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Functional Biomarkers for the Selenium Status in a Human Nutritional Intervention Study (2020)
Müller, Sandra ; Dawczynski, Christine ; Wiest, Johanna ; Lorkowski, Stefan ; Kipp, Anna P. ; Schwerdtle, Tanja
Soils in Germany are commonly low in selenium; consequently, a sufficient dietary supply is not always ensured. The extent of such provision adequacy is estimated by the optimal effect range of biomarkers, which often reflects the physiological requirement. Preceding epidemiological studies indicate that low selenium serum concentrations could be related to cardiovascular diseases. Inter alia, risk factors for cardiovascular diseases are physical inactivity, overweight, as well as disadvantageous eating habits. In order to assess whether these risk factors can be modulated, a cardio-protective diet comprising fixed menu plans combined with physical exercise was applied in the German MoKaRi (modulation of cardiovascular risk factors) intervention study. We analyzed serum samples of the MoKaRi cohort (51 participants) for total selenium, GPx activity, and selenoprotein P at different timepoints of the study (0, 10, 20, 40 weeks) to explore the suitability of these selenium-associated markers as indicators of selenium status. Overall, the time-dependent fluctuations in serum selenium concentration suggest a successful change in nutritional and lifestyle behavior. Compared to baseline, a pronounced increase in GPx activity and selenoprotein P was observed, while serum selenium decreased in participants with initially adequate serum selenium content. SELENOP concentration showed a moderate positive monotonic correlation (r = 0.467, p < 0.0001) to total Se concentration, while only a weak linear relationship was observed for GPx activity versus total Se concentration (r = 0.186, p = 0.021). Evidently, other factors apart from the available Se pool must have an impact on the GPx activity, leading to the conclusion that, without having identified these factors, GPx activity should not be used as a status marker for Se
Functional Biomarkers for the Selenium Status in a Human Nutritional Intervention Study (2020)
Müller, Sandra ; Dawczynski, Christine ; Wiest, Johanna ; Lorkowski, Stefan ; Kipp, Anna P. ; Schwerdtle, Tanja
Soils in Germany are commonly low in selenium; consequently, a sufficient dietary supply is not always ensured. The extent of such provision adequacy is estimated by the optimal effect range of biomarkers, which often reflects the physiological requirement. Preceding epidemiological studies indicate that low selenium serum concentrations could be related to cardiovascular diseases. Inter alia, risk factors for cardiovascular diseases are physical inactivity, overweight, as well as disadvantageous eating habits. In order to assess whether these risk factors can be modulated, a cardio-protective diet comprising fixed menu plans combined with physical exercise was applied in the German MoKaRi (modulation of cardiovascular risk factors) intervention study. We analyzed serum samples of the MoKaRi cohort (51 participants) for total selenium, GPx activity, and selenoprotein P at different timepoints of the study (0, 10, 20, 40 weeks) to explore the suitability of these selenium-associated markers as indicators of selenium status. Overall, the time-dependent fluctuations in serum selenium concentration suggest a successful change in nutritional and lifestyle behavior. Compared to baseline, a pronounced increase in GPx activity and selenoprotein P was observed, while serum selenium decreased in participants with initially adequate serum selenium content. SELENOP concentration showed a moderate positive monotonic correlation (r = 0.467, p < 0.0001) to total Se concentration, while only a weak linear relationship was observed for GPx activity versus total Se concentration (r = 0.186, p = 0.021). Evidently, other factors apart from the available Se pool must have an impact on the GPx activity, leading to the conclusion that, without having identified these factors, GPx activity should not be used as a status marker for Se
Subcellular Localization of Copper (2020)
Witt, Barbara ; Schaumlöffel, Dirk ; Schwerdtle, Tanja
As an essential trace element, copper plays a pivotal role in physiological body functions. In fact, dysregulated copper homeostasis has been clearly linked to neurological disorders including Wilson and Alzheimer’s disease. Such neurodegenerative diseases are associated with progressive loss of neurons and thus impaired brain functions. However, the underlying mechanisms are not fully understood. Characterization of the element species and their subcellular localization is of great importance to uncover cellular mechanisms. Recent research activities focus on the question of how copper contributes to the pathological findings. Cellular bioimaging of copper is an essential key to accomplish this objective. Besides information on the spatial distribution and chemical properties of copper, other essential trace elements can be localized in parallel. Highly sensitive and high spatial resolution techniques such as LA-ICP-MS, TEM-EDS, S-XRF and NanoSIMS are required for elemental mapping on subcellular level. This review summarizes state-of-the-art techniques in the field of bioimaging. Their strengths and limitations will be discussed with particular focus on potential applications for the elucidation of copper-related diseases. Based on such investigations, further information on cellular processes and mechanisms can be derived under physiological and pathological conditions. Bioimaging studies might enable the clarification of the role of copper in the context of neurodegenerative diseases and provide an important basis to develop therapeutic strategies for reduction or even prevention of copper-related disorders and their pathological consequences.
Subcellular Localization of Copper (2020)
Witt, Barbara ; Schaumlöffel, Dirk ; Schaumlöffel, Dirk ; Schwerdtle, Tanja
As an essential trace element, copper plays a pivotal role in physiological body functions. In fact, dysregulated copper homeostasis has been clearly linked to neurological disorders including Wilson and Alzheimer’s disease. Such neurodegenerative diseases are associated with progressive loss of neurons and thus impaired brain functions. However, the underlying mechanisms are not fully understood. Characterization of the element species and their subcellular localization is of great importance to uncover cellular mechanisms. Recent research activities focus on the question of how copper contributes to the pathological findings. Cellular bioimaging of copper is an essential key to accomplish this objective. Besides information on the spatial distribution and chemical properties of copper, other essential trace elements can be localized in parallel. Highly sensitive and high spatial resolution techniques such as LA-ICP-MS, TEM-EDS, S-XRF and NanoSIMS are required for elemental mapping on subcellular level. This review summarizes state-of-the-art techniques in the field of bioimaging. Their strengths and limitations will be discussed with particular focus on potential applications for the elucidation of copper-related diseases. Based on such investigations, further information on cellular processes and mechanisms can be derived under physiological and pathological conditions. Bioimaging studies might enable the clarification of the role of copper in the context of neurodegenerative diseases and provide an important basis to develop therapeutic strategies for reduction or even prevention of copper-related disorders and their pathological consequences.
Understanding the link between obesity and colorectal cancer (2020)
Aleksandrova, Krasimira
Regulation of the organokines FGF21 and chemerin by diet (2020)
Seebeck, Nicole
The hepatokine FGF21 and the adipokine chemerin have been implicated as metabolic regulators and mediators of inter-tissue crosstalk. While FGF21 is associated with beneficial metabolic effects and is currently being tested as an emerging therapeutic for obesity and diabetes, chemerin is linked to inflammation-mediated insulin resistance. However, dietary regulation of both organokines and their role in tissue interaction needs further investigation. The LEMBAS nutritional intervention study investigated the effects of two diets differing in their protein content in obese human subjects with non-alcoholic fatty liver disease (NAFLD). The study participants consumed hypocaloric diets containing either low (LP: 10 EN%, n = 10) or high (HP: 30 EN%, n = 9) dietary protein 3 weeks prior to bariatric surgery. Before and after the intervention the participants were anthropometrically assessed, blood samples were drawn, and hepatic fat content was determined by MRS. During bariatric surgery, paired subcutaneous and visceral adipose tissue biopsies as well as liver biopsies were collected. The aim of this thesis was to investigate circulating levels and tissue-specific regulation of (1) FGF21 and (2) chemerin in the LEMBAS cohort. The results were compared to data obtained in 92 metabolically healthy subjects with normal glucose tolerance and normal liver fat content. (1) Serum FGF21 concentrations were elevated in the obese subjects, and strongly associated with intrahepatic lipids (IHL). In accordance, FGF21 serum concentrations increased with severity of NAFLD as determined histologically in the liver biopsies. Though both diets were successful in reducing IHL, the effect was more pronounced in the HP group. FGF21 serum concentrations and mRNA expression were bi-directionally regulated by dietary protein, independent from metabolic improvements. In accordance, in the healthy study subjects, serum FGF21 concentrations dropped by more than 60% in response to the HP diet. A short-term HP intervention confirmed the acute downregulation of FGF21 within 24 hours. Lastly, experiments in HepG2 cell cultures and primary murine hepatocytes identified nitrogen metabolites (NH4Cl and glutamine) to dose-dependently suppress FGF21 expression. (2) Circulating chemerin concentrations were considerably elevated in the obese versus lean study participants and differently associated with markers of obesity and NAFLD in the two cohorts. The adipokine decreased in response to the hypocaloric interventions while an unhealthy high-fat diet induced a rise in chemerin serum levels. In the lean subjects, mRNA expression of RARRES2, encoding chemerin, was strongly and positively correlated with expression of several cytokines, including MCP1, TNFα, and IL6, as well as markers of macrophage infiltration in the subcutaneous fat depot. However, RARRES2 was not associated with any cytokine assessed in the obese subjects and the data indicated an involvement of chemerin not only in the onset but also resolution of inflammation. Analyses of the tissue biopsies and experiments in human primary adipocytes point towards a role of chemerin in adipogenesis while discrepancies between the in vivo and in vitro data were detected. Taken together, the results of this thesis demonstrate that circulating FGF21 and chemerin levels are considerably elevated in obesity and responsive to dietary interventions. FGF21 was acutely and bi-directionally regulated by dietary protein in a hepatocyte-autonomous manner. Given that both, a lack in essential amino acids and excessive nitrogen intake, exert metabolic stress, FGF21 may serve as an endocrine signal for dietary protein balance. Lastly, the data revealed that chemerin is derailed in obesity and associated with obesity-related inflammation. However, future studies on chemerin should consider functional and regulatory differences between secreted and tissue-specific isoforms.
Comprehensive Characterization and Relative Quantification of α-Amylase/Trypsin Inhibitors from Wheat Cultivars by Targeted HPLC-MS/MS (2020)
Sagu, Sorel Tchewonpi ; Zimmermann, Lynn ; Landgräber, Eva ; Homann, Thomas ; Huschek, Gerd ; Özpinar, Haydar ; Schweigert, Florian J. ; Rawel, Harshadrai M.
The α-amylase/trypsin inhibitors (ATIs) are discussed as being responsible for non-celiac wheat sensitivity (NCWS), besides being known as allergenic components for baker’s asthma. Different approaches for characterization and quantification including proteomics-based methods for wheat ATIs have been documented. In these studies generally the major ATIs have been addressed. The challenge of current study was then to develop a more comprehensive workflow encompassing all reviewed wheat-ATI entries in UniProt database. To substantially test proof of concept, 46 German and Turkish wheat samples were used. Two extractions systems based on chloroform/methanol mixture (CM) and under buffered denaturing conditions were evaluated. Three aspects were optimized, tryptic digestion, chromatographic separation, and targeted tandem mass spectrometric analysis (HPLC-MS/MS). Preliminary characterization with sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) documented the purity of the extracted ATIs with CM mixture and the amylase (60–80%)/trypsin (10–20%) inhibition demonstrated the bifunctional activity of ATIs. Thirteen (individual/common) biomarkers were established. Major ATIs (7–34%) were differently represented in samples. Finally, to our knowledge, the proposed HPLC-MS/MS method allowed for the first time so far the analysis of all 14 reviewed wheat ATI entries reported.
Comprehensive Characterization and Relative Quantification of α-Amylase/Trypsin Inhibitors from Wheat Cultivars by Targeted HPLC-MS/MS (2020)
Sagu, Sorel Tchewonpi ; Zimmermann, Lynn ; Landgräber, Eva ; Homann, Thomas ; Huschek, Gerd ; Özpinar, Haydar ; Schweigert, Florian J. ; Rawel, Harshadrai M.
The α-amylase/trypsin inhibitors (ATIs) are discussed as being responsible for non-celiac wheat sensitivity (NCWS), besides being known as allergenic components for baker’s asthma. Different approaches for characterization and quantification including proteomics-based methods for wheat ATIs have been documented. In these studies generally the major ATIs have been addressed. The challenge of current study was then to develop a more comprehensive workflow encompassing all reviewed wheat-ATI entries in UniProt database. To substantially test proof of concept, 46 German and Turkish wheat samples were used. Two extractions systems based on chloroform/methanol mixture (CM) and under buffered denaturing conditions were evaluated. Three aspects were optimized, tryptic digestion, chromatographic separation, and targeted tandem mass spectrometric analysis (HPLC-MS/MS). Preliminary characterization with sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) documented the purity of the extracted ATIs with CM mixture and the amylase (60–80%)/trypsin (10–20%) inhibition demonstrated the bifunctional activity of ATIs. Thirteen (individual/common) biomarkers were established. Major ATIs (7–34%) were differently represented in samples. Finally, to our knowledge, the proposed HPLC-MS/MS method allowed for the first time so far the analysis of all 14 reviewed wheat ATI entries reported.
Extension of the German Diabetes Risk Score with regard to risk communication and cardiovascular outcomes (2020)
Schiborn, Catarina
A Multi-Endpoint Approach to Base Excision Repair Incision Activity Augmented by PARylation and DNA Damage Levels in Mice (2020)
Winkelbeiner, Nicola ; Wandt, Viktoria K. ; Ebert, Franziska ; Lossow, Kristina ; Bankoglu, Ezgi E. ; Martin, Maximilian ; Mangerich, Aswin ; Stopper, Helga ; Bornhorst, Julia ; Kipp, Anna P. ; Schwerdtle, Tanja
Investigation of processes that contribute to the maintenance of genomic stability is one crucial factor in the attempt to understand mechanisms that facilitate ageing. The DNA damage response (DDR) and DNA repair mechanisms are crucial to safeguard the integrity of DNA and to prevent accumulation of persistent DNA damage. Among them, base excision repair (BER) plays a decisive role. BER is the major repair pathway for small oxidative base modifications and apurinic/apyrimidinic (AP) sites. We established a highly sensitive non-radioactive assay to measure BER incision activity in murine liver samples. Incision activity can be assessed towards the three DNA lesions 8-oxo-2’-deoxyguanosine (8-oxodG), 5-hydroxy-2’-deoxyuracil (5-OHdU), and an AP site analogue. We applied the established assay to murine livers of adult and old mice of both sexes. Furthermore, poly(ADP-ribosyl)ation (PARylation) was assessed, which is an important determinant in DDR and BER. Additionally, DNA damage levels were measured to examine the overall damage levels. No impact of ageing on the investigated endpoints in liver tissue were found. However, animal sex seems to be a significant impact factor, as evident by sex-dependent alterations in all endpoints investigated. Moreover, our results revealed interrelationships between the investigated endpoints indicative for the synergetic mode of action of the cellular DNA integrity maintaining machinery.
A Multi-Endpoint Approach to Base Excision Repair Incision Activity Augmented by PARylation and DNA Damage Levels in Mice (2020)
Winkelbeiner, Nicola ; Wandt, Viktoria K. ; Ebert, Franziska ; Lossow, Kristina ; Bankoglu, Ezgi E. ; Martin, Maximilian ; Mangerich, Aswin ; Stopper, Helga ; Bornhorst, Julia ; Kipp, Anna P. ; Schwerdtle, Tanja
Investigation of processes that contribute to the maintenance of genomic stability is one crucial factor in the attempt to understand mechanisms that facilitate ageing. The DNA damage response (DDR) and DNA repair mechanisms are crucial to safeguard the integrity of DNA and to prevent accumulation of persistent DNA damage. Among them, base excision repair (BER) plays a decisive role. BER is the major repair pathway for small oxidative base modifications and apurinic/apyrimidinic (AP) sites. We established a highly sensitive non-radioactive assay to measure BER incision activity in murine liver samples. Incision activity can be assessed towards the three DNA lesions 8-oxo-2’-deoxyguanosine (8-oxodG), 5-hydroxy-2’-deoxyuracil (5-OHdU), and an AP site analogue. We applied the established assay to murine livers of adult and old mice of both sexes. Furthermore, poly(ADP-ribosyl)ation (PARylation) was assessed, which is an important determinant in DDR and BER. Additionally, DNA damage levels were measured to examine the overall damage levels. No impact of ageing on the investigated endpoints in liver tissue were found. However, animal sex seems to be a significant impact factor, as evident by sex-dependent alterations in all endpoints investigated. Moreover, our results revealed interrelationships between the investigated endpoints indicative for the synergetic mode of action of the cellular DNA integrity maintaining machinery.
Comparison of batch and continuous wet-processing of coffee (2020)
Figueroa Campos, Gustavo A. ; Sagu Tchewonpi, Sorel ; Saravia Celis, Pedro ; Rawel, Harshadrai M.
Many technical challenges still need to be overcome to improve the quality of the green coffee beans. In this work, the wet Arabica coffee processing in batch and continuous modus were investigated. Coffee beans samples as well as by-products and wastewaters collected at different production steps were analyzed in terms of their content in total phenols, antioxidant capacity, caffeine content, organic acids, reducing sugars, free amino group and protein content. The results showed that 40% of caffeine was removed with pulp. Green coffee beans showed highest concentration of organic acids and sucrose (4.96 ± 0.25 and 5.07 ± 0.39 g/100 g DW for the batch and continuous processing). Batch green coffee beans contained higher amount of phenols. 5-caffeoylquinic Acid (5-CQA) was the main constituent (67.1 and 66.0% for the batch and continuous processing, respectively). Protein content was 15 and 13% in the green coffee bean in batch and continuous processing, respectively. A decrease of 50 to 64% for free amino groups during processing was observed resulting in final amounts of 0.8 to 1.4% in the processed beans. Finally, the batch processing still revealed by-products and wastewater with high nutrient content encouraging a better concept for valorization.
Comparison of batch and continuous wet-processing of coffee (2020)
Figueroa Campos, Gustavo A. ; Sagu Tchewonpi, Sorel ; Saravia Celis, Pedro ; Rawel, Harshadrai M.
Many technical challenges still need to be overcome to improve the quality of the green coffee beans. In this work, the wet Arabica coffee processing in batch and continuous modus were investigated. Coffee beans samples as well as by-products and wastewaters collected at different production steps were analyzed in terms of their content in total phenols, antioxidant capacity, caffeine content, organic acids, reducing sugars, free amino group and protein content. The results showed that 40% of caffeine was removed with pulp. Green coffee beans showed highest concentration of organic acids and sucrose (4.96 ± 0.25 and 5.07 ± 0.39 g/100 g DW for the batch and continuous processing). Batch green coffee beans contained higher amount of phenols. 5-caffeoylquinic Acid (5-CQA) was the main constituent (67.1 and 66.0% for the batch and continuous processing, respectively). Protein content was 15 and 13% in the green coffee bean in batch and continuous processing, respectively. A decrease of 50 to 64% for free amino groups during processing was observed resulting in final amounts of 0.8 to 1.4% in the processed beans. Finally, the batch processing still revealed by-products and wastewater with high nutrient content encouraging a better concept for valorization.
Toxische Effekte von Arsenolipiden in humanen Kulturzellen und Caenorhabditis elegans (2020)
Ziemann, Vanessa
Relative Abundance of Alpha-Amylase/Trypsin Inhibitors in Selected Sorghum Cultivars (2020)
Sagu, Sorel Tchewonpi ; Landgräber, Eva ; Rackiewicz, Michal ; Huschek, Gerd ; Rawel, Harshadrai
Sorghum is of growing interest and considered as a safe food for wheat related disorders. Besides the gluten, α-amylase/trypsin-inhibitors (ATIs) have been identified as probable candidates for these disorders. Several studies focused on wheat-ATIs although there is still a lack of data referring to the relative abundance of sorghum-ATIs. The objective of this work was therefore to contribute to the characterization of sorghum ATI profiles by targeted proteomics tools. Fifteen sorghum cultivars from different regions were investigated with raw proteins ranging from 7.9 to 17.0 g/100 g. Ammonium bicarbonate buffer in combination with urea was applied for protein extraction, with concentration from 0.588 ± 0.047 to 4.140 ± 0.066 mg/mL. Corresponding electrophoresis data showed different protein profiles. UniProtKB data base research reveals two sorghum ATIs, P81367 and P81368; both reviewed and a targeted LC–MS/MS method was developed to analyze these. Quantifier peptides ELAAVPSR (P81367) and TYMVR (P81368) were identified and retained as biomarkers for relative quantification. Different reducing and alkylating agents were assessed and combination of tris (2 carboxyethyl) phosphine/iodoacetamide gave the best response. Linearity was demonstrated for the quantifier peptides with standard recovery between 92.2 and 107.6%. Nine sorghum cultivars presented up to 60 times lower ATI contents as compared to wheat samples. This data suggests that sorghum can effectively be considered as a good alternative to wheat.
Relative Abundance of Alpha-Amylase/Trypsin Inhibitors in Selected Sorghum Cultivars (2020)
Sagu, Sorel Tchewonpi ; Landgräber, Eva ; Rackiewicz, Michal ; Huschek, Gerd ; Rawel, Harshadrai
Sorghum is of growing interest and considered as a safe food for wheat related disorders. Besides the gluten, α-amylase/trypsin-inhibitors (ATIs) have been identified as probable candidates for these disorders. Several studies focused on wheat-ATIs although there is still a lack of data referring to the relative abundance of sorghum-ATIs. The objective of this work was therefore to contribute to the characterization of sorghum ATI profiles by targeted proteomics tools. Fifteen sorghum cultivars from different regions were investigated with raw proteins ranging from 7.9 to 17.0 g/100 g. Ammonium bicarbonate buffer in combination with urea was applied for protein extraction, with concentration from 0.588 ± 0.047 to 4.140 ± 0.066 mg/mL. Corresponding electrophoresis data showed different protein profiles. UniProtKB data base research reveals two sorghum ATIs, P81367 and P81368; both reviewed and a targeted LC–MS/MS method was developed to analyze these. Quantifier peptides ELAAVPSR (P81367) and TYMVR (P81368) were identified and retained as biomarkers for relative quantification. Different reducing and alkylating agents were assessed and combination of tris (2 carboxyethyl) phosphine/iodoacetamide gave the best response. Linearity was demonstrated for the quantifier peptides with standard recovery between 92.2 and 107.6%. Nine sorghum cultivars presented up to 60 times lower ATI contents as compared to wheat samples. This data suggests that sorghum can effectively be considered as a good alternative to wheat.
