@phdthesis{Baeseler2021, author = {Baeseler, Jessica}, title = {Trace element effects on longevity and neurodegeneration with focus on C. elegans}, school = {Universit{\"a}t Potsdam}, pages = {X,114,VIII}, year = {2021}, abstract = {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.}, language = {en} } @phdthesis{Vogel2021, author = {Vogel, Heike}, title = {Genetics of obesity and type 2 diabetes}, address = {Potsdam}, school = {Universit{\"a}t Potsdam}, pages = {183}, year = {2021}, abstract = {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.}, language = {en} } @article{TchewonpiSaguLandgraeberHenkeletal.2021, author = {Tchewonpi Sagu, Sorel and Landgr{\"a}ber, Eva and Henkel, Ina M. and Huschek, Gerd and Homann, Thomas and Bußler, Sara and Schl{\"u}ter, Oliver K. and Rawel, Harshadrai Manilal}, title = {Effect of cereal α-amylase/trypsin inhibitors on developmental characteristics and abundance of digestive enzymes of mealworm larvae (Tenebrio molitor L.)}, series = {Insects}, volume = {12}, journal = {Insects}, number = {5}, publisher = {MDPI}, address = {Basel}, issn = {2075-4450}, doi = {10.3390/insects12050454}, pages = {16}, year = {2021}, abstract = {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.}, language = {en} } @article{SaguTchewonpiHuschekHomannetal.2021, author = {Sagu Tchewonpi, Sorel and Huschek, Gerd and Homann, Thomas and Rawel, Harshadrai Manilal}, title = {Effect of sample preparation on the detection and quantification of selected nuts allergenic proteins by LC-MS/MS}, series = {Molecules : a journal of synthetic chemistry and natural product chemistry / Molecular Diversity Preservation International}, volume = {26}, journal = {Molecules : a journal of synthetic chemistry and natural product chemistry / Molecular Diversity Preservation International}, number = {15}, publisher = {MDPI}, address = {Basel}, issn = {1420-3049}, doi = {10.3390/molecules26154698}, pages = {21}, year = {2021}, abstract = {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.}, language = {en} } @article{dePinhoTavaresLealdaSilvaRochaGomesetal.2021, author = {de Pinho Tavares Leal, Pedro Ernesto and da Silva, Alexandre Alves and Rocha-Gomes, Arthur and Riul, Tania Regina and Cunha, Rennan Augusto and Reichetzeder, Christoph and Villela, Daniel Campos}, title = {High-Salt Diet in the Pre- and Postweaning Periods Leads to Amygdala Oxidative Stress and Changes in Locomotion and Anxiety-Like Behaviors of Male Wistar Rats}, series = {Frontiers in Behavioral Neuroscience}, volume = {15}, journal = {Frontiers in Behavioral Neuroscience}, publisher = {Frontiers Research Foundation}, address = {Lausanne, Schweiz}, issn = {1662-5153}, doi = {10.3389/fnbeh.2021.779080}, pages = {1 -- 12}, year = {2021}, abstract = {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.}, language = {en} } @phdthesis{Reichmann2021, author = {Reichmann, Robin}, title = {Novel applications of machine learning techniques in epidemiology of age-related diseases}, school = {Universit{\"a}t Potsdam}, pages = {164, xlv}, year = {2021}, language = {en} } @phdthesis{Laeger2021, author = {Laeger, Thomas}, title = {Protein-dependent regulation of feeding, metabolism, and development of type 2 diabetes}, school = {Universit{\"a}t Potsdam}, pages = {224}, year = {2021}, abstract = {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.}, language = {en} } @phdthesis{Herpich2021, author = {Herpich, Catrin}, title = {Fibroblast growth factor 21 and its association with nutritional stimuli in older age}, school = {Universit{\"a}t Potsdam}, pages = {75}, year = {2021}, abstract = {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.}, language = {en} } @article{Reichetzeder2021, author = {Reichetzeder, Christoph}, title = {Overweight and obesity in pregnancy}, series = {European journal of clinical nutrition}, volume = {75}, journal = {European journal of clinical nutrition}, number = {12}, publisher = {Springer Nature}, address = {London}, issn = {0954-3007}, doi = {10.1038/s41430-021-00905-6}, pages = {1710 -- 1722}, year = {2021}, abstract = {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.}, language = {en} } @article{PatheNeuschaeferRubeNeuschaeferRubePueschel2021, author = {Pathe-Neusch{\"a}fer-Rube, Andrea and Neusch{\"a}fer-Rube, Frank and P{\"u}schel, Gerhard Paul}, title = {Cell-based reporter release assay to determine the activity of calcium-dependent neurotoxins and neuroactive pharmaceuticals}, series = {Toxins / Molecular Diversity Preservation International (MDPI)}, volume = {13}, journal = {Toxins / Molecular Diversity Preservation International (MDPI)}, number = {4}, publisher = {MDPI}, address = {Basel}, issn = {2072-6651}, doi = {10.3390/toxins13040247}, pages = {13}, year = {2021}, abstract = {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.}, language = {en} } @phdthesis{Hauffe2021, author = {Hauffe, Robert}, title = {Investigating metabolic consequences of an HSP60 reduction during diet-induced obesity}, doi = {10.25932/publishup-50929}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-509294}, school = {Universit{\"a}t Potsdam}, pages = {xxi, 116}, year = {2021}, abstract = {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.}, language = {en} } @phdthesis{Schjeide2021, author = {Schjeide, Brit-Maren}, title = {Development and characterization of the MoN-Light BoNT assay to determine the toxicity of botulinum neurotoxin in motor neurons differentiated from CRISPR-modified induced pluripotent stem cells}, doi = {10.25932/publishup-51627}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-516278}, school = {Universit{\"a}t Potsdam}, pages = {e, xviii, 265}, year = {2021}, abstract = {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.}, language = {en} } @misc{PatheNeuschaeferRubeNeuschaeferRubePueschel2021, author = {Pathe-Neusch{\"a}fer-Rube, Andrea and Neusch{\"a}fer-Rube, Frank and P{\"u}schel, Gerhard Paul}, title = {Cell-based reporter release assay to determine the activity of calcium-dependent neurotoxins and neuroactive pharmaceuticals}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {1139}, issn = {1866-8372}, doi = {10.25932/publishup-50322}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-503225}, pages = {15}, year = {2021}, abstract = {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.}, language = {en} } @phdthesis{Saussenthaler2021, author = {Saussenthaler, Sophie}, title = {The impact of DNA methylation on susceptibility to typ 2 diabetes in NZO mice}, school = {Universit{\"a}t Potsdam}, pages = {XIX, 150}, year = {2021}, abstract = {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.}, language = {en} } @article{RauschBrockmeyerSchwerdtle2021, author = {Rausch, Ann-Kristin and Brockmeyer, Robert and Schwerdtle, Tanja}, title = {Development and validation of a liquid chromatography tandem mass spectrometry multi-method for the determination of 41 free and modified mycotoxins in beer}, series = {Food chemistry}, volume = {338}, journal = {Food chemistry}, publisher = {Elsevier}, address = {New York, NY}, issn = {1873-7072}, doi = {10.1016/j.foodchem.2020.127801}, year = {2021}, abstract = {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.}, language = {en} } @misc{dePinhoTavaresLealdaSilvaRochaGomesetal.2021, author = {de Pinho Tavares Leal, Pedro Ernesto and da Silva, Alexandre Alves and Rocha-Gomes, Arthur and Riul, Tania Regina and Cunha, Rennan Augusto and Reichetzeder, Christoph and Villela, Daniel Campos}, title = {High-Salt Diet in the Pre- and Postweaning Periods Leads to Amygdala Oxidative Stress and Changes in Locomotion and Anxiety-Like Behaviors of Male Wistar Rats}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1866-8372}, doi = {10.25932/publishup-55743}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-557432}, pages = {1 -- 12}, year = {2021}, abstract = {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.