are found in food products of animal origin as well as the environment (e.g., soil or surface water). Several transformation processes can alter the original veterinary drug, ranging from biotransformation in living organism to environmental degradation processes like photolysis, hydrolysis, or microbial processes. In this thesis, four veterinary drugs were investigated, three ionophore antibiotics Monensin, Salinomycin and Lasalocid and the macrocyclic lactone Moxidectin. Ionophore antibiotics are mainly used to cure and prevent coccidiosis in poultry especially prophylactic in broiler farming. Moxidectin is an antiparasitic drug that is used for the treatment of internal and external parasites in food-producing and companion animals. The main objective of this work is to employ different laboratory approaches to generate and identify transformation products. The identification was conducted using high-resolution mass spectrometry (HRMS). A major focus was placed on the application of electrochemistry for simulation of transformation processes. The electrochemical reactor – equipped with a three-electrode flow-through cell – enabled the oxidation or reduction by applying a potential. The transformation products derived were analyzed by online coupling of the electrochemical reactor and a HRMS and offline by liquid chromatography (LC) combined with HRMS. The main modification reaction of the identified transformation products differed for each investigated veterinary drug. Monensin showed decarboxylation and demethylation as the main modification reactions, for Salinomycin mostly decarbonylation occurred and for Lasalocid methylation was prevalent. For Moxidectin, I observed an oxidation (hydroxylation) reaction and adduct formation with solvent. In general, for Salinomycin and Lasalocid, more transient transformation products (online measurement) than stable transformation products (offline measurements) were detected. By contrast, the number of transformation products using online and offline measurements were identical for Monensin and Moxidectin. As a complementary approach, metabolism tests with rat or human liver microsomes were conducted for the ionophore antibiotics. Monensin was investigated by using rat liver microsomes and the transformation products identified were based on decarboxylation and demethylation. Salinomycin and Lasalocid were converted by human and rat liver microsomes. For both substances, more transformation products were found by using human liver microsomes. The transformation products of the rat liver microsome conversion were redundant, and the transformation products were also found at the human liver microsome assay. Oxidation (hydroxylation) was found to be the main modification reaction for both. In addition, a frequent ion exchange between sodium and potassium was identified. The final two experiments were performed for one substance each, whereby the hydrolysis of Monensin and the photolysis of Moxidectin was investigated. The transformation products of the pH-dependent hydrolysis were based on ring-opening and dehydration. Moxidectin formed several transformation products by irradiation with UV-C light and the main modification reactions were isomeric changes, (de-)hydration and changes of the methoxime moiety. In summary, transformation products of the four investigated veterinary drugs were generated by the different laboratory approaches. Most of the transformation products were identified for the first time. The resulting findings provide an improved understanding of clarifying the transformation behavior.
Western-style obesity-promoting diets are associated with increased inflammation, higher disease incidence and mortality.
In contrast, plant-based diets (PBDs), which incorporate large amounts of vegetables and fruit, legumes, whole grains and only a small amount of meat, are generally associated with better health and lower mortality.
This narrative review summarizes the evidence on health and life span in adults adhering to PBDs and discusses the potentially longevity-promoting mechanism of PBDs as well as limitations due to nutrient deficiencies.
Epidemiologic studies consistently report lower mortality rates in adults who adhering to PBDs when compared with people whose diet regularly includes meat.
PBDs are associated with many health benefits, such as improved metabolic and inflammatory profile.
In turn, the incidence of cardiovascular disease is lower in adults consuming PBDs, which contributes to their better health. The health-promoting effects of PBDs are still not entirely clear but most likely multifactorial and include modulation of the gut microbiome. The interest in possible longevity-promoting mechanisms of PBDs has increased in recent years, as many characteristics of PBDs such as protein restriction and restriction of certain amino acids are known to extend the life span.
While there is ample evidence from animal studies, large-scale human studies, which also provide insight into the specific mechanisms of the effect of PBDs on longevity, are missing.
However, due to the lower protein content of PBDs, there appears to be an age limit for the anticipated health effects, as adults over 65 require larger amounts of protein.
Glucosinolates are plant secondary metabolites found in cruciferous vegetables (Brassicaceae) that are valued for their potential health benefits. Frequently consumed representatives of these vegetables, for example, are white or red cabbage, which are typically boiled before consumption. Recently, 3-alk(en)yl-4-hydroxythiazolidine-2-thiones were identified as a class of thermal glucosinolate degradation products that are formed during the boiling of cabbage. Since these newly discovered compounds are frequently consumed, this raises questions about their potential uptake and their possible bioactive functions. Therefore, 3-allyl-4-hydroxythiazolidine-2-thione (allyl HTT) and 4-hydroxy-3-(4-(methylsulfinyl) butyl)thiazolidine-2-thione (4-MSOB HTT) as degradation products of the respective glucosinolates sinigrin and glucoraphanin were investigated. After consumption of boiled red cabbage broth, recoveries of consumed amounts of the degradation products in urine collected for 24 h were 18 +/- 5% for allyl HTT and 21 +/- 4% for 4-MSOB HTT (mean +/- SD, n = 3). To investigate the stability of the degradation products during uptake and to elucidate the uptake mechanism, both an in vitro stomach and an in vitro intestinal model were applied. The results indicate that the uptake of allyl HTT and 4-MSOB HTT occurs by passive diffusion. Both compounds show no acute cell toxicity, no antioxidant potential, and no change in NAD(P)H dehydrogenase quinone 1 (NQO1) activity up to 100 mu M. However, inhibition of glycogen synthase kinases-3 (GSK-3) in the range of 20% for allyl HTT for the isoform GSK-3 beta and 29% for 4-MSOB HTT for the isoform GSK-3 alpha at a concentration of 100 mu M was found. Neither health-promoting nor toxic effects of 3-alk(en)yl-4-hydroxythiazolidine-2-thiones were found in the four tested assays carried out in this study, which contrasts with the properties of other glucosinolate degradation products, such as isothiocyanates.
With the advent of Nanotechnology, the use of nanomaterials in consumer products is increasing on a daily basis, due to which a deep understanding and proper investigation regarding their safety and risk assessment should be a major priority. To date, there is no investigation regarding the microrheological properties of nanomaterials (NMs) in biological media.
In our study, we utilized in silico models to select the suitable NMs based on their physicochemical properties such as solubility and lipophilicity. Then, we established a new method based on dynamic light scattering (DLS) microrheology to get the mean square displacement (MSD) and viscoelastic property of two model NMs that are dendrimers and cerium dioxide nanoparticles in Dulbecco's Modified Eagle Medium (DMEM) complete media at three different concentrations for both NMs. Subsequently, we established the cytotoxicological profiling using water-soluble tetrazolium salt-1 (WST-1) and a reactive oxygen species (ROS) assay.
To take one step forward, we further looked into the tight junction properties of the cells using immunostaining with Zonula occluden-1 (ZO-1) antibodies and found that the tight junction function or transepithelial resistance (TEER) was affected in response to the microrheology and cytotoxicity. The quantitative polymerase chain reaction (q-PCR) results in the gene expression of ZO-1 after the 24 h treatment with NPs further validates the findings of immunostaining results.
This new method that we established will be a reference point for other NM studies which are used in our day-to-day consumer products.
Over the last few years, the vegan diet has become increasingly popular in Germany. It has been proposed that this diet is generally lower in fat, but less is known about the impact on fatty acid (FA) profiles. Therefore, the cross-sectional "Risks and Benefits of a Vegan Diet" (RBVD) study (n = 72) was used to investigate dietary FA intake as well as plasma phospholipid FA in vegans (n = 36) compared to omnivores (n = 36). Vegans had a significantly lower dietary intake of total fat (median 86 g/day, IQR 64-111) in comparison to omnivores (median 104 g/day, IQR 88-143, p = 0.004). Further, vegans had a lower intake of saturated fatty acids (SFA) (p < 0.0001) and monounsaturated fatty acids (MUFA) (p = 0.001) compared to omnivores. Vegans had a higher intake in total polyunsaturated fatty acids (PUFA), omega-3 and omega-6 PUFA compared to omnivores, but without statistical significance after Bonferroni correction. According to plasma phospholipid profiles, relatively lower proportions of SFA (p < 0.0001), total trans fatty acids (TFA) (p = 0.0004) and omega-3-FA (p < 0.0001), but higher proportions of omega-6-FA (p < 0.0001) were observed in vegans. With the exception of omega-3 PUFA, a vegan diet is associated with a more favorable dietary fat intake and more favorable plasma FA profiles and therefore may reduce cardiovascular risk.
Diabetes is hallmarked by high blood glucose levels, which cause progressive generalised vascular damage, leading to microvascular and macrovascular complications. Diabetes-related complications cause severe and prolonged morbidity and are a major cause of mortality among people with diabetes. Despite increasing attention to risk factors of type 2 diabetes, existing evidence is scarce or inconclusive regarding vascular complications and research investigating both micro- and macrovascular complications is lacking. This thesis aims to contribute to current knowledge by identifying risk factors – mainly related to lifestyle – of vascular complications, addressing methodological limitations of previous literature and providing comparative data between micro- and macrovascular complications.
To address this overall aim, three specific objectives were set. The first was to investigate the effects of diabetes complication burden and lifestyle-related risk factors on the incidence of (further) complications. Studies suggest that diabetes complications are interrelated. However, they have been studied mainly independently of individuals’ complication burden. A five-state time-to-event model was constructed to examine the longitudinal patterns of micro- (kidney disease, neuropathy and retinopathy) and macrovascular complications (myocardial infarction and stroke) and their association with the occurrence of subsequent complications. Applying the same model, the effect of modifiable lifestyle factors, assessed alone and in combination with complication load, on the incidence of diabetes complications was studied. The selected lifestyle factors were body mass index (BMI), waist circumference, smoking status, physical activity, and intake of coffee, red meat, whole grains, and alcohol. Analyses were conducted in a cohort of 1199 participants with incident type 2 diabetes from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam, who were free of vascular complications at diabetes diagnosis. During a median follow-up time of 11.6 years, 96 cases of macrovascular complications (myocardial infarction and stroke) and 383 microvascular complications (kidney disease, neuropathy and retinopathy) were identified. In multivariable-adjusted models, the occurrence of a microvascular complication was associated with a higher incidence of further micro- (Hazard ratio [HR] 1.90; 95% Confidence interval [CI] 0.90, 3.98) and macrovascular complications (HR 4.72; 95% CI 1.25, 17.68), compared with persons without a complication burden. In addition, participants who developed a macrovascular event had a twofold higher risk of future microvascular complications (HR 2.26; 95% CI 1.05, 4.86). The models were adjusted for age, sex, state duration, education, lifestyle, glucose-lowering medication, and pre-existing conditions of hypertension and dyslipidaemia. Smoking was positively associated with macrovascular disease, while an inverse association was observed with higher coffee intake. Whole grain and alcohol intake were inversely associated with microvascular complications, and a U-shaped association was observed for red meat intake. BMI and waist circumference were positively associated with microvascular events. The associations between lifestyle factors and incidence of complications were not modified by concurrent complication burden, except for red meat intake and smoking status, where the associations were attenuated among individuals with a previous complication.