Analysis of motor neurons differentiated from human induced pluripotent stem cells for the use in cell-based Botulinum neurotoxin activity assays (2020)
Schenke, Maren ; Schjeide, Brit-Maren ; Püschel, Gerhard Paul ; Seeger, Bettina
Botulinum neurotoxins (BoNTs) are potent neurotoxins produced by bacteria, which inhibit neurotransmitter release, specifically in their physiological target known as motor neurons (MNs). For the potency assessment of BoNTs produced for treatment in traditional and aesthetic medicine, the mouse lethality assay is still used by the majority of manufacturers, which is ethically questionable in terms of the 3Rs principle. In this study, MNs were differentiated from human induced pluripotent stem cells based on three published protocols. The resulting cell populations were analyzed for their MN yield and their suitability for the potency assessment of BoNTs. MNs produce specific gangliosides and synaptic proteins, which are bound by BoNTs in order to be taken up by receptor-mediated endocytosis, which is followed by cleavage of specific soluble N-ethylmaleimide-sensitive-factor attachment receptor (SNARE) proteins required for neurotransmitter release. The presence of receptors and substrates for all BoNT serotypes was demonstrated in MNs generated in vitro. In particular, the MN differentiation protocol based on Du et al. yielded high numbers of MNs in a short amount of time with high expression of BoNT receptors and targets. The resulting cells are more sensitive to BoNT/A1 than the commonly used neuroblastoma cell line SiMa. MNs are, therefore, an ideal tool for being combined with already established detection methods.
Toxicological Characterization of Arsenolipids in vitro and Analysis of Global DNA (Hydroxy)methylation in the Context of Aging, Trace Element Status, and Genomic Stability (2020)
Finke, Hannah
Impact of element species on DNA repair processes (2020)
Winkelbeiner, Nicola Lisa
Einfluss von Prostaglandin E2 auf die Entstehung von Insulinresistenz und die Regulation der Entzündungsantwort bei der Diät-induzierten nicht-alkoholischen Fettlebererkrankung (2020)
Henkel-Oberländer, Janin
Weltweit sind fast 40 % der Bevölkerung übergewichtig und die Prävalenz von Adipositas, Insulinresistenz und den resultierenden Folgeerkrankungen wie dem Metabolischen Syndrom und Typ-2-Diabetes steigt rapide an. Als häufigste Ursachen werden diätetisches Fehlverhalten und mangelnde Bewegung angesehen. Die nicht-alkoholische Fettlebererkrankung (NAFLD), deren Hauptcharakteristikum die exzessive Akkumulation von Lipiden in der Leber ist, korreliert mit dem Body Mass Index (BMI). NAFLD wird als hepatische Manifestation des Metabolischen Syndroms angesehen und ist inzwischen die häufigste Ursache für Leberfunktionsstörungen. Die Erkrankung umfasst sowohl die benigne hepatische Steatose (Fettleber) als auch die progressive Form der nicht-alkoholischen Steatohepatitis (NASH), bei der die Steatose von Entzündung und Fibrose begleitet ist. Die Ausbildung einer NASH erhöht das Risiko, ein hepatozelluläres Karzinom (HCC) zu entwickeln und kann zu irreversibler Leberzirrhose und terminalem Organversagen führen. Nahrungsbestandteile wie Cholesterol und Fett-reiche Diäten werden als mögliche Faktoren diskutiert, die den Übergang einer einfachen Fettleber zur schweren Verlaufsform der Steatohepatitis / NASH begünstigen. Eine Ausdehnung des Fettgewebes wird von Insulinresistenz und einer niedrig-gradigen chronischen Entzündung des Fettgewebes begleitet. Neben Endotoxinen aus dem Darm gelangen Entzündungsmediatoren aus dem Fettgewebe zur Leber. Als Folge werden residente Makrophagen der Leber, die Kupfferzellen, aktiviert, die eine Entzündungsantwort initiieren und weitere pro-inflammatorische Mediatoren freisetzen, zu denen Chemokine, Cytokine und Prostanoide wie Prostaglandin E2 (PGE2) gehören. In dieser Arbeit soll aufgeklärt werden, welchen Beitrag PGE2 an der Ausbildung von Insulinresistenz, hepatischer Steatose und Entzündung im Rahmen von Diät-induzierter NASH im komplexen Zusammenspiel mit der Regulation der Cytokin-Produktion und anderen Co-Faktoren wie Hyperinsulinämie und Hyperlipidämie hat. In murinen und humanen Makrophagen-Populationen wurde untersucht, welche Faktoren die Bildung von PGE2 fördern und wie PGE2 die Entzündungsantwort aktivierter Makrophagen reguliert. In primären Hepatozyten der Ratte sowie in isolierten humanen Hepatozyten und Zelllinien wurde der Einfluss von PGE2 allein und in Kombination mit Cytokinen, deren Bildung durch PGE2 beeinflusst werden kann, auf die Insulin-abhängige Regulation des Glucose- und Lipid-stoffwechsels untersucht. Um den Einfluss von PGE2 im komplexen Zusammenspiel der Zelltypen in der Leber und im Gesamtorganismus zu erfassen, wurden Mäuse, in denen die PGE2-Synthese durch die Deletion der mikrosomalen PGE-Synthase 1 (mPGES1) vermindert war, mit einer NASH-induzierenden Diät gefüttert. In Lebern von Patienten mit NASH oder in Mäusen mit Diät-induzierter NASH war die Expression der PGE2-synthetisierenden Enzyme Cyclooxygenase 2 (COX2) und mPGES1 sowie die Bildung von PGE2 im Vergleich zu gesunden Kontrollen gesteigert und korrelierte mit dem Schweregrad der Lebererkrankung. In primären Makrophagen aus den Spezies Mensch, Maus und Ratte sowie in humanen Makrophagen-Zelllinien war die Bildung pro-inflammatorischer Mediatoren wie Chemokinen, Cytokinen und Prostaglandinen wie PGE2 verstärkt, wenn die Zellen mit Endotoxinen wie Lipopolysaccharid (LPS), Fettsäuren wie Palmitinsäure, Cholesterol und Cholesterol-Kristallen oder Insulin, das als Folge der kompensatorischen Hyperinsulinämie bei Insulinresistenz verstärkt freigesetzt wird, inkubiert wurden. Insulin steigerte dabei synergistisch mit LPS oder Palmitinsäure die Synthese von PGE2 sowie der anderen Entzündungsmediatoren wie Interleukin (IL) 8 und IL-1β. PGE2 reguliert die Entzündungsantwort: Neben der Induktion der eigenen Synthese-Enzyme verstärkte PGE2 die Expression der Immunzell-rekrutierenden Chemokine IL-8 und (C-C-Motiv)-Ligand 2 (CCL2) sowie die der pro-inflammatorischen Cytokine IL-1β und IL-6 in Makrophagen und kann so zur Verstärkung der Entzündungsreaktion beitragen. Außerdem förderte PGE2 die Bildung von Oncostatin M (OSM) und OSM induzierte in einer positiven Rückkopplungsschleife die Expression der PGE2-synthetisierenden Enzyme. Andererseits hemmte PGE2 die basale und LPS-vermittelte Bildung des potenten pro-inflammatorischen Cytokins Tumornekrosefaktor α (TNFα) und kann so die Entzündungsreaktion abschwächen. In primären Hepatozyten der Ratte und humanen Hepatozyten beeinträchtigte PGE2 direkt die Insulin-abhängige Aktivierung der Insulinrezeptor-Signalkette zur Steigerung der Glucose-Verwertung, in dem es durch Signalketten, die den verschiedenen PGE2-Rezeptoren nachgeschaltet sind, Kinasen wie ERK1/2 und IKKβ aktivierte und eine inhibierende Serin-Phosphorylierung der Insulinrezeptorsubstrate bewirkte. PGE2 verstärkte außerdem die IL-6- oder OSM-vermittelte Insulinresistenz und Steatose in primären Hepatozyten der Ratte. Die Wirkung von PGE2 im Gesamtorganismus sollte in Mäusen mit Diät-induzierter NASH untersucht werden. Die Fütterung einer Hochfett-Diät mit Schmalz als Fettquelle, das vor allem gesättigte Fettsäuren enthält, verursachte Fettleibigkeit, Insulinresistenz und eine hepatische Steatose in Wildtyp-Mäusen. In Tieren, die eine Hochfett-Diät mit Sojaöl als Fettquelle, das vor allem (ω-6)-mehrfach-ungesättigte Fettsäuren (PUFAs) enthält, oder eine Niedrigfett-Diät mit Cholesterol erhielten, war lediglich eine hepatische Steatose nachweisbar, jedoch keine verstärkte Gewichtszunahme im Vergleich zu Geschwistertieren, die eine Standard-Diät bekamen. Im Gegensatz dazu verursachte die Fütterung einer Hochfett-Diät mit PUFA-reichem Sojaöl als Fettquelle in Kombination mit Cholesterol sowohl Fettleibigkeit und Insulinresistenz als auch hepatische Steatose mit Hepatozyten-Hypertrophie, lobulärer Entzündung und beginnender Fibrose in Wildtyp-Mäusen. Diese Tiere spiegelten alle klinischen und histologischen Parameter der humanen NASH im Metabolischen Syndrom wider. Nur die Kombination von hohen Mengen ungesättigter Fettsäuren aus Sojaöl und Cholesterol in der Nahrung führte zu einer exzessiven Akkumulation des Cholesterols und der Bildung von Cholesterol-Kristallen in den Hepatozyten, die zur Schädigung der Mitochondrien, schwerem oxidativem Stress und schließlich zum Absterben der Zellen führten. Als Konsequenz phagozytieren Kupfferzellen die Zelltrümmer der Cholesterol-überladenen Hepatozyten, werden dadurch aktiviert, setzen Chemokine, Cytokine und PGE2 frei, die die Entzündungsreaktion verstärken und die Infiltration von weiteren Immunzellen initiieren können und verursachen so eine Progression zur Steatohepatitis (NASH). Die Deletion der mikrosomalen PGE-Synthase 1 (mPGES1), dem induzierbaren Enzym der PGE2-Synthese aus Cyclooxygenase-abhängigen Vorstufen, reduzierte die Diät-abhängige Bildung von PGE2 in der Leber. Die Fütterung der NASH-induzierenden Diät verursachte in Wildtyp- und mPGES1-defizienten Mäusen eine ähnliche Fettleibigkeit und Zunahme der Fettmasse sowie die Ausbildung von hepatischer Steatose mit Entzündung und Fibrose (NASH) im histologischen Bild. In mPGES1-defizienten Mäusen waren jedoch Parameter für die Infiltration von Entzündungszellen und die Diät-abhängige Schädigung der Leber im Vergleich zu Wildtyp-Tieren erhöht, was sich auch in einer stärkeren Diät-induzierten systemischen Insulinresistenz widerspiegelte. Die Bildung des pro-inflammatorischen und pro-apoptotischen Cytokins TNFα war in mPGES1-defizienten Mäusen durch die Aufhebung der negativen Rückkopplungshemmung verstärkt, was einen gesteigerten Diät-induzierten Zelluntergang gestresster Lipid-überladener Hepatozyten und eine nach-geschaltete Entzündungsantwort zur Folge hatte. Zusammenfassend wurde unter den gewählten Versuchsbedingungen in vivo eine anti-inflammatorische Rolle von PGE2 verifiziert, da das Prostanoid vor allem indirekt durch die Hemmung der TNFα-vermittelten Entzündungsreaktion die Schädigung der Leber, die Verstärkung der Entzündung und die Ausbildung von Insulinresistenz im Rahmen der Diät-abhängigen Fettlebererkrankung abschwächte.
Effects of Dietary Methionine and Protein Restriction on the Prevention and Treatment of Type 2 Diabetes (2020)
Martinez, Maria Teresa Castaño
Produktentwicklung eines luteinhaltigen, kolloidalen Nahrungsergänzungsmittels: physikochemische und ernährungsphysiologische Aspekte (2020)
Wolf, Kristine
Sekundäre Pflanzenstoffe und ihre gesundheitsfördernden Eigenschaften sind in den letzten zwei Jahrzehnten vielfach ernährungsphysiologisch untersucht und spezifische positive Effekte im humanen Organismus zum Teil sehr genau beschrieben worden. Zu den Carotinoiden zählend ist der sekundäre Pflanzenstoff Lutein insbesondere in der Prävention von ophthalmologischen Erkrankungen in den Mittelpunkt der Forschung gerückt. Das ausschließlich von Pflanzen und einigen Algen synthetisierte Xanthophyll wird über die pflanzliche Nahrung insbesondere grünes Blattgemüse in den humanen Organismus aufgenommen. Dort akkumuliert es bevorzugt im Makulapigment der Retina des menschlichen Auges und ist bedeutend im Prozess der Aufrechterhaltung der Funktionsfähigkeit der Photorezeptorzellen. Im Laufe des Alterns kann die Abnahme der Dichte des Makulapigments und der Abbau von Lutein beobachtet werden. Die dadurch eintretende Destabilisierung der Photorezeptorzellen im Zusammenhang mit einer veränderten Stoffwechsellage im alternden Organismus kann zur Ausprägung der altersbedingten Makuladegeneration (AMD) führen. Die pathologische Symptomatik der Augenerkrankung reicht vom Verlust der Sehschärfe bis hin zum irreversiblen Erblinden. Da therapeutische Mittel ausschließlich ein Fortschreiten verhindern, bestehen hier Forschungsansätze präventive Maßnahmen zu finden. Die Supplementierung von luteinhaltigen Präparaten bietet dabei einen Ansatzpunkt. Auf dem Markt finden sich bereits Nahrungsergänzungsmittel (NEM) mit Lutein in verschiedenen Applikationen. Limitierend ist dabei die Stabilität und Bioverfügbarkeit von Lutein, welches teilweise kostenintensiv und mit unbekannter Reinheit zu erwerben ist. Aus diesem Grund wäre die Verwendung von Luteinestern als die pflanzliche Speicherform des Luteins im Rahmen eines NEMs vorteilhaft. Neben ihrer natürlichen, höheren Stabilität sind Luteinester nachhaltig und kostengünstig einsetzbar. In dieser Arbeit wurden physikochemische und ernährungsphysiologisch relevante Aspekte in dem Produktentwicklungsprozess eines NEMs mit Luteinestern in einer kolloidalen Formulierung untersucht. Die bisher einzigartige Anwendung von Luteinestern in einem Mundspray sollte die Aufnahme des Wirkstoffes insbesondere für ältere Menschen erleichtern und verbessern. Unter Beachtung der Ergebnisse und der ernährungsphysiologischen Bewertung sollten u.a. Empfehlungen für die Rezepturzusammensetzungen einer Miniemulsion (Emulsion mit Partikelgrößen <1,0 µm) gegeben werden. Eine Einschätzung der Bioverfügbarkeit der Luteinester aus den entwickelten, kolloidalen Formulierungen konnte anhand von Studien zur Resorption- und Absorptionsverfügbarkeit in vitro ermöglicht werden. In physikalischen Untersuchungen wurden zunächst Basisbestandteile für die Formulierungen präzisiert. In ersten wirkstofffreien Musteremulsionen konnten ausgewählte Öle als Trägerphase sowie Emulgatoren und Löslichkeitsvermittler (Peptisatoren) hinsichtlich ihrer Eignung zur Bereitstellung einer Miniemulsion physikalisch geprüft werden. Die beste Stabilität und optimale Eigenschaften einer Miniemulsion zeigten sich bei der Verwendung von MCT-Öl (engl. medium chain triglyceride) bzw. Rapsöl in der Trägerphase sowie des Emulgators Tween® 80 (Tween 80) allein oder in Kombination mit dem Molkenproteinhydrolysat Biozate® 1 (Biozate 1). Aus den physikalischen Untersuchungen der Musteremulsionen gingen die Präemulsionen als Prototypen hervor. Diese enthielten den Wirkstoff Lutein in verschiedenen Formen. So wurden Präemulsionen mit Lutein, mit Luteinestern sowie mit Lutein und Luteinestern konzipiert, welche den Emulgator Tween 80 oder die Kombination mit Biozate 1 enthielten. Bei der Herstellung der Präemulsionen führte die Anwendung der Emulgiertechniken Ultraschall mit anschließender Hochdruckhomogenisation zu den gewünschten Miniemulsionen. Beide eingesetzten Emulgatoren boten optimale Stabilisierungseffekte. Anschließend erfolgte die physikochemische Charakterisierung der Wirkstoffe. Insbesondere Luteinester aus Oleoresin erwiesen sich hier als stabil gegenüber verschiedenen Lagerungsbedingungen. Ebenso konnte bei einer kurzzeitigen Behandlung der Wirkstoffe unter spezifischen mechanischen, thermischen, sauren und basischen Bedingungen eine Stabilität von Lutein und Luteinestern gezeigt werden. Die Zugabe von Biozate 1 bot dabei nur für Lutein einen zusätzlichen Schutz. Bei längerer physikochemischer Behandlung unterlagen die in den Miniemulsionen eingebrachten Wirkstoffe moderaten Abbauvorgängen. Markant war deren Sensitivität gegenüber dem basischen Milieu. Im Rahmen der Rezepturentwicklung des NEMs war hier die Empfehlung, eine Miniemulsion mit einem leicht saurem pH-Milieu zum Schutz des Wirkstoffes durch kontrollierte Zugabe weiterer Inhaltstoffe zu gestalten. Im weiteren Entwicklungsprozess des NEMs wurden Fertigrezepturen mit dem Wirkstoff Luteinester aufgestellt. Die alleinige Anwendung des Emulgators Biozate 1 zeigte sich dabei als ungeeignet. Die weiterhin zur Verfügung stehenden Fertigrezepturen enthielten in der Öl-phase neben dem Wirkstoff das MCT-ÖL oder Rapsöl sowie a-Tocopherol zur Stabilisierung. Die Wasserphase bestand aus dem Emulgator Tween 80 oder einer Kombination aus Tween 80 und Biozate 1. Zusatzstoffe waren zudem als mikrobiologischer Schutz Ascorbinsäure und Kaliumsorbat sowie für sensorische Effekte Xylitol und Orangenaroma. Die Anordnung der Basisrezeptur und das angewendete Emulgierverfahren lieferten stabile Miniemulsionen. Weiterhin zeigten langfristige Lagerungsversuche mit den Fertigrezepturen bei 4°C, dass eine Aufrechterhaltung der geforderten Luteinestermenge im Produkt gewährleistet war. Analoge Untersuchungen an einem luteinhaltigen, marktgängigen Präparat bestätigten dagegen eine bereits bei kurzfristiger Lagerung auftretende Instabilität von Lutein. Abschließend wurde durch Resorptions- und Absorptionsstudien in vitro mit den Präemulsionen und Fertigrezepturen die Bioverfügbarkeit von Luteinestern geprüft. Nach Behandlung in einem etablierten in vitro Verdaumodell konnte eine geringfügige Resorptionsverfügbarkeit der Luteinester definiert werden. Limitiert war eine Micellarisierung des Wirkstoffes aus den konzipierten Formulierungen zu beobachten. Eine enzymatische Spaltung der Luteinester zu freiem Lutein wurde nur begrenzt festgestellt. Spezifität und Aktivität von entsprechenden hydrolytischen Lipasen sind als äußerst gering gegenüber Luteinestern zu bewerten. In sich anschließenden Zellkulturversuchen mit der Zelllinie Caco-2 wurden keine zytotoxischen Effekte durch die relevanten Inhaltsstoffe in den Präemulsionen gezeigt. Dagegen konnten eine Sensibilität gegenüber den Fertigrezepturen beobachtet werden. Diese sollte im Zusammenhang mit Irritationen der Schleimhäute des Magen-Darm-Traktes bedacht werden. Eine weniger komplexe Rezeptur könnte die beobachteten Einschränkungen möglicherweise minimieren. Abschließende Absorptionsstudien zeigten, dass grundsätzlich eine geringfügige Aufnahme von vorrangig Lutein, aber auch Luteinmonoestern in den Enterocyten aus Miniemulsionen erfolgen kann. Dabei hatte weder Tween 80 noch Biozate 1 einen förderlichen Einfluss auf die Absorptionsrate von Lutein oder Luteinestern. Die Metabolisierung der Wirkstoffe durch vorherigen in vitro-Verdau steigerte die zelluläre Aufnahme von Wirkstoffen aus Formulierungen mit Lutein und Luteinestern gleichermaßen. Die beobachtete Aufnahme von Lutein und Luteinmonoestern in den Enterocyten scheint über passive Diffusion zu erfolgen, wobei auch der aktive Transport nicht ausgeschlossen werden kann. Dagegen können Luteindiester aufgrund ihrer Molekülgröße nicht über den Weg der Micellarisierung und einfachen Diffusion in die Enterocyten gelangen. Ihre Aufnahme in die Dünndarmepithelzellen bedarf einer vorherigen hydrolytischen Spaltung durch spezifische Lipasen. Dieser Schritt limitiert wiederum die effektive Aufnahme der Luteinester in die Zellen bzw. stellt eine Einschränkung in ihrer Bioverfügbarkeit im Vergleich zu freiem Lutein dar. Zusammenfassend konnte für die physikochemisch stabilen Luteinester eine geringe Bioverfügbarkeit aus kolloidalen Formulierungen gezeigt werden. Dennoch ist die Verwendung als Wirkstoffquelle für den sekundären Pflanzenstoff Lutein in einem NEM zu empfehlen. Im Zusammenhang mit der Aufnahme von luteinreichen, pflanzlichen Lebensmitteln kann trotz der zu erwartenden geringen Bioverfügbarkeit der Luteinester aus dem NEM ein Beitrag zur Verbesserung des Luteinstatus erreicht werden. Entsprechende Publikationen zeigten eindeutige Korrelationen zwischen der Aufnahme von luteinesterhaltigen Präparaten und einem Anstieg der Luteinkonzentration im Serum bzw. der Makulapigmentdichte in vivo. Die geringfügig bessere Bioverfügbarkeit von freiem Lutein steht im kritischen Zusammenhang mit seiner Instabilität und Kostenintensität. Bilanzierend wurde im Rahmen dieser Arbeit das marktgängige Produkt Vita Culus® konzipiert. Im Ausblick sollten humane Interventionsstudien mit dem NEM die abschließende Bewertung der Bioverfügbarkeit von Luteinestern aus dem Präparat möglich machen.