}, language = {en} } @misc{TchewonpiSaguLandgraeberHenkeletal.2021, author = {Tchewonpi Sagu, Sorel and Landgr{\"a}ber, Eva and Henkel, Ina M. and Huschek, Gerd and Homann, Thomas and Bußler, Sara and Schl{\"u}ter, Oliver K. and Rawel, Harshadrai Manilal}, title = {Effect of cereal α-amylase/trypsin inhibitors on developmental characteristics and abundance of digestive enzymes of mealworm larvae (Tenebrio molitor L.)}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {5}, issn = {1866-8372}, doi = {10.25932/publishup-52092}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-520924}, pages = {18}, year = {2021}, abstract = {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.}, language = {en} } @misc{TchewonpiSaguHuschekHomannetal.2021, author = {Tchewonpi Sagu, Sorel and Huschek, Gerd and Homann, Thomas and Rawel, Harshadrai Manilal}, title = {Effect of sample preparation on the detection and quantification of selected nuts allergenic proteins by LC-MS/MS}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {15}, issn = {1866-8372}, doi = {10.25932/publishup-52187}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-521871}, pages = {16}, year = {2021}, abstract = {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.}, language = {en} } @misc{HenkelOberlaenderKlauderStatzetal.2021, author = {Henkel-Oberl{\"a}nder, Janin and Klauder, Julia and Statz, Meike and Wohlenberg, Anne-Sophie and Kuipers, Sonja and Vahrenbrink, Madita}, title = {Enhanced Palmitate-Induced Interleukin-8 Formation in Human Macrophages by Insulin or Prostaglandin E₂}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {1149}, issn = {1866-8372}, doi = {10.25932/publishup-51837}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-518377}, pages = {12}, year = {2021}, abstract = {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.}, language = {en} } @article{HenkelOberlaenderKlauderStatzetal.2021, author = {Henkel-Oberl{\"a}nder, Janin and Klauder, Julia and Statz, Meike and Wohlenberg, Anne-Sophie and Kuipers, Sonja and Vahrenbrink, Madita and P{\"u}schel, Gerhard}, title = {Enhanced Palmitate-Induced Interleukin-8 Formation in Human Macrophages by Insulin or Prostaglandin E₂}, series = {Biomedicines : open access journal}, volume = {9}, journal = {Biomedicines : open access journal}, number = {5}, publisher = {MDPI}, address = {Basel}, issn = {2227-9059}, doi = {10.3390/biomedicines9050449}, pages = {10}, year = {2021}, abstract = {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.}, language = {en} } @article{HauffeRathSchelletal.2021, author = {Hauffe, Robert and Rath, Michaela and Schell, Mareike and Ritter, Katrin and Kappert, Kai and Deubel, Stefanie and Ott, Christiane and J{\"a}hnert, Markus and Jonas, Wenke and Sch{\"u}rmann, Annette and Kleinridders, Andr{\´e}}, title = {HSP60 reduction protects against diet-induced obesity by modulating energy metabolism in adipose tissue}, series = {Molecular Metabolism}, volume = {53}, journal = {Molecular Metabolism}, publisher = {Elsevier}, address = {Amsterdam, Niederlande}, issn = {2212-8778}, doi = {10.1016/j.molmet.2021.101276}, pages = {1 -- 14}, year = {2021}, abstract = {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.}, language = {en} } @article{RauschBrockmeyerSchwerdtle2021, author = {Rausch, Ann-Kristin and Brockmeyer, Robert and Schwerdtle, Tanja}, title = {Development, validation, and application of a multi-method for the determination of mycotoxins, plant growth regulators, tropane alkaloids, and pesticides in cereals by two-dimensional liquid chromatography tandem mass spectrometry}, series = {Analytical \& bioanalytical chemistry : a merger of Fresenius' journal of analytical chemistry, Analusis and Quimica analitica}, volume = {413}, journal = {Analytical \& bioanalytical chemistry : a merger of Fresenius' journal of analytical chemistry, Analusis and Quimica analitica}, number = {11}, publisher = {Springer}, address = {Berlin}, issn = {1618-2650}, doi = {10.1007/s00216-021-03239-1}, pages = {3041 -- 3054}, year = {2021}, abstract = {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.}, language = {en} } @article{GohlkeManciniGarciaCarrizoetal.2021, author = {Gohlke, Sabrina and Mancini, Carola and Garcia-Carrizo, Francisco and Schulz, Tim J.}, title = {Loss of the ciliary gene Bbs4 results in defective thermogenesis due to metabolic inefficiency and impaired lipid metabolism}, series = {The FASEB journal : the official journal of the Federation of American Societies for Experimental Biology}, volume = {35}, journal = {The FASEB journal : the official journal of the Federation of American Societies for Experimental Biology}, number = {11}, publisher = {Wiley}, address = {Hoboken}, issn = {1530-6860}, doi = {10.1096/fj.202100772RR}, pages = {13}, year = {2021}, abstract = {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.}, language = {en} } @article{HackethalKoppSarvanetal.2021, author = {Hackethal, Christin and Kopp, Johannes Florian and Sarvan, Irmela and Schwerdtle, Tanja and Lindtner, Oliver}, title = {Total arsenic and water-soluble arsenic species in foods of the first German total diet study (BfR MEAL Study)}, series = {Food chemistry}, volume = {346}, journal = {Food chemistry}, publisher = {Elsevier}, address = {Amsterdam [u.a.]}, issn = {0308-8146}, doi = {10.1016/j.foodchem.2020.128913}, pages = {10}, year = {2021}, abstract = {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.}, language = {en} } @phdthesis{Wandt2021, author = {Wandt, Viktoria Klara Veronika}, title = {Trace elements, ageing, and sex}, school = {Universit{\"a}t Potsdam}, pages = {iii, 204}, year = {2021}, language = {en} } @article{WittStibollerRaschkeetal.2021, author = {Witt, Barbara and Stiboller, Michael and Raschke, Stefanie and Friese, Sharleen and Ebert, Franziska and Schwerdtle, Tanja}, title = {Characterizing effects of excess copper levels in a human astrocytic cell line with focus on oxidative stress markers}, series = {Journal of trace elements in medicine and biology : organ of the Society for Minerals and Trace Elements, GMS}, volume = {65}, journal = {Journal of trace elements in medicine and biology : organ of the Society for Minerals and Trace Elements, GMS}, publisher = {Elsevier}, address = {M{\"u}nchen}, issn = {1878-3252}, doi = {10.1016/j.jtemb.2021.126711}, pages = {9}, year = {2021}, abstract = {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.}, language = {en} } @inproceedings{SchenkeSchjeidePuescheletal.2021, author = {Schenke, Maren and Schjeide, Brit-Maren and P{\"u}schel, Gerhard Paul and Seeger, Bettina}, title = {Serotype-specific sensitivity to Botulinum neurotoxins of iPSC-derived motor neurons}, series = {Naunyn-Schmiedeberg's archives of pharmacology}, volume = {394}, booktitle = {Naunyn-Schmiedeberg's archives of pharmacology}, number = {Suppl. 1}, publisher = {Springer}, address = {Berlin ; Heidelberg}, issn = {0028-1298}, doi = {10.1007/s00210-021-02066-6}, pages = {S4 -- S4}, year = {2021}, language = {en} } @phdthesis{Burkhardt2021, author = {Burkhardt, Wiebke}, title = {Role of dietary sulfonates in the stimulation of gut bacteria promoting intestinal inflammation}, doi = {10.25932/publishup-51368}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-513685}, school = {Universit{\"a}t Potsdam}, pages = {XX, 79, XXXIX}, year = {2021}, abstract = {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.