The second objective was to perform an in-depth investigation of the association between BMI and BMI change and risk of micro- and macrovascular complications. There is an ongoing debate on the association between obesity and risk of macrovascular and microvascular outcomes in type 2 diabetes, with studies suggesting a protective effect among people with overweight or obesity. These findings, however, might be limited due to suboptimal control for smoking, pre-existing chronic disease, or short-follow-up. After additional exclusion of persons with cancer history at diabetes onset, the associations between pre-diagnosis BMI and relative annual change between pre- and post-diagnosis BMI and incidence of complications were evaluated in multivariable-adjusted Cox models. The analyses were adjusted for age, sex, education, smoking status and duration, physical activity, alcohol consumption, adherence to the Mediterranean diet, and family history of diabetes and cardiovascular disease (CVD). Among 1083 EPIC-Potsdam participants, 85 macrovascular and 347 microvascular complications were identified during a median follow-up period of 10.8 years. Higher pre-diagnosis BMI was associated with an increased risk of total microvascular complications (HR per 5 kg/m2 1.21; 95% CI 1.07, 1.36), kidney disease (HR 1.39; 95% CI 1.21, 1.60) and neuropathy (HR 1.12; 95% CI 0.96, 1.31); but no association was observed for macrovascular complications (HR 1.05; 95% CI 0.81, 1.36). Effect modification was not evident by sex, smoking status, or age groups. In analyses according to BMI change categories, BMI loss of more than 1% indicated a decreased risk of total microvascular complications (HR 0.62; 95% CI 0.47, 0.80), kidney disease (HR 0.57; 95% CI 0.40, 0.81) and neuropathy (HR 0.73; 95% CI 0.52, 1.03), compared with participants with a stable BMI. No clear association was observed for macrovascular complications (HR 1.04; 95% CI 0.62, 1.74). The impact of BMI gain on diabetes-related vascular disease was less evident. Associations were consistent across strata of age, sex, pre-diagnosis BMI, or medication but appeared stronger among never-smokers than current or former smokers.
The last objective was to evaluate whether individuals with a high-risk profile for diabetes and cardiovascular disease (CVD) also have a greater risk of complications. Within the EPIC-Potsdam study, two accurate prognostic tools were developed, the German Diabetes Risk Score (GDRS) and the CVD Risk Score (CVDRS), which predict the 5-year type 2 diabetes risk and 10-year CVD risk, respectively. Both scores provide a non-clinical and clinical version. Components of the risk scores include age, sex, waist circumference, prevalence of hypertension, family history of diabetes or CVD, lifestyle factors, and clinical factors (only in clinical versions). The association of the risk scores with diabetes complications and their discriminatory performance for complications were assessed. In crude Cox models, both versions of GDRS and CVDRS were positively associated with macrovascular complications and total microvascular complications, kidney disease and neuropathy. Higher GDRS was also associated with an elevated risk of retinopathy. The discrimination of the scores (clinical and non-clinical) was poor for all complications, with the C-index ranging from 0.58 to 0.66 for macrovascular complications and from 0.60 to 0.62 for microvascular complications.
In conclusion, this work illustrates that the risk of complication development among individuals with type 2 diabetes is related to the existing complication load, and attention should be given to regular monitoring for future complications. It underlines the importance of weight management and adherence to healthy lifestyle behaviours, including high intake of whole grains, moderation in red meat and alcohol consumption and avoidance of smoking to prevent major diabetes-associated complications, regardless of complication burden. Risk scores predictive for type 2 diabetes and CVD were related to elevated risks of complications. By optimising several lifestyle and clinical factors, the risk score can be improved and may assist in lowering complication risk.
Individuals with diabetes face higher risks for macro- and microvascular complications than their non-diabetic counterparts. The concept of precision medicine in diabetes aims to optimise treatment decisions for individual patients to reduce the risk of major diabetic complications, including cardiovascular outcomes, retinopathy, nephropathy, neuropathy and overall mortality. In this context, prognostic models can be used to estimate an individual's risk for relevant complications based on individual risk profiles. This review aims to place the concept of prediction modelling into the context of precision prognostics. As opposed to identification of diabetes subsets, the development of prediction models, including the selection of predictors based on their longitudinal association with the outcome of interest and their discriminatory ability, allows estimation of an individual's absolute risk of complications. As a consequence, such models provide information about potential patient subgroups and their treatment needs. This review provides insight into the methodological issues specifically related to the development and validation of prediction models for diabetes complications. We summarise existing prediction models for macro- and microvascular complications, commonly included predictors, and examples of available validation studies. The review also discusses the potential of non-classical risk markers and omics-based predictors. Finally, it gives insight into the requirements and challenges related to the clinical applications and implementation of developed predictions models to optimise medical decision making.
Deep lipidomics in human plasma: cardiometabolic disease risk and effect of dietary fat modulation
(2022)
Background: In blood and tissues, dietary and endogenously generated fatty acids (FAs) occur in free form or as part of complex lipid molecules that collectively represent the lipidome of the respective tissue. We assessed associations of plasma lipids derived from high-resolution lipidomics with incident cardiometabolic diseases and subsequently tested if the identified risk-associated lipids were sensitive to dietary fat modification. Methods: The EPIC Potsdam cohort study (European Prospective Investigation into Cancer and Nutrition) comprises 27 548 participants recruited within an age range of 35 to 65 years from the general population around Potsdam, Germany. We generated 2 disease-specific case cohorts on the basis of a fixed random subsample (n=1262) and all respective cohort-wide identified incident primary cardiovascular disease (composite of fatal and nonfatal myocardial infarction and stroke; n=551) and type 2 diabetes (n=775) cases. We estimated the associations of baseline plasma concentrations of 282 class-specific FA abundances (calculated from 940 distinct molecular species across 15 lipid classes) with the outcomes in multivariable-adjusted Cox models. We tested the effect of an isoenergetic dietary fat modification on risk-associated lipids in the DIVAS randomized controlled trial (Dietary Intervention and Vascular Function; n=113). Participants consumed either a diet rich in saturated FAs (control), monounsaturated FAs, or a mixture of monounsaturated and n-6 polyunsaturated FAs for 16 weeks. Results: Sixty-nine lipids associated (false discovery rate<0.05) with at least 1 outcome (both, 8; only cardiovascular disease, 49; only type 2 diabetes, 12). In brief, several monoacylglycerols and FA16:0 and FA18:0 in diacylglycerols were associated with both outcomes; cholesteryl esters, free fatty acids, and sphingolipids were largely cardiovascular disease specific; and several (glycero)phospholipids were type 2 diabetes specific. In addition, 19 risk-associated lipids were affected (false discovery rate<0.05) by the diets rich in unsaturated dietary FAs compared with the saturated fat diet (17 in a direction consistent with a potential beneficial effect on long-term cardiometabolic risk). For example, the monounsaturated FA-rich diet decreased diacylglycerol(FA16:0) by 0.4 (95% CI, 0.5-0.3) SD units and increased triacylglycerol(FA22:1) by 0.5 (95% CI, 0.4-0.7) SD units. Conclusions: We identified several lipids associated with cardiometabolic disease risk. A subset was beneficially altered by a dietary fat intervention that supports the substitution of dietary saturated FAs with unsaturated FAs as a potential tool for primary disease prevention.
Background
Fetuin-A is a hepatokine which has the capacity to prevent vascular calcification. Moreover, it is linked to the induction of metabolic dysfunction, insulin resistance and associated with increased risk of diabetes.
It has not been clarified whether fetuin-A associates with risk of vascular, specifically microvascular, complications in patients with diabetes.
We aimed to investigate whether pre-diagnostic plasma fetuin-A is associated with risk of complications once diabetes develops.
Methods
Participants with incident type 2 diabetes and free of micro- and macrovascular disease from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam cohort (n = 587) were followed for microvascular and macrovascular complications (n = 203 and n = 60, respectively, median follow-up: 13 years).
Plasma fetuin-A was measured approximately 4 years prior to diabetes diagnosis. Prospective associations between baseline fetuin-A and risk of complications were assessed with Cox regression.
Results
In multivariable models, fetuin-A was linearly inversely associated with incident total and microvascular complications, hazard ratio (HR, 95% CI) per standard deviation (SD) increase: 0.86 (0.74; 0.99) for total, 0.84 (0.71; 0.98) for microvascular and 0.92 (0.68; 1.24) for macrovascular complications. After additional adjustment for cardiometabolic plasma biomarkers, including triglycerides and high-density lipoprotein, the associations were slightly attenuated: 0.88 (0.75; 1.02) for total, 0.85 (0.72; 1.01) for microvascular and 0.95 (0.67; 1.34) for macrovascular complications. No interaction by sex could be observed (p > 0.10 for all endpoints).
Conclusions
Our data show that lower plasma fetuin-A levels measured prior to the diagnosis of diabetes may be etiologically implicated in the development of diabetes-associated microvascular disease.
Purpose UK guidelines recommend dietary saturated fatty acids (SFAs) should not exceed 10% total energy (%TE) for cardiovascular disease prevention, with benefits observed when SFAs are replaced with unsaturated fatty acids (UFAs). This study aimed to assess the efficacy of a dietary exchange model using commercially available foods to replace SFAs with UFAs. Methods Healthy men (n = 109, age 48, SD 11 year) recruited to the Reading, Imperial, Surrey, Saturated fat Cholesterol Intervention-1 (RISSCI-1) study (ClinicalTrials.Gov n degrees NCT03270527) followed two sequential 4-week isoenergetic moderate-fat (34%TE) diets: high-SFA (18%TE SFAs, 16%TE UFAs) and low-SFA (10%TE SFAs, 24%TE UFAs). Dietary intakes were assessed using 4-day weighed diet diaries. Nutrient intakes were analysed using paired t-tests, fasting plasma phospholipid fatty acid (PL-FA) profiles and dietary patterns were analysed using orthogonal partial least square discriminant analyses. Results Participants exchanged 10.2%TE (SD 4.1) SFAs for 9.7%TE (SD 3.9) UFAs between the high and low-SFA diets, reaching target intakes with minimal effect on other nutrients or energy intakes. Analyses of dietary patterns confirmed successful incorporation of recommended foods from commercially available sources (e.g. dairy products, snacks, oils, and fats), without affecting participants' overall dietary intakes. Analyses of plasma PL-FAs indicated good compliance to the dietary intervention and foods of varying SFA content. Conclusions RISSCI-1 dietary exchange model successfully replaced dietary SFAs with UFAs in free-living healthy men using commercially available foods, and without altering their dietary patterns. Further intervention studies are required to confirm utility and feasibility of such food-based dietary fat replacement models at a population level.
Aim
There is little evidence of the impact of diabetes risk scores on individual diabetes risk factors, motivation for behaviour changes and mental health. The aim of this study was to investigate the effect of applying a noninvasive diabetes risk score in primary care as component of routine health checks on physical activity and secondary outcomes.
Methods
Cluster randomised trial, in which primary care physicians (PCPs), randomised (1:1) by minimisation, enrolled participants with statutory health insurance without known diabetes, >= 35 years of age with a body mass index >= 27.0 kg/m(2). The German Diabetes Risk Score was applied as add-on to the standard routine health check, conducted in the controls. Primary outcome was the difference in participants' physical activity (International Physical Activity Questionnaire) after 12 months. Secondary outcomes included body mass index, perceived health, anxiety, depression, and motivation for lifestyle change. Analysis was by intention-to-treat principle using mixed models.