In silico Analyse zur Klärung der Beteiligung von micro-RNAs, die in QTL lokalisiert sind, an den metabolischen Erkrankungen Adipositas und Typ-2-Diabetes mit Hilfe von Mausmodellen (2019)
Gottmann, Pascal
Relevance of biomarkers for the diagnosis of the frailty syndrome (2019)
Kochlik, Bastian Max
Frailty and sarcopenia share some underlying characteristics like loss of muscle mass, low muscle strength, and low physical performance. Imaging parameters and functional examinations mainly assess frailty and sarcopenia criteria; however, these measures can have limitations in clinical settings. Therefore, finding suitable biomarkers that reflect a catabolic muscle state e.g. an elevated muscle protein turnover as suggested in frailty, are becoming more relevant concerning frailty diagnosis and risk assessment. 3-Methylhistidine (3-MH) and its ratios 3-MH-to-creatinine (3-MH/Crea) and 3 MH-to-estimated glomerular filtration rate (3-MH/eGFR) are under discussion as possible biomarkers for muscle protein turnover and might support the diagnosis of frailty. However, there is some skepticism about the reliability of 3-MH measures since confounders such as meat and fish intake might influence 3-MH plasma concentrations. Therefore, the influence of dietary habits and an intervention with white meat on plasma 3-MH was determined in young and healthy individuals. In another study, the cross-sectional associations of plasma 3-MH, 3-MH/Crea and 3-MH/eGFR with the frailty status (robust, pre-frail and frail) were investigated. Oxidative stress (OS) is a possible contributor to frailty development, and high OS levels as well as low micronutrient levels are associated with the frailty syndrome. However, data on simultaneous measures of OS biomarkers together with micronutrients are lacking in studies including frail, pre-frail and robust individuals. Therefore, cross-sectional associations of protein carbonyls (PrCarb), 3-nitrotyrosine (3-NT) and several micronutrients with the frailty status were determined. A validated UPLC-MS/MS (ultra-performance liquid chromatography tandem mass spectrometry) method for the simultaneous quantification of 3-MH and 1-MH (1 methylhistidine, as marker for meat and fish consumption) was presented and used for further analyses. Omnivores showed higher plasma 3-MH and 1-MH concentrations than vegetarians and a white meat intervention resulted in an increase in plasma 3-MH, 3 MH/Crea, 1-MH and 1-MH/Crea in omnivores. Elevated 3-MH and 3-MH/Crea levels declined significantly within 24 hours after this white meat intervention. Thus, 3-MH and 3-MH/Crea might be used as biomarker for muscle protein turnover when subjects did not consume meat 24 hours prior to blood samplings. Plasma 3-MH, 3-MH/Crea and 3-MH/eGFR were higher in frail individuals than in robust individuals. Additionally, these biomarkers were positively associated with frailty in linear regression models, and higher odds to be frail were found for every increase in 3 MH and 3-MH/eGFR quintile in multivariable logistic regression models adjusted for several confounders. This was the first study using 3-MH/eGFR and it is concluded that plasma 3-MH, 3-MH/Crea and 3-MH/eGFR might be used to identify frail individuals or individuals at higher risk to be frail, and that there might be threshold concentrations or ratios to support these diagnoses. Higher vitamin D3, lutein/zeaxanthin, γ-tocopherol, α-carotene, β-carotene, lycopene and β-cryptoxanthin concentrations and additionally lower PrCarb concentrations were found in robust compared to frail individuals in multivariate linear models. Frail subjects had higher odds to be in the lowest than in the highest tertile for vitamin D3 α-tocopherol, α-carotene, β-carotene, lycopene, lutein/zeaxanthin, and β cryptoxanthin, and had higher odds to be in the highest than in the lowest tertile for PrCarb than robust individuals in multivariate logistic regression models. Thus, a low micronutrient together with a high PrCarb status is associated with pre-frailty and frailty.
Novel adipokines as inflammatory biomarkers of chronic disease risk (2019)
Eichelmann, Fabian
New pharmacological approaches targeting vascular calcification in chronic kidney disease (2019)
Gaballa, Mohamed Mahmoud Salem Ahmed
Der Einfluss zweier immun-assoziierter GTPasen auf die Entstehung einer Hepatosteatose (2019)
Schwerbel, Kristin
Reduced Oxidative Stress and Enhanced FGF21 Formation in Livers of Endurance-Exercised Rats with Diet-Induced NASH (2019)
Henkel, Janin ; Buchheim-Dieckow, Katja ; Castro, José Pedro ; Laeger, Thomas ; Wardelmann, Kristina ; Kleinridders, André ; Jöhrens, Korinna ; Püschel, Gerhard Paul
Non-alcoholic fatty liver diseases (NAFLD) including the severe form with steatohepatitis (NASH) are highly prevalent ailments to which no approved pharmacological treatment exists. Dietary intervention aiming at 10% weight reduction is efficient but fails due to low compliance. Increase in physical activity is an alternative that improved NAFLD even in the absence of weight reduction. The underlying mechanisms are unclear and cannot be studied in humans. Here, a rat NAFLD model was developed that reproduces many facets of the diet-induced NAFLD in humans. The impact of endurance exercise was studied in this model. Male Wistar rats received control chow or a NASH-inducing diet rich in fat, cholesterol, and fructose. Both diet groups were subdivided into a sedentary and an endurance exercise group. Animals receiving the NASH-inducing diet gained more body weight, got glucose intolerant and developed a liver pathology with steatosis, hepatocyte hypertrophy, inflammation and fibrosis typical of NAFLD or NASH. Contrary to expectations, endurance exercise did not improve the NASH activity score and even enhanced hepatic inflammation. However, endurance exercise attenuated the hepatic cholesterol overload and the ensuing severe oxidative stress. In addition, exercise improved glucose tolerance possibly in part by induction of hepatic FGF21 production.
Reduced Oxidative Stress and Enhanced FGF21 Formation in Livers of Endurance-Exercised Rats with Diet-Induced NASH (2019)
Henkel, Janin ; Buchheim-Dieckow, Katja ; Castro, José Pedro ; Laeger, Thomas ; Wardelmann, Kristina ; Kleinridders, André ; Jöhrens, Korinna ; Püschel, Gerhard Paul
Non-alcoholic fatty liver diseases (NAFLD) including the severe form with steatohepatitis (NASH) are highly prevalent ailments to which no approved pharmacological treatment exists. Dietary intervention aiming at 10% weight reduction is efficient but fails due to low compliance. Increase in physical activity is an alternative that improved NAFLD even in the absence of weight reduction. The underlying mechanisms are unclear and cannot be studied in humans. Here, a rat NAFLD model was developed that reproduces many facets of the diet-induced NAFLD in humans. The impact of endurance exercise was studied in this model. Male Wistar rats received control chow or a NASH-inducing diet rich in fat, cholesterol, and fructose. Both diet groups were subdivided into a sedentary and an endurance exercise group. Animals receiving the NASH-inducing diet gained more body weight, got glucose intolerant and developed a liver pathology with steatosis, hepatocyte hypertrophy, inflammation and fibrosis typical of NAFLD or NASH. Contrary to expectations, endurance exercise did not improve the NASH activity score and even enhanced hepatic inflammation. However, endurance exercise attenuated the hepatic cholesterol overload and the ensuing severe oxidative stress. In addition, exercise improved glucose tolerance possibly in part by induction of hepatic FGF21 production.
Hormonal regulation of neuronal mitochondrial unfolded protein response and its impact on metabolism (2019)
Wardelmann, Kristina
The hypothalamus is the main brain area of central regulation of whole body metabolism through impacting food intake and energy expenditure. For the complex regulation, high amounts of energy are needed and mainly provided by mitochondria. Hence, mitochondrial function is crucial for cell homeostasis and modulates central insulin sensitivity. Thus, mitochondrial dysfunction is associated with insulin resistance in the brain and therefore is involved in the pathogenesis of type-2 diabetes (T2D). Mitochondrial health and protein homeostasis is propagated by mitochondrial stress responses like e.g. mitochondrial unfolded protein response (UPRmt). Therefore, studies regarding the regulation of mitochondrial homeostasis are crucial for understanding its effects on the central nervous system (CNS) for the progression of metabolic and nutrition-dependent disorders. One main aim of this thesis was to investigate the metabolic regulation of mitochondrial stress responsiveness in the hypothalamus. The observed results showed that functional ERK-dependent insulin signaling is needed for regulation of mitochondrial stress response (MSR) genes and positively impacted the metabolism by controlling mitochondrial proteostasis without affecting mitochondrial biogenesis. To further explore the role of MSR genes for brain cell homeostasis and its consequences for the metabolism, one of the key players - the mitochondrial chaperone heat shock protein 10 (Hsp10) – was studied in detail. Hsp10 expression was decreased in insulin-resistant, hyperglycemic db/db mice brains along with increased protein oxidation. Leptin, another key hormone in regulating metabolism, was able to induce Hsp10 in neurons. Appropriately, lentiviral-mediated knock down (KD) of Hsp10 introduced into hypothalamic CLU-183 cells induced mitochondrial dysfunction, altered mitochondrial dynamics and increased contact sites between mitochondria and endoplasmic reticulum (ER). In addition, Hsp10 KD caused cellular insulin resistance along with increasing oxidative stress specifically in mitochondrial fraction. Interestingly, acute Hsp10 KD in the arcuate nucleus of the hypothalamus in C57BL/6N male mice did not change body weight or food intake, but it increased plasma leptin concentrations suggesting an effect on global leptin signaling. It increased hepatic markers of gluconeogenesis and hepatic insulin resistance along with features of low-grade inflammation. Long-term studies of hypothalamic Hsp10 KD mice revealed unaltered systemic insulin sensitivity. The demonstrated increase in markers of hepatic gluconeogenesis of acute Hsp10 KD was still exhibited after 13 weeks, but insulin resistance in the liver was no longer observed. In conclusion, hypothalamic insulin action regulates MSR and ensures proper mitochondrial function which positively affects metabolism. In addition, hypothalamic Hsp10 acts as a modulator of both insulin and leptin signaling and is identified as pivotal for the regulation of central mitochondrial function as well as insulin sensitivity in the brain and it impacts liver function. It may present a regulator of brain-liver crosstalk influencing hepatic gluconeogenesis and insulin sensitivity through a novel regulatory signaling mechanism.
The impact of metabolic stress and aging on functionality and integrity of pancreatic islets and beta-cells (2019)
Kehm, Richard
The increasing age of worldwide population is a major contributor for the rising prevalence of major pathologies and disease, such as type 2 diabetes, mediated by massive insulin resistance and a decline in functional beta-cell mass, highly associated with an elevated incidence of obesity. Thus, the impact of aging under physiological conditions and in combination with diet-induced metabolic stress on characteristics of pancreatic islets and beta-cells, with the focus on functionality and structural integrity, were investigated in the present dissertation. Primarily induced by malnutrition due to chronic and excess intake of high caloric diets, containing large amounts of carbohydrates and fats, obesity followed by systemic inflammation and peripheral insulin resistance occurs over time, initiating metabolic stress conditions. Elevated insulin demands initiate an adaptive response by beta-cell mass expansion due to increased proliferation, but prolonged stress conditions drive beta-cell failure and loss. Aging has been also shown to affect beta-cell functionality and morphology, in particular by proliferative limitations. However, most studies in rodents were performed under beta-cell challenging conditions, such as high-fat diet interventions. Thus, in the first part of the thesis (publication I), a characterization of age-related alterations on pancreatic islets and beta-cells was performed by using plasma samples and pancreatic tissue sections of standard diet-fed C57BL/6J wild-type mice in several age groups (2.5, 5, 10, 15 and 21 months). Aging was accompanied by decreased but sustained islet proliferative potential as well as an induction of cellular senescence. This was associated with a progressive islet expansion to maintain normoglycemia throughout lifespan. Moreover, beta-cell function and mass were not impaired although the formation and accumulation of AGEs occurred, located predominantly in the islet vasculature, accompanied by an induction of oxidative and nitrosative (redox) stress. The nutritional behavior throughout human lifespan; however, is not restricted to a balanced diet. This emphasizes the significance to investigate malnutrition by the intake of high-energy diets, inducing metabolic stress conditions that synergistically with aging might amplify the detrimental effects on endocrine pancreas. Using diabetes-prone NZO mice aged 7 weeks, fed a dietary regimen of carbohydrate restriction for different periods (young mice - 11 weeks, middle-aged mice - 32 weeks) followed by a carbohydrate intervention for 3 weeks, offered the opportunity to distinguish the effects of diet-induced metabolic stress in different ages on the functionality and integrity of pancreatic islets and their beta-cells (publication II, manuscript). Interestingly, while young NZO mice exhibited massive hyperglycemia in response to diet-induced metabolic stress accompanied by beta-cell dysfunction and apoptosis, middle-aged animals revealed only moderate hyperglycemia by the maintenance of functional beta-cells. The loss of functional beta-cell mass in islets of young mice was associated with reduced expression of PDX1 transcription factor, increased endocrine AGE formation and related redox stress as well as TXNIP-dependent induction of the mitochondrial death pathway. Although the amounts of secreted insulin and the proliferative potential were comparable in both age groups, islets of middle-aged mice exhibited sustained PDX1 expression, almost regular insulin secretory function, increased capacity for cell cycle progression as well as maintained redox potential. The results of the present thesis indicate a loss of functional beta-cell mass in young diabetes-prone NZO mice, occurring by redox imbalance and induction of apoptotic signaling pathways. In contrast, aging under physiological conditions in C57BL/6J mice and in combination with diet-induced metabolic stress in NZO mice does not appear to have adverse effects on the functionality and structural integrity of pancreatic islets and beta-cells, associated with adaptive responses on changing metabolic demands. However, considering the detrimental effects of aging, it has to be assumed that the compensatory potential of mice might be exhausted at a later point of time, finally leading to a loss of functional beta-cell mass and the onset and progression of type 2 diabetes. The polygenic, diabetes-prone NZO mouse is a suitable model for the investigation of human obesity-associated type 2 diabetes. However, mice at advanced age attenuated the diabetic phenotype or do not respond to the dietary stimuli. This might be explained by the middle age of mice, corresponding to the human age of about 38-40 years, in which the compensatory mechanisms of pancreatic islets and beta cells towards metabolic stress conditions are presumably more active.
Monitoring the Sphingolipid de novo Synthesis by Stable-Isotope Labeling and Liquid Chromatography-Mass Spectrometry (2019)
Wigger, Dominik ; Gulbins, Erich ; Kleuser, Burkhard ; Schumacher, Fabian
Sphingolipids are a class of lipids that share a sphingoid base backbone. They exert various effects in eukaryotes, ranging from structural roles in plasma membranes to cellular signaling. De novo sphingolipid synthesis takes place in the endoplasmic reticulum (ER), where the condensation of the activated C₁₆ fatty acid palmitoyl-CoA and the amino acid L-serine is catalyzed by serine palmitoyltransferase (SPT). The product, 3-ketosphinganine, is then converted into more complex sphingolipids by additional ER-bound enzymes, resulting in the formation of ceramides. Since sphingolipid homeostasis is crucial to numerous cellular functions, improved assessment of sphingolipid metabolism will be key to better understanding several human diseases. To date, no assay exists capable of monitoring de novo synthesis sphingolipid in its entirety. Here, we have established a cell-free assay utilizing rat liver microsomes containing all the enzymes necessary for bottom-up synthesis of ceramides. Following lipid extraction, we were able to track the different intermediates of the sphingolipid metabolism pathway, namely 3-ketosphinganine, sphinganine, dihydroceramide, and ceramide. This was achieved by chromatographic separation of sphingolipid metabolites followed by detection of their accurate mass and characteristic fragmentations through high-resolution mass spectrometry and tandem-mass spectrometry. We were able to distinguish, unequivocally, between de novo synthesized sphingolipids and intrinsic species, inevitably present in the microsome preparations, through the addition of stable isotope-labeled palmitate-d₃ and L-serine-d₃. To the best of our knowledge, this is the first demonstration of a method monitoring the entirety of ER-associated sphingolipid biosynthesis. Proof-of-concept data was provided by modulating the levels of supplied cofactors (e.g., NADPH) or the addition of specific enzyme inhibitors (e.g., fumonisin B₁). The presented microsomal assay may serve as a useful tool for monitoring alterations in sphingolipid de novo synthesis in cells or tissues. Additionally, our methodology may be used for metabolism studies of atypical substrates – naturally occurring or chemically tailored – as well as novel inhibitors of enzymes involved in sphingolipid de novo synthesis.
Monitoring the Sphingolipid de novo Synthesis by Stable-Isotope Labeling and Liquid Chromatography-Mass Spectrometry (2019)
Wigger, Dominik ; Gulbins, Erich ; Kleuser, Burkhard ; Schumacher, Fabian
Sphingolipids are a class of lipids that share a sphingoid base backbone. They exert various effects in eukaryotes, ranging from structural roles in plasma membranes to cellular signaling. De novo sphingolipid synthesis takes place in the endoplasmic reticulum (ER), where the condensation of the activated C₁₆ fatty acid palmitoyl-CoA and the amino acid L-serine is catalyzed by serine palmitoyltransferase (SPT). The product, 3-ketosphinganine, is then converted into more complex sphingolipids by additional ER-bound enzymes, resulting in the formation of ceramides. Since sphingolipid homeostasis is crucial to numerous cellular functions, improved assessment of sphingolipid metabolism will be key to better understanding several human diseases. To date, no assay exists capable of monitoring de novo synthesis sphingolipid in its entirety. Here, we have established a cell-free assay utilizing rat liver microsomes containing all the enzymes necessary for bottom-up synthesis of ceramides. Following lipid extraction, we were able to track the different intermediates of the sphingolipid metabolism pathway, namely 3-ketosphinganine, sphinganine, dihydroceramide, and ceramide. This was achieved by chromatographic separation of sphingolipid metabolites followed by detection of their accurate mass and characteristic fragmentations through high-resolution mass spectrometry and tandem-mass spectrometry. We were able to distinguish, unequivocally, between de novo synthesized sphingolipids and intrinsic species, inevitably present in the microsome preparations, through the addition of stable isotope-labeled palmitate-d₃ and L-serine-d₃. To the best of our knowledge, this is the first demonstration of a method monitoring the entirety of ER-associated sphingolipid biosynthesis. Proof-of-concept data was provided by modulating the levels of supplied cofactors (e.g., NADPH) or the addition of specific enzyme inhibitors (e.g., fumonisin B₁). The presented microsomal assay may serve as a useful tool for monitoring alterations in sphingolipid de novo synthesis in cells or tissues. Additionally, our methodology may be used for metabolism studies of atypical substrates – naturally occurring or chemically tailored – as well as novel inhibitors of enzymes involved in sphingolipid de novo synthesis.
Anti-Inflammatory Diets and Fatigue (2019)
Haß, Ulrike ; Herpich, Catrin ; Norman, Kristina
Accumulating data indicates a link between a pro-inflammatory status and occurrence of chronic disease-related fatigue. The questions are whether the observed inflammatory profile can be (a) improved by anti-inflammatory diets, and (b) if this improvement can in turn be translated into a significant fatigue reduction. The aim of this narrative review was to investigate the effect of anti-inflammatory nutrients, foods, and diets on inflammatory markers and fatigue in various patient populations. Next to observational and epidemiological studies, a total of 21 human trials have been evaluated in this work. Current available research is indicative, rather than evident, regarding the effectiveness of individuals’ use of single nutrients with anti-inflammatory and fatigue-reducing effects. In contrast, clinical studies demonstrate that a balanced diet with whole grains high in fibers, polyphenol-rich vegetables, and omega-3 fatty acid-rich foods might be able to improve disease-related fatigue symptoms. Nonetheless, further research is needed to clarify conflicting results in the literature and substantiate the promising results from human trials on fatigue.