}, language = {en} } @article{BurkhardtRauschKlopfleischetal.2021, author = {Burkhardt, Wiebke and Rausch, Theresa and Klopfleisch, Robert and Blaut, Michael and Braune, Annett}, title = {Impact of dietary sulfolipid-derived sulfoquinovose on gut microbiota composition and inflammatory status of colitis-prone interleukin-10-deficient mice}, series = {International journal of medical microbiology : IJMM}, volume = {311}, journal = {International journal of medical microbiology : IJMM}, number = {3}, publisher = {Elsevier}, address = {M{\"u}nchen}, issn = {1618-0607}, doi = {10.1016/j.ijmm.2021.151494}, pages = {11}, year = {2021}, abstract = {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.}, language = {en} } @misc{NaserKadowSchumacheretal.2021, author = {Naser, Eyad and Kadow, Stephanie and Schumacher, Fabian and Mohamed, Zainelabdeen H. and Kappe, Christian and Hessler, Gabriele and Pollmeier, Barbara and Kleuser, Burkhard and Arenz, Christoph and Becker, Katrin Anne and Gulbins, Erich and Carpinteiro, Alexander}, title = {Characterization of the small molecule ARC39}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {6}, issn = {1866-8372}, doi = {10.25932/publishup-51663}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-516635}, pages = {17}, year = {2021}, abstract = {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.}, language = {en} } @article{FinkSchumacherSchlegeletal.2021, author = {Fink, Julian and Schumacher, Fabian and Schlegel, Jan and Stenzel, Philipp and Wigger, Dominik and Sauer, Markus and Kleuser, Burkhard and Seibel, J{\"u}rgen}, title = {Azidosphinganine enables metabolic labeling and detection of sphingolipid de novo synthesis}, series = {Organic \& biomolecular chemistry : an international journal of synthetic, physical and biomolecular organic chemistry}, volume = {19}, journal = {Organic \& biomolecular chemistry : an international journal of synthetic, physical and biomolecular organic chemistry}, number = {10}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1477-0520}, doi = {10.1039/d0ob02592e}, pages = {2203 -- 2212}, year = {2021}, abstract = {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.}, language = {en} } @article{NaserKadowSchumacheretal.2021, author = {Naser, Eyad and Kadow, Stephanie and Schumacher, Fabian and Mohamed, Zainelabdeen H. and Kappe, Christian and Hessler, Gabriele and Pollmeier, Barbara and Kleuser, Burkhard and Arenz, Christoph and Becker, Katrin Anne and Gulbins, Erich and Carpinteiro, Alexander}, title = {Characterization of the small molecule ARC39}, series = {Journal of Lipid Research}, volume = {61}, journal = {Journal of Lipid Research}, number = {6}, publisher = {American Society for Biochemistry and Molecular Biology}, address = {Bethesda}, issn = {1539-7262}, doi = {10.1194/jlr.RA120000682}, pages = {896 -- 910}, year = {2021}, abstract = {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.}, language = {en} } @misc{WardelmannRathCastroetal.2021, author = {Wardelmann, Kristina and Rath, Michaela and Castro, Jos{\´e} Pedro and Bl{\"u}mel, Sabine and Schell, Mareike and Hauffe, Robert and Schumacher, Fabian and Flore, Tanina and Ritter, Katrin and Wernitz, Andreas and Hosoi, Toru and Ozawa, Koichiro and Kleuser, Burkhard and Weiß, J{\"u}rgen and Sch{\"u}rmann, Annette and Kleinridders, Andr{\´e}}, title = {Central acting Hsp10 regulates mitochondrial function, fatty acid metabolism and insulin sensitivity in the hypothalamus}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {5}, issn = {1866-8372}, doi = {10.25932/publishup-52298}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-522985}, pages = {24}, year = {2021}, abstract = {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.}, language = {en} } @article{WetzelScholtkaSchumacheretal.2021, author = {Wetzel, Alexandra Nicole and Scholtka, Bettina and Schumacher, Fabian and Rawel, Harshadrai Manilal and Geisend{\"o}rfer, Birte and Kleuser, Burkhard}, title = {Epigenetic DNA methylation of EBI3 modulates human interleukin-35 formation via NFkB signaling}, series = {International journal of molecular sciences}, volume = {22}, journal = {International journal of molecular sciences}, number = {10}, publisher = {MDPI}, address = {Basel}, issn = {1422-0067}, doi = {10.3390/ijms22105329}, pages = {21}, year = {2021}, abstract = {Ulcerative colitis (UC), a severe chronic disease with unclear etiology that is associated with increased risk for colorectal cancer, is accompanied by dysregulation of cytokines. Epstein-Barr virus-induced gene 3 (EBI3) encodes a subunit in the unique heterodimeric IL-12 cytokine family of either pro- or anti-inflammatory function. After having recently demonstrated that upregulation of EBI3 by histone acetylation alleviates disease symptoms in a dextran sulfate sodium (DSS)-treated mouse model of chronic colitis, we now aimed to examine a possible further epigenetic regulation of EBI3 by DNA methylation under inflammatory conditions. Treatment with the DNA methyltransferase inhibitor (DNMTi) decitabine (DAC) and TNF alpha led to synergistic upregulation of EBI3 in human colon epithelial cells (HCEC). Use of different signaling pathway inhibitors indicated NF kappa B signaling was necessary and proportional to the synergistic EBI3 induction. MALDI-TOF/MS and HPLC-ESIMS/MS analysis of DAC/TNF alpha-treated HCEC identified IL-12p35 as the most probable binding partner to form a functional protein. EBI3/IL-12p35 heterodimers (IL-35) induce their own gene upregulation, something that was indeed observed in HCEC cultured with media from previously DAC/TNF alpha-treated HCEC. These results suggest that under inflammatory and demethylating conditions the upregulation of EBI3 results in the formation of anti-inflammatory IL-35, which might be considered as a therapeutic target in colitis.}, language = {en} } @article{WardelmannRathCastroetal.2021, author = {Wardelmann, Kristina and Rath, Michaela and Castro, Jos{\´e} Pedro and Bl{\"u}mel, Sabine and Schell, Mareike and Hauffe, Robert and Schumacher, Fabian and Flore, Tanina and Ritter, Katrin and Wernitz, Andreas and Hosoi, Toru and Ozawa, Koichiro and Kleuser, Burkhard and Weiß, J{\"u}rgen and Sch{\"u}rmann, Annette and Kleinridders, Andr{\´e}}, title = {Central acting Hsp10 regulates mitochondrial function, fatty acid metabolism and insulin sensitivity in the hypothalamus}, series = {Antioxidants}, volume = {10}, journal = {Antioxidants}, number = {5}, publisher = {MDPI}, address = {Basel}, issn = {2076-3921}, doi = {10.3390/antiox10050711}, pages = {22}, year = {2021}, abstract = {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.