Results
36 PCPs were randomised; remaining 30 PCPs (intervention: n = 16; control: n = 14) recruited 315 participants (intervention: n = 153; controls: n = 162). A slight increase in physical activity was observed in the intervention group with an adjusted mean change of 388 (95% confidence interval: - 235; 1011) metabolic equivalents minutes per week. There were no relevant changes in secondary outcomes.
Conclusions
The application of a noninvasive diabetes risk score alone is not effective in promoting physical activity in primary care. Clinical Trial Registration: ClinicalTrials.gov (NCT03234322, registration date: July 31, 2017).
Objective:
Current data regarding the roles of branched-chain amino acids (BCAA) in metabolic health are rather conflicting, as positive and negative effects have been attributed to their intake.
Methods:
To address this, individual effects of leucine and valine were elucidated in vivo (C57BL/6JRj mice) with a detailed phenotyping of these supplementations in high-fat (HF) diets and further characterization with in vitro approaches (C2C12 myocytes).
Results:
Here, we demonstrate that under HF conditions, leucine mediates beneficial effects on adiposity and insulin sensitivity, in part due to increasing energy expenditure-likely contributing partially to the beneficial effects of a higher milk protein intake. On the other hand, valine feeding leads to a worsening of HF-induced health impairments, specifically reducing glucose tolerance/ insulin sensitivity. These negative effects are driven by an accumulation of the valine-derived metabolite 3-hydroxyisobutyrate (3HIB). Higher plasma 3-HIB levels increase basal skeletal muscle glucose uptake which drives glucotoxicity and impairs myocyte insulin signaling.
Conclusion:
These data demonstrate the detrimental role of valine in an HF context and elucidate additional targetable pathways in the etiology of BCAA-induced obesity and insulin resistance.
Pannexin 1
(2022)
Hypoxic pulmonary vasoconstriction is an active alveolar hypoxia-caused physiological response redirecting pulmonary blood flow from poorly ventilated areas to better oxygenated lung regions in order to optimize oxygen supply. However, the signaling pathways underlying this pulmonary vascular response remain an area under investigation. In the present study I investigated the functional relevance of Pannexin 1 (Panx1)-mediated ATP release in hypoxic pulmonary vasoconstriction and chronic hypoxic pulmonary hypertension using murine isolated perfused lungs, chronic hypoxic mice, and pulmonary artery smooth muscle cell culture. In isolated mouse lungs, switch to hypoxic gas induced a marked increase in pulmonary artery pressure. Pharmacological inhibition of Panx1 using probenecid, Panx1 specific inhibitory peptide (10Panx1) or spironolactone as well as genetic deletion of Panx1 in smooth muscle cells diminished hypoxic pulmonary vasoconstriction in isolated perfused mouse lungs. Fura-2 imaging revealed a reduced Ca2+ response to hypoxia in pulmonary artery smooth muscle cells treated with spironolactone or 10Panx1. Although these findings suggested an important role of Panx1 in HPV, neither smooth muscle cell nor endothelial cell specific genetic deletion of Panx1 prevented the development of pulmonary hypertension in chronic hypoxic mice. Surprisingly, hypoxia did not induce ATP release and inhibition of purinergic receptors or ATP degradation by ATPase failed to decrease the pulmonary vasoconstriction response to hypoxia in isolated perfused mouse lungs. However, Panx1 antagonism as well as TRPV4 inhibition prevented the hypoxia-induced increase in intracellular Ca2+ concentration in pulmonary artery smooth muscle cells in an additive manner suggesting that Panx1 might modulate intracellular Ca2+ signaling independently of the ATP-P2-TRPV4 signaling axis. In line with this assumption, overexpression of Panx1 in HeLa cells increased intracellular Ca2+ concentrations in response to acute hypoxia. Conclusion: In this study I identifiy Panx1 as novel regulator of HPV.. Yet, the role of Panx1 was not attributable to the release of ATP and downstream P2 signaling pathways or activation of TRPV4 but rathter relates to a role of Panx1 as indirect or direct modulator of the Ca2+ response to hypoxia in PASMCs. Genetic deletion of Panx1 did not influence the development of chronic hypoxic pulmonary hypertension in mice.
A new evidence-based diet score to capture associations of food consumption and chronic disease risk
(2022)
Previously, the attempt to compile German dietary guidelines into a diet score was predominantly not successful with regards to preventing chronic diseases in the EPIC-Potsdam study. Current guidelines were supplemented by the latest evidence from systematic reviews and expert papers published between 2010 and 2020 on the prevention potential of food groups on chronic diseases such as type 2 diabetes, cardiovascular diseases and cancer. A diet score was developed by scoring the food groups according to a recommended low, moderate or high intake. The relative validity and reliability of the diet score, assessed by a food frequency questionnaire, was investigated. The consideration of current evidence resulted in 10 key food groups being preventive of the chronic diseases of interest. They served as components in the diet score and were scored from 0 to 1 point, depending on their recommended intake, resulting in a maximum of 10 points. Both the reliability (r = 0.53) and relative validity (r = 0.43) were deemed sufficient to consider the diet score as a stable construct in future investigations. This new diet score can be a promising tool to investigate dietary intake in etiological research by concentrating on 10 key dietary determinants with evidence-based prevention potential for chronic diseases.
The trace elements zinc and manganese are essential for human health, especially due to their enzymatic and protein stabilizing functions. If these elements are ingested in amounts exceeding the requirements, regulatory processes for maintaining their physiological concentrations (homeostasis) can be disturbed. Those homeostatic dysregulations can cause severe health effects including the emergence of neurodegenerative disorders such as Parkinson’s disease (PD). The concentrations of essential trace elements also change during the aging process. However, the relations of cause and consequence between increased manganese and zinc uptake and its influence on the aging process and the emergence of the aging-associated PD are still rarely understood. This doctoral thesis therefore aimed to investigate the influence of a nutritive zinc and/or manganese oversupply on the metal homeostasis during the aging process. For that, the model organism Caenorhabditis elegans (C. elegans) was applied. This nematode suits well as an aging and PD model due to properties such as its short life cycle and its completely sequenced, genetically amenable genome. Different protocols for the propagation of zinc- and/or manganese-supplemented young, middle-aged and aged C. elegans were established. Therefore, wildtypes, as well as genetically modified worm strains modeling inheritable forms of parkinsonism were applied. To identify homeostatic and neurological alterations, the nematodes were investigated with different methods including the analysis of total metal contents via inductively-coupled plasma tandem mass spectrometry, a specific probe-based method for quantifying labile zinc, survival assays, gene expression analysis as well as fluorescence microscopy for the identification and quantification of dopaminergic neurodegeneration.. During aging, the levels of iron, as well as zinc and manganese increased.. Furthermore, the simultaneous oversupply with zinc and manganese increased the total zinc and manganese contents to a higher extend than the single metal supplementation. In this relation the C. elegans metallothionein 1 (MTL-1) was identified as an important regulator of metal homeostasis. The total zinc content and the concentration of labile zinc were age-dependently, but differently regulated. This elucidates the importance of distinguishing these parameters as two independent biomarkers for the zinc status. Not the metal oversupply, but aging increased the levels of dopaminergic neurodegeneration. Additionally, nearly all these results yielded differences in the aging-dependent regulation of trace element homeostasis between wildtypes and PD models. This confirms that an increased zinc and manganese intake can influence the aging process as well as parkinsonism by altering homeostasis although the underlying mechanisms need to be clarified in further studies.
By using mouse outcross populations in combination with bioinformatic approaches, it was possible to identify and characterize novel genes regulating body weight, fat mass and β-cell function, which all contribute to the pathogenesis of obesity and T2D. In detail, the presented studies identified 1. Ifi202b/IFI16 as adipogenic gene involved in adipocyte commitment, maintenance of white adipocyte identity, fat cell size and the inflammatory state of adipose tissue. 2. Pla2g4a/PLA2G4A as gene linked to increased body weight and fat mass with a higher expression in adipose tissue of obese mice and pigs as well as in obese human subjects. 3. Ifgga2/IRGM as novel regulator of lipophagy protecting from excess hepatic lipid accumulation. 4. Nidd/DBA as a diabetogenic locus containing Kti12, Osbpl9, Ttc39a and Calr4 with differential expression in pancreatic islets and/or genetic variants. 5. miR-31 to be higher expressed in adipose tissue of obese and diabetic mice and humans targeting PPARy and GLUT4 and thereby involved in adipogenesis and insulin signaling. 6. Gjb4 as novel gene triggering the development of T2D by reducing insulin secretion, inducing apoptosis and inhibiting proliferation. The performed studies confirmed the complexity and strong genetic heritability character of obesity and T2D. A high number of genetic variations, each with a small effect, are collectively influencing the degree and severity of the disease. The use of mouse outcross populations is a valid tool for disease gene identification; however, to facilitate and accelerate the process of gene identification the combination of mouse cross data with advanced sequencing resources and the publicly available data sets are essential. The main goal for future studies should be the translation of these novel molecular discoveries to useful treatment therapies. More recently, several classes of novel unimolecular combination therapeutics have emerged with superior efficacy than currently prescribed options and pose the potential to reverse obesity and T2D (Finan et al., 2015). The glucagon-like peptide-1 (GLP-1)- estrogen conjugate, which targets estrogen into cells expressing GLP-1 receptors, was shown to improve energy, glucose and lipid metabolism as well as to reduce food reward (Finan et al., 2012; Schwenk et al., 2014; Vogel et al., 2016). Another possibility is the development of miRNA-based therapeutics to prevent obesity and T2D, such as miRNA mimetics, anti-miRNA oligonucleotides and exosomes loaded with miRNAs (Ji and Guo, 2019; Gottmann et al., 2020). As already described, genome-wide association studies for polygenic obesity and T2D traits in humans have also led to the identification of numerous gene variants with modest effect, most of them having an unknown function (Yazdi et al., 2015). These discoveries resulted in novel animal models and have illuminated new biologic pathways. Therefore, the integration of mouse-human genetic approaches and the utilization of the synergistic effects have the potential to lead to the identification of more genes responsible for common Mendelian forms of obesity and T2D, as well as gene × gene and gene × environment interactions (Yazdi et al., 2015; Ingelsson and McCarthy, 2018). This combination may help to unravel the missing heritability of obesity and T2D, to identify novel drug targets and to design more efficient and personalized obesity prevention and management programs.