Anti-Inflammatory Diets and Fatigue (2019)
Haß, Ulrike ; Herpich, Catrin ; Norman, Kristina
Accumulating data indicates a link between a pro-inflammatory status and occurrence of chronic disease-related fatigue. The questions are whether the observed inflammatory profile can be (a) improved by anti-inflammatory diets, and (b) if this improvement can in turn be translated into a significant fatigue reduction. The aim of this narrative review was to investigate the effect of anti-inflammatory nutrients, foods, and diets on inflammatory markers and fatigue in various patient populations. Next to observational and epidemiological studies, a total of 21 human trials have been evaluated in this work. Current available research is indicative, rather than evident, regarding the effectiveness of individuals’ use of single nutrients with anti-inflammatory and fatigue-reducing effects. In contrast, clinical studies demonstrate that a balanced diet with whole grains high in fibers, polyphenol-rich vegetables, and omega-3 fatty acid-rich foods might be able to improve disease-related fatigue symptoms. Nonetheless, further research is needed to clarify conflicting results in the literature and substantiate the promising results from human trials on fatigue.
A New Approach of Extraction of α-Amylase/trypsin Inhibitors from Wheat (Triticum aestivum L.), Based on Optimization Using Plackett–Burman and Box–Behnken Designs (2019)
Sagu, Sorel Tchewonpi ; Huschek, Gerd ; Bönick, Josephine ; Homann, Thomas ; Rawel, Harshadrai Manilal
Wheat is one of the most consumed foods in the world and unfortunately causes allergic reactions which have important health effects. The α-amylase/trypsin inhibitors (ATIs) have been identified as potentially allergen components of wheat. Due to a lack of data on optimization of ATI extraction, a new wheat ATIs extraction approach combining solvent extraction and selective precipitation is proposed in this work. Two types of wheat cultivars (Triticum aestivum L.), Julius and Ponticus were used and parameters such as solvent type, extraction time, temperature, stirring speed, salt type, salt concentration, buffer pH and centrifugation speed were analyzed using the Plackett-Burman design. Salt concentration, extraction time and pH appeared to have significant effects on the recovery of ATIs (p < 0.01). In both wheat cultivars, Julius and Ponticus, ammonium sulfate substantially reduced protein concentration and inhibition of amylase activity (IAA) compared to sodium chloride. The optimal conditions with desirability levels of 0.94 and 0.91 according to the Doehlert design were: salt concentrations of 1.67 and 1.22 M, extraction times of 53 and 118 min, and pHs of 7.1 and 7.9 for Julius and Ponticus, respectively. The corresponding responses were: protein concentrations of 0.31 and 0.35 mg and IAAs of 91.6 and 83.3%. Electrophoresis and MALDI-TOF/MS analysis showed that the extracted ATIs masses were between 10 and 20 kDa. Based on the initial LC-MS/MS analysis, up to 10 individual ATIs were identified in the extracted proteins under the optimal conditions. The positive implication of the present study lies in the quick assessment of their content in different varieties especially while considering their allergenic potential.
A New Approach of Extraction of α-Amylase/trypsin Inhibitors from Wheat (Triticum aestivum L.), Based on Optimization Using Plackett–Burman and Box–Behnken Designs (2019)
Sagu, Sorel Tchewonpi ; Huschek, Gerd ; Bönick, Josephine ; Homann, Thomas ; Rawel, Harshadrai Manilal
Wheat is one of the most consumed foods in the world and unfortunately causes allergic reactions which have important health effects. The α-amylase/trypsin inhibitors (ATIs) have been identified as potentially allergen components of wheat. Due to a lack of data on optimization of ATI extraction, a new wheat ATIs extraction approach combining solvent extraction and selective precipitation is proposed in this work. Two types of wheat cultivars (Triticum aestivum L.), Julius and Ponticus were used and parameters such as solvent type, extraction time, temperature, stirring speed, salt type, salt concentration, buffer pH and centrifugation speed were analyzed using the Plackett-Burman design. Salt concentration, extraction time and pH appeared to have significant effects on the recovery of ATIs (p < 0.01). In both wheat cultivars, Julius and Ponticus, ammonium sulfate substantially reduced protein concentration and inhibition of amylase activity (IAA) compared to sodium chloride. The optimal conditions with desirability levels of 0.94 and 0.91 according to the Doehlert design were: salt concentrations of 1.67 and 1.22 M, extraction times of 53 and 118 min, and pHs of 7.1 and 7.9 for Julius and Ponticus, respectively. The corresponding responses were: protein concentrations of 0.31 and 0.35 mg and IAAs of 91.6 and 83.3%. Electrophoresis and MALDI-TOF/MS analysis showed that the extracted ATIs masses were between 10 and 20 kDa. Based on the initial LC-MS/MS analysis, up to 10 individual ATIs were identified in the extracted proteins under the optimal conditions. The positive implication of the present study lies in the quick assessment of their content in different varieties especially while considering their allergenic potential.
Technical note: Rapid field test for the quantification of vitamin E, beta-carotene, and vitamin A in whole blood and plasma of dairy cattle (2019)
Ghaffari, Morteza Hosseini ; Bernhoeft, Katrin ; Etheve, Stephane ; Immig, Irmgard ; Hoelker, Michael ; Sauerwein, Helga ; Schweigert, Florian J.
Fast and easy tests for quantifying fat-soluble vitamins such as vitamin E and vitamin A, as well as beta-carotene, in whole blood without a need to preprocess blood samples could facilitate assessment of the vitamin status of dairy cattle. The objective of this study was to validate a field-portable fluorometer/spectrophotometer assay for the rapid quantification of these vitamins in whole blood and plasma of dairy cows and calves. We measured the concentrations of vitamin E and beta-carotene in whole blood and plasma from 28 dairy cows and 11 calves using the iCheck test (Bio-Analyt GmbH, Teltow, Germany) and compared the results with the current analytical standard (HPLC) in 2 independent laboratories, one at the University of Potsdam (Germany) and at one at DSM Nutritional Products Ltd. (Kaiseraugst, Switzerland). For vitamin A, the HPLC measurements were done only in the laboratory in Germany. The whole-blood concentrations of vitamin E as determined by iCheck (blood-hematocritcorrected) ranged from 1.82 to 4.99 mg/L in dairy cows and 0.34 to 3.40 mg/L in calves. These findings were moderately correlated (R-2 = 0.66) with the values assessed by HPLC in dairy cattle (cows + calves). When calves were excluded, the correlation was higher (R-2 = 0.961). The beta-carotene and vitamin A values obtained by the reference method HPLC were highly correlated with the iCheck methods in whole blood (R-2 = 0.99 and 0.88, respectively). In plasma, we observed strong correlations between the concentrations assessed by iCheck and those of HPLC for vitamin E (R-2 = 0.97), beta-carotene (R-2 = 0.98), and vitamin A (R-2 = 0.92) in dairy cattle (cows + calves). For vitamin E, beta-carotene, and vitamin A, we compared the relationship between the differences obtained by the iCheck assay and the HPLC measurements, as well as the magnitude of measurements, using Bland-Altman plots to test for systematic bias. For all 3 vitamins, the differences values were not outside the 95% acceptability limits; we found no systematic error between the 2 methods for all 3 analytes.
Associations of short stature and components of height with incidence of type 2 diabetes (2019)
Wittenbecher, Clemens ; Kuxhaus, Olga ; Boeing, Heiner ; Stefan, Norbert ; Schulze, Matthias B.
Aims/hypothesis This study aimed to evaluate associations of height as well as components of height (sitting height and leg length) with risk of type 2 diabetes and to explore to what extent associations are explainable by liver fat and cardiometabolic risk markers. Methods A case-cohort study within the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam study comprising 26,437 participants who provided blood samples was designed. We randomly selected a subcohort of 2500 individuals (2029 diabetes-free at baseline and with anamnestic, anthropometrical and metabolic data for analysis). Of the 820 incident diabetes cases identified in the full cohort during 7 years of follow-up, 698 remained for analyses after similar exclusions. Results After adjustment for age, potential lifestyle confounders, education and waist circumference, greater height was related to lower diabetes risk (HR per 10 cm, men 0.59 [95% CI 0.47, 0.75] and women 0.67 [0.51, 0.88], respectively). Leg length was related to lower risk among men and women, but only among men if adjusted for total height. Adjustment for liver fat and triacylglycerols, adiponectin and C-reactive protein substantially attenuated associations between height and diabetes risk, particularly among women. Conclusions/interpretation We observed inverse associations between height and risk of type 2 diabetes, which was largely related to leg length among men. The inverse associations may be partly driven by lower liver fat content and a more favourable cardiometabolic profile.
Domain-specific physical activity patterns and cardiorespiratory fitness among adults in Germany (2019)
Zeiher, Johannes ; Duch, M. ; Kroll, Lars Eric ; Mensink, Gerhardus Bernardus Maria ; Finger, Jonas David ; Keil, Thomas
Background Studies show that occupational physical activity (OPA) has less health-enhancing effects than leisure-time physical activity (LTPA). The spare data available suggests that OPA rarely includes aerobic PAs with little or no enhancing effects on cardiorespiratory fitness (CRF) as a possible explanation. This study aims to investigate the associations between patterns of OPA and LTPA and CRF among adults in Germany. Methods 1,204 men and 1,303 women (18-64 years), who participated in the German Health Interview and Examination Survey 2008-2011, completed a standardized sub-maximal cycle ergometer test to estimate maximal oxygen consumption (VO2max). Job positions were coded according to the level of physical effort to construct an occupational PA index and categorized as low vs. high OPA. LTPA was assessed via questionnaires and dichotomized in no vs. any LTPA participation. A combined LTPA/OPA variable was used (high OPA/ LTPA, low OPA/LTPA, high OPA/no LTPA, low OPA/no LTPA). Information on potential confounders was obtained via questionnaires (e.g., smoking and education) or physical measurements (e.g., waist circumference). Multi-variable logistic regression was used to analyze associations between OPA/LTPA patterns and VO2max. Results Preliminary analyses showed that less-active men were more likely to have a low VO2max with odds ratios (ORs) of 0.80 for low OPA/LTPA, 1.84 for high OPA/no LTPA and 3.46 for low OPA/no LTPA compared to high OPA/LTPA. The corresponding ORs for women were 1.11 for low OPA/LTPA, 3.99 for high OPA/no LTPA and 2.44 for low OPA/no LTPA, indicating the highest likelihood of low fitness for women working in physically demanding jobs and not engaging in LTPA. Conclusions Findings confirm a strong association between LTPA and CRF and suggest an interaction between OPA and LTPA patterns on CRF within the workforce in Germany. Women without LTPA are at high risk of having a low CRF, especially if they work in physically demanding jobs. Key messages Women not practicing leisure-time physical activity are at risk of having a low cardiorespiratory fitness, especially if they work in physically demanding jobs. Different impact of domains of physical activity should be considered when planning interventions to enhance fitness among the adult population.
Boiling and steaming induced changes in secondary metabolites in three different cultivars of pak choi (Brassica rapa subsp. chinensis) (2019)
Chen, Xiaomin ; Hanschen, Franziska S. ; Neugart, Susanne ; Schreiner, Monika ; Vargas, Sara A. ; Gutschmann, Björn ; Baldermann, Susanne
Pak choi (Brassica rapa subsp. chinensis) is a leafy vegetable that is widely available in Asia and consumed in rising quantities in Europe. Pak choi contains high levels of secondary plant metabolites, such as carotenoids, chlorophylls, glucosinolates, phenolic compounds, and vitamin K, which are beneficial for humans if consumed on a regular basis. The evaluation of the genotype-induced variation of secondary plant metabolites revealed that the cultivar ‘Amur’ contained the highest concentration of secondary plant metabolites. Furthermore, steaming retained more chlorophylls, glucosinolates, phenolic acids and flavonoid compounds than boiling. In contrast, both domestic cooking methods – boiling, and steaming – reduced the formation of glucosinolate breakdown products, especially the undesired epithionitriles and nitriles but less of the health-beneficial isothiocyanates.
Formation of trans-epoxy fatty acids correlates with formation of isoprostanes and could serve as biomarker of oxidative stress (2019)
Rund, Katharina M. ; Heylmann, Daniel ; Seiwert, Nina ; Wecklein, Sabine ; Oger, Camille ; Galano, Jean-Marie ; Durand, Thierry ; Chen, Rongjun ; Güler, Faikah ; Fahrer, Jörg ; Bornhorst, Julia ; Schebb, Nils Helge
In mammals, epoxy-polyunsaturated fatty acids (epoxy-PUFA) are enzymatically formed from naturally occurring all-cis PUFA by cytochrome P450 monooxygenases leading to the generation of cis-epoxy-PUFA (mixture of R,S- and S,R-enantiomers). In addition, also non-enzymatic chemical peroxidation gives rise to epoxy-PUFA leading to both, cis- and trans-epoxy-PUFA (mixture of R,R- and S,S-enantiomers). Here, we investigated for the first time trans-epoxy-PUFA and the trans/cis-epoxy-PUFA ratio as potential new biomarker of lipid peroxidation. Their formation was analyzed in correlation with the formation of isoprostanes (IsoP), which are commonly used as biomarkers of oxidative stress. Five oxidative stress models were investigated including incubations of three human cell lines as well as the in vivo model Caenorhabditis elegans with tert-butyl hydroperoxide (t-BOOH) and analysis of murine kidney tissue after renal ischemia reperfusion injury (IRI). A comprehensive set of IsoP and epoxy-PUFA derived from biologically relevant PUFA (ARA, EPA and DHA) was simultaneously quantified by LC-ESI(-)-MS/MS. Following renal IRI only a moderate increase in the kidney levels of IsoP and no relevant change in the trans/cis-epoxy-PUFA ratio was observed. In all investigated cell lines (HCT-116, HepG2 and Caki-2) as well as C. elegans a dose dependent increase of both, IsoP and the trans/cis-epoxy-PUFA ratio in response to the applied t-BOOH was observed. The different cell lines showed a distinct time dependent pattern consistent for both classes of autoxidatively formed oxylipins. Clear and highly significant correlations of the trans/cisepoxy-PUFA ratios with the IsoP levels were found in all investigated cell lines and C. elegans. Based on this, we suggest the trans/cis-epoxy-PUFA ratio as potential new biomarker of oxidative stress, which warrants further investigation.
Effects of a blend of green tea and curcuma extract supplementation on lipopolysaccharide-induced inflammation in horses and ponies (2019)
Starzonek, Janine ; Roscher, Katja ; Blither, Matthias ; Blaue, Dominique ; Schedlbauer, Carola ; Hire, Manuela ; Raila, Jens ; Vervuert, Ingrid
Background. In horses and ponies numerous medical conditions are known to be linked with inflammation in different tissues, especially in the liver. Besides affecting other metabolic pathways such as the expression of certain interleukins (IL), inflammation is associated with stress of the endoplasmic reticulum (ER). In particular, ER stress leads to adaptive stress response and can be measured by several markers of inflammatory and stress signalling pathways, like nuclear factor kappa B (NF-kB). Objectives. To investigate lipopolysaccharide (LPS)-induced inflammatory reactions and their modulation in horses and ponies by feeding a polyphenol-rich supplement consisting of green tea and curcuma. Methods. In a cross-over study, 11 animals were allocated to either a placebo or a supplement group and supplemented with 10 g of a blend of green tea and curcuma extract (GCE) or a placebo (calcium carbonate) once daily. After 21 days of supplementation, all animals underwent a LPS challenge to induce moderate systemic inflammation. Blood samples and liver biopsies were taken at standardized time points: 24 hours before and 12 hours after LPS challenge. Inflammatory blood parameters such as serum amyloid A (SAA), haptoglobin and retinol binding protein 4 (RBP4) were measured in serum. Hepatic mRNA levels of selected markers of inflammation such as haptoglobin, tumor necrosis factor alpha (TNF-alpha), IL-1 beta, IL-6, cluster of differentiation 68 (CD68), fibroblast growth factor 21 (FGF-21), NF-kappa B, activating transcription factor 4 (ATF4) were quantified by RT-qPCR. In addition, liver biopsies were examined histologically for inflammatory alterations. Results. Blood markers of acute inflammatory response increased after LPS challenge. In the liver, the proinflammatory cytokine IL-1 beta showed significantly lower mRNA levels after LPS challenge in the supplemented group (P = 0.04) compared to the placebo group. Levels of the hepatic CD68 mRNA increased significantly in the placebo group (P = 0.04). There were no significant differences between supplemented and placebo groups concerning other markers of inflammation and markers of ER stress within the liver. The number of hepatic macrophages were not different after LPS challenge in both feeding groups. Conclusion. LPS was able to induce inflammation but seemed less suitable to induce ER stress in the horses and ponies. The polyphenol-rich supplement showed some potential to reduce inflammatory responses. Nevertheless, the supplementation did not exert an overall anti-inflammatory effect in horses and ponies.
Selen und Jod: essenzielle Spurenelemente für die Schilddrüse (2019)
Lossow, Kristina ; Schwerdtle, Tanja ; Kipp, Anna
Selen und Jod sind essenzielle Spurenelemente, die gemeinsam für eine optimale Funktionstüchtigkeit der Schilddrüse erforderlich sind. Der Mangel eines oder beider Elemente führt zu Verschiebungen auf Ebene der Schilddrüsenhormonproduktion mit weitreichenden Konsequenzen für Stoffwechselprozesse, neurologische Entwicklung und Erkrankungen. Auch bei Autoimmunerkrankungen der Schilddrüse spielt die Versorgung mit Jod und Selen eine wichtige Rolle. Als Biomarker für den Selenstatus eignet sich der Gehalt des Gesamtselens oder der des Selenoproteins P im Serum. Zur Bestimmung des Jodstatus wird in der Regel der Jodgehalt im Urin herangezogen. Um den Versorgungszustand an diesen und vier weiteren essenziellen Spurenelementen besser zu erfassen, charakterisiert die Forschungsgruppe TraceAge alters- und geschlechtsspezifische Spurenelementprofile und neue funktionelle Biomarker der einzelnen Spurenelemente. Außerdem sollen Interaktionen weiterer Spurenelemente genauer untersucht werden.
Assessing autophagy in murine skeletal muscle: current findings to modulate and quantify the autophagic flux (2019)
König, Jeannette ; Grune, Tilman ; Ott, Christiane
Purpose of review In addition to the currently available lysosomotropic drugs and autophagy whole-body knockout mouse models, we provide alternative methods that enable the modulation and detection of autophagic flux in vivo, discussing advantages and disadvantages of each method. Recent findings With the autophagosome-lysosome fusion inhibitor colchicine in skeletal muscle and temporal downregulation of autophagy using a novel Autophagy related 5-short hairpin RNA (Atg5-shRNA) mouse model we mention two models that directly modulate autophagy flux in vivo. Furthermore, methods to quantify autophagy flux, such as mitophagy transgenic reporters, in situ immunofluorescent staining and multispectral imaging flow cytometry, in mature skeletal muscle and cells are addressed. To achieve clinical benefit, less toxic, temporary and cell-type-specific modulation of autophagy should be pursued further. A temporary knockdown as described for the Atg5-shRNA mice could provide a first insight into possible implications of autophagy inhibition. However, it is also important to take a closer look into the methods to evaluate autophagy after harvesting the tissue. In particular caution is required when experimental conditions can influence the final measurement and this should be pretested carefully.
Zn homeostasis in genetic models of Parkinson’s disease in Caenorhabditis elegans (2019)
Baesler, Jessica ; Kopp, Johannes F. ; Pohl, Gabriele ; Aschner, Michael ; Haase, Hajo ; Schwerdtle, Tanja ; Bornhorst, Julia
Selenoneine ameliorates peroxide-induced oxidative stress in C. elegans (2019)
Rohn, Isabelle ; Kroepfl, Nina ; Aschner, Michael ; Bornhorst, Julia ; Kuehnelt, Doris ; Schwerdtle, Tanja
Scope: Selenoneine (2-selenyl-N-alpha, N-alpha, N-alpha-trimethyl-L-histidine), the selenium (Se) analogue of the ubiquitous thiol compound and putative antioxidant ergothioneine, is the major organic selenium species in several marine fish species. Although its antioxidant efficacy has been proposed, selenoneine has been poorly characterized, preventing conclusions on its possible beneficial health effects. Methods and results: Treatment of Caenorhabditis elegans (C. elegans) with selenoneine for 18 h attenuated the induction of reactive oxygen and nitrogen species (RONS). However, the effect was not immediate, occurring 48 h post-treatment. Total Se and Se speciation analysis revealed that selenoneine was efficiently taken up and present in its original form directly after treatment, with no metabolic transformations observed. 48 h posttreatment, total Se in worms was slightly higher compared to controls and no selenoneine could be detected. Conclusion: The protective effect of selenoneine may not be attributed to the presence of the compound itself, but rather to the activation of molecular mechanisms with consequences at more protracted time points.
Pancreatic adipocytes mediate hypersecretion of insulin in diabetes-susceptible mice (2019)
Quiclet, Charline ; Dittberner, Nicole ; Gaessler, Anneke ; Stadion, Mandy ; Gerst, Felicia ; Helms, Anett ; Baumeier, Christian ; Schulz, Tim J. ; Schurmann, Annette
Objective: Ectopic fat accumulation in the pancreas in response to obesity and its implication on the onset of type 2 diabetes remain poorly understood. Intermittent fasting (IF) is known to improve glucose homeostasis and insulin resistance. However, the effects of IF on fat in the pancreas and beta-cell function remain largely unknown. Our aim was to evaluate the impact of IF on pancreatic fat accumulation and its effects on islet function. Methods: New Zealand Obese (NZO) mice were fed a high-fat diet ad libitum (NZO-AL) or fasted every other day (intermittent fasting, NZO-IF) and pancreatic fat accumulation, glucose homoeostasis, insulin sensitivity, and islet function were determined and compared to ad libitum-fed B6.V-Lep(ob/ob) (ob/ob) mice. To investigate the crosstalk of pancreatic adipocytes and islets, co-culture experiments were performed. Results: NZO-IF mice displayed better glucose homeostasis and lower fat accumulation in both the pancreas (-32%) and the liver (-35%) than NZO-AL mice. Ob/ob animals were insulin-resistant and had low fat in the pancreas but high fat in the liver. NZO-AL mice showed increased fat accumulation in both organs and exhibited an impaired islet function. Co-culture experiments demonstrated that pancreatic adipocytes induced a hypersecretion of insulin and released higher levels of free fatty adds than adipocytes of inguinal white adipose tissue. Conclusions: These results suggest that pancreatic fat participates in diabetes development, but can be prevented by IF. (C) 2019 Published by Elsevier Inc.