}, language = {en} } @article{SchellWardelmannKleinridders2021, author = {Schell, Mareike and Wardelmann, Kristina and Kleinridders, Andre}, title = {Untangling the effect of insulin action on brain mitochondria and metabolism}, series = {Journal of neuroendocrinology}, volume = {33}, journal = {Journal of neuroendocrinology}, number = {4}, publisher = {Wiley}, address = {Hoboken}, issn = {0953-8194}, doi = {10.1111/jne.12932}, pages = {14}, year = {2021}, abstract = {The regulation of energy homeostasis is controlled by the brain and, besides requiring high amounts of energy, it relies on functional insulin/insulin-like growth factor (IGF)-1 signalling in the central nervous system. This energy is mainly provided by mitochondria in form of ATP. Thus, there is an intricate interplay between mitochondrial function and insulin/IGF-1 action to enable functional brain signalling and, accordingly, propagate a healthy metabolism. To adapt to different nutritional conditions, the brain is able to sense the current energy status via mitochondrial and insulin signalling-dependent pathways and exerts an appropriate metabolic response. However, regional, cell type and receptor-specific consequences of this interaction occur and are linked to diverse outcomes such as altered nutrient sensing, body weight regulation or even cognitive function. Impairments of this cross-talk can lead to obesity and glucose intolerance and are linked to neurodegenerative diseases, yet they also induce a self-sustainable, dysfunctional 'metabolic triangle' characterised by insulin resistance, mitochondrial dysfunction and inflammation in the brain. The identification of causal factors deteriorating insulin action, mitochondrial function and concomitantly a signature of metabolic stress in the brain is of utter importance to offer novel mechanistic insights into development of the continuously rising prevalence of non-communicable diseases such as type 2 diabetes and neurodegeneration. This review aims to determine the effect of insulin action on brain mitochondrial function and energy metabolism. It precisely outlines the interaction and differences between insulin action, insulin-like growth factor (IGF)-1 signalling and mitochondrial function; distinguishes between causality and association; and reveals its consequences for metabolism and cognition. We hypothesise that an improvement of at least one signalling pathway can overcome the vicious cycle of a self-perpetuating metabolic dysfunction in the brain present in metabolic and neurodegenerative diseases.}, language = {en} } @inproceedings{WandtWinkelbeinerLossowetal.2021, author = {Wandt, Viktoria Klara Veronika and Winkelbeiner, Nicola and Loßow, Kristina and Kopp, Johannes and Simon, Luise and Ebert, Franziska and Kipp, Anna Patricia and Schwerdtle, Tanja}, title = {Trace elements, ageing, and sex. Impact on genome stability}, series = {Naunyn-Schmiedeberg's archives of pharmacology}, volume = {394}, booktitle = {Naunyn-Schmiedeberg's archives of pharmacology}, number = {Suppl. 1}, publisher = {Springer}, address = {Berlin ; Heidelberg}, issn = {0028-1298}, doi = {10.1007/s00210-021-02066-6}, pages = {S13 -- S13}, year = {2021}, language = {en} } @article{HerpichHassKochliketal.2021, author = {Herpich, Catrin and Haß, Ulrike and Kochlik, Bastian Max and Franz, Kristina and Laeger, Thomas and Klaus, Susanne and Bosy-Westphal, Anja and Norman, Kristina}, title = {Postprandial dynamics and response of fibroblast growth factor 21 in older adults}, series = {Clinical Nutrition}, volume = {40}, journal = {Clinical Nutrition}, number = {6}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0261-5614}, doi = {10.1016/j.clnu.2021.04.037}, pages = {3765 -- 3771}, year = {2021}, abstract = {Background \& aims: Fibroblast growth factor 21 (FGF21) plays a pivotal role in glucose and lipid metabolism and has been proposed as a longevity hormone. However, elevated plasma FGF21 concentrations are paradoxically associated with mortality in higher age and little is known about the postprandial regulation of FGF21 in older adults. In this parallel group study, we investigated postprandial FGF21 dynamics and response in older (65-85 years) compared to younger (18-35 years) adults following test meals with varying macronutrient composition. Methods: Participants (n = 60 older; n = 60 younger) were randomized to one of four test meals: dextrose, high carbohydrate (HC), high fat (HF) or high protein (HP). Blood was drawn before and 15, 30, 60, 120, 240 min after meal ingestion. Postprandial dynamics were evaluated using repeated measures ANCOVA. FGF21 response was assessed by incremental area under the curve. Results: Fasting FGF21 concentrations were significantly higher in older adults. FGF21 dynamics were affected by test meal (p < 0.001) and age (p = 0.013), when adjusted for BMI and fasting FGF21. Postprandial FGF21 concentrations steadily declined over 240 min in both age groups after HF and HP, but not after dextrose or HC ingestion. At 240 min, FGF21 concentrations were significantly higher in older than in younger adults following dextrose (133 pg/mL, 95\%CI: 103, 172 versus 91.2 pg/mL, 95\%CI: 70.4, 118; p = 0.044), HC (109 pg/mL, 95\%CI: 85.1, 141 versus 70.3 pg/mL, 95\%CI: 55.2, 89.6; p = 0.014) and HP ingestion (45.4 pg/mL, 95\%CI: 34.4, 59.9 versus 27.9 pg/mL 95\%CI: 20.9, 37.1; p = 0.018). FGF21 dynamics and response to HF were similar for both age groups. Conclusions: The age-specific differences in postprandial FGF21 dynamics and response in healthy adults, potentially explain higher FGF21 concentrations in older age. Furthermore, there appears to be a significant impact of acute and recent protein intake on FGF21 secretion.}, language = {en} } @misc{FigueroaCamposPerezBlocketal.2021, author = {Figueroa Campos, Gustavo A. and Perez, Jeffrey Paulo H. and Block, Inga and Tchewonpi Sagu, Sorel and Saravia Celis, Pedro and Taubert, Andreas and Rawel, Harshadrai Manilal}, title = {Preparation of activated carbons from spent coffee and coffee parchment and assessment of their adsorbent efficiency}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {8}, issn = {1866-8372}, doi = {10.25932/publishup-52191}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-521914}, pages = {20}, year = {2021}, abstract = {The valorization of coffee wastes through modification to activated carbon has been considered as a low-cost adsorbent with prospective to compete with commercial carbons. So far, very few studies have referred to the valorization of coffee parchment into activated carbon. Moreover, low-cost and efficient activation methods need to be more investigated. The aim of this work was to prepare activated carbon from spent coffee grounds and parchment, and to assess their adsorption performance. The co-calcination processing with calcium carbonate was used to prepare the activated carbons, and their adsorption capacity for organic acids, phenolic compounds and proteins was evaluated. Both spent coffee grounds and parchment showed yields after the calcination and washing treatments of around 9.0\%. The adsorption of lactic acid was found to be optimal at pH 2. The maximum adsorption capacity of lactic acid with standard commercial granular activated carbon was 73.78 mg/g, while the values of 32.33 and 14.73 mg/g were registered for the parchment and spent coffee grounds activated carbons, respectively. The Langmuir isotherm showed that lactic acid was adsorbed as a monolayer and distributed homogeneously on the surface. Around 50\% of total phenols and protein content from coffee wastewater were adsorbed after treatment with the prepared activated carbons, while 44, 43, and up to 84\% of hydrophobic compounds were removed using parchment, spent coffee grounds and commercial activated carbon, respectively; the adsorption efficiencies of hydrophilic compounds ranged between 13 and 48\%. Finally, these results illustrate the potential valorization of coffee by-products parchment and spent coffee grounds into activated carbon and their use as low-cost adsorbent for the removal of organic compounds from aqueous solutions.}, language = {en} } @article{WiggerSchumacherSchneiderSchauliesetal.2021, author = {Wigger, Dominik and Schumacher, Fabian and Schneider-Schaulies, Sibylle and Kleuser, Burkhard}, title = {Sphingosine 1-phosphate metabolism and insulin signaling}, series = {Cellular signalling}, volume = {82}, journal = {Cellular signalling}, publisher = {Elsevier Science}, address = {Amsterdam [u.a.]