The objective of this work was to investigate the potential effect of cereal α-amylase/trypsin inhibitors (ATIs) on growth parameters and selective digestive enzymes of Tenebrio molitor L. larvae. The approach consisted of feeding the larvae with wheat, sorghum and rice meals containing different levels and composition of α-amylase/trypsin inhibitors. The developmental and biochemical characteristics of the larvae were assessed over feeding periods of 5 h, 5 days and 10 days, and the relative abundance of α-amylase and selected proteases in larvae were determined using liquid chromatography tandem mass spectrometry. Overall, weight gains ranged from 21% to 42% after five days of feeding. The larval death rate significantly increased in all groups after 10 days of feeding (p < 0.05), whereas the pupation rate was about 25% among larvae fed with rice (Oryza sativa L.) and Siyazan/Esperya wheat meals, and only 8% and 14% among those fed with Damougari and S35 sorghum meals. As determined using the Lowry method, the protein contents of the sodium phosphate extracts ranged from 7.80 ± 0.09 to 9.42 ± 0.19 mg/mL and those of the ammonium bicarbonate/urea reached 19.78 ± 0.16 to 37.47 ± 1.38 mg/mL. The total protein contents of the larvae according to the Kjeldahl method ranged from 44.0 and 49.9 g/100 g. The relative abundance of α-amylase, CLIP domain-containing serine protease, modular serine protease zymogen and C1 family cathepsin significantly decreased in the larvae, whereas dipeptidylpeptidase I and chymotrypsin increased within the first hours after feeding (p < 0.05). Trypsin content was found to be constant independently of time or feed material. Finally, based on the results we obtained, it was difficult to substantively draw conclusions on the likely effects of meal ATI composition on larval developmental characteristics, but their effects on the digestive enzyme expression remain relevant.
The detection and quantification of nut allergens remains a major challenge. The liquid chroma-tography tandem mass spectrometry (LC-MS/MS) is emerging as one of the most widely used methods, but sample preparation prior to the analysis is still a key issue. The objective of this work was to establish optimized protocols for extraction, tryptic digestion and LC-MS analysis of almond, cashew, hazelnut, peanut, pistachio and walnut samples. Ammonium bicar-bonate/urea extraction (Ambi/urea), SDS buffer extraction (SDS), polyvinylpolypyrroli-done (PVPP) extraction, trichloroacetic acid/acetone extraction (TCA/acetone) and chloro-form/methanol/sodium chloride precipitation (CM/NaCl) as well as the performances of con-ventional tryptic digestion and microwave-assisted breakdown were investigated. Overall, the protein extraction yields ranged from 14.9 ± 0.5 (almond extract from CM/NaCl) to 76.5 ± 1.3% (hazelnut extract from Ambi/urea). Electrophoretic profiling showed that the SDS extraction method clearly presented a high amount of extracted proteins in the range of 0–15 kDa, 15–35 kDa, 35–70 kDa and 70–250 kDa compared to the other methods. The linearity of the LC-MS methods in the range of 0 to 0.4 µg equivalent defatted nut flour was assessed and recovery of internal standards GWGG and DPLNV(d8)LKPR ranged from 80 to 120%. The identified bi-omarkers peptides were used to relatively quantifier selected allergenic protein form the inves-tigated nut samples. Considering the overall results, it can be concluded that SDS buffer allows a better protein extraction from almond, peanut and walnut samples while PVPP buffer is more appropriate for cashew, pistachio and hazelnut samples. It was also found that conventional overnight digestion is indicated for cashew, pistachio and hazelnut samples, while microwave assisted tryptic digestion is recommended for almond, hazelnut and peanut extracts.
High-salt (HS) diets have recently been linked to oxidative stress in the brain, a fact that may be a precursor to behavioral changes, such as those involving anxiety-like behavior. However, to the best of our knowledge, no study has evaluated the amygdala redox status after consuming a HS diet in the pre- or postweaning periods. This study aimed to evaluate the amygdala redox status and anxiety-like behaviors in adulthood, after inclusion of HS diet in two periods: preconception, gestation, and lactation (preweaning); and only after weaning (postweaning). Initially, 18 females and 9 male Wistar rats received a standard (n = 9 females and 4 males) or a HS diet (n = 9 females and 5 males) for 120 days. After mating, females continued to receive the aforementioned diets during gestation and lactation. Weaning occurred at 21-day-old Wistar rats and the male offspring were subdivided: control-control (C-C)—offspring of standard diet fed dams who received a standard diet after weaning (n = 9–11), control-HS (C-HS)—offspring of standard diet fed dams who received a HS diet after weaning (n = 9–11), HS-C—offspring of HS diet fed dams who received a standard diet after weaning (n = 9–11), and HS-HS—offspring of HS diet fed dams who received a HS diet after weaning (n = 9–11). At adulthood, the male offspring performed the elevated plus maze and open field tests. At 152-day-old Wistar rats, the offspring were euthanized and the amygdala was removed for redox state analysis. The HS-HS group showed higher locomotion and rearing frequency in the open field test. These results indicate that this group developed hyperactivity. The C-HS group had a higher ratio of entries and time spent in the open arms of the elevated plus maze test in addition to a higher head-dipping frequency. These results suggest less anxiety-like behaviors. In the analysis of the redox state, less activity of antioxidant enzymes and higher levels of the thiobarbituric acid reactive substances (TBARS) in the amygdala were shown in the amygdala of animals that received a high-salt diet regardless of the period (pre- or postweaning). In conclusion, the high-salt diet promoted hyperactivity when administered in the pre- and postweaning periods. In animals that received only in the postweaning period, the addition of salt induced a reduction in anxiety-like behaviors. Also, regardless of the period, salt provided amygdala oxidative stress, which may be linked to the observed behaviors.
Food intake is driven by the need for energy but also by the demand for essential nutrients such as protein. Whereas it was well known how diets high in protein mediate satiety, it remained unclear how diets low in protein induce appetite. Therefore, this thesis aims to contribute to the research area of the detection of restricted dietary protein and adaptive responses.
This thesis provides clear evidence that the liver-derived hormone fibroblast growth factor 21 (FGF21) is an endocrine signal of a dietary protein restriction, with the cellular amino acid sensor general control nonderepressible 2 (GCN2) kinase acting as an upstream regulator of FGF21 during protein restriction. In the brain, FGF21 is mediating the protein-restricted metabolic responses, e.g. increased energy expenditure, food intake, insulin sensitivity, and improved glucose homeostasis. Furthermore, endogenous FGF21 induced by dietary protein or methionine restriction is preventing the onset of type 2 diabetes in the New Zealand Obese mouse.
Overall, FGF21 plays an important role in the detection of protein restriction and macronutrient imbalance in rodents and humans, and mediates both the behavioral and metabolic responses to dietary protein restriction. This makes FGF21 a critical physiological signal of dietary protein restriction, highlighting the important but often overlooked impact of dietary protein on metabolism and eating behavior, independent of dietary energy content.
Fibroblast growth differentiation factor 21 (FGF21) is known as a pivotal regulator of the glucose and lipid metabolism. As such, it is considered beneficial and has even been labelled a longevity hormone. Nevertheless, recent observational studies have shown that FGF21 is increased in higher age with possible negative effects such as loss of lean and bone mass as well as decreased survival. Hepatic FGF21 secretion can be induced by various nutritional stimuli such as starvation, high carbohydrate and fat intake as well as protein deficiency.. So far it is still unclear whether the FGF21 response to different macronutrients is altered in older age. An altered response would potentially contribute to explain the higher FGF21 concentrations found in older age. In this publication-based doctoral dissertation, a cross-sectional study as well as a dietary challenge were conducted to investigate the influence of nutrition on FGF21 concentrations and response in older age. In a cross-sectional study, FGF21 concentrations were assessed in older patients with and without cachexia anorexia syndrome anorexia syndrome compared to an older community-dwelling control group. Cachexia anorexia syndrome is a multifactorial syndrome frequently occurring in old age or in the context of an underlying disease. It is characterized by a severe involuntary weight loss, loss of appetite (anorexia) and reduced food intake, therefore representing a state of severe nutrient deficiency, in some aspects similar to starvation. The highest FGF21 concentrations were found in patients with cachexia anorexia syndrome. Moreover, FGF21 was positively correlated with weight loss and loss of appetite. In addition, cachexia anorexia syndrome itself was associated with FGF21 independent of sex, age and body mass index. As cachectic patients presumably exhibit protein malnutrition and FGF21 has been proposed a marker for protein insufficiency, the higher levels of FGF21 in patients with cachexia anorexia syndrome might be partly explained by insufficient protein intake. In order to investigate the acute response of FGF21 to different nutritional stimuli, a dietary challenge with a parallel group design was conducted. Here, healthy older (65-85 years) and younger (18-35 years) adults were randomized to one of four test meals: a dextrose drink, a high carbohydrate, high fat or high protein meal. Over the course of four hours, postprandial FGF21 concentrations (dynamics) were assessed and the FGF21 response (incremental area under the curve) to each test meal was examined.. In a sub-group of older and younger women, also the adiponectin response was investigated, as adiponectin is a known mediator of FGF21 effects on glucose and lipid metabolism. The dietary meal challenge revealed that dextrose and high carbohydrate intake result in higher FGF21 concentrations after four hours in older adults. This was partly explained by higher postprandial glucose concentrations in the old. For high fat ingestion no age differences were found. For the first time, acute FGF21 response to high protein intake was shown. Here, protein ingestion resulted in lower FGF21 concentrations in younger compared to older adults. Furthermore, sufficient protein intake, according to age-dependent recommendations, of the previous day, was associated with lower FGF21 concentrations in both age groups. The higher FGF21 response to dextrose ingestion resulted in a higher adiponectin response in older women, independent of fat mass, insulin resistance, triglyceride concentrations, inflammation and oxidative stress. Following the high fat meal, adiponectin concentrations declined in older women. Adiponectin response was not affected by meal composition in younger women. In summary, this thesis showed a positive association of FGF21 and cachexia anorexia syndrome with concomitant anorexia in older patients. Regarding the acute FGF21 response, a higher response following dextrose and carbohydrate ingestion was found in older compared with younger subjects. This might be attributed to a higher glucose response in older age. Furthermore, it was shown that the higher FGF21 response after dextrose ingestion possibly contributes to a higher adiponectin response in older women, independent of potential metabolic and inflammatory confounders. Acute protein ingestion resulted in a significant decrease in FGF21 concentrations. Moreover, protein intake of the previous day was inversely associated with fasting FGF21 concentrations. This might explain why FGF21 concentrations are higher in cachexia anorexia syndrome. These results therefore support the role of FGF21 as a sensor of protein restriction.
Over the last few decades, the prevalence of obesity has risen to epidemic proportions worldwide. Consequently, the number of obesity in pregnancy has risen drastically. Gestational overweight and obesity are associated with impaired outcomes for mother and child. Furthermore, studies show that maternal obesity can lead to long-term consequences in the offspring, increasing the risk for obesity and cardiometabolic disease in later life. In addition to genetic mechanisms, mounting evidence demonstrates the induction of epigenetic alterations by maternal obesity, which can affect the offspring's phenotype, thereby influencing the later risk of obesity and cardiometabolic disease. Clear evidence in this regard comes from various animal models of maternal obesity. Evidence derived from clinical studies remains limited. The current article gives an overview of pathophysiological changes associated with maternal obesity and their consequences on placental structure and function. Furthermore, a short excurse is given on epigenetic mechanisms and emerging data regarding a putative interaction between metabolism and epigenetics. Finally, a summary of important findings of animal and clinical studies investigating maternal obesity-related epigenetic effects is presented also addressing current limitations of clinical studies.