Financial impact of sarcopenia or low muscle mass - a short review (2019)
Norman, Kristina ; Otten, Lindsey
Background & aims: Low muscle mass is associated with increased falls, medical complications, length of hospital stay and loss of independence. An increasing number of studies has also shown the association between sarcopenia and health care expenditure. The following narrative review summarizes the current evidence on the economic relevance of low muscle mass (MM) or sarcopenia. Methods: An extensive search of the literature in Medline identified twelve studies in English, which evaluated direct and indirect health care expenditure in patients with low muscle mass or sarcopenia (low MM and strength or mobility). Results: Three studies analysed the cost of age-related loss of MM or strength in large surveys of the general, older population. Six retrospective analyses evaluated perioperative medical costs related to low MM in primarily older patients from different medical areas. One prospective study presented hospital costs related to sarcopenia in patients with gastric cancer. Two studies presented data from general hospital patients. Despite the difference in diagnostic criteria, study population and statistical design, low MM and sarcopenia were consistently identified as predictors of increased health care expenditure in community, perioperative and general hospital settings. Conclusions: Low MM and sarcopenia are prevalent and associated with significantly higher health care costs. Considering the demographic change, which will lead to an increasing number of patients with sarcopenia, every effort should be made to identify and treat patients with sarcopenia. The use of a unified definition and diagnostic criteria would allow a better comparison of data. (C) 2018 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.
Low breastmilk vitamin A concentration is prevalent in rural Ethiopia (2019)
Abebe, Zeweter ; Haki, Gulelat Desse ; Schweigert, Florian J. ; Henkel, Ina M. ; Baye, Kaleab
Background There is scant information on the breastmilk vitamin A (BMVA) concentration of lactating women in developing countries, partly due to lack of methods applicable in-field. Objective To assess BMVA concentrations of samples collected from lactating women of children aged 6-23 months, in Mecha district, Ethiopia. Subjects/methods Data on socio-demographic and anthropometric characteristics were collected from randomly selected lactating women (n = 104). Breast milk samples were collected and vitamin A concentrations were analyzed using HPLC and iCheck FLUORO then the two measurements were compared. Results The prevalence of underweight (BMI < 18.5 kg/m(2)) among lactating women was 17%. Seventy six percent of the BMVA values were < 1.05 mu mol/l and 81% were < 8 mu g/g fat. The mean BMVA concentration accounted to 41% of the estimated average value for mothers in developing countries. The BMVA values from HPLC and iCheck were correlated (r = 0.59, p = < 0.001), but it was not strong. Conclusions The result indicates the low vitamin A status of the lactating women and their children. It further indicates that intake assessments should not use average BMVA composition. The possibility of using iCheck for monitoring interventions designed to improve vitamin A status of lactating women with low BMVA requires further investigation.
Low birth weight, a risk factor for diseases in later life, is a surrogate of insulin resistance at birth (2019)
Tian, Mei ; Reichetzeder, Christoph ; Li, Jian ; Hocher, Berthold
Low birth weight (LBW) is associated with diseases in adulthood. The birthweight attributed risk is independent of confounding such as gestational age, sex of the newborn but also social factors. The birthweight attributed risk for diseases in later life holds for the whole spectrum of birthweight. This raises the question what pathophysiological principle is actually behind the association. In this review, we provide evidence that LBW is a surrogate of insulin resistance. Insulin resistance has been identified as a key factor leading to type 2 diabetes, cardiovascular disease as well as kidney diseases. We first provide evidence linking LBW to insulin resistance during intrauterine life. This might be caused by both genetic (genetic variations of genes controlling glucose homeostasis) and/or environmental factors (due to alterations of macronutrition and micronutrition of the mother during pregnancy, but also effects of paternal nutrition prior to conception) leading via epigenetic modifications to early life insulin resistance and alterations of intrauterine growth, as insulin is a growth factor in early life. LBW is rather a surrogate of insulin resistance in early life - either due to inborn genetic or environmental reasons - rather than a player on its own.
Dynamic changes of muscle insulin sensitivity after metabolic surgery (2019)
Gancheva, Sofiya ; Ouni, Meriem ; Jelenik, Tomas ; Koliaki, Chrysi ; Szendroedi, Julia ; Toledo, Frederico G. S. ; Markgraf, Daniel Frank ; Pesta, Dominik H. ; Mastrototaro, Lucia ; De Filippo, Elisabetta ; Herder, Christian ; Jähnert, Markus ; Weiss, Jürgen ; Strassburger, Klaus ; Schlensak, Matthias ; Schürmann, Annette ; Roden, Michael
The mechanisms underlying improved insulin sensitivity after surgically-induced weight loss are still unclear. We monitored skeletal muscle metabolism in obese individuals before and over 52 weeks after metabolic surgery. Initial weight loss occurs in parallel with a decrease in muscle oxidative capacity and respiratory control ratio. Persistent elevation of intramyocellular lipid intermediates, likely resulting from unrestrained adipose tissue lipolysis, accompanies the lack of rapid changes in insulin sensitivity. Simultaneously, alterations in skeletal muscle expression of genes involved in calcium/lipid metabolism and mitochondrial function associate with subsequent distinct DNA methylation patterns at 52 weeks after surgery. Thus, initial unfavorable metabolic changes including insulin resistance of adipose tissue and skeletal muscle precede epigenetic modifications of genes involved in muscle energy metabolism and the long-term improvement of insulin sensitivity.
Management of malnutrition in older patients (2019)
Volkert, Dorothee ; Beck, Anne Marie ; Cederholm, Tommy ; Cereda, Emanuele ; Cruz-Jentoft, Alfonso J. ; Goisser, Sabine ; de Groot, Lisette ; Grosshauser, Franz ; Kiesswetter, Eva ; Norman, Kristina ; Pourhassan, Maryam ; Reinders, Ilse ; Roberts, Helen C. ; Rolland, Yves ; Schneider, Stéphane M. ; Sieber, Cornel ; Thiem, Ulrich ; Visser, Marjolein ; Wijnhoven, Hanneke ; Wirth, Rainer
Malnutrition is widespread in older people and represents a major geriatric syndrome with multifactorial etiology and severe consequences for health outcomes and quality of life. The aim of the present paper is to describe current approaches and evidence regarding malnutrition treatment and to highlight relevant knowledge gaps that need to be addressed. Recently published guidelines of the European Society for Clinical Nutrition and Metabolism (ESPEN) provide a summary of the available evidence and highlight the wide range of different measures that can be taken—from the identification and elimination of potential causes to enteral and parenteral nutrition—depending on the patient’s abilities and needs. However, more than half of the recommendations therein are based on expert consensus because of a lack of evidence, and only three are concern patient-centred outcomes. Future research should further clarify the etiology of malnutrition and identify the most relevant causes in order to prevent malnutrition. Based on limited and partly conflicting evidence and the limitations of existing studies, it remains unclear which interventions are most effective in which patient groups, and if specific situations, diseases or etiologies of malnutrition require specific approaches. Patient-relevant outcomes such as functionality and quality of life need more attention, and research methodology should be harmonised to allow for the comparability of studies.
Medicago TERPENE SYNTHASE 10 is involved in defense against an oomycete root pathogen (2019)
Yadav, Heena ; Dreher, Dorothée ; Athmer, Benedikt ; Porzel, Andrea ; Gavrin, Aleksandr ; Baldermann, Susanne ; Tissier, Alain ; Hause, Bettina
In nature, plants interact with numerous beneficial or pathogenic soil-borne microorganisms. Plants have developed various defense strategies to expel pathogenic microbes, some of which function soon after pathogen infection. We used Medicago truncatula and its oomycete pathogen Aphanomyces euteiches to elucidate early responses of the infected root. A. euteiches causes root rot disease in legumes and is a limiting factor in legume production. Transcript profiling of seedlings and adult plant roots inoculated with A. euteiches zoospores for 2 h revealed specific upregulation of a gene encoding a putative sesquiterpene synthase (M. truncatula TERPENE SYNTHASE 10 [MtTPS10]) in both developmental stages. MtTPS10 was specifically expressed in roots upon oomycete infection. Heterologous expression of MtTPS10 in yeast led to production of a blend of sesquiterpenes and sesquiterpene alcohols, with NMR identifying a major peak corresponding to himalachol. Moreover, plants carrying a tobacco (Nicotiana tabacum) retrotransposon Tnt1 insertion in MtTPS10 lacked the emission of sesquiterpenes upon A. euteiches infection, supporting the assumption that the identified gene encodes a multiproduct sesquiterpene synthase. Mttps10 plants and plants with reduced MtTPS10 transcript levels created by expression of an MtTPS10-artificial microRNA in roots were more susceptible to A. euteiches infection than were the corresponding wild-type plants and roots transformed with the empty vector, respectively. Sesquiterpenes produced by expression of MtTPS10 in yeast also inhibited mycelial growth and A. euteiches zoospore germination. These data suggest that sesquiterpene production in roots by MtTPS10 plays a previously unrecognized role in the defense response of M. truncatula against A. euteiches.
Investigation of the post mortem zinc protoporphyrin IX fluorescence with respect to its protein-bound and unbound occurrence in aqueous meat extracts (2019)
Khozroughi, Amin Ghadiri ; Braga, Tess Waldbach ; Wagner, Janine ; Rawel, Harshadrai
Zinc protoporphyrin IX (ZnPP) is known to accumulate in most meat products during storage. However, the pathway of its formation is not yet completely clarified. To gain more insights into the specificity of ZnPP occurrence, a SEC-HPLC-UV-fluorescence setup was established to screen the proteins in aqueous meat extracts for their ZnPP fluorescence during incubation. In accordance with previous studies it was identified by SDS-PAGE and MALDI-TOF-MS that ZnPP formation takes place in myoglobin. In this study, valuable new insights into the ZnPP forming pathway were gained, as our results indicated that a significant part of ZnPP - after being formed within the protein - is transitioned into free ZnPP during incubation. Additionally, the obtained results implied that ZnPP may also occur in proteins of higher molecular weight (> 100 kDa).
Methyl jasmonate-induced changes of flavor profiles during the processing of Green, Oolong, and Black Tea (2019)
Shi, Jiang ; Xie, Dongchao ; Qi, Dandan ; Peng, Qunhua ; Chen, Zongmao ; Schreiner, Monika ; Lin, Zhi ; Baldermann, Susanne
Tea aroma is one of the most important factors affecting the character and quality of tea. Here we describe the practical application of methyl jasmonate (MeJA) to improve the aroma quality of teas. The changes of selected metabolites during crucial tea processing steps, namely, withering, fixing and rolling, and fermentation, were analyzed. MeJA treatment of tea leaves (12, 24, 48, and 168 h) greatly promotes the aroma quality of green, oolong, and black tea products when comparing with untreated ones (0 h) and as confirmed by sensory evaluation. MeJA modulates the aroma profiles before, during, and after processing. Benzyl alcohol, benzaldehyde, 2-phenylethyl alcohol, phenylacetaldehyde, and trans-2-hexenal increased 1.07- to 3-fold in MeJA-treated fresh leaves and the first two maintained at a higher level in black tea and the last two in green tea. This correlates with a decrease in aromatic amino acids by more than twofold indicating a direct relation to tryptophan- and phenylalanine-derived volatiles. MeJA-treated oolong tea was characterized by a more pleasant aroma. Especially the terpenoids linalool and oxides, geraniol, and carvenol increased by more than twofold.
Mussel-inspired coatings with tunable wettability, for enhanced antibacterial efficiency and reduced bacterial adhesion (2019)
Li, Mingjun ; Schlaich, Christoph ; Kulka, Michael Willem ; Donskyi, Ievgen S. ; Schwerdtle, Tanja ; Unger, Wolfgang E. S. ; Haag, Rainer
Over the last few decades, there has been a tremendous increase in research on antibacterial surface coatings as an alternative strategy against bacterial infections. Although there are several examples of effective strategies to prevent bacterial adhesion, the effect of the wetting properties on the coating was rarely considered as a crucial factor. Here we report an in-depth study on the effect of extreme wettability on the antibacterial efficiency of a silver nanoparticles ( AgNPs)-based coating. By controlling surface polymerization of mussel-inspired dendritic polyglycerol ( MI-dPG) and post-functionalization, surfaces with wetting properties ranging from superhydrophilic to superhydrophobic were fabricated. Subsequently, AgNPs were embedded into the coatings by applying in situ reduction using the free catechols-moieties present in the MI-dPG coating. The resulting polymer coatings exhibited excellent antibacterial ability against planktonic Escherichia coli ( E. coli) DH5a and Staphylococcus aureus ( S. aureus) SH1000. The antibacterial efficiency of the coatings was analyzed by using inductively coupled plasma mass spectrometry ( ICP-MS) and bacterial viability tests. Furthermore, the antifouling properties of the coatings in relation to the antibacterial properties were evaluated.
Measles Virus Infection Fosters Dendritic Cell Motility in a 3D Environment to Enhance Transmission to Target Cells in the Respiratory Epithelium (2019)
Derakhshani, Shaghayegh ; Kurz, Andreas ; Japtok, Lukasz ; Schumacher, Fabian ; Pilgram, Lisa ; Steinke, Maria ; Kleuser, Burkhard ; Sauer, Markus ; Schneider-Schaulies, Sibylle ; Avota, Elita
Transmission of measles virus (MV) from dendritic to airway epithelial cells is considered as crucial to viral spread late in infection. Therefore, pathways and effectors governing this process are promising targets for intervention. To identify these, we established a 3D respiratory tract model where MV transmission by infected dendritic cells (DCs) relied on the presence of nectin-4 on H358 lung epithelial cells. Access to recipient cells is an important prerequisite for transmission, and we therefore analyzed migration of MV-exposed DC cultures within the model. Surprisingly, enhanced motility toward the epithelial layer was observed for MV-infected DCs as compared to their uninfected siblings. This occurred independently of factors released from H358 cells indicating that MV infection triggered cytoskeletal remodeling associated with DC polarization enforced velocity. Accordingly, the latter was also observed for MV-infected DCs in collagen matrices and was particularly sensitive to ROCK inhibition indicating infected DCs preferentially employed the amoeboid migration mode. This was also implicated by loss of podosomes and reduced filopodial activity both of which were retained in MV-exposed uninfected DCs. Evidently, sphingosine kinase (SphK) and sphingosine-1-phosphate (S1P) as produced in response to virus-infection in DCs contributed to enhanced velocity because this was abrogated upon inhibition of sphingosine kinase activity. These findings indicate that MV infection promotes a push-and-squeeze fast amoeboid migration mode via the SphK/S1P system characterized by loss of filopodia and podosome dissolution. Consequently, this enables rapid trafficking of virus toward epithelial cells during viral exit.
Crosstalk of Nrf2 with the Trace Elements Selenium, Iron, Zinc, and Copper (2019)
Schwarz, Maria ; Lossow, Kristina ; Kopp, Johannes F. ; Schwerdtle, Tanja ; Kipp, Anna P.
Trace elements, like Cu, Zn, Fe, or Se, are important for the proper functioning of antioxidant enzymes. However, in excessive amounts, they can also act as pro-oxidants. Accordingly, trace elements influence redox-modulated signaling pathways, such as the Nrf2 pathway. Vice versa, Nrf2 target genes belong to the group of transport and metal binding proteins. In order to investigate whether Nrf2 directly regulates the systemic trace element status, we used mice to study the effect of a constitutive, whole-body Nrf2 knockout on the systemic status of Cu, Zn, Fe, and Se. As the loss of selenoproteins under Se-deprived conditions has been described to further enhance Nrf2 activity, we additionally analyzed the combination of Nrf2 knockout with feeding diets that provide either suboptimal, adequate, or supplemented amounts of Se. Experiments revealed that the Nrf2 knockout partially affected the trace element concentrations of Cu, Zn, Fe, or Se in the intestine, liver, and/or plasma. However, aside from Fe, the other three trace elements were only marginally modulated in an Nrf2-dependent manner. Selenium deficiency mainly resulted in increased plasma Zn levels. One putative mediator could be the metal regulatory transcription factor 1, which was up-regulated with an increasing Se supply and downregulated in Se-supplemented Nrf2 knockout mice.
A quick and simple method for the determination of six trace elements in mammalian serum samples using ICP-MS/MS (2019)
Kopp, Johannes Florian ; Müller, Sandra Marie ; Pohl, Gabriele ; Lossow, Kristina ; Kipp, Anna Patricia ; Schwerdtle, Tanja
In order to assess the individual trace element status of humans for either medical or scientific purposes, amongst others, blood serum levels are determined. Furthermore, animal models are used to study interactions of trace elements. Most published methods require larger amounts (500-1000 mu L) of serum to achieve a reliable determination of multiple trace elements. However, oftentimes, these amounts of serum cannot be dedicated to a single analysis and the amount available for TE-determination is much lower. Therefore, a published ICP-MS/MS method for trace element determination in serum was miniaturized, optimized and validated for the measurement of Mn, Fe, Cu Zn, I and Se in as little as 50 mu L of human and murine serum and is presented in this work. For validation, recoveries of multiple LOTs and levels from commercially available human reference serum samples were determined, infra- and inter-day variations were assessed and limits of detection and quantification determined. It is shown, that the method is capable of giving accurate and reproducible results for all six elements within the relevant concentration ranges for samples from humans living in central Europe as well as from laboratory mice. As a highlight, the achieved limits of detection and quantification for Mn were found to be at 0.02 mu g/L serum and 0.05 mu g/L serum, respectively, while using an alkaline diluent for the parallel determination of iodine.
Evaluation of the DNA damage in lymphocytes, sperm and buccal cells of workers under environmental and occupational boron exposure conditions (2019)
Basaran, Nursen ; Duydu, Yalcin ; Ustundag, Aylin ; Taner, Gokce ; Aydin, Sevtap ; Anlar, Hatice Gul ; Yalcin, Can Ozgur ; Bacanli, Merve ; Aydos, Kaan ; Atabekoglu, Cem Somer ; Golka, Klaus ; Ickstadt, Katja ; Schwerdtle, Tanja ; Werner, Matthias ; Meyer, Sören ; Bolt, Hermann M.
Industrial production and use of boron compounds have increased during the last decades, especially for the manufacture of borosilicate glass, fiberglass, metal alloys and flame retardants. This study was conducted in two districts of Balikesir; Bandirma and Bigadic, which geographically belong to the Marmara Region of Turkey. Bandirma is the production and exportation zone for the produced boric acid and some borates and Bigadic has the largest B deposits in Turkey. 102 male workers who were occupationally exposed to boron from Bandirma and 110 workers who were occupationally and environmentally exposed to boron from Bigadic participated to our study. In this study the DNA damage in the sperm, blood and buccal cells of 212 males was evaluated by comet and micronucleus assays. No significant increase in the DNA damage in blood, sperm and buccal cells was observed in the residents exposed to boron both occupationally and environmentally (p = 0.861) for Comet test in the sperm samples, p = 0.116 for Comet test in the lymphocyte samples, p = 0.042 for micronucleus (MN) test, p = 0.955 for binucleated cells (BN), p = 1.486 for condensed chromatin (CC), p = 0.455 for karyorrhectic cells (KHC), p = 0.541 for karyolitic cells (KLY), p = 1.057 for pyknotic cells (PHC), p = 0.331 for nuclear bud (NBUD)). No correlations were seen between blood boron levels and tail intensity values of the sperm samples, lymphocyte samples, frequencies of MN, BN, KHC, KYL, PHC and NBUD. The results of this study came to the same conclusions of the previous studies that boron does not induce DNA damage even under extreme exposure conditions.