}, issn = {0898-6568}, doi = {10.1016/j.cellsig.2021.109959}, pages = {16}, year = {2021}, abstract = {Insulin is the main anabolic hormone secreted by 13-cells of the pancreas stimulating the assimilation and storage of glucose in muscle and fat cells. It modulates the postprandial balance of carbohydrates, lipids and proteins via enhancing lipogenesis, glycogen and protein synthesis and suppressing glucose generation and its release from the liver. Resistance to insulin is a severe metabolic disorder related to a diminished response of peripheral tissues to the insulin action and signaling. This leads to a disturbed glucose homeostasis that precedes the onset of type 2 diabetes (T2D), a disease reaching epidemic proportions. A large number of studies reported an association between elevated circulating fatty acids and the development of insulin resistance. The increased fatty acid lipid flux results in the accumulation of lipid droplets in a variety of tissues. However, lipid intermediates such as diacylglycerols and ceramides are also formed in response to elevated fatty acid levels. These bioactive lipids have been associated with the pathogenesis of insulin resistance. More recently, sphingosine 1-phosphate (S1P), another bioactive sphingolipid derivative, has also been shown to increase in T2D and obesity. Although many studies propose a protective role of S1P metabolism on insulin signaling in peripheral tissues, other studies suggest a causal role of S1P on insulin resistance. In this review, we critically summarize the current state of knowledge of S1P metabolism and its modulating role on insulin resistance. A particular emphasis is placed on S1P and insulin signaling in hepatocytes, skeletal muscle cells, adipocytes and pancreatic 13-cells. In particular, modulation of receptors and enzymes that regulate S1P metabolism can be considered as a new therapeutic option for the treatment of insulin resistance and T2D.}, language = {en} } @article{PanMaLiuetal.2021, author = {Pan, Yuanwei and Ma, Xuehua and Liu, Chuang and Xing, Jie and Zhou, Suqiong and Parshad, Badri and Schwerdtle, Tanja and Li, Wenzhong and Wu, Aiguo and Haag, Rainer}, title = {Retinoic acid-loaded dendritic polyglycerol-conjugated gold nanostars for targeted photothermal therapy in breast cancer stem cells}, series = {ACS nano}, volume = {15}, journal = {ACS nano}, number = {9}, publisher = {American Chemical Society}, address = {Washington}, issn = {1936-0851}, doi = {10.1021/acsnano.1c05452}, pages = {15069 -- 15084}, year = {2021}, abstract = {The existence of cancer stem cells (CSCs) poses a major obstacle for the success of current cancer therapies, especially the fact that non-CSCs can spontaneously turn into CSCs, which lead to the failure of the treatment and tumor relapse. Therefore, it is very important to develop effective strategies for the eradication of the CSCs. In this work, we have developed a CSCs-specific targeted, retinoic acid (RA)-loaded gold nanostars-dendritic polyglycerol (GNSs-dPG) nanoplatform for the efficient eradication of CSCs. The nanocomposites possess good biocompatibility and exhibit effective CSCs-specific multivalent targeted capability due to hyaluronic acid (HA) decorated on the multiple attachment sites of the bioinert dendritic polyglycerol (dPG). With the help of CSCs differentiation induced by RA, the self-renewal of breast CSCs and tumor growth were suppressed by the high therapeutic efficacy of photothermal therapy (PTT) in a synergistic inhibitory manner. Moreover, the stemness gene expression and CSC-driven tumorsphere formation were significantly diminished. In addition, the in vivo tumor growth and CSCs were also effectively eliminated, which indicated superior anticancer activity, effective CSCs suppression, and prevention of relapse. Taken together, we developed a CSCs-specific targeted, RA-loaded GNSs-dPG nanoplatform for the targeted eradication of CSCs and for preventing the relapse.}, language = {en} } @article{KlausIgualGilOst2021, author = {Klaus, Susanne and Igual Gil, Carla and Ost, Mario}, title = {Regulation of diurnal energy balance by mitokines}, series = {Cellular and molecular life sciences : CMLS}, volume = {78}, journal = {Cellular and molecular life sciences : CMLS}, number = {7}, publisher = {Springer International Publishing AG}, address = {Cham (ZG)}, issn = {1420-682X}, doi = {10.1007/s00018-020-03748-9}, pages = {3369 -- 3384}, year = {2021}, abstract = {The mammalian system of energy balance regulation is intrinsically rhythmic with diurnal oscillations of behavioral and metabolic traits according to the 24 h day/night cycle, driven by cellular circadian clocks and synchronized by environmental or internal cues such as metabolites and hormones associated with feeding rhythms. Mitochondria are crucial organelles for cellular energy generation and their biology is largely under the control of the circadian system. Whether mitochondrial status might also feed-back on the circadian system, possibly via mitokines that are induced by mitochondrial stress as endocrine-acting molecules, remains poorly understood. Here, we describe our current understanding of the diurnal regulation of systemic energy balance, with focus on fibroblast growth factor 21 (FGF21) and growth differentiation factor 15 (GDF15), two well-known endocrine-acting metabolic mediators. FGF21 shows a diurnal oscillation and directly affects the output of the brain master clock. Moreover, recent data demonstrated that mitochondrial stress-induced GDF15 promotes a day-time restricted anorexia and systemic metabolic remodeling as shown in UCP1-transgenic mice, where both FGF21 and GDF15 are induced as myomitokines. In this mouse model of slightly uncoupled skeletal muscle mitochondria GDF15 proved responsible for an increased metabolic flexibility and a number of beneficial metabolic adaptations. However, the molecular mechanisms underlying energy balance regulation by mitokines are just starting to emerge, and more data on diurnal patterns in mouse and man are required. This will open new perspectives into the diurnal nature of mitokines and action both in health and disease.}, language = {en} } @phdthesis{Rausch2021, author = {Rausch, Ann-Kristin}, title = {Development of LC-MS/MS Multi-Methods for the Analysis of Contaminants and Residues}, school = {Universit{\"a}t Potsdam}, pages = {IX, 234, v}, year = {2021}, abstract = {Mycotoxins are secondary metabolites produced by several filamentous fungal species, thus occurring ubiquitously in the environment and food. While the heterogeneous group shows differences in their bioavailability and toxicity, the low-molecular-weight xenobiotics are capable of impacting human and animal health acutely and chronically. Therefore, maximum levels for the major mycotoxins in food and feed are regulated in the current European legislation. Besides free mycotoxins, naturally occurring modified mycotoxins are gaining more attention in recent years. Modified mycotoxins constitute toxins altered by plants, microorganisms, and living organisms in different metabolic pathways or food processing steps. The toxicological relevant compounds often co-occur with their free forms in infested food and feed. Thus, the toxins may contribute to the overall toxicity of mycotoxins, wherefore their presence and toxicity should be considered in risk assessment. Until now, however, there are no regulated limits for modified mycotoxins within the European Union. In this thesis, rapid, sensitive, and robust methods for the analysis of mycotoxins and their modified forms were developed and validated using state-of-the-art high performance liquid chromatography tandem mass spectrometry (LC-MS/MS) systems. Firstly, two analytical methods for determining 38 mycotoxins in cereals and 41 mycotoxins in beer were established since agricultural products count