The suitability of a newly developed cell-based functional assay was tested for the detection of the activity of a range of neurotoxins and neuroactive pharmaceuticals which act by stimulation or inhibition of calcium-dependent neurotransmitter release. In this functional assay, a reporter enzyme is released concomitantly with the neurotransmitter from neurosecretory vesicles. The current study showed that the release of a luciferase from a differentiated human neuroblastoma-based reporter cell line (SIMA-hPOMC1-26-GLuc cells) can be stimulated by a carbachol-mediated activation of the Gq-coupled muscarinic-acetylcholine receptor and by the Ca2+-channel forming spider toxin α-latrotoxin. Carbachol-stimulated luciferase release was completely inhibited by the muscarinic acetylcholine receptor antagonist atropine and α-latrotoxin-mediated release by the Ca2+-chelator EGTA, demonstrating the specificity of luciferase-release stimulation. SIMA-hPOMC1-26-GLuc cells express mainly L- and N-type and to a lesser extent T-type VGCC on the mRNA and protein level. In accordance with the expression profile a depolarization-stimulated luciferase release by a high K+-buffer was effectively and dose-dependently inhibited by L-type VGCC inhibitors and to a lesser extent by N-type and T-type inhibitors. P/Q- and R-type inhibitors did not affect the K+-stimulated luciferase release. In summary, the newly established cell-based assay may represent a versatile tool to analyze the biological efficiency of a range of neurotoxins and neuroactive pharmaceuticals which mediate their activity by the modulation of calcium-dependent neurotransmitter release.
The mitochondrial chaperone complex HSP60/HSP10 facilitates mitochondrial protein homeostasis by folding more than 300 mitochondrial matrix proteins. It has been shown previously that HSP60 is downregulated in brains of type 2 diabetic (T2D) mice and patients,
causing mitochondrial dysfunction and insulin resistance. As HSP60 is also decreased in peripheral tissues in T2D animals, this thesis investigated the effect of overall reduced HSP60 in the development of obesity and associated co-morbidities.
To this end, both female and male C57Bl/6N control (i.e. without further alterations in their genome, Ctrl) and heterozygous whole-body Hsp60 knock-out (Hsp60+/-) mice, which exhibit a 50 % reduction of HSP60 in all tissues, were fed a normal chow diet (NCD) or a highfat diet (HFD, 60 % calories from fat) for 16 weeks and were subjected to extensive metabolic phenotyping including indirect calorimetry, NMR spectroscopy, insulin, glucose and pyruvate tolerance tests, vena cava insulin injections, as well as histological and molecular analysis.
Interestingly, NCD feeding did not result in any striking phenotype, only a mild increase in energy expenditure in Hsp60+/- mice. Exposing mice to a HFD however revealed an increased body weight due to higher muscle mass in female Hsp60+/- mice, with a simultaneous decrease in energy expenditure. Additionally, these mice displayed decreased fasting glycemia. Opposingly, male Hsp60+/- compared to control mice showed lower body weight gain due to decreased fat mass and an increased energy expenditure, strikingly independent of lean mass. Further, only male Hsp60+/- mice display improved HOMA-IR and Matsuda
insulin sensitivity indices.
Despite the opposite phenotype in regards to body weight development, Hsp60+/- mice of both sexes show a significantly higher cell number, as well as a reduction in adipocyte size in the subcutaneous and gonadal white adipose tissue (sc/gWAT). Curiously, this adipocyte hyperplasia – usually associated with positive aspects of WAT function – is disconnected from metabolic improvements, as the gWAT of male Hsp60+/- mice shows mitochondrial dysfunction, oxidative stress, and insulin resistance. Transcriptomic analysis of gWAT shows an up
regulation of genes involved in macroautophagy. Confirmatory, expression of microtubuleassociated protein 1A/1B light chain 3B (LC3), as a protein marker of autophagy, and direct measurement of lysosomal activity is increased in the gWAT of male Hsp60+/- mice.
In summary, this thesis revealed a novel gene-nutrient interaction. The reduction of the crucial chaperone HSP60 did not have large effects in mice fed a NCD, but impacted metabolism during DIO in a sex-specific manner, where, despite opposing body weight and
body composition phenotypes, both female and male Hsp60+/- mice show signs of protection from high fat diet-induced systemic insulin resistance.
Botulinum neurotoxin (BoNT) is produced by the anaerobic bacterium Clostridium botulinum. It is one of the most potent toxins found in nature and can enter motor neurons (MN) to cleave proteins necessary for neurotransmission, resulting in flaccid paralysis. The toxin has applications in both traditional and esthetic medicine. Since BoNT activity varies between batches despite identical protein concentrations, the activity of each lot must be assessed. The gold standard method is the mouse lethality assay, in which mice are injected with a BoNT dilution series to determine the dose at which half of the animals suffer death from peripheral asphyxia. Ethical concerns surrounding the use of animals in toxicity testing necessitate the creation of alternative model systems to measure the potency of BoNT.
Prerequisites of a successful model are that it is human specific; it monitors the complete toxic pathway of BoNT; and it is highly sensitive, at least in the range of the mouse lethality assay. One model system was developed by our group, in which human SIMA neuroblastoma cells were genetically modified to express a reporter protein (GLuc), which is packaged into neurosecretory vesicles, and which, upon cellular depolarization, can be released – or inhibited by BoNT – simultaneously with neurotransmitters. This assay has great potential, but includes the inherent disadvantages that the GLuc sequence was randomly inserted into the genome and the tumor cells only have limited sensitivity and specificity to BoNT. This project aims to improve these deficits, whereby induced pluripotent stem cells (iPSCs) were genetically modified by the CRISPR/Cas9 method to insert the GLuc sequence into the AAVS1 genomic safe harbor locus, precluding genetic disruption through non-specific integrations. Furthermore, GLuc was modified to associate with signal peptides that direct to the lumen of both large dense core vesicles (LDCV), which transport neuropeptides, and synaptic vesicles (SV), which package neurotransmitters. Finally, the modified iPSCs were differentiated into motor neurons (MNs), the true physiological target of BoNT, and hypothetically the most sensitive and specific cells available for the MoN-Light BoNT assay.
iPSCs were transfected to incorporate one of three constructs to direct GLuc into LDCVs, one construct to direct GLuc into SVs, and one “no tag” GLuc control construct. The LDCV constructs fused GLuc with the signal peptides for proopiomelanocortin (hPOMC-GLuc), chromogranin-A (CgA-GLuc), and secretogranin II (SgII-GLuc), which are all proteins found in the LDCV lumen. The SV construct comprises a VAMP2-GLuc fusion sequence, exploiting the SV membrane-associated protein synaptobrevin (VAMP2). The no tag GLuc expresses GLuc non-specifically throughout the cell and was created to compare the localization of vesicle-directed GLuc.
The clones were characterized to ensure that the GLuc sequence was only incorporated into the AAVS1 safe harbor locus and that the signal peptides directed GLuc to the correct vesicles. The accurate insertion of GLuc was confirmed by PCR with primers flanking the AAVS1 safe harbor locus, capable of simultaneously amplifying wildtype and modified alleles. The PCR amplicons, along with an insert-specific amplicon from candidate clones were Sanger sequenced to confirm the correct genomic region and sequence of the inserted DNA. Off-target integrations were analyzed with the newly developed dc-qcnPCR method, whereby the insert DNA was quantified by qPCR against autosomal and sex-chromosome encoded genes. While the majority of clones had off-target inserts, at least one on-target clone was identified for each construct.
Finally, immunofluorescence was utilized to localize GLuc in the selected clones. In iPSCs, the vesicle-directed GLuc should travel through the Golgi apparatus along the neurosecretory pathway, while the no tag GLuc should not follow this pathway. Initial analyses excluded the CgA-GLuc and SgII-GLuc clones due to poor quality protein visualization. The colocalization of GLuc with the Golgi was analyzed by confocal microscopy and quantified. GLuc was strongly colocalized with the Golgi in the hPOMC-GLuc clone (r = 0.85±0.09), moderately in the VAMP2-GLuc clone (r = 0.65±0.01), and, as expected, only weakly in the no tag GLuc clone (r = 0.44±0.10). Confocal microscopy of differentiated MNs was used to analyze the colocalization of GLuc with proteins associated with LDCVs and SVs, SgII in the hPOMC-GLuc clone (r = 0.85±0.08) and synaptophysin in the VAMP2-GLuc clone (r = 0.65±0.07). GLuc was also expressed in the same cells as the MN-associated protein, Islet1.
A significant portion of GLuc was found in the correct cell type and compartment. However, in the MoN-Light BoNT assay, the hPOMC-GLuc clone could not be provoked to reliably release GLuc upon cellular depolarization. The depolarization protocol for hPOMC-GLuc must be further optimized to produce reliable and specific release of GLuc upon exposure to a stimulus. On the other hand, the VAMP2-GLuc clone could be provoked to release GLuc upon exposure to the muscarinic and nicotinic agonist carbachol. Furthermore, upon simultaneous exposure to the calcium chelator EGTA, the carbachol-provoked release of GLuc could be significantly repressed, indicating the detection of GLuc was likely associated with vesicular fusion at the presynaptic terminal. The application of the VAMP2-GLuc clone in the MoN-Light BoNT assay must still be verified, but the results thus far indicate that this clone could be appropriate for the application of BoNT toxicity assessment.
The suitability of a newly developed cell-based functional assay was tested for the detection of the activity of a range of neurotoxins and neuroactive pharmaceuticals which act by stimulation or inhibition of calcium-dependent neurotransmitter release. In this functional assay, a reporter enzyme is released concomitantly with the neurotransmitter from neurosecretory vesicles. The current study showed that the release of a luciferase from a differentiated human neuroblastoma-based reporter cell line (SIMA-hPOMC1-26-GLuc cells) can be stimulated by a carbachol-mediated activation of the Gq-coupled muscarinic-acetylcholine receptor and by the Ca2+-channel forming spider toxin α-latrotoxin. Carbachol-stimulated luciferase release was completely inhibited by the muscarinic acetylcholine receptor antagonist atropine and α-latrotoxin-mediated release by the Ca2+-chelator EGTA, demonstrating the specificity of luciferase-release stimulation. SIMA-hPOMC1-26-GLuc cells express mainly L- and N-type and to a lesser extent T-type VGCC on the mRNA and protein level. In accordance with the expression profile a depolarization-stimulated luciferase release by a high K+-buffer was effectively and dose-dependently inhibited by L-type VGCC inhibitors and to a lesser extent by N-type and T-type inhibitors. P/Q- and R-type inhibitors did not affect the K+-stimulated luciferase release. In summary, the newly established cell-based assay may represent a versatile tool to analyze the biological efficiency of a range of neurotoxins and neuroactive pharmaceuticals which mediate their activity by the modulation of calcium-dependent neurotransmitter release.