Acid sphingomyelinase deficiency ameliorates Farber disease (2019)
Beckmann, Nadine ; Becker, Katrin Anne ; Kadow, Stephanie ; Schumacher, Fabian ; Kramer, Melanie ; Kühn, Claudine ; Schulz-Schaeffer, Walter J. ; Edwards, Michael J. ; Kleuser, Burkhard ; Gulbins, Erich ; Carpinteiro, Alexander
Farber disease is a rare lysosomal storage disorder resulting from acid ceramidase deficiency and subsequent ceramide accumulation. No treatments for Farber disease are clinically available, and affected patients have a severely shortened lifespan. We have recently reported a novel acid ceramidase deficiency model that mirrors the human disease closely. Acid sphingomyelinase is the enzyme that generates ceramide upstream of acid ceramidase in the lysosomes. Using our acid ceramidase deficiency model, we tested if acid sphingomyelinase could be a potential novel therapeutic target for the treatment of Farber disease. A number of functional acid sphingomyelinase inhibitors are clinically available and have been used for decades to treat major depression. Using these as a therapeutic for Farber disease, thus, has the potential to improve central nervous symptoms of the disease as well, something all other treatment options for Farber disease can’t achieve so far. As a proof-of-concept study, we first cross-bred acid ceramidase deficient mice with acid sphingomyelinase deficient mice in order to prevent ceramide accumulation. Double-deficient mice had reduced ceramide accumulation, fewer disease manifestations, and prolonged survival. We next targeted acid sphingomyelinase pharmacologically, to test if these findings would translate to a setting with clinical applicability. Surprisingly, the treatment of acid ceramidase deficient mice with the acid sphingomyelinase inhibitor amitriptyline was toxic to acid ceramidase deficient mice and killed them within a few days of treatment. In conclusion, our study provides the first proof-of-concept that acid sphingomyelinase could be a potential new therapeutic target for Farber disease to reduce disease manifestations and prolong survival. However, we also identified previously unknown toxicity of the functional acid sphingomyelinase inhibitor amitriptyline in the context of Farber disease, strongly cautioning against the use of this substance class for Farber disease patients
A Zinpyr-1-based fluorimetric microassay for free zinc in human serum (2019)
Alker, Wiebke ; Schwerdtle, Tanja ; Schomburg, Lutz ; Haase, Hajo
Zinc is an essential trace element, making it crucial to have a reliable biomarker for evaluating an individual’s zinc status. The total serum zinc concentration, which is presently the most commonly used biomarker, is not ideal for this purpose, but a superior alternative is still missing. The free zinc concentration, which describes the fraction of zinc that is only loosely bound and easily exchangeable, has been proposed for this purpose, as it reflects the highly bioavailable part of serum zinc. This report presents a fluorescence-based method for determining the free zinc concentration in human serum samples, using the fluorescent probe Zinpyr-1. The assay has been applied on 154 commercially obtained human serum samples. Measured free zinc concentrations ranged from 0.09 to 0.42 nM with a mean of 0.22 ± 0.05 nM. It did not correlate with age or the total serum concentrations of zinc, manganese, iron or selenium. A negative correlation between the concentration of free zinc and total copper has been seen for sera from females. In addition, the free zinc concentration in sera from females (0.21 ± 0.05 nM) was significantly lower than in males (0.23 ± 0.06 nM). The assay uses a sample volume of less than 10 µL, is rapid and cost-effective and allows us to address questions regarding factors influencing the free serum zinc concentration, its connection with the body’s zinc status, and its suitability as a future biomarker for an individual’s zinc status.
Role of GDF15 in active lifestyle induced metabolic adaptations and acute exercise response in mice (2019)
Gil, Carla Igual ; Ost, Mario ; Kasch, Juliane ; Schumann, Sara ; Heider, Sarah ; Klaus, Susanne
Physical activity is an important contributor to muscle adaptation and metabolic health. Growth differentiation factor 15 (GDF15) is established as cellular and nutritional stress-induced cytokine but its physiological role in response to active lifestyle or acute exercise is unknown. Here, we investigated the metabolic phenotype and circulating GDF15 levels in lean and obese male C57BI/6J mice with long-term voluntary wheel running (VWR) intervention. Additionally, treadmill running capacity and exercise-induced muscle gene expression was examined in GDF15-ablated mice. Active lifestyle mimic via VWR improved treadmill running performance and, in obese mice, also metabolic phenotype. The post-exercise induction of skeletal muscle transcriptional stress markers was reduced by VWR. Skeletal muscle GDF15 gene expression was very low and only transiently increased post-exercise in sedentary but not in active mice. Plasma GDF15 levels were only marginally affected by chronic or acute exercise. In obese mice, VWR reduced GDF15 gene expression in different tissues but did not reverse elevated plasma GDF15. Genetic ablation of GDF15 had no effect on exercise performance but augmented the post exercise expression of transcriptional exercise stress markers (Atf3, Atf6, and Xbp1s) in skeletal muscle. We conclude that skeletal muscle does not contribute to circulating GDF15 in mice, but muscle GDF15 might play a protective role in the exercise stress response.
Narrow-Banded UVB Affects the Stability of Secondary Plant Metabolites in Kale (Brassica oleracea var. sabellica) and Pea (Pisum sativum) Leaves Being Added to Lentil Flour Fortified Bread: A Novel Approach for Producing Functional Foods (2019)
Klopsch, Rebecca ; Baldermann, Susanne ; Voss, Alexander ; Rohn, Sascha ; Schreiner, Monika ; Neugart, Susanne
Young kale and pea leaves are rich in secondary plant metabolites (SPMs) whose profile can be affected by ultraviolet B (UVB) radiation. Carotenoids and flavonoids in kale and pea exposed to narrow-banded UVB, produced by innovative light-emitting diodes (LEDs), and subsequently used for breadmaking were investigated for the first time, thus combining two important strategies to increase the SPMs intake. Breads were also fortified with protein-rich lentil flour. Antioxidant activity in the ‘vegetable breads’ indicated health-promoting effects. Lentil flour increased the antioxidant activity in all of the ‘vegetable breads’. While carotenoids and chlorophylls showed a minor response to UVB treatment, kaempferol glycosides decreased in favor of increasing quercetin glycosides, especially in kale. Additionally, breadmaking caused major decreases in carotenoids and a conversion of chlorophyll to bioactive degradation products. In ‘kale breads’ and ‘pea breads’, 20% and 84% of flavonoid glycosides were recovered. Thus, kale and pea leaves seem to be suitable natural ingredients for producing innovative Functional Foods.
Severe Weight Loss and Its Association with Fatigue in Old Patients at Discharge from a Geriatric Hospital (2019)
Franz, Kristina ; Otten, Lindsey ; Müller-Werdan, Ursula ; Döhner, Wolfram ; Norman, Kristina
Although malnutrition is frequent in the old, little is known about its association with fatigue. We evaluated the relation of self-reported severe weight loss with fatigue and the predictors for fatigue in old patients at hospital discharge. Severe weight loss was defined according to involuntary weight loss >= 5% in the last three months. We determined fatigue with the validated Brief Fatigue Inventory questionnaire. The regression analyses were adjusted for age, sex, number of comorbidities, medications/day, and BMI. Of 424 patients aged between 61 and 98 y, 34.1% had severe weight loss. Fatigue was higher in patients with severe weight loss (3.7 +/- 2.3 vs. 3.2 +/- 2.3 points, p = 0.021). In a multinomial regression model, weight loss was independently associated with higher risk for moderate fatigue (OR:1.172, CI:1.026-1.338, p = 0.019) and with increased risk for severe fatigue (OR:1.209, CI:1.047-1.395, p = 0.010) together with the number of medications/day (OR:1.220, CI:1.023-1.455, p = 0.027). In a binary regression model, severe weight loss predicted moderate-to-severe fatigue in the study population (OR:1.651, CI:1.052-2.590, p = 0.029). In summary, patients with self-reported severe weight loss at hospital discharge exhibited higher fatigue levels and severe weight loss was an independent predictor of moderate and severe fatigue, placing these patients at risk for impaired outcome in the post-hospital period.
Brassica-enriched wheat bread: Unraveling the impact of ontogeny and breadmaking on bioactive secondary plant metabolites of pak choi and kale (2019)
Klopsch, Rebecca ; Baldermann, Susanne ; Hanschen, Franziska S. ; Voss, Alexander ; Rohn, Sascha ; Schreiner, Monika ; Neugart, Susanne
Consumption of Brassica vegetables is linked to health benefits, as they contain high concentrations of the following secondary plant metabolites (SPMs): glucosinolate breakdown products, carotenoids, chlorophylls, and phenolic compounds. Especially Brassica vegetables are consumed as microgreens (developed cotyledons). It was investigated how different ontogenetic stages (microgreens or leaves) of pak choi (Brassica rapa subsp. chinensis) and kale (Brassica oleracea var. sabellica) differ in their SPM concentration. The impact of breadmaking on SPMs in microgreens (7 days) and leaves (14 days) in pak choi and kale as a supplement in mixed wheat bread was assessed. In leaves, carotenoids, chlorophylls, and phenolic compounds were higher compared to those of microgreens. Breadmaking caused a decrease of SPMs. Chlorophyll degradation was observed, leading to pheophytin and pyropheophytin formation. In kale, sinapoylgentiobiose, a hydroxycinnamic acid derivative, concentration increased. Thus, leaves of Brassica species are suitable as natural ingredients for enhancing bioactive SPM concentrations in bread.
Dermal Delivery of the High-Molecular-Weight Drug Tacrolimus by Means of Polyglycerol-Based Nanogels (2019)
Rancan, Fiorenza ; Volkmann, Hildburg ; Giulbudagian, Michael ; Schumacher, Fabian ; Stanko, Jessica Isolde ; Kleuser, Burkhard ; Blume-Peytavi, Ulrike ; Calderon, Marcelo ; Vogt, Annika
Polyglycerol-based thermoresponsive nanogels (tNGs) have been shown to have excellent skin hydration properties and to be valuable delivery systems for sustained release of drugs into skin. In this study, we compared the skin penetration of tacrolimus formulated in tNGs with a commercial 0.1% tacrolimus ointment. The penetration of the drug was investigated in ex vivo abdominal and breast skin, while different methods for skin barrier disruption were investigated to improve skin permeability or simulate inflammatory conditions with compromised skin barrier. The amount of penetrated tacrolimus was measured in skin extracts by liquid chromatography tandem-mass spectrometry (LC-MS/MS), whereas the inflammatory markers IL-6 and IL-8 were detected by enzyme-linked immunosorbent assay (ELISA). Higher amounts of tacrolimus penetrated in breast as compared to abdominal skin or in barrier-disrupted as compared to intact skin, confirming that the stratum corneum is the main barrier for tacrolimus skin penetration. The anti-proliferative effect of the penetrated drug was measured in skin tissue/Jurkat cells co-cultures. Interestingly, tNGs exhibited similar anti-proliferative effects as the 0.1% tacrolimus ointment. We conclude that polyglycerol-based nanogels represent an interesting alternative to paraffin-based formulations for the treatment of inflammatory skin conditions.
Gene-lifestyle interaction on risk of type 2 diabetes (2019)
Dietrich, Stefan ; Jacobs, Simone ; Zheng, Ju-Sheng ; Meidtner, Karina ; Schwingshackl, Lukas ; Schulze, Matthias B.
The pathophysiological influence of gene-lifestyle interactions on the risk to develop type 2 diabetes (T2D) is currently under intensive research. This systematic review summarizes the evidence for gene-lifestyle interactions regarding T2D incidence. MEDLINE, EMBASE, and Web of Science were systematically searched until 31 January 2019 to identify publication with (a) prospective study design; (b) T2D incidence; (c) gene-diet, gene-physical activity, and gene-weight loss intervention interaction; and (d) population who are healthy or prediabetic. Of 66 eligible publications, 28 reported significant interactions. A variety of different genetic variants and dietary factors were studied. Variants at TCF7L2 were most frequently investigated and showed interactions with fiber and whole grain on T2D incidence. Further gene-diet interactions were reported for, eg, a western dietary pattern with a T2D-GRS, fat and carbohydrate with IRS1 rs2943641, and heme iron with variants of HFE. Physical activity showed interaction with HNF1B, IRS1, PPAR gamma, ADRA2B, SLC2A2, and ABCC8 variants and weight loss interventions with ENPP1, PPAR gamma, ADIPOR2, ADRA2B, TNF alpha, and LIPC variants. However, most findings represent single study findings obtained in European ethnicities. Although some interactions have been reported, their conclusiveness is still low, as most findings were not yet replicated across multiple study populations.
1-Methoxy-3-indolylmethyl DNA adducts in six tissues, and blood protein adducts, in mice under pak choi diet: time course and persistence (2019)
Wiesner-Reinhold, Melanie ; Barknowitz, Gitte ; Florian, Simone ; Mewis, Inga ; Schumacher, Fabian ; Schreiner, Monika ; Glatt, Hansruedi
We previously showed that purified 1-methoxy-3-indolylmethyl (1-MIM) glucosinolate, a secondary plant metabolite in Brassica species, is mutagenic in various in vitro systems and forms DNA and protein adducts in mouse models. In the present study, we administered 1-MIM glucosinolate in a natural matrix to mice, by feeding a diet containing pak choi powder and extract. Groups of animals were killed after 1, 2, 4 and 8 days of pak choi diet, directly or, in the case of the 8-day treatment, after 0, 8 and 16 days of recovery with pak choi-free diet. DNA adducts [N-2-(1-MIM)-dG, N-6-(1-MIM)-dA] in six tissues, as well as protein adducts [tau N-(1-MIM)-His] in serum albumin (SA) and hemoglobin (Hb) were determined using UPLC-MS/MS with isotopically labeled internal standards. None of the samples from the 12 control animals under standard diet contained any 1-MIM adducts. All groups receiving pak choi diet showed DNA adducts in all six tissues (exception: lung of mice treated for a single day) as well as SA and Hb adducts. During the feeding period, all adduct levels continuously increased until day 8 (in the jejunum until day 4). During the 14-day recovery period, N-2-(1-MIM)-dG in liver, kidney, lung, jejunum, cecum and colon decreased to 52, 41, 59, 11, 7 and 2%, respectively, of the peak level. The time course of N-6-(1-MIM)-dA was similar. Immunohistochemical analyses indicated that cell turnover is a major mechanism of DNA adduct elimination in the intestine. In the same recovery period, protein adducts decreased more rapidly in SA than in Hb, to 0.7 and 37%, respectively, of the peak level, consistent with the differential turnover of these proteins. In conclusion, the pak choi diet lead to the formation of high levels of adducts in mice. Cell and protein turnover was a major mechanism of adduct elimination, at least in gut and blood.
Role of GDF15 in active lifestyle induced metabolic adaptations and acute exercise response in mice (2019)
Gil, Carla Igual ; Ost, Mario ; Kasch, Juliane ; Schumann, Sara ; Heider, Sarah ; Klaus, Susanne
Physical activity is an important contributor to muscle adaptation and metabolic health. Growth differentiation factor 15 (GDF15) is established as cellular and nutritional stress-induced cytokine but its physiological role in response to active lifestyle or acute exercise is unknown. Here, we investigated the metabolic phenotype and circulating GDF15 levels in lean and obese male C57BI/6J mice with long-term voluntary wheel running (VWR) intervention. Additionally, treadmill running capacity and exercise-induced muscle gene expression was examined in GDF15-ablated mice. Active lifestyle mimic via VWR improved treadmill running performance and, in obese mice, also metabolic phenotype. The post-exercise induction of skeletal muscle transcriptional stress markers was reduced by VWR. Skeletal muscle GDF15 gene expression was very low and only transiently increased post-exercise in sedentary but not in active mice. Plasma GDF15 levels were only marginally affected by chronic or acute exercise. In obese mice, VWR reduced GDF15 gene expression in different tissues but did not reverse elevated plasma GDF15. Genetic ablation of GDF15 had no effect on exercise performance but augmented the post exercise expression of transcriptional exercise stress markers (Atf3, Atf6, and Xbp1s) in skeletal muscle. We conclude that skeletal muscle does not contribute to circulating GDF15 in mice, but muscle GDF15 might play a protective role in the exercise stress response.
Reproducibility of novel immune-inflammatory biomarkers over 4 months (2019)
Schenk, Matthew ; Eichelmann, Fabian ; Schulze, Matthias Bernd ; Rudovich, Natalia ; Pfeiffer, Andreas F. ; di Giuseppe, Romina ; Böing, Heiner ; Aleksandrova, Krasimira
Aim: Assessment of the feasibility and reliability of immune-inflammatory biomarker measurements. Methods: The following biomarkers were assessed in 207 predominantly healthy participants at baseline and after 4 months: MMF, TGF-beta, suPAR and clusterin. Results: Intraclass correlation coefficients (95% CIs) ranged from good for TGF-beta (0.75 [95% CI: 0.33-0.90]) to excellent for MMF (0.81 [95% CI: 0.64-0.90]), clusterin (0.83 [95% CI: 0.78-0.87]) and suPAR (0.91 [95% CI: 0.88-0.93]). Measurement of TGF-beta was challenged by the large number of values below the detection limit. Conclusion: Single measurements of suPAR, clusterin and MMF could serve as feasible and reliable biomarkers of immune-inflammatory pathways in biomedical research.
Mechanisms of GLP-1 receptor-independent renoprotective effects of the dipeptidyl peptidase type 4 inhibitor linagliptin in GLP-1 receptor knockout mice with 5/6 nephrectomy (2019)
Hasan, Ahmed Abdallah Abdalrahman Mohamed ; von Websky, Karoline ; Reichetzeder, Christoph ; Tsuprykov, Oleg ; Gaballa, Mohamed Mahmoud Salem Ahmed ; Guo, Jingli ; Zeng, Shufei ; Delic, Denis ; Tammen, Harald ; Klein, Thomas ; Kleuser, Burkhard ; Hocher, Berthold
Dipeptidyl peptidase type 4 (DPP-4) inhibitors were reported to have beneficial effects in experimental models of chronic kidney disease. The underlying mechanisms are not completely understood. However, these effects could be mediated via the glucagon-like peptide-1 (GLP-1)/GLP-1 receptor (GLP1R) pathway. Here we investigated the renal effects of the DPP-4 inhibitor linagliptin in Glp1r-/- knock out and wild-type mice with 5/6 nephrectomy (5/6Nx). Mice were allocated to groups: sham + wild type + placebo; 5/6Nx+ wild type + placebo; 5/6Nx+ wild type + linagliptin; sham + knock out+ placebo; 5/6Nx + knock out+ placebo; 5/6Nx + knock out+ linagliptin. 5/6Nx caused the development of renal interstitial fibrosis, significantly increased plasma cystatin C and creatinine levels and suppressed renal gelatinase/collagenase, matrix metalloproteinase-1 and -13 activities; effects counteracted by linagliptin treatment in wildtype and Glp1r-/- mice. Two hundred ninety-eight proteomics signals were differentially regulated in kidneys among the groups, with 150 signals specific to linagliptin treatment as shown by mass spectrometry. Treatment significantly upregulated three peptides derived from collagen alpha-1(I), thymosin beta 4 and heterogeneous nuclear ribonucleoprotein Al (HNRNPA1) and significantly downregulated one peptide derived from Y box binding protein-1 (YB-1). The proteomics results were further confirmed using western blot and immunofluorescence microscopy. Also, 5/6Nx led to significant up-regulation of renal transforming growth factor-beta 1 and pSMAD3 expression in wild type mice and linagliptin significantly counteracted this up-regulation in wild type and GIplr-/- mice. Thus, the renoprotective effects of linagliptin cannot solely be attributed to the GLP-1/GLP1R pathway, highlighting the importance of other signaling pathways (collagen I homeostasis, HNRNPA1,YB-1,thymosin beta 4 and TGF-beta 1) influenced by DPP-4 inhibition.
Side-directed transfer and presystemic metabolism of selenoneine in a human intestinal barrier model (2019)
Rohn, Isabelle ; Kroepfl, Nina ; Bornhorst, Julia ; Kühnelt, Doris ; Schwerdtle, Tanja
Scope: Selenoneine, a recently discovered selenium (Se) species mainly present in marine fish, is the Se analogue of ergothioneine, a sulfur-containing purported antioxidant. Although similar properties have been proposed for selenoneine, data on its relevance to human health are yet scarce. Here, the transfer and presystemic metabolism of selenoneine in an in vitro model of the human intestinal barrier are investigated. Methods and results: Selenoneine and the reference species Se-methylselenocysteine (MeSeCys) and selenite are applied to the Caco-2 intestinal barrier model. Selenoneine is transferred in higher amounts, but with similar kinetics as selenite, while MeSeCys shows the highest permeability. In contrast to the reference species, transfer of selenoneine is directed toward the blood side. Cellular Se contents demonstrate that selenoneine is efficiently taken up by Caco-2 cells. Moreover, HPLC/MS-based Se speciation studies reveal a partial metabolism to Se-methylselenoneine, a metabolite previously detected in human blood and urine. Conclusions: Selenoneine is likely to pass the intestinal barrier via transcellular, carrier-mediated transport, is highly bioavailable to Caco-2 cells and undergoes metabolic transformations. Therefore, further studies are needed to elucidate its possible health effects and to characterize the metabolism of selenoneine in humans.
Sarkopene Adipositas und Inflammation (2019)
Norman, Kristina ; Herder, Christian
Hintergrund: Die Kombination aus Übergewicht/Adipositas und reduzierter Skelettmuskelmasse (Sarkopenie) führt zu einem prognostisch ungünstigen Phänotyp, der als sarkopene Adipositas bezeichnet wird. Ziel der Arbeit: Ziel dieser Arbeit ist, eine Übersicht über Diagnosekriterien der sarkopenen Adipositas, ihre klinischen Implikationen, die pathophysiologischen Ursachen mit besonderem Fokus auf der subklinischen Inflammation und den verfügbaren therapeutischen Optionen zu geben. Ergebnisse: In aktuellen Studien werden verschiedene Diagnosekriterien der sarkopenen Adipositas verwendet, was einen Vergleich zwischen den Arbeiten erschwert und in Prävalenzschätzungen von 2–48 % in verschiedenen Studienpopulationen resultiert. Nichtsdestotrotz scheint die sarkopene Adipositas einen Risikofaktor für erhöhte Morbidität und Mortalität darzustellen, wobei kardiometabolische Erkrankungen und funktionelle Einschränkungen am besten erforscht sind. Neben Lebensstil- und genetischen Faktoren werden altersassoziierte endokrine und neuromuskuläre Parameter diskutiert. Sowohl hohes Lebensalter als auch Adipositas führen zu einer subklinischen Inflammation, die über einen fatalen Feedbackmechanismus zum Muskelabbau und zur Zunahme der Fettmasse beiträgt. Hinsichtlich Therapieoptionen stehen derzeit kombinierte Ernährungs- und Bewegungsinterventionen im Vordergrund. Schlussfolgerung: Die sarkopene Adipositas stellt einen klinisch relevanten Phänotyp dar, dessen Pathogenese aber nur z. T. verstanden ist, was Maßnahmen der Prävention und Therapie begrenzt. Neue Strategien zu Muskelaufbau und Fettreduktion sind daher dringend erforderlich, um gesundheitliche Beeinträchtigungen im höheren Lebensalter zu minimieren.