as the primary source of mycotoxin contamination. For the analysis of cereal samples, a QuEChERS- based extraction approach was pursued, while analytes from beer samples were extracted using an acetonitrile precipitation scheme. Validation in cereals, namely wheat, corn, rice, and barley, as well as in beer, demonstrated satisfactory results. To obtain information regarding the natural occurrence of mycotoxins in food products, the developed methods were applied to the analysis of several commercial samples partly produced worldwide. The Fusarium toxins deoxynivalenol and its conjugated metabolite deoxynivalenol-3-glucoside turned out to be the most abundant toxins. None of the other modified mycotoxins were quantified in the samples. However, one cereal sample showed traces of zearalenone- 14-sulfate below the limit of quantification. Moreover, pesticides, plant growth regulators, and tropane alkaloids were investigated in this thesis. Pesticides present biologically highly effective compounds applied in the environment to protect humans from the hazardous effects of pests. While plant growth regulators show similar functions, mainly improving agricultural production, tropane alkaloids are naturally occurring secondary metabolites mainly in the species of Solanaceae that may pose unintended poisoning of humans. The third part of the present thesis aimed to analyze cereal-relevant compounds simultaneously, wherefore a multi-method for the analysis of (modified) mycotoxins, pesticides, plant growth regulators, and tropane alkaloids was established. After processing the samples, this should be done in a single extraction step with subsequent one-time measurements. Various sample preparation procedures were compared, whereby an approach based on an acidified acetonitrile/water extraction, followed by an online clean-up, was finally chosen. The simultaneous determination of more than 350 analytes required an analytical tool that offered an increased resolving power, represented as an enhanced peak capacity, and the possibility of analyzing a broad polarity range. Thus, a two-dimensional LC-MS/MS system based on two different separation mechanisms that performed orthogonal to one another was used for the analysis. Validation of the developed method revealed good performance characteristics for most analytes, while subsequent application showed that 86\% of the samples were contaminated with at least one compound. In summary, this thesis provides novel insights into the analysis of food-relevant (modified) mycotoxins. Different sample preparation and LC-MS/MS approaches were introduced, resulting in the development of three new analytical methods. For the first time, such a high number of modified mycotoxins was included in multi-mycotoxin methods and a multi-method ranging both contaminants and residues. Although first steps towards the analysis of modified mycotoxins have been made, further research is needed to elucidate their (co-) occurrence and toxicological behavior in order to understand their relevance to human health in the future.}, language = {en} } @article{SilvaOliveiraCostaTchewonpietal.2021, author = {Silva, Bibiana and Oliveira Costa, Ana Carolina and Tchewonpi, Sorel Sagu and B{\"o}nick, Josephine and Huschek, Gerd and Gonzaga, Luciano Valdemiro and Fett, Roseane and Baldermann, Susanne and Rawel, Harshadrai Manilal}, title = {Comparative quantification and differentiation of bracatinga (Mimosa scabrella Bentham) honeydew honey proteins using targeted peptide markers identified by high-resolution mass spectrometry}, series = {Food research international}, volume = {141}, journal = {Food research international}, publisher = {Elsevier}, address = {New York, NY [u.a.]}, issn = {0963-9969}, doi = {10.1016/j.foodres.2020.109991}, pages = {10}, year = {2021}, abstract = {Honey traceability is an important topic, especially for honeydew honeys, due to the increased incidence of adulteration. This study aimed to establish specific markers to quantify proteins in honey. A proteomics strategy to identify marker peptides from bracatinga honeydew honey was therefore developed. The proteomics approach was based on initial untargeted identification of honey proteins and peptides by LC-ESI-Triple-TOF-MS/MS, which identified the major royal jelly proteins (MRJP) presence. Afterwards, the peptides were selected by the in silico digestion. The marker peptides were quantified by the developed targeted LC-QqQ-MS/MS method, which provided good linearity and specificity, besides recoveries between 92 and 100\% to quantify peptides from bracatinga honeydew honey. The uniqueness and high response in mass spectrometry were backed by further complementary protein analysis (SDS-PAGE). The selected marker peptides EALPHVPIFDR (MRJP 1), ILGANVK (MRJP 2), TFVTIER (MRJP 3), QNIDVVAR (MRJP 4), FINNDYNFNEVNFR (MRJP 5) and LLQPYPDWSWTK (MRJP 7), quantified by LC-QqQ-MS/MS, highlighted that the content of QNIDVVAR from MRJP 4 could be used to differentiate bracatinga honeydew honey from floral honeys (p < 0.05) as a potential marker for its authentication. Finally, principal components analysis highlighted the QNIDVVAR content as a good descriptor of the analyzed bracatinga honeydew honey samples.}, language = {en} } @phdthesis{AgaBarfknecht2021, author = {Aga-Barfknecht, Heja}, title = {Investigation of the phenotype and genetic variant(s) of the diabetes locus Nidd/DBA}, school = {Universit{\"a}t Potsdam}, year = {2021}, abstract = {Diabetes is a major public health problem with increasing global prevalence. Type 2 diabetes (T2D), which accounts for 90\% of all diagnosed cases, is a complex polygenic disease also modulated by epigenetics and lifestyle factors. For the identification of T2D-associated genes, linkage analyses combined with mouse breeding strategies and bioinformatic tools were useful in the past. In a previous study in which a backcross population of the lean and diabetes-prone dilute brown non-agouti (DBA) mouse and the obese and diabetes-susceptible New Zealand obese (NZO) mouse was characterized, a major diabetes quantitative trait locus (QTL) was identified on chromosome 4. The locus was designated non-insulin dependent diabetes from DBA (Nidd/DBA). The aim of this thesis was (i) to perform a detailed phenotypic characterization of the Nidd/DBA mice, (ii) to further narrow the critical region and (iii) to identify the responsible genetic variant(s) of the Nidd/DBA locus. The phenotypic characterization of recombinant congenic mice carrying a 13.6 Mbp Nidd/DBA fragment with 284 genes presented a gradually worsening metabolic phenotype. Nidd/DBA allele carriers exhibited severe hyperglycemia (~19.9 mM) and impaired glucose clearance at 12 weeks of age. Ex vivo perifusion experiments with islets of 13-week-old congenic mice revealed a tendency towards reduced insulin secretion in homozygous DBA mice. In addition, 16-week-old mice showed a severe loss of β-cells and reduced pancreatic insulin content. Pathway analysis of transcriptome data from islets of congenic mice pointed towards a downregulation of cell survival genes. Morphological analysis of pancreatic sections displayed a reduced number of bi-hormonal cells co-expressing glucagon and insulin in homozygous DBA mice, which could indicate a reduced plasticity of endocrine cells in response to hyperglycemic stress. Further generation and phenotyping of recombinant congenic mice enabled the isolation of a 3.3 Mbp fragment that was still able to induce hyperglycemia and contained 61 genes. Bioinformatic analyses including haplotype mapping, sequence and transcriptome analysis were integrated in order to further reduce the number of candidate genes and to identify the presumable causative gene variant. Four putative candidate genes (Ttc39a, Kti12, Osbpl9, Calr4) were defined, which were either differentially expressed or carried a sequence variant. In addition, in silico ChIP-Seq analyses of the 3.3 Mbp region indicated a high number of SNPs located in active regions of binding sites of β-cell transcription factors. This points towards potentially altered cis-regulatory elements that could be responsible for the phenotype conferred by the Nidd/DBA locus. In summary, the Nidd/DBA locus mediates impaired glucose homeostasis and reduced insulin secretion capacity which finally leads to β-cell death. The downregulation of cell survival genes and reduced plasticity of endocrine cells could further contribute to the β-cell loss. The critical region was narrowed down to a 3.3 Mbp fragment containing 61 genes, of which four might be involved in the development of the diabetogenic Nidd/DBA phenotype.