The development of type 2 diabetes (T2D) is driven by genetic as well as life style factors. However, even genetically identical female NZO mice on a high-fat diet show a broad variation in T2D onset. The main objective of this study was to elucidate and investigate early epigenetic determinants of type 2 diabetes. Prior to other experiments, early fat content of the liver (<55.2 HU) in combination with blood glucose concentrations (>8.8 mM) were evaluated as best predictors of diabetes in NZO females. Then, DNA methylome and transcriptome were profiled to identify molecular pathophysiological changes in the liver before diabetes onset. The major finding of this thesis is that alterations in the hepatic DNA methylome precede diabetes onset. Of particular interest were 702 differentially methylated regions (DMRs), of which 506 DMRs had genic localization. These inter-individual DMRs were enriched by fivefold in the KEGG pathway type 2 diabetes mellitus, independent of the level of gene expression, demonstrating an epigenetic predisposition toward diabetes. Interestingly, among the list of hepatic DMRs, eleven DMRs were associated with known imprinted genes in the mouse genome. Thereby, six DMRs (Nap1l5, Mest, Plagl1, Gnas, Grb10 and Slc38a4) localized to imprinting control regions, including five iDMRs that exhibited hypermethylation in livers of diabetes-prone mice. This suggests that gain of DNA methylation in multiple loci of the paternal alleles has unfavourable metabolic consequences for the offspring. Further, the comparative liver transcriptome analysis demonstrated differences in expression levels of 1492 genes related to metabolically relevant pathways, such as citrate cycle and fatty acid metabolism. The integration of hepatic transcriptome and DNA methylome indicated that 449 differentially expressed genes were potentially regulated by DNA methylation, including genes implicated in insulin signaling. In addition, liver transcriptomic profiling of diabetes-resistant and diabetes-prone mice revealed a potential transcriptional dysregulation of 17 hepatokines, in particular Hamp. The hepatic expression of Hamp was decreased by 52% in diabetes-prone mice, on account of an increase in DNA methylation of promoter CpG-118. Hence, HAMP protein levels were lower in mice prone to develop diabetes, which correlated to higher liver triglyceride levels.. In sum, the identified DNA methylation changes appear to collectively favor the initiation and progression of diabetes in female NZO mice. In near future, epigenetic biomarkers are likely to contribute to improved diagnosis for T2D.
A fast high performance liquid chromatography tandem mass spectrometry multi-method based on an ACN-precipitation extraction was developed for the analysis of 41 (modified) mycotoxins in beer. Validation according to the performance criteria defined by the European Commission (EC) in Commission Decision no. 657/2002 revealed good linearity (R2 > 0.99), repeatability (RSDr < 15%), reproducibility (RSDR < 15%), and recovery (79–100%). Limits of quantification ranging from 0.04 to 75 µg/L were obtained. Matrix effects varied from −67 to +319% and were compensated for using standard addition. In total, 87 beer samples, produced worldwide, were analyzed for the presence of mycotoxins with a focus on modified mycotoxins, whereof 76% of the samples were contaminated with at least one mycotoxin. The most prevalent mycotoxins were deoxynivalenol-3-glucoside (63%), HT-2 toxin (15%), and tenuazonic acid (13%). Exposure estimates of deoxynivalenol and its metabolites for German beer revealed no significant contribution to intake of deoxynivalenol.
High-salt (HS) diets have recently been linked to oxidative stress in the brain, a fact that may be a precursor to behavioral changes, such as those involving anxiety-like behavior. However, to the best of our knowledge, no study has evaluated the amygdala redox status after consuming a HS diet in the pre- or postweaning periods. This study aimed to evaluate the amygdala redox status and anxiety-like behaviors in adulthood, after inclusion of HS diet in two periods: preconception, gestation, and lactation (preweaning); and only after weaning (postweaning). Initially, 18 females and 9 male Wistar rats received a standard (n = 9 females and 4 males) or a HS diet (n = 9 females and 5 males) for 120 days. After mating, females continued to receive the aforementioned diets during gestation and lactation. Weaning occurred at 21-day-old Wistar rats and the male offspring were subdivided: control-control (C-C)—offspring of standard diet fed dams who received a standard diet after weaning (n = 9–11), control-HS (C-HS)—offspring of standard diet fed dams who received a HS diet after weaning (n = 9–11), HS-C—offspring of HS diet fed dams who received a standard diet after weaning (n = 9–11), and HS-HS—offspring of HS diet fed dams who received a HS diet after weaning (n = 9–11). At adulthood, the male offspring performed the elevated plus maze and open field tests. At 152-day-old Wistar rats, the offspring were euthanized and the amygdala was removed for redox state analysis. The HS-HS group showed higher locomotion and rearing frequency in the open field test. These results indicate that this group developed hyperactivity. The C-HS group had a higher ratio of entries and time spent in the open arms of the elevated plus maze test in addition to a higher head-dipping frequency. These results suggest less anxiety-like behaviors. In the analysis of the redox state, less activity of antioxidant enzymes and higher levels of the thiobarbituric acid reactive substances (TBARS) in the amygdala were shown in the amygdala of animals that received a high-salt diet regardless of the period (pre- or postweaning). In conclusion, the high-salt diet promoted hyperactivity when administered in the pre- and postweaning periods. In animals that received only in the postweaning period, the addition of salt induced a reduction in anxiety-like behaviors. Also, regardless of the period, salt provided amygdala oxidative stress, which may be linked to the observed behaviors.
Insulinresistenz ist ein zentraler Bestandteil des metabolischen Syndroms und trägt maßgeblich zur Ausbildung eines Typ-2-Diabetes bei. Eine mögliche Ursache für die Entstehung von Insulinresistenz ist eine chronische unterschwellige Entzündung, welche ihren Ursprung im Fettgewebe übergewichtiger Personen hat. Eingewanderte Makrophagen produzieren vermehrt pro-inflammatorische Mediatoren, wie Zytokine und Prostaglandine, wodurch die Konzentrationen dieser Substanzen sowohl lokal als auch systemisch erhöht sind. Darüber hinaus weisen übergewichtige Personen einen gestörten Fettsäuremetabolismus und eine erhöhte Darmpermeabilität auf. Ein gesteigerter Flux an freien Fettsäuren vom Fettgewebe in andere Organe führt zu einer lokalen Konzentrationssteigerung in diesen Organen. Eine erhöhte Darmpermeabilität erleichtert das Eindringen von Pathogenen und anderer körperfremder Substanzen in den Körper.
Ziel dieser Arbeit war es, zu untersuchen, ob hohe Konzentrationen von Insulin, des bakteriellen Bestandteils Lipopolysaccharid (LPS) oder der freien Fettsäure Palmitat eine Entzündungsreaktion in Makrophagen auslösen oder verstärken können und ob diese Entzündungsantwort zur Ausbildung einer Insulinresistenz beitragen kann. Weiterhin sollte untersucht werden, ob Metabolite und Signalsubstanzen, deren Konzentrationen beim metabolischen Syndrom erhöht sind, die Produktion des Prostaglandins (PG) E2 begünstigen können und ob dieses wiederum die Entzündungsreaktion und seine eigene Produktion in Makrophagen regulieren kann. Um den Einfluss dieser Faktoren auf die Produktion pro-inflammatorischer Mediatoren in Makrophagen zu untersuchen, wurden Monozyten-artigen Zelllinien und primäre humane Monozyten, welche aus dem Blut gesunder Probanden isoliert wurden, in Makrophagen differenziert und mit Insulin, LPS, Palmitat und/ oder PGE2 inkubiert. Überdies wurden primäre Hepatozyten der Ratte isoliert und mit Überständen Insulin-stimulierter Makrophagen inkubiert, um zu untersuchen, ob die Entzündungsanwort in Makrophagen an der Ausbildung einer Insulinresistenz in Hepatozyten beteiligt ist.
Insulin induzierte die Expression pro-inflammatorischer Zytokine in Makrophagen-artigen Zelllinien wahrscheinlich vorrangig über den Phosphoinositid-3-Kinase (PI3K)-Akt-Signalweg mit anschließender Aktiverung des Transkriptionsfaktors NF-κB (nuclear factor 'kappa-light-chain-enhancer' of activated B-cells). Die dabei ausgeschütteten Zytokine hemmten in primären Hepatozyten der Ratte die Insulin-induzierte Expression der Glukokinase durch Überstände Insulin-stimulierter Makrophagen.
Auch LPS oder Palmitat, deren lokale Konzentrationen im Zuge des metabolischen Syndroms erhöht sind, waren in der Lage, die Expression pro-inflammatorischer Zytokine in Makrophagen-artigen Zelllinien zu stimulieren. Während LPS seine Wirkung, laut Literatur, unbestritten über eine Aktivierung des Toll-ähnlichen Rezeptors (toll-like receptor; TLR) 4 vermittelt, scheint Palmitat jedoch weitestgehend TLR4-unabhängig wirken zu können. Vielmehr schien die de novo-Ceramidsynthese eine entscheidene Rolle zu spielen. Darüber hinaus verstärkte Insulin sowohl die LPS- als auch die Palmitat-induzierte Ent-zündungsantwort in beiden Zelllinien. Die in Zelllinien gewonnenen Ergebnisse wurden größtenteils in primären humanen Makrophagen bestätigt.
Desweiteren induzierten sowohl Insulin als auch LPS oder Palmitat die Produktion von PGE2 in den untersuchten Makrophagen. Die Daten legen nahe, dass dies auf eine gesteigerte Expression PGE2-synthetisierender Enzyme zurückzuführen ist.
PGE2 wiederum hemmte auf der einen Seite die Stimulus-abhängige Expression des pro-inflammatorischen Zytokins Tumornekrosefaktor (TNF) α in U937-Makrophagen. Auf der anderen Seite verstärkte es jedoch die Expression der pro-inflammatorischen Zytokine Interleukin- (IL-) 1β und IL-8. Darüber hinaus verstärkte es die Expression von IL-6-Typ-Zytokinen, welche sowohl pro- als auch anti-inflammatorisch wirken können. Außerdem vestärkte PGE2 die Expression PGE2-synthetisierender Enzyme. Es scheint daher in der Lage zu sein, seine eigene Synthese zu verstärken.
Zusammenfassend kann die Freisetzung pro-inflammatorischer Mediatoren aus Makro-phagen im Zuge einer Hyperinsulinämie die Entstehung einer Insulinresistenz begünstigen. Insulin ist daher in der Lage, einen Teufelskreis der immer stärker werdenden Insulin-resistenz in Gang zu setzen.
Auch Metabolite und Signalsubstanzen, deren Konzentrationen beim metabolischen Syndrom erhöht sind (zum Beispiel LPS, freie Fettsäuren und PGE2), lösten Entzündungsantworten in Makrophagen aus. Das wechselseitige Zusammenspiel von Insulin und diesen Metaboliten und Signalsubstanzen löste eine stärkere Entzündungsantwort in Makrophagen aus als jeder der Einzelkomponenten. Die dadurch freigesetzten Zytokine könnten zur Manifestation einer Insulinresistenz und des metabolischen Syndroms beitragen.