Generalizability of a Diabetes-Associated Country-Specific Exploratory Dietary Pattern Is Feasible Across European Populations (2019)
Jannasch, Franziska ; Kröger, Janine ; Agnoli, Claudia ; Barricarte, Aurelio ; Boeing, Heiner ; Cayssials, Valérie ; Colorado-Yohar, Sandra ; Dahm, Christina C. ; Dow, Courtney ; Fagherazzi, Guy ; Franks, Paul W. ; Freisling, Heinz ; Gunter, Marc J. ; Kerrison, Nicola D. ; Key, Timothy J. ; Khaw, Kay-Tee ; Kühn, Tilman ; Kyro, Cecilie ; Mancini, Francesca Romana ; Mokoroa, Olatz ; Nilsson, Peter ; Overvad, Kim ; Palli, Domenico ; Panico, Salvatore ; Quiros Garcia, Jose Ramon ; Rolandsson, Olov ; Sacerdote, Carlotta ; Sanchez, Maria-Jose ; Sahrai, Mohammad Sediq ; Schübel, Ruth ; Sluijs, Ivonne ; Spijkerman, Annemieke M. W. ; Tjonneland, Anne ; Tong, Tammy Y. N. ; Tumino, Rosario ; Riboli, Elio ; Langenberg, Claudia ; Sharp, Stephen J. ; Forouhi, Nita G. ; Schulze, Matthias B. ; Wareham, Nicholas J.
Background: Population-specificity of exploratory dietary patterns limits their generalizability in investigations with type 2 diabetes incidence. Objective: The aim of this study was to derive country-specific exploratory dietary patterns, investigate their association with type 2 diabetes incidence, and replicate diabetes-associated dietary patterns in other countries. Methods: Dietary intake data were used, assessed by country-specific questionnaires at baseline of 11,183 incident diabetes cases and 14,694 subcohort members (mean age 52.9 y) from 8 countries, nested within the European Prospective Investigation into Cancer and Nutrition study (mean follow-up time 6.9 y). Exploratory dietary patterns were derived by principal component analysis. HRs for incident type 2 diabetes were calculated by Prentice-weighted Cox proportional hazard regression models. Diabetes-associated dietary patterns were simplified or replicated to be applicable in other countries. A meta-analysis across all countries evaluated the generalizability of the diabetes-association. Results: Two dietary patterns per country/UK-center, of which overall 3 dietary patterns were diabetes-associated, were identified. A risk-lowering French dietary pattern was not confirmed across other countries: pooled HRFrance per 1 SD: 1.00; 95% CI: 0.90, 1.10. Risk-increasing dietary patterns, derived in Spain and UK-Norfolk, were confirmed, but only the latter statistically significantly: HRSpain: 1.09; 95% CI: 0.97, 1.22 and HRUK-Norfolk: 1.12; 95% CI: 1.04, 1.20. Respectively, this dietary pattern was characterized by relatively high intakes of potatoes, processed meat, vegetable oils, sugar, cake and cookies, and tea. Conclusions: Only few country/center-specific dietary patterns (3 of 18) were statistically significantly associated with diabetes incidence in this multicountry European study population. One pattern, whose association with diabetes was confirmed across other countries, showed overlaps in the food groups potatoes and processed meat with identified diabetes-associated dietary patterns from other studies. The study demonstrates that replication of associations of exploratory patterns with health outcomes is feasible and a necessary step to overcome population-specificity in associations from such analyses.
Identification of functional lipid metabolism biomarkers of brown adipose tissue aging (2019)
Gohlke, Sabrina ; Zagoriy, Vyacheslav ; Inostroza, Alvaro Cuadros ; Meret, Michael ; Mancini, Carola ; Japtok, Lukasz ; Schumacher, Fabian ; Kuhlow, Doreen ; Graja, Antonia ; Stephanowitz, Heike ; Jähnert, Markus ; Krause, Eberhard ; Wernitz, Andreas ; Petzke, Klaus-Juergen ; Schürmann, Annette ; Kleuser, Burkhard ; Schulz, Tim Julius
Objective: Aging is accompanied by loss of brown adipocytes and a decline in their thermogenic potential, which may exacerbate the development of adiposity and other metabolic disorders. Presently, only limited evidence exists describing the molecular alterations leading to impaired brown adipogenesis with aging and the contribution of these processes to changes of systemic energy metabolism. Methods: Samples of young and aged murine brown and white adipose tissue were used to compare age-related changes of brown adipogenic gene expression and thermogenesis-related lipid mobilization. To identify potential markers of brown adipose tissue aging, non-targeted proteomic and metabolomic as well as targeted lipid analyses were conducted on young and aged tissue samples. Subsequently, the effects of several candidate lipid classes on brown adipocyte function were examined. Results: Corroborating previous reports of reduced expression of uncoupling protein-1, we observe impaired signaling required for lipid mobilization in aged brown fat after adrenergic stimulation. Omics analyses additionally confirm the age-related impairment of lipid homeostasis and reveal the accumulation of specific lipid classes, including certain sphingolipids, ceramides, and dolichols in aged brown fat. While ceramides as well as enzymes of dolichol metabolism inhibit brown adipogenesis, inhibition of sphingosine 1-phosphate receptor 2 induces brown adipocyte differentiation. Conclusions: Our functional analyses show that changes in specific lipid species, as observed during aging, may contribute to reduced thermogenic potential. They thus uncover potential biomarkers of aging as well as molecular mechanisms that could contribute to the degradation of brown adipocytes, thereby providing potential treatment strategies of age-related metabolic conditions.
Sex-specific differences in the association of vitamin D with low lean mass and frailty (2019)
Spira, Dominik ; Buchmann, Nikolaus ; Koenig, Maximilian ; Rosada, Adrian ; Steinhagen-Thiessen, Elisabeth ; Demuth, Ilja ; Norman, Kristina
Background: Sex-specific differences in factors associated with aging and lifespan, such as sarcopenia and disease development, are increasingly recognized. The study aims to assess sex-specific aspects of the association between vitamin D insufficiency and low lean mass as well as between vitamin D insufficiency and the frailty phenotype. Methods: A total of 1102 participants (51% women) from the Berlin Aging Study II were included in this cross-sectional study. Vitamin D insufficiency was defined as a 25(OH)D level <50 nmol/L. Lean mass was assessed with dual-energy x-ray absorptiometry and corrected by body mass index. Low lean mass was defined according to the Foundations for the National Institutes of Health Sarcopenia Project criteria (appendicular lean mass/body mass index <0.789 in men and <0.512 in women) and frailty defined according to the Fried criteria. Results: In a risk factor adjusted analysis, the association of vitamin D insufficiency was significantly influenced by sex (P for interaction < 0.001). Men with vitamin D insufficiency had 1.8 times higher odds of having low lean mass, with no association between vitamin D insufficiency and low lean mass in women. Participants with vitamin D insufficiency had 1.5 higher odds of being prefrail/frail with no significant effect modification by sex. Conclusions: We found notable sex-specific differences in the association of vitamin D insufficiency with low lean mass but not of vitamin D insufficiency with frailty. Vitamin D might play a relevant role in the loss of lean mass in men but not women and might be a biological marker of an unfavorable aging process associated with early development of frailty regardless of sex.
Treatment of caenorhabditis elegans with small selenium species enhances antioxidant defense systems (2019)
Rohn, Isabelle ; Raschke, Stefanie ; Aschner, Michael ; Tuck, Simon ; Kuehnelt, Doris ; Kipp, Anna Patricia ; Schwerdtle, Tanja ; Bornhorst, Julia
ScopeSmall selenium (Se) species play a key role in Se metabolism and act as dietary sources of the essential trace element. However, they are redox-active and trigger pro- and antioxidant responses. As health outcomes are strongly species-dependent, species-specific characteristics of Se compounds are tested in vivo. Methods and resultsIn the model organism Caenorhabditis elegans (C. elegans), immediate and sustained effects of selenite, selenomethionine (SeMet), and Se-methylselenocysteine (MeSeCys) are studied regarding their bioavailability, incorporation into proteins, as well as modulation of the cellular redox status. While all tested Se compounds are bioavailable, only SeMet persistently accumulates and is non-specifically incorporated into proteins. However, the protection toward chemically-induced formation of reactive species is independent of the applied Se compound. Increased thioredoxin reductase (TXNRD) activity and changes in mRNA expression levels of antioxidant proteins indicate the activation of cellular defense mechanisms. However, in txnrd-1 deletion mutants, no protective effects of the Se species are observed anymore, which is also reflected by differential gene expression data. ConclusionSe species protect against chemically-induced reactive species formation. The identified immediate and sustained systemic effects of Se species give rise to speculations on possible benefits facing subsequent periods of inadequate Se intake.
Metabolic footprint and intestinal microbial changes in response to dietary proteins in a pig model (2019)
Schutkowski, Alexandra ; König, Bettina ; Kluge, Holger ; Hirche, Frank ; Henze, Andrea ; Schwerdtle, Tanja ; Lorkowski, Stefan ; Dawczynski, Christine ; Gabel, Alexander ; Grosse, Ivo ; Stangl, Gabriele I.
Epidemiological studies revealed that dietary proteins can contribute to the modulation of the cardiovascular disease risk. Still, direct effects of dietary proteins on serum metabolites and other health-modulating factors have not been fully explored. Here, we compared the effects of dietary lupin protein with the effects of beef protein and casein on the serum metabolite profile, cardiovascular risk markers and the fecal microbiome. Pigs were fed diets containing 15% of the respective proteins for 4 weeks. A classification analysis of the serum metabolites revealed six biomarker sets of two metabolites each that discriminated between the intake of lupin protein, lean beef or casein. These biomarker sets included 1- and 3-methylhistidine, betaine, carnitine, homoarginine and methionine. The study revealed differences in the serum levels of the metabolites 1- and 3- methylhistidine, homoarginine, methionine and homocysteine, which are involved in the one-carbon cycle. However, these changes were not associated with differences in the methylation capacity or the histone methylation pattern. With the exception of serum homocysteine and homoarginine levels, other cardiovascular risk markers, such as the homeostatic model assessment index, trimethylamine-N-oxide and lipids, were not influenced by the dietary protein source. However, the composition of the fecal microorganisms was markedly changed by the dietary protein source. Lupin-protein-fed pigs exhibited more species from the phyla Bacteroidetes and Firmicutes than the other two groups. In conclusion, different dietary protein sources induce distinct serum metabolic fingerprints, have an impact on the cardiovascular risk and modulate the composition of the fecal microbiome. (C) 2019 Elsevier Inc. All rights reserved.
Maternal and fetal genetic effects on birth weight and their relevance to cardio-metabolic risk factors (2019)
Warrington, Nicole ; Beaumont, Robin ; Horikoshi, Momoko ; Day, Felix R. ; Helgeland, Øyvind ; Laurin, Charles ; Bacelis, Jonas ; Peng, Shouneng ; Hao, Ke ; Feenstra, Bjarke ; Wood, Andrew R. ; Mahajan, Anubha ; Tyrrell, Jessica ; Robertson, Neil R. ; Rayner, N. William ; Qiao, Zhen ; Moen, Gunn-Helen ; Vaudel, Marc ; Marsit, Carmen ; Chen, Jia ; Nodzenski, Michael ; Schnurr, Theresia M. ; Zafarmand, Mohammad Hadi ; Bradfield, Jonathan P. ; Grarup, Niels ; Kooijman, Marjolein N. ; Li-Gao, Ruifang ; Geller, Frank ; Ahluwalia, Tarunveer Singh ; Paternoster, Lavinia ; Rueedi, Rico ; Huikari, Ville ; Hottenga, Jouke-Jan ; Lyytikäinen, Leo-Pekka ; Cavadino, Alana ; Metrustry, Sarah ; Cousminer, Diana L. ; Wu, Ying ; Thiering, Elisabeth Paula ; Wang, Carol A. ; Have, Christian Theil ; Vilor-Tejedor, Natalia ; Joshi, Peter K. ; Painter, Jodie N. ; Ntalla, Ioanna ; Myhre, Ronny ; Pitkänen, Niina ; van Leeuwen, Elisabeth M. ; Joro, Raimo ; Lagou, Vasiliki ; Richmond, Rebecca C. ; Espinosa, Ana ; Barton, Sheila J. ; Inskip, Hazel M. ; Holloway, John W. ; Santa-Marina, Loreto ; Estivill, Xavier ; Ang, Wei ; Marsh, Julie A. ; Reichetzeder, Christoph ; Marullo, Letizia ; Hocher, Berthold ; Lunetta, Kathryn L. ; Murabito, Joanne M. ; Relton, Caroline L. ; Kogevinas, Manolis ; Chatzi, Leda ; Allard, Catherine ; Bouchard, Luigi ; Hivert, Marie-France ; Zhang, Ge ; Muglia, Louis J. ; Heikkinen, Jani ; Morgen, Camilla S. ; van Kampen, Antoine H. C. ; van Schaik, Barbera D. C. ; Mentch, Frank D. ; Langenberg, Claudia ; Scott, Robert A. ; Zhao, Jing Hua ; Hemani, Gibran ; Ring, Susan M. ; Bennett, Amanda J. ; Gaulton, Kyle J. ; Fernandez-Tajes, Juan ; van Zuydam, Natalie R. ; Medina-Gomez, Carolina ; de Haan, Hugoline G. ; Rosendaal, Frits R. ; Kutalik, Zoltán ; Marques-Vidal, Pedro ; Das, Shikta ; Willemsen, Gonneke ; Mbarek, Hamdi ; Müller-Nurasyid, Martina ; Standl, Marie ; Appel, Emil V. R. ; Fonvig, Cilius Esmann ; Trier, Caecilie ; van Beijsterveldt, Catharina E. M. ; Murcia, Mario ; Bustamante, Mariona ; Bonàs-Guarch, Sílvia ; Hougaard, David M. ; Mercader, Josep M. ; Linneberg, Allan ; Schraut, Katharina E. ; Lind, Penelope A. ; Medland, Sarah Elizabeth ; Shields, Beverley M. ; Knight, Bridget A. ; Chai, Jin-Fang ; Panoutsopoulou, Kalliope ; Bartels, Meike ; Sánchez, Friman ; Stokholm, Jakob ; Torrents, David ; Vinding, Rebecca K. ; Willems, Sara M. ; Atalay, Mustafa ; Chawes, Bo L. ; Kovacs, Peter ; Prokopenko, Inga ; Tuke, Marcus A. ; Yaghootkar, Hanieh ; Ruth, Katherine S. ; Jones, Samuel E. ; Loh, Po-Ru ; Murray, Anna ; Weedon, Michael N. ; Tönjes, Anke ; Stumvoll, Michael ; Michaelsen, Kim Fleischer ; Eloranta, Aino-Maija ; Lakka, Timo A. ; van Duijn, Cornelia M. ; Kiess, Wieland ; Koerner, Antje ; Niinikoski, Harri ; Pahkala, Katja ; Raitakari, Olli T. ; Jacobsson, Bo ; Zeggini, Eleftheria ; Dedoussis, George V. ; Teo, Yik-Ying ; Saw, Seang-Mei ; Montgomery, Grant W. ; Campbell, Harry ; Wilson, James F. ; Vrijkotte, Tanja G. M. ; Vrijheid, Martine ; de Geus, Eco J. C. N. ; Hayes, M. Geoffrey ; Kadarmideen, Haja N. ; Holm, Jens-Christian ; Beilin, Lawrence J. ; Pennell, Craig E. ; Heinrich, Joachim ; Adair, Linda S. ; Borja, Judith B. ; Mohlke, Karen L. ; Eriksson, Johan G. ; Widen, Elisabeth E. ; Hattersley, Andrew T. ; Spector, Tim D. ; Kaehoenen, Mika ; Viikari, Jorma S. ; Lehtimaeki, Terho ; Boomsma, Dorret I. ; Sebert, Sylvain ; Vollenweider, Peter ; Sorensen, Thorkild I. A. ; Bisgaard, Hans ; Bonnelykke, Klaus ; Murray, Jeffrey C. ; Melbye, Mads ; Nohr, Ellen A. ; Mook-Kanamori, Dennis O. ; Rivadeneira, Fernando ; Hofman, Albert ; Felix, Janine F. ; Jaddoe, Vincent W. V. ; Hansen, Torben ; Pisinger, Charlotta ; Vaag, Allan A. ; Pedersen, Oluf ; Uitterlinden, Andre G. ; Jarvelin, Marjo-Riitta ; Power, Christine ; Hypponen, Elina ; Scholtens, Denise M. ; Lowe, William L. ; Smith, George Davey ; Timpson, Nicholas J. ; Morris, Andrew P. ; Wareham, Nicholas J. ; Hakonarson, Hakon ; Grant, Struan F. A. ; Frayling, Timothy M. ; Lawlor, Debbie A. ; Njolstad, Pal R. ; Johansson, Stefan ; Ong, Ken K. ; McCarthy, Mark I. ; Perry, John R. B. ; Evans, David M. ; Freathy, Rachel M.
Birth weight variation is influenced by fetal and maternal genetic and non-genetic factors, and has been reproducibly associated with future cardio-metabolic health outcomes. In expanded genome-wide association analyses of own birth weight (n = 321,223) and offspring birth weight (n = 230,069 mothers), we identified 190 independent association signals (129 of which are novel). We used structural equation modeling to decompose the contributions of direct fetal and indirect maternal genetic effects, then applied Mendelian randomization to illuminate causal pathways. For example, both indirect maternal and direct fetal genetic effects drive the observational relationship between lower birth weight and higher later blood pressure: maternal blood pressure-raising alleles reduce offspring birth weight, but only direct fetal effects of these alleles, once inherited, increase later offspring blood pressure. Using maternal birth weight-lowering genotypes to proxy for an adverse intrauterine environment provided no evidence that it causally raises offspring blood pressure, indicating that the inverse birth weight-blood pressure association is attributable to genetic effects, and not to intrauterine programming.
Environmental boron exposure does not induce DNA damage in lymphocytes and buccal cells of females DNA damage in lymphocytes and buccal cells of boron exposed females (2019)
Başaran, Nurşen ; Duydu, Yalçın ; Üstündağ, Aylin ; Taner, Gökçe ; Aydin Dilsiz, Sevtap ; Anlar, Hatice Gül ; Yalçin, Can Özgür ; Bacanli, Merve ; Golka, Klaus ; Schwerdtle, Tanja ; Bolt, Hermann M.
Boron (B) compounds are essential for plants and animals and beneficial for humans in nutritional amounts. I animals and humans increasing evidence have shown beneficial effects on B compounds on nutrition and on antioxidant status. The genotoxic effects of environmental B exposure in women living in boron-rich and boronpoor areas was examined in this study. For this purpose, the DNA damage in the lymphocytes and buccal cells of females were assessed by Comet and micronucleus (MN) assays respectively. No significant difference was observed in the DNA damage of the lymphocytes of B exposed groups of female volunteers in Comet assay. Even buccal micronucleus (MN) frequency observed in the high exposure group was significantly lower than the low exposure group (p < 0.05). The results of this study came to the same conclusions of the previous studies that boron does not induce DNA damage even under extreme exposure conditions.
Prediction of transformation products of monensin by electrochemistry compared to microsomal assay and hydrolysis (2019)
Kotthoff, Lisa ; Lisec, Jan ; Schwerdtle, Tanja ; Koch, Matthias
The knowledge of transformation pathways and identification of transformation products (TPs) of veterinary drugs is important for animal health, food, and environmental matters. The active agent Monensin (MON) belongs to the ionophore antibiotics and is widely used as a veterinary drug against coccidiosis in broiler farming. However, no electrochemically (EC) generated TPs of MON have been described so far. In this study, the online coupling of EC and mass spectrometry (MS) was used for the generation of oxidative TPs. EC-conditions were optimized with respect to working electrode material, solvent, modifier, and potential polarity. Subsequent LC/HRMS (liquid chromatography/high resolution mass spectrometry) and MS/MS experiments were performed to identify the structures of derived TPs by a suspected target analysis. The obtained EC-results were compared to TPs observed in metabolism tests with microsomes and hydrolysis experiments of MON. Five previously undescribed TPs of MON were identified in our EC/MS based study and one TP, which was already known from literature and found by a microsomal assay, could be confirmed. Two and three further TPs were found as products in microsomal tests and following hydrolysis, respectively. We found decarboxylation, O-demethylation and acid-catalyzed ring-opening reactions to be the major mechanisms of MON transformation.