}, language = {en} } @misc{PerezCornagoCroweApplebyetal.2021, author = {Perez-Cornago, Aurora and Crowe, Francesca L. and Appleby, Paul N. and Bradbury, Kathryn E. and Wood, Angela M. and Jakobsen, Marianne Uhre and Johnson, Laura and Sacerdote, Carlotta and Steur, Marinka and Weiderpass, Elisabete and Wurtz, Anne Mette L. and Kuhn, Tilman and Katzke, Verena and Trichopoulou, Antonia and Karakatsani, Anna and La Vecchia, Carlo and Masala, Giovanna and Tumino, Rosario and Panico, Salvatore and Sluijs, Ivonne and Skeie, Guri and Imaz, Liher and Petrova, Dafina and Quiros, J. Ramon and Yohar, Sandra Milena Colorado and Jakszyn, Paula and Melander, Olle and Sonestedt, Emily and Andersson, Jonas and Wennberg, Maria and Aune, Dagfinn and Riboli, Elio and Schulze, Matthias Bernd and di Angelantonio, Emanuele and Wareham, Nicholas J. and Danesh, John and Forouhi, Nita G. and Butterworth, Adam S. and Key, Timothy J.}, title = {Plant foods, dietary fibre and risk of ischaemic heart disease in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {1}, issn = {1866-8372}, doi = {10.25932/publishup-56034}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-560340}, pages = {13}, year = {2021}, abstract = {Background: Epidemiological evidence indicates that diets rich in plant foods are associated with a lower risk of ischaemic heart disease (IHD), but there is sparse information on fruit and vegetable subtypes and sources of dietary fibre. This study examined the associations of major plant foods, their subtypes and dietary fibre with risk of IHD in the European Prospective Investigation into Cancer and Nutrition (EPIC). Methods: We conducted a prospective analysis of 490 311 men and women without a history of myocardial infarction or stroke at recruitment (12.6 years of follow-up, n cases = 8504), in 10 European countries. Dietary intake was assessed using validated questionnaires, calibrated with 24-h recalls. Multivariable Cox regressions were used to estimate hazard ratios (HR) of IHD. Results: There was a lower risk of IHD with a higher intake of fruit and vegetables combined [HR per 200 g/day higher intake 0.94, 95\% confidence interval (CI): 0.90-0.99, P-trend = 0.009], and with total fruits (per 100 g/day 0.97, 0.95-1.00, P-trend = 0.021). There was no evidence for a reduced risk for fruit subtypes, except for bananas. Risk was lower with higher intakes of nuts and seeds (per 10 g/day 0.90, 0.82-0.98, Ptrend = 0.020), total fibre (per 10 g/day 0.91, 0.85-0.98, P-trend = 0.015), fruit and vegetable fibre (per 4 g/day 0.95, 0.91-0.99, P-trend = 0.022) and fruit fibre (per 2 g/day 0.97, 0.95-1.00, P-trend = 0.045). No associations were observed between vegetables, vegetables subtypes, legumes, cereals and IHD risk. Conclusions: In this large prospective study, we found some small inverse associations between plant foods and IHD risk, with fruit and vegetables combined being the most strongly inversely associated with risk. Whether these small associations are causal remains unclear.}, language = {en} } @article{WeitkunatBishopWittmuessetal.2021, author = {Weitkunat, Karolin and Bishop, Christopher Allen and Wittm{\"u}ss, Maria and Machate, Tina and Schifelbein, Tina and Schulze, Matthias Bernd and Klaus, Susanne}, title = {Effect of microbial status on hepatic odd-chain fatty acids is diet-dependent}, series = {Nutrients / Molecular Diversity Preservation International (MDPI)}, volume = {13}, journal = {Nutrients / Molecular Diversity Preservation International (MDPI)}, number = {5}, publisher = {MDPI}, address = {Basel}, issn = {2072-6643}, doi = {10.3390/nu13051546}, pages = {15}, year = {2021}, abstract = {Odd-chain fatty acids (OCFA) are inversely associated with type-2-diabetes in epidemiological studies. They are considered as a biomarker for dairy intake because fermentation in ruminants yields high amounts of propionate, which is used as the primer for lipogenesis. Recently, we demonstrated endogenous OCFA synthesis from propionate in humans and mice, but how this is affected by microbial colonization is still unexplored. Here, we investigated the effect of increasing microbiota complexity on hepatic lipid metabolism and OCFA levels in different dietary settings. Germ-free (GF), gnotobiotic (SIH, simplified human microbiota) or conventional (CONV) C3H/HeOuJ-mice were fed a CHOW or high-fat diet with inulin (HFI) to induce microbial fermentation. We found that hepatic lipogenesis was increased with increasing microbiota complexity, independently of diet. In contrast, OCFA formation was affected by diet as well as microbiota. On CHOW, hepatic OCFA and intestinal gluconeogenesis decreased with increasing microbiota complexity (GF > SIH > CONV), while cecal propionate showed a negative correlation with hepatic OCFA. On HFI, OCFA levels were highest in SIH and positively correlated with cecal propionate. The propionate content in the CHOW diet was 10 times higher than that of HFI. We conclude that bacterial propionate production affects hepatic OCFA formation, unless this effect is masked by dietary propionate intake.}, language = {en} } @article{PerezCornagoCroweApplebyetal.2021, author = {Perez-Cornago, Aurora and Crowe, Francesca L. and Appleby, Paul N. and Bradbury, Kathryn E. and Wood, Angela M. and Jakobsen, Marianne Uhre and Johnson, Laura and Sacerdote, Carlotta and Steur, Marinka and Weiderpass, Elisabete and Wurtz, Anne Mette L. and Kuhn, Tilman and Katzke, Verena and Trichopoulou, Antonia and Karakatsani, Anna and La Vecchia, Carlo and Masala, Giovanna and Tumino, Rosario and Panico, Salvatore and Sluijs, Ivonne and Skeie, Guri and Imaz, Liher and Petrova, Dafina and Quiros, J. Ramon and Yohar, Sandra Milena Colorado and Jakszyn, Paula and Melander, Olle and Sonestedt, Emily and Andersson, Jonas and Wennberg, Maria and Aune, Dagfinn and Riboli, Elio and Schulze, Matthias Bernd and di Angelantonio, Emanuele and Wareham, Nicholas J. and Danesh, John and Forouhi, Nita G. and Butterworth, Adam S. and Key, Timothy J.