The objective of this work was to investigate the potential effect of cereal α-amylase/trypsin inhibitors (ATIs) on growth parameters and selective digestive enzymes of Tenebrio molitor L. larvae. The approach consisted of feeding the larvae with wheat, sorghum and rice meals containing different levels and composition of α-amylase/trypsin inhibitors. The developmental and biochemical characteristics of the larvae were assessed over feeding periods of 5 h, 5 days and 10 days, and the relative abundance of α-amylase and selected proteases in larvae were determined using liquid chromatography tandem mass spectrometry. Overall, weight gains ranged from 21% to 42% after five days of feeding. The larval death rate significantly increased in all groups after 10 days of feeding (p < 0.05), whereas the pupation rate was about 25% among larvae fed with rice (Oryza sativa L.) and Siyazan/Esperya wheat meals, and only 8% and 14% among those fed with Damougari and S35 sorghum meals. As determined using the Lowry method, the protein contents of the sodium phosphate extracts ranged from 7.80 ± 0.09 to 9.42 ± 0.19 mg/mL and those of the ammonium bicarbonate/urea reached 19.78 ± 0.16 to 37.47 ± 1.38 mg/mL. The total protein contents of the larvae according to the Kjeldahl method ranged from 44.0 and 49.9 g/100 g. The relative abundance of α-amylase, CLIP domain-containing serine protease, modular serine protease zymogen and C1 family cathepsin significantly decreased in the larvae, whereas dipeptidylpeptidase I and chymotrypsin increased within the first hours after feeding (p < 0.05). Trypsin content was found to be constant independently of time or feed material. Finally, based on the results we obtained, it was difficult to substantively draw conclusions on the likely effects of meal ATI composition on larval developmental characteristics, but their effects on the digestive enzyme expression remain relevant.
The detection and quantification of nut allergens remains a major challenge. The liquid chroma-tography tandem mass spectrometry (LC-MS/MS) is emerging as one of the most widely used methods, but sample preparation prior to the analysis is still a key issue. The objective of this work was to establish optimized protocols for extraction, tryptic digestion and LC-MS analysis of almond, cashew, hazelnut, peanut, pistachio and walnut samples. Ammonium bicar-bonate/urea extraction (Ambi/urea), SDS buffer extraction (SDS), polyvinylpolypyrroli-done (PVPP) extraction, trichloroacetic acid/acetone extraction (TCA/acetone) and chloro-form/methanol/sodium chloride precipitation (CM/NaCl) as well as the performances of con-ventional tryptic digestion and microwave-assisted breakdown were investigated. Overall, the protein extraction yields ranged from 14.9 ± 0.5 (almond extract from CM/NaCl) to 76.5 ± 1.3% (hazelnut extract from Ambi/urea). Electrophoretic profiling showed that the SDS extraction method clearly presented a high amount of extracted proteins in the range of 0–15 kDa, 15–35 kDa, 35–70 kDa and 70–250 kDa compared to the other methods. The linearity of the LC-MS methods in the range of 0 to 0.4 µg equivalent defatted nut flour was assessed and recovery of internal standards GWGG and DPLNV(d8)LKPR ranged from 80 to 120%. The identified bi-omarkers peptides were used to relatively quantifier selected allergenic protein form the inves-tigated nut samples. Considering the overall results, it can be concluded that SDS buffer allows a better protein extraction from almond, peanut and walnut samples while PVPP buffer is more appropriate for cashew, pistachio and hazelnut samples. It was also found that conventional overnight digestion is indicated for cashew, pistachio and hazelnut samples, while microwave assisted tryptic digestion is recommended for almond, hazelnut and peanut extracts.
Macrophages in pathologically expanded dysfunctional white adipose tissue are exposed to a mix of potential modulators of inflammatory response, including fatty acids released from insulin-resistant adipocytes, increased levels of insulin produced to compensate insulin resistance, and prostaglandin E₂ (PGE₂) released from activated macrophages. The current study addressed the question of how palmitate might interact with insulin or PGE₂ to induce the formation of the chemotactic pro-inflammatory cytokine interleukin-8 (IL-8). Human THP-1 cells were differentiated into macrophages. In these macrophages, palmitate induced IL-8 formation. Insulin enhanced the induction of IL-8 formation by palmitate as well as the palmitate-dependent stimulation of PGE₂ synthesis. PGE₂ in turn elicited IL-8 formation on its own and enhanced the induction of IL-8 release by palmitate, most likely by activating the EP4 receptor. Since IL-8 causes insulin resistance and fosters inflammation, the increase in palmitate-induced IL-8 formation that is caused by hyperinsulinemia and locally produced PGE₂ in chronically inflamed adipose tissue might favor disease progression in a vicious feed-forward cycle.
Macrophages in pathologically expanded dysfunctional white adipose tissue are exposed to a mix of potential modulators of inflammatory response, including fatty acids released from insulin-resistant adipocytes, increased levels of insulin produced to compensate insulin resistance, and prostaglandin E₂ (PGE₂) released from activated macrophages. The current study addressed the question of how palmitate might interact with insulin or PGE₂ to induce the formation of the chemotactic pro-inflammatory cytokine interleukin-8 (IL-8). Human THP-1 cells were differentiated into macrophages. In these macrophages, palmitate induced IL-8 formation. Insulin enhanced the induction of IL-8 formation by palmitate as well as the palmitate-dependent stimulation of PGE₂ synthesis. PGE₂ in turn elicited IL-8 formation on its own and enhanced the induction of IL-8 release by palmitate, most likely by activating the EP4 receptor. Since IL-8 causes insulin resistance and fosters inflammation, the increase in palmitate-induced IL-8 formation that is caused by hyperinsulinemia and locally produced PGE₂ in chronically inflamed adipose tissue might favor disease progression in a vicious feed-forward cycle.
Objective
Insulin regulates mitochondrial function, thereby propagating an efficient metabolism. Conversely, diabetes and insulin resistance are linked to mitochondrial dysfunction with a decreased expression of the mitochondrial chaperone HSP60. The aim of this investigation was to determine the effect of a reduced HSP60 expression on the development of obesity and insulin resistance.
Methods
Control and heterozygous whole-body HSP60 knockout (Hsp60+/−) mice were fed a high-fat diet (HFD, 60% calories from fat) for 16 weeks and subjected to extensive metabolic phenotyping. To understand the effect of HSP60 on white adipose tissue, microarray analysis of gonadal WAT was performed, ex vivo experiments were performed, and a lentiviral knockdown of HSP60 in 3T3-L1 cells was conducted to gain detailed insights into the effect of reduced HSP60 levels on adipocyte homeostasis.
Results
Male Hsp60+/− mice exhibited lower body weight with lower fat mass. These mice exhibited improved insulin sensitivity compared to control, as assessed by Matsuda Index and HOMA-IR. Accordingly, insulin levels were significantly reduced in Hsp60+/− mice in a glucose tolerance test. However, Hsp60+/− mice exhibited an altered adipose tissue metabolism with elevated insulin-independent glucose uptake, adipocyte hyperplasia in the presence of mitochondrial dysfunction, altered autophagy, and local insulin resistance.
Conclusions
We discovered that the reduction of HSP60 in mice predominantly affects adipose tissue homeostasis, leading to beneficial alterations in body weight, body composition, and adipocyte morphology, albeit exhibiting local insulin resistance.
Mycotoxins and pesticides regularly co-occur in agricultural products worldwide. Thus, humans can be exposed to both toxic contaminants and pesticides simultaneously, and multi-methods assessing the occurrence of various food contaminants and residues in a single method are necessary. A two-dimensional high performance liquid chromatography tandem mass spectrometry method for the analysis of 40 (modified) mycotoxins, two plant growth regulators, two tropane alkaloids, and 334 pesticides in cereals was developed. After an acetonitrile/water/formic acid (79:20:1, v/v/v) multi-analyte extraction procedure, extracts were injected into the two-dimensional setup, and an online clean-up was performed. The method was validated according to Commission Decision (EC) no. 657/2002 and document N° SANTE/12682/2019. Good linearity (R2 > 0.96), recovery data between 70-120%, repeatability and reproducibility values < 20%, and expanded measurement uncertainties < 50% were obtained for a wide range of analytes, including very polar substances like deoxynivalenol-3-glucoside and methamidophos. However, results for fumonisins, zearalenone-14,16-disulfate, acid-labile pesticides, and carbamates were unsatisfying. Limits of quantification meeting maximum (residue) limits were achieved for most analytes. Matrix effects varied highly (−85 to +1574%) and were mainly observed for analytes eluting in the first dimension and early-eluting analytes in the second dimension. The application of the method demonstrated the co-occurrence of different types of cereals with 28 toxins and pesticides. Overall, 86% of the samples showed positive findings with at least one mycotoxin, plant growth regulator, or pesticide.
Adipose tissue is central to the regulation of energy balance. While white adipose tissue (WAT) is responsible for triglyceride storage, brown adipose tissue specializes in energy expenditure. Deterioration of brown adipocyte function contributes to the development of metabolic complications like obesity and diabetes. These disorders are also leading symptoms of the Bardet-Biedl syndrome (BBS), a hereditary disorder in humans which is caused by dysfunctions of the primary cilium and which therefore belongs to the group of ciliopathies. The cilium is a hair-like organelle involved in cellular signal transduction. The BBSome, a supercomplex of several Bbs gene products, localizes to the basal body of cilia and is thought to be involved in protein sorting to and from the ciliary membrane. The effects of a functional BBSome on energy metabolism and lipid mobilization in brown and white adipocytes were tested in whole-body Bbs4 knockout mice that were subjected to metabolic challenges. Chronic cold exposure reveals cold-intolerance of knockout mice but also ameliorates the markers of metabolic pathology detected in knockouts prior to cold. Hepatic triglyceride content is markedly reduced in knockout mice while circulating lipids are elevated, altogether suggesting that defective lipid metabolism in adipose tissue creates increased demand for systemic lipid mobilization to meet energetic demands of reduced body temperatures. These findings taken together suggest that Bbs4 is essential for the regulation of adipose tissue lipid metabolism, representing a potential target to treat metabolic disorders.
Arsenic can occur in foods as inorganic and organic forms. Inorganic arsenic is more toxic than most watersoluble organic arsenic compounds such as arsenobetaine, which is presumed to be harmless for humans. Within the first German total diet study, total arsenic, inorganic arsenic, arsenobetaine, dimethylarsinic acid and monomethylarsonic acid were analyzed in various foods. Highest levels of total arsenic were found in fish, fish products and seafood (mean: 1.43 mg kg(-1); n = 39; min-max: 0.01-6.15 mg kg(-1)), with arsenobetaine confirmed as the predominant arsenic species (1.233 mg kg 1; n = 39; min-max: 0.01-6.23 mg kg (1)). In contrast, inorganic arsenic was determined as prevalent arsenic species in terrestrial foods (0.02 mg kg (1); n = 38; min-max: 0-0.11 mg kg (1)). However, the toxicity of arsenic species varies and measurements are necessary to gain information about the composition and changes of arsenic species in foods due to household processing of foods.
Background: Being an essential trace element, copper is involved in diverse physiological processes. However, excess levels might lead to adverse effects. Disrupted copper homeostasis, particularly in the brain, has been associated with human diseases including the neurodegenerative disorders Wilson and Alzheimer?s disease. In this context, astrocytes play an important role in the regulation of the copper homeostasis in the brain and likely in the prevention against neuronal toxicity, consequently pointing them out as a potential target for the neurotoxicity of copper. Major toxic mechanisms are discussed to be directed against mitochondria probably via oxidative stress. However, the toxic potential and mode of action of copper in astrocytes is poorly understood, so far. Methods: In this study, excess copper levels affecting human astrocytic cell model and their involvement in the neurotoxic mode of action of copper, as well as, effects on the homeostasis of other trace elements (Mn, Fe, Ca and Mg) were investigated. Results: Copper induced substantial cytotoxic effects in the human astrocytic cell line following 48 h incubation (EC30: 250 ?M) and affected mitochondrial function, as observed via reduction of mitochondrial membrane potential and increased ROS production, likely originating from mitochondria. Moreover, cellular GSH metabolism was altered as well. Interestingly, not only cellular copper levels were affected, but also the homeostasis of other elements (Ca, Fe and Mn) were disrupted. Conclusion: One potential toxic mode of action of copper seems to be effects on the mitochondria along with induction of oxidative stress in the human astrocytic cell model. Moreover, excess copper levels seem to interact with the homeostasis of other essential elements such as Ca, Fe and Mn. Disrupted element homeostasis might also contribute to the induction of oxidative stress, likely involved in the onset and progression of neurodegenerative disorders. These insights in the toxic mechanisms will help to develop ideas and approaches for therapeutic strategies against copper-mediated diseases.
Role of dietary sulfonates in the stimulation of gut bacteria promoting intestinal inflammation
(2021)
The interplay between intestinal microbiota and host has increasingly been recognized as a major factor impacting health. Studies indicate that diet is the most influential determinant affecting the gut microbiota. A diet rich in saturated fat was shown to stimulate the growth of the colitogenic bacterium Bilophila wadsworthia by enhancing the secretion of the bile acid taurocholate (TC). The sulfonated taurine moiety of TC is utilized as a substrate by B. wadsworthia. The resulting overgrowth of B. wadsworthia was accompanied by an increased incidence and severity of colitis in interleukin (IL)-10-deficient mice, which are genetically prone to develop inflammation.
Based on these findings, the question arose whether the intake of dietary sulfonates also stimulates the growth of B. wadsworthia and thereby promotes intestinal inflammation in genetically susceptible mice. Dietary sources of sulfonates include green vegetables and cyanobacteria, which contain the sulfolipids sulfoquinovosyl diacylglycerols (SQDG) in considerable amounts. Based on literature reports, the gut commensal Escherichia coli is able to release sulfoquinovose (SQ) from SQDG and in further steps, convert SQ to 2,3-dihydroxypropane-1-sulfonate (DHPS) and dihydroxyacetone phosphate. DHPS may then be utilized as a growth substrate by B. wadsworthia, which results in the formation of sulfide. Both, sulfide formation and a high abundance of B. wadsworthia have been associated with intestinal inflammation.
In the present study, conventional IL-10-deficient mice were fed either a diet supplemented with the SQDG-rich cyanobacterium Spirulina (20%, SD) or a control diet. In addition SQ, TC, or water were orally applied to conventional or gnotobiotic IL-10-deficient mice. The gnotobiotic mice harbored a simplified human intestinal microbiota (SIHUMI) either with or without B. wadsworthia. During the intervention period, the body weight of the mice was monitored, the colon permeability was assessed and fecal samples were collected. After the three-week intervention, the animals were examined with regard to inflammatory parameters, microbiota composition and sulfonate concentrations in different intestinal sites.
None of the mice treated with the above-mentioned sulfonates showed weight loss or intestinal inflammation. Solely mice fed SD or gavaged with TC displayed a slight immune response. These mice also displayed an altered microbiota composition, which was not observed in mice gavaged with SQ. The abundance of B. wadsworthia was strongly reduced in mice fed SD, while that of mice treated with SQ or TC was in part slightly increased. The intestinal SQ-concentration was elevated in mice orally treated with SD or SQ, whereas neither TC nor taurine concentrations were consistently elevated in mice gavaged with TC. Additional colonization of SIHUMI mice with B. wadsworthia resulted in a mild inflammatory response, but only in mice treated with TC. In general, TC-mediated effects on the immune system and abundance of B. wadsworthia were not as strong as described in the literature.
In summary, neither the tested dietary sulfonates nor TC led to bacteria-induced intestinal inflammation in the IL-10-deficient mouse model, which was consistently observed in both conventional and gnotobiotic mice. For humans, this means that foods containing SQDG, such as spinach or Spirulina, do not increase the risk of intestinal inflammation.
The interplay between diet, intestinal microbiota and host is a major factor impacting health. A diet rich in unsaturated fatty acids has been reported to stimulate the growth of Bilophila wadsworthia by increasing the proportion of the sulfonated bile acid taurocholate (TC). The taurine-induced overgrowth of B. wadsworthia promoted the development of colitis in interleukin-10-deficient (IL-10(-/-)) mice. This study aimed to investigate whether intake of the sulfonates sulfoquinovosyl diacylglycerols (SQDG) with a dietary supplement or their degradation product sulfoquinovose (SQ), stimulate the growth of B. wadsworthia in a similar manner and, thereby, cause intestinal inflammation. Conventional IL-10(-/-) mice were fed a diet supplemented with the SQDG-rich cyanobacterium Arthrospira platensis (Spirulina). SQ or TC were orally applied to conventional IL-10(-/-) mice and gnotobiotic IL-10(-/-) mice harboring a simplified human intestinal microbiota with or without B. wadsworthia. Analyses of inflammatory parameters revealed that none of the sulfonates induced severe colitis, but both, Spirulina and TC, induced expression of pro-inflammatory cytokines in cecal mucosa. Cell numbers of B. wadsworthia decreased almost two orders of magnitude by Spirulina feeding but slightly increased in gnotobiotic SQ and conventional TC mice. Changes in microbiota composition were observed in feces as a result of Spirulina or TC feeding in conventional mice. In conclusion, the dietary sulfonates SQDG and their metabolite SQ did not elicit bacteria-induced intestinal inflammation in IL-10(-/-) mice and, thus, do not promote colitis.
Inhibition of acid sphingomyelinase (ASM), a lysosomal enzyme that catalyzes the hydrolysis of sphingomyelin into ceramide and phosphorylcholine, may serve as an investigational tool or a therapeutic intervention to control many diseases. Specific ASM inhibitors are currently not sufficiently characterized. Here, we found that 1-aminodecylidene bis-phosphonic acid (ARC39) specifically and efficiently (>90%) inhibits both lysosomal and secretory ASM in vitro. Results from investigating sphingomyelin phosphodiesterase 1 (SMPD1/Smpd1) mRNA and ASM protein levels suggested that ARC39 directly inhibits ASM's catalytic activity in cultured cells, a mechanism that differs from that of functional inhibitors of ASM. We further provide evidence that ARC39 dose- and time-dependently inhibits lysosomal ASM in intact cells, and we show that ARC39 also reduces platelet- and ASM-promoted adhesion of tumor cells. The observed toxicity of ARC39 is low at concentrations relevant for ASM inhibition in vitro, and it does not strongly alter the lysosomal compartment or induce phospholipidosis in vitro. When applied intraperitoneally in vivo, even subtoxic high doses administered short-term induced sphingomyelin accumulation only locally in the peritoneal lavage without significant accumulation in plasma, liver, spleen, or brain. These findings require further investigation with other possible chemical modifications. In conclusion, our results indicate that ARC39 potently and selectively inhibits ASM in vitro and highlight the need for developing compounds that can reach tissue concentrations sufficient for ASM inhibition in vivo.
Here were report the combination of biocompatible click chemistry of omega-azidosphinganine with fluorescence microscopy and mass spectrometry as a powerful tool to elaborate the sphingolipid metabolism. The azide probe was efficiently synthesized over 13 steps starting from l-serine in an overall yield of 20% and was used for live-cell fluorescence imaging of the endoplasmic reticulum in living cells by bioorthogonal click reaction with a DBCO-labeled fluorophore revealing that the incorporated analogue is mainly localized in the endoplasmic membrane like the endogenous species. A LC-MS(/MS)-based microsomal in vitro assay confirmed that omega-azidosphinganine mimics the natural species enabling the identification and analysis of metabolic breakdown products of sphinganine as a key starting intermediate in the complex sphingolipid biosynthetic pathways. Furthermore, the sphinganine-fluorophore conjugate after click reaction was enzymatically tolerated to form its dihydroceramide and ceramide metabolites. Thus, omega-azidosphinganine represents a useful biofunctional tool for metabolic investigations both by in vivo fluorescence imaging of the sphingolipid subcellular localization in the ER and by in vitro high-resolution mass spectrometry analysis. This should reveal novel insights of the molecular mechanisms sphingolipids and their processing enzymes have e.g. in infection.
Inhibition of acid sphingomyelinase (ASM), a lysosomal enzyme that catalyzes the hydrolysis of sphingomyelin into ceramide and phosphorylcholine, may serve as an investigational tool or a therapeutic intervention to control many diseases. Specific ASM inhibitors are currently not sufficiently characterized. Here, we found that 1-aminodecylidene bis-phosphonic acid (ARC39) specifically and efficiently (>90%) inhibits both lysosomal and secretory ASM in vitro. Results from investigating sphingomyelin phosphodiesterase 1 (SMPD1/Smpd1) mRNA and ASM protein levels suggested that ARC39 directly inhibits ASM's catalytic activity in cultured cells, a mechanism that differs from that of functional inhibitors of ASM. We further provide evidence that ARC39 dose- and time-dependently inhibits lysosomal ASM in intact cells, and we show that ARC39 also reduces platelet- and ASM-promoted adhesion of tumor cells. The observed toxicity of ARC39 is low at concentrations relevant for ASM inhibition in vitro, and it does not strongly alter the lysosomal compartment or induce phospholipidosis in vitro. When applied intraperitoneally in vivo, even subtoxic high doses administered short-term induced sphingomyelin accumulation only locally in the peritoneal lavage without significant accumulation in plasma, liver, spleen, or brain. These findings require further investigation with other possible chemical modifications. In conclusion, our results indicate that ARC39 potently and selectively inhibits ASM in vitro and highlight the need for developing compounds that can reach tissue concentrations sufficient for ASM inhibition in vivo.
Mitochondria are critical for hypothalamic function and regulators of metabolism. Hypothalamic mitochondrial dysfunction with decreased mitochondrial chaperone expression is present in type 2 diabetes (T2D). Recently, we demonstrated that a dysregulated mitochondrial stress response (MSR) with reduced chaperone expression in the hypothalamus is an early event in obesity development due to insufficient insulin signaling. Although insulin activates this response and improves metabolism, the metabolic impact of one of its members, the mitochondrial chaperone heat shock protein 10 (Hsp10), is unknown. Thus, we hypothesized that a reduction of Hsp10 in hypothalamic neurons will impair mitochondrial function and impact brain insulin action. Therefore, we investigated the role of chaperone Hsp10 by introducing a lentiviral-mediated Hsp10 knockdown (KD) in the hypothalamic cell line CLU-183 and in the arcuate nucleus (ARC) of C57BL/6N male mice. We analyzed mitochondrial function and insulin signaling utilizing qPCR, Western blot, XF96 Analyzer, immunohistochemistry, and microscopy techniques. We show that Hsp10 expression is reduced in T2D mice brains and regulated by leptin in vitro. Hsp10 KD in hypothalamic cells induced mitochondrial dysfunction with altered fatty acid metabolism and increased mitochondria-specific oxidative stress resulting in neuronal insulin resistance. Consequently, the reduction of Hsp10 in the ARC of C57BL/6N mice caused hypothalamic insulin resistance with acute liver insulin resistance.