Transglutaminase 1 Replacement Therapy Successfully Mitigates the Autosomal Recessive Congenital Ichthyosis Phenotype in Full-Thickness Skin Disease Equivalents (2019)
Plank, Roswitha ; Yealland, Guy ; Miceli, Enrico ; Cunha, Dulce Lima ; Graff, Patrick ; Thomforde, Sari ; Gruber, Robert ; Moosbrugger-Martinz, Verena ; Eckl, Katja ; Calderon, Marcelo ; Hennies, Hans Christian ; Hedtrich, Sarah
Core-multishell nanocarriers enhance drug penetration and reach keratinocytes and antigen-presenting cells in intact human skin (2019)
Frombach, Janna ; Unbehauen, Michael ; Kurniasih, Indah N. ; Schumacher, Fabian ; Volz, Pierre ; Hadam, Sabrina ; Rancan, Fiorenza ; Blume-Peytavi, Ulrike ; Kleuser, Burkhard ; Haag, Rainer ; Alexiev, Ulrike ; Vogt, Annika
In reconstructed skin and diffusion cell studies, core-multishell nanocarriers (CMS-NC) showed great potential for drug delivery across the skin barrier. Herein, we investigated penetration, release of dexamethasone (DXM), in excised full-thickness human skin with special focus on hair follicles (HF). Four hours and 16 h after topical application of clinically relevant dosages of 10 mu g DXM/cm(2) skin encapsulated in CMS-NC (12 nm diameter, 5.8% loading), presence of DXM in the tissue as assessed by fluorescence microscopy of anti-DXM-stained tissue sections as well as ELISA and HPLC-MS/MS in tissue extracts was enhanced compared to standard LAW-creme but lower compared to DXM aqueous/alcoholic solution. Such enhanced penetration compared to conventional cremes offers high potential for topical therapies, as recurrent applications of corticosteroid solutions face limitations with regard to tolerability and fast drainage. The findings encourage more detailed investigations on where and how the nanocarrier and drug dissociate within the skin and what other factors, e.g. thermodynamic activity, influence the penetration of this formulations. Microscopic studies on the spatial distribution within the skin revealed accumulation in HF and furrows accompanied by limited cellular uptake assessed by flow cytometry (up to 9% of total epidermal cells). FLIM clearly visualized the presence of CMS-NC in the viable epidermis and dermis. When exposed in situ a fraction of up to 25% CD1a(+) cells were found within the epidermal CMS-NC+ population compared to approximately 3% CD1a(+)/CMS-NC+ cells after in vitro exposure in short-term cultures of epidermal cell suspensions. The latter reflects the natural percentage of Langerhans cells (LC) in epidermis suspensions and indicated that CMS-NC were not preferentially internalized by one cell type. The increased CMS-NC+ LC proportion after exposure within the tissue is in accordance with the strategic suprabasal LC-localization. More specifically we postulate that the extensive dendrite meshwork, their position around HF orifices and their capacity to modulate tight junctions facilitated a preferential uptake of CMS-NC by LC within the skin. This newly identified aspect of CMS-NC penetration underlines the potential of CMS-NC for dermatotherapy and encourages further investigations of CMS-NC for the delivery of other molecule classes for which intracellular delivery is even more crucial.
Abscisic acid related metabolites in sweet cherry buds (Prunus avium L.) (2018)
Chmielewski, Frank M. ; Baldermann, Susanne ; Götz, Klaus Peter ; Homann, Thomas ; Gödeke, Kristin ; Schumacher, Fabian ; Huschek, Gerd ; Rawel, Harshadrai Manilal
As our climate changes, plant mechanisms involved for dormancy release become increasingly important for commercial orchards. It is generally believed that abscisic acid (ABA) is a key hormone that responds to various environmental stresses which affects bud dormancy. For this reason, a multi-year study was initiated to obtain data on plant metabolites during winter rest and ontogenetic development in sweet cherry buds (Prunus avium L.). In this paper, we report on metabolites involved in ABA synthesis and catabolism and its effect on bud dormancy in the years 2014/15-2016/17. In previous work, the timings of the different phases of para-, endo-, ecodormancy and ontogenetic development for cherry flower buds of the cultivar ‘Summit’ were determined, based on classical climate chamber experiments and changes in the bud’s water content. Based on these time phases, we focused now on the different aspects of the ABA-metabolism. The results show that there is a continual synthesis of ABA about 5 weeks before leaf fall, and a degradation of ABA during ecodormancy and bud development until the phenological stage ‘open cluster’. This is confirmed by relating the ABA content to that of the total precursor carotenoids, neoxanthin and violaxanthin. The tentative monitoring of individual intermediate metabolites revealed that dihydroxyphaseic acid is the most abundant catabolite of ABA and ABA glucosyl ester is in terms of mass intensity, the most abundant ABA metabolite observed in this study. The results suggest that the direct route for ABA biosynthesis from farnesyl pyrophosphate may also be relevant in cherry flower buds.
The role of the commensal gut bacterium Akkermansia muciniphila in acute and chronic intestinal inflammation (2018)
Ring, Christiane
Microbiota analyses of patients suffering from various diseases suggest a beneficial role of Akkermansia muciniphila in the maintenance of health, whereas several studies in animal models of intestinal inflammation report that this organism may aggravate inflammation. Therefore, it is important to clarify under which circumstances A. muciniphila exerts negative effects in the intestine of its host. The previously reported observation that A. muciniphila aggravates acute intestinal inflammation in the Salmonella enterica serovar Typhimurium infection mouse model colonized with a simplified human intestinal microbiota was investigated in this study. To unravel the underlying mechanism that led to the observed phenomenon, the time course of events following the infection was analyzed. In mice colonized with a simplified human intestinal microbiota, Salmonella infection induced clear signs of intestinal inflammation three days post infection. The inflammatory response was similar in mice colonized with A. muciniphila before Salmonella infection. These observations were independent of the time when colonization with the simplified human intestinal microbiota occurred, right after birth or only after weaning, and contradict the previous report. To find out whether A. muciniphila influences the development of chronic intestinal inflammation in a genetically predisposed host, mono-associated interleukin-10-deficient (Il10-/-) mice, Il10-/- mice dual-associated with A. muciniphila and colitogenic Escherichia coli NC101, as well as Il10-/- mice associated with A. muciniphila and a simplified human intestinal microbiota were compared to the respective mice without A. muciniphila. The data clearly show that in these gnotobiotic Il10-/- mice, A. muciniphila neither induces intestinal inflammation itself nor modulates it after induction by a colitogenic bacterium or by a simplified human intestinal microbiota. The experiments lead to the conclusion that the promotion of intestinal inflammation is not an intrinsic feature of this bacterium. The results of this study encourage the proposed use of A. muciniphila for the prevention or treatment of metabolic disorders.
Cell-Based Reporter Release Assay to Determine the Potency of Proteolytic Bacterial Neurotoxins (2018)
Pathe-Neuschäfer-Rube, Andrea ; Neuschäfer-Rube, Frank ; Haas, Gerald ; Langoth-Fehringer, Nina ; Püschel, Gerhard Paul
Despite the implementation of cell-based replacement methods, the mouse lethality assay is still frequently used to determine the activity of botulinum toxin (BoNT) for medical use. One explanation is that due to the use of neoepitope-specific antibodies to detect the cleaved BoNT substrate, the currently devised assays can detect only one specific serotype of the toxin. Recently, we developed a cell-based functional assay, in which BoNT activity is determined by inhibiting the release of a reporter enzyme that is liberated concomitantly with the neurotransmitter from neurosecretory vesicles. In theory, this assay should be suitable to detect the activity of any BoNT serotype. Consistent with this assumption, the current study shows that the stimulus-dependent release of a luciferase from a differentiated human neuroblastoma-based reporter cell line (SIMA-hPOMC1-26-GLuc cells) was inhibited by BoNT-A and-C. Furthermore, this was also inhibited by BoNT-B and tetanus toxin to a lesser extent and at higher concentrations. In order to provide support for the suitability of this technique in practical applications, a dose–response curve obtained with a pharmaceutical preparation of BoNT-A closely mirrored the activity determined in the mouse lethality assay. In summary, the newly established cell-based assay may represent a versatile and specific alternative to the mouse lethality assay and other currently established cell-based assays.
Cell-Based Reporter Release Assay to Determine the Potency of Proteolytic Bacterial Neurotoxins (2018)
Pathe-Neuschäfer-Rube, Andrea ; Neuschäfer-Rube, Frank ; Haas, Gerald ; Langoth-Fehringer, Nina ; Püschel, Gerhard Paul
Despite the implementation of cell-based replacement methods, the mouse lethality assay is still frequently used to determine the activity of botulinum toxin (BoNT) for medical use. One explanation is that due to the use of neoepitope-specific antibodies to detect the cleaved BoNT substrate, the currently devised assays can detect only one specific serotype of the toxin. Recently, we developed a cell-based functional assay, in which BoNT activity is determined by inhibiting the release of a reporter enzyme that is liberated concomitantly with the neurotransmitter from neurosecretory vesicles. In theory, this assay should be suitable to detect the activity of any BoNT serotype. Consistent with this assumption, the current study shows that the stimulus-dependent release of a luciferase from a differentiated human neuroblastoma-based reporter cell line (SIMA-hPOMC1-26-GLuc cells) was inhibited by BoNT-A and-C. Furthermore, this was also inhibited by BoNT-B and tetanus toxin to a lesser extent and at higher concentrations. In order to provide support for the suitability of this technique in practical applications, a dose–response curve obtained with a pharmaceutical preparation of BoNT-A closely mirrored the activity determined in the mouse lethality assay. In summary, the newly established cell-based assay may represent a versatile and specific alternative to the mouse lethality assay and other currently established cell-based assays.
Soybean Oil-Derived Poly-Unsaturated Fatty Acids Enhance Liver Damage in NAFLD Induced by Dietary Cholesterol (2018)
Henkel, Janin ; Alfine, Eugenia ; Saín, Juliana ; Jöhrens, Korinna ; Weber, Daniela ; Castro, José Pedro ; König, Jeannette ; Stuhlmann, Christin ; Vahrenbrink, Madita ; Wenke, Jonas ; Kleinridders, André ; Püschel, Gerhard Paul
While the impact of dietary cholesterol on the progression of atherosclerosis has probably been overestimated, increasing evidence suggests that dietary cholesterol might favor the transition from blunt steatosis to non-alcoholic steatohepatitis (NASH), especially in combination with high fat diets. It is poorly understood how cholesterol alone or in combination with other dietary lipid components contributes to the development of lipotoxicity. The current study demonstrated that liver damage caused by dietary cholesterol in mice was strongly enhanced by a high fat diet containing soybean oil-derived ω6-poly-unsaturated fatty acids (ω6-PUFA), but not by a lard-based high fat diet containing mainly saturated fatty acids. In contrast to the lard-based diet the soybean oil-based diet augmented cholesterol accumulation in hepatocytes, presumably by impairing cholesterol-eliminating pathways. The soybean oil-based diet enhanced cholesterol-induced mitochondrial damage and amplified the ensuing oxidative stress, probably by peroxidation of poly-unsaturated fatty acids. This resulted in hepatocyte death, recruitment of inflammatory cells, and fibrosis, and caused a transition from steatosis to NASH, doubling the NASH activity score. Thus, the recommendation to reduce cholesterol intake, in particular in diets rich in ω6-PUFA, although not necessary to reduce the risk of atherosclerosis, might be sensible for patients suffering from non-alcoholic fatty liver disease.
Soybean Oil-Derived Poly-Unsaturated Fatty Acids Enhance Liver Damage in NAFLD Induced by Dietary Cholesterol (2018)
Henkel, Janin ; Alfine, Eugenia ; Saín, Juliana ; Jöhrens, Korinna ; Weber, Daniela ; Castro, José Pedro ; König, Jeannette ; Stuhlmann, Christin ; Vahrenbrink, Madita ; Wenke, Jonas ; Kleinridders, André ; Püschel, Gerhard Paul
While the impact of dietary cholesterol on the progression of atherosclerosis has probably been overestimated, increasing evidence suggests that dietary cholesterol might favor the transition from blunt steatosis to non-alcoholic steatohepatitis (NASH), especially in combination with high fat diets. It is poorly understood how cholesterol alone or in combination with other dietary lipid components contributes to the development of lipotoxicity. The current study demonstrated that liver damage caused by dietary cholesterol in mice was strongly enhanced by a high fat diet containing soybean oil-derived ω6-poly-unsaturated fatty acids (ω6-PUFA), but not by a lard-based high fat diet containing mainly saturated fatty acids. In contrast to the lard-based diet the soybean oil-based diet augmented cholesterol accumulation in hepatocytes, presumably by impairing cholesterol-eliminating pathways. The soybean oil-based diet enhanced cholesterol-induced mitochondrial damage and amplified the ensuing oxidative stress, probably by peroxidation of poly-unsaturated fatty acids. This resulted in hepatocyte death, recruitment of inflammatory cells, and fibrosis, and caused a transition from steatosis to NASH, doubling the NASH activity score. Thus, the recommendation to reduce cholesterol intake, in particular in diets rich in ω6-PUFA, although not necessary to reduce the risk of atherosclerosis, might be sensible for patients suffering from non-alcoholic fatty liver disease.
Augmented liver inflammation in a microsomal prostaglandin E synthase 1 (mPGES-1)-deficient diet-induced mouse NASH model (2018)
Henkel, Janin ; Coleman Mac Gregor of Inneregny, Charles Dominic ; Schraplau, Anne ; Jöhrens, Korinna ; Weiss, Thomas Siegfried ; Jonas, Wenke ; Schürmann, Annette ; Püschel, Gerhard Paul
In a subset of patients, non-alcoholic fatty liver disease (NAFLD) is complicated by cell death and inflammation resulting in non-alcoholic steatohepatitis (NASH), which may progress to fibrosis and subsequent organ failure. Apart from cytokines, prostaglandins, in particular prostaglandin E-2 (PGE(2)), play a pivotal role during inflammatory processes. Expression of the key enzymes of PGE(2) synthesis, cyclooxygenase 2 and microsomal PGE synthase 1 (mPGES-1), was increased in human NASH livers in comparison to controls and correlated with the NASH activity score. Both enzymes were also induced in NASH-diet-fed wild-type mice, resulting in an increase in hepatic PGE(2) concentration that was completely abrogated in mPGES-1-deficient mice. PGE(2) is known to inhibit TNF-alpha synthesis in macrophages. A strong infiltration of monocyte-derived macrophages was observed in NASH-diet-fed mice, which was accompanied with an increase in hepatic TNF-alpha expression. Due to the impaired PGE(2) production, TNF-alpha expression increased much more in livers of mPGES-1-deficient mice or in the peritoneal macrophages of these mice. The increased levels of TNF-alpha resulted in an enhanced IL-1 beta production, primarily in hepatocytes, and augmented hepatocyte apoptosis. In conclusion, attenuation of PGE(2) production by mPGES-1 ablation enhanced the TNF-alpha-triggered inflammatory response and hepatocyte apoptosis in diet-induced NASH.
Augmented liver inflammation in a microsomal prostaglandin E synthase 1 (mPGES-1)-deficient diet-induced mouse NASH model (2018)
Henkel, Janin ; Coleman Mac Gregor of Inneregny, Charles Dominic ; Schraplau, Anne ; Jöhrens, Korinna ; Weiss, Thomas Siegfried ; Jonas, Wenke ; Schürmann, Annette ; Püschel, Gerhard Paul
In a subset of patients, non-alcoholic fatty liver disease (NAFLD) is complicated by cell death and inflammation resulting in non-alcoholic steatohepatitis (NASH), which may progress to fibrosis and subsequent organ failure. Apart from cytokines, prostaglandins, in particular prostaglandin E-2 (PGE(2)), play a pivotal role during inflammatory processes. Expression of the key enzymes of PGE(2) synthesis, cyclooxygenase 2 and microsomal PGE synthase 1 (mPGES-1), was increased in human NASH livers in comparison to controls and correlated with the NASH activity score. Both enzymes were also induced in NASH-diet-fed wild-type mice, resulting in an increase in hepatic PGE(2) concentration that was completely abrogated in mPGES-1-deficient mice. PGE(2) is known to inhibit TNF-alpha synthesis in macrophages. A strong infiltration of monocyte-derived macrophages was observed in NASH-diet-fed mice, which was accompanied with an increase in hepatic TNF-alpha expression. Due to the impaired PGE(2) production, TNF-alpha expression increased much more in livers of mPGES-1-deficient mice or in the peritoneal macrophages of these mice. The increased levels of TNF-alpha resulted in an enhanced IL-1 beta production, primarily in hepatocytes, and augmented hepatocyte apoptosis. In conclusion, attenuation of PGE(2) production by mPGES-1 ablation enhanced the TNF-alpha-triggered inflammatory response and hepatocyte apoptosis in diet-induced NASH.
The role of the fatty acid profile and its modulation by cytokines in the systemic inflammation in cancer cachexia (2018)
Radloff, Katrin
Systemic inflammation is a hallmark of cancer cachexia. Among tumor-host interactions, the white adipose tissue (WAT) is an important contributor to inflammation as it suffers morphological reorganization and lipolysis, releasing free fatty acids (FA), bioactive lipid mediators (LM) and pro-inflammatory cytokines, which accentuate the activation of pro-inflammatory signaling pathways and the recruitment of immune cells to the tissue. This project aimed to investigate which inflammatory factors are involved in the local adipose tissue inflammation and what is the influence of such factors upon enzymes involved in FA or LM metabolism in healthy individuals (Control), weight stable gastro-intestinal cancer patients (WSC) and cachectic cancer patients (CC). The results demonstrated that the inflammatory signature of systemic inflammation is different from local adipose tissue inflammation. The systemic inflammation of the cachectic cancer patients was characterized by higher levels of circulating saturated fatty acids (SFA), tumor-necrosis-factor-α (TNF-α), interleukins IL-6, IL-8 and CRP while levels of polyunsaturated fatty acids (PUFAs), especially n3-PUFAs, were lower in CC than in the other groups. In vitro and in adipose tissue explants, pro-inflammatory cytokines and SFAs were shown to increase the chemokines IL-8 and CXCL10 that were found to be augmented in adipose tissue inflammation in CC which was more profound in the visceral adipose tissue (VAT) than in subcutaneous adipose tissue (SAT). Systemic inflammation was negatively associated with the expression of PUFA synthesizing enzymes, though gene and protein expression did hardly differ between groups. The effects of inflammatory factors on enzymes in the whole tissue could have been masked by differentiated modulation of the diverse cell types in the same tissue. In vitro experiments showed that the expression of FA-modifying enzymes such as desaturases and elongases in adipocytes and macrophages was regulated into opposing directions by TNF-α, IL-6, LPS or palmitate. The higher plasma concentration of the pro-resolving LM resolvin D1 in CC cannot compensate the overall inflammatory status and the results indicate that inflammatory cytokines interfere with synthesis pathways of pro-resolving LM. In summary, the data revealed a complex inter-tissue and inter-cellular crosstalk mediated by pro-inflammatory cytokines and lipid compounds enhancing inflammation in cancer cachexia by feed-forward mechanisms.
Kohlenhydratarme, n-6-reiche Diät versus fettarme Diät (2018)
Dambeck, Ulrike
GLP-1 receptor-independent mechanisms of DPP-4 inhibition on renal disease progression (2018)
Hasan, Ahmed Abdallah Abdalahmann Mohamed
Untersuchung der molekularen Toxizität von Pyrrolizidinalkaloiden in der humanen Hepatomzelllinie HepaRG (2018)
Waizenegger, Julia
Selected Plant Metabolites Involved in Oxidation-Reduction Processes during Bud Dormancy and Ontogenetic Development in Sweet Cherry Buds (Prunus avium L.) (2018)
Baldermann, Susanne ; Homann, Thomas ; Neugart, Susanne ; Chmielewski, Frank M. ; Götz, Klaus-Peter ; Gödeke, Kristin ; Huschek, Gerd ; Morlock, Gertrud E. ; Rawel, Harshadrai Manilal
Many biochemical processes are involved in regulating the consecutive transition of different phases of dormancy in sweet cherry buds. An evaluation based on a metabolic approach has, as yet, only been partly addressed. The aim of this work, therefore, was to determine which plant metabolites could serve as biomarkers for the different transitions in sweet cherry buds. The focus here was on those metabolites involved in oxidation-reduction processes during bud dormancy, as determined by targeted and untargeted mass spectrometry-based methods. The metabolites addressed included phenolic compounds, ascorbate/dehydroascorbate, reducing sugars, carotenoids and chlorophylls. The results demonstrate that the content of phenolic compounds decrease until the end of endodormancy. After a long period of constancy until the end of ecodormancy, a final phase of further decrease followed up to the phenophase open cluster. The main phenolic compounds were caffeoylquinic acids, coumaroylquinic acids and catechins, as well as quercetin and kaempferol derivatives. The data also support the protective role of ascorbate and glutathione in the para- and endodormancy phases. Consistent trends in the content of reducing sugars can be elucidated for the different phenophases of dormancy, too. The untargeted approach with principle component analysis (PCA) clearly differentiates the different timings of dormancy giving further valuable information.
Selected Plant Metabolites Involved in Oxidation-Reduction Processes during Bud Dormancy and Ontogenetic Development in Sweet Cherry Buds (Prunus avium L.) (2018)
Baldermann, Susanne ; Homann, Thomas ; Neugart, Susanne ; Chmielewski, Frank M. ; Götz, Klaus-Peter ; Gödeke, Kristin ; Huschek, Gerd ; Morlock, Gertrud E. ; Rawel, Harshadrai Manilal
Many biochemical processes are involved in regulating the consecutive transition of different phases of dormancy in sweet cherry buds. An evaluation based on a metabolic approach has, as yet, only been partly addressed. The aim of this work, therefore, was to determine which plant metabolites could serve as biomarkers for the different transitions in sweet cherry buds. The focus here was on those metabolites involved in oxidation-reduction processes during bud dormancy, as determined by targeted and untargeted mass spectrometry-based methods. The metabolites addressed included phenolic compounds, ascorbate/dehydroascorbate, reducing sugars, carotenoids and chlorophylls. The results demonstrate that the content of phenolic compounds decrease until the end of endodormancy. After a long period of constancy until the end of ecodormancy, a final phase of further decrease followed up to the phenophase open cluster. The main phenolic compounds were caffeoylquinic acids, coumaroylquinic acids and catechins, as well as quercetin and kaempferol derivatives. The data also support the protective role of ascorbate and glutathione in the para- and endodormancy phases. Consistent trends in the content of reducing sugars can be elucidated for the different phenophases of dormancy, too. The untargeted approach with principle component analysis (PCA) clearly differentiates the different timings of dormancy giving further valuable information.
Identifizierung früher epigenetischer Veränderungen, die zur