}, title = {Plant foods, dietary fibre and risk of ischaemic heart disease in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort}, series = {International journal of epidemiology}, volume = {50}, journal = {International journal of epidemiology}, number = {1}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0300-5771}, doi = {10.1093/ije/dyaa155}, pages = {212 -- 222}, year = {2021}, abstract = {Background: Epidemiological evidence indicates that diets rich in plant foods are associated with a lower risk of ischaemic heart disease (IHD), but there is sparse information on fruit and vegetable subtypes and sources of dietary fibre. This study examined the associations of major plant foods, their subtypes and dietary fibre with risk of IHD in the European Prospective Investigation into Cancer and Nutrition (EPIC). Methods: We conducted a prospective analysis of 490 311 men and women without a history of myocardial infarction or stroke at recruitment (12.6 years of follow-up, n cases = 8504), in 10 European countries. Dietary intake was assessed using validated questionnaires, calibrated with 24-h recalls. Multivariable Cox regressions were used to estimate hazard ratios (HR) of IHD. Results: There was a lower risk of IHD with a higher intake of fruit and vegetables combined [HR per 200 g/day higher intake 0.94, 95\% confidence interval (CI): 0.90-0.99, P-trend = 0.009], and with total fruits (per 100 g/day 0.97, 0.95-1.00, P-trend = 0.021). There was no evidence for a reduced risk for fruit subtypes, except for bananas. Risk was lower with higher intakes of nuts and seeds (per 10 g/day 0.90, 0.82-0.98, Ptrend = 0.020), total fibre (per 10 g/day 0.91, 0.85-0.98, P-trend = 0.015), fruit and vegetable fibre (per 4 g/day 0.95, 0.91-0.99, P-trend = 0.022) and fruit fibre (per 2 g/day 0.97, 0.95-1.00, P-trend = 0.045). No associations were observed between vegetables, vegetables subtypes, legumes, cereals and IHD risk. Conclusions: In this large prospective study, we found some small inverse associations between plant foods and IHD risk, with fruit and vegetables combined being the most strongly inversely associated with risk. Whether these small associations are causal remains unclear.}, language = {en} } @article{JannaschNickelSchulze2021, author = {Jannasch, Franziska and Nickel, Daniela and Schulze, Matthias Bernd}, title = {The reliability and relative validity of predefined dietary patterns were higher than that of exploratory dietary patterns in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam population}, series = {British journal of nutrition : BJN : an international journal of nutritional science / published on behalf of The Nutrition Society}, volume = {125}, journal = {British journal of nutrition : BJN : an international journal of nutritional science / published on behalf of The Nutrition Society}, number = {11}, publisher = {Cambridge University Press}, address = {Cambridge}, issn = {1475-2662}, doi = {10.1017/S0007114520003517}, pages = {1270 -- 1280}, year = {2021}, abstract = {The aim of this study was to assess the ability of the FFQ to describe reliable and valid dietary pattern (DP) scores. In a total of 134 participants of the European Prospective Investigation into Cancer and Nutrition-Potsdam study aged 35-67 years, the FFQ was applied twice (baseline and after 1 year) to assess its reliability. Between November 1995 and March 1997, twelve 24-h dietary recalls (24HDR) as reference instrument were applied to assess the validity of the FFQ. Exploratory DP were derived by principal component analyses. Investigated predefined DP were the Alternative Healthy Eating Index (AHEI) and two Mediterranean diet indices. From dietary data of each FFQ, two exploratory DP were retained, but differed in highly loading food groups, resulting in moderate correlations (r 0 center dot 45-0 center dot 58). The predefined indices showed higher correlations between the FFQ (r(AHEI) 0 center dot 62, r(Mediterranean Diet Pyramid Index (MedPyr)) 0 center dot 62 and r(traditional Mediterranean Diet Score (tMDS)) 0 center dot 51). From 24HDR dietary data, one exploratory DP retained differed in composition to the first FFQ-based DP, but showed similarities to the second DP, reflected by a good correlation (r 0 center dot 70). The predefined DP correlated moderately (r 0 center dot 40-0 center dot 60). To conclude, long-term analyses on exploratory DP should be interpreted with caution, due to only moderate reliability. The validity differed extensively for the two exploratory DP. The investigated predefined DP showed a better reliability and a moderate validity, comparable to other studies. Within the two Mediterranean diet indices, the MedPyr performed better than the tMDs in this middle-aged, semi-urban German study population.}, language = {en} } @phdthesis{Mancini2021, author = {Mancini, Carola}, title = {Analysis of the effects of age-related changes of metabolic flux on brown adipocyte formation and function}, doi = {10.25932/publishup-51266}, school = {Universit{\"a}t Potsdam}, pages = {xvii, 134}, year = {2021}, abstract = {Brown adipose tissue (BAT) is responsible for non-shivering thermogenesis, thereby allowing mammals to maintain a constant body temperature in a cold environment. Thermogenic capacity of this tissue is due to a high mitochondrial density and expression of uncoupling protein 1 (UCP1), a unique brown adipocyte marker which dissipates the mitochondrial proton gradient to produce heat instead of ATP. BAT is actively involved in whole-body metabolic homeostasis and during aging there is a loss of classical brown adipose tissue with concomitantly reduced browning capacity of white adipose tissue. Therefore, an age-dependent decrease of BAT-related energy expenditure capacity may exacerbate the development of metabolic diseases, including obesity and type 2 diabetes mellitus. Given that direct effects of age-related changes of BAT-metabolic flux have yet to be unraveled, the aim of the current thesis is to investigate potential metabolic mechanisms involved in BAT-dysfunction during aging and to identify suitable metabolic candidates as functional biomarkers of BAT-aging. To this aim, integration of transcriptomic, metabolomic and proteomic data analyses of BAT from young and aged mice was performed, and a group of candidates with age-related changes was revealed. Metabolomic analysis showed age-dependent alterations of metabolic intermediates involved in energy, nucleotide and vitamin metabolism, with major alterations regarding the purine nucleotide pool. These data suggest a potential role of nucleotide intermediates in age-related BAT defects. In addition, the screening of transcriptomic and proteomic data sets from BAT of young and aged mice allowed identification of a 60-kDa lysophospholipase, also known as L-asparaginase (Aspg), whose expression declines during BAT-aging. Involvement of Aspg in brown adipocyte thermogenic function was subsequently analyzed at the molecular level using in vitro approaches and animal models. The findings revealed sensitivity of Aspg expression to β3-adrenergic activation via different metabolic cues, including cold exposure and treatment with β3-adrenergic agonist CL. To further examine ASPG function in BAT, an over-expression model of Aspg in a brown adipocyte cell line was established and showed that these cells were metabolically more active compared to controls, revealing increased expression of the main brown-adipocyte specific marker UCP1, as well as higher lipolysis rates. An in vitro loss-of-function model of Aspg was also functionally analyzed, revealing reduced brown adipogenic characteristics and an impaired lipolysis, thus confirming physiological relevance of Aspg in brown adipocyte function. Characterization of a transgenic mouse model with whole-body inactivation of the Aspg gene (Aspg-KO) allowed investigation of the role of ASPG under in vivo conditions, indicating a mild obesogenic phenotype, hypertrophic white adipocytes, impairment of the early thermogenic response upon cold-stimulation and dysfunctional insulin sensitivity. Taken together, these data show that ASPG may represent a new functional biomarker of BAT-aging that regulates thermogenesis and therefore a potential target for the treatment of age-related metabolic disease.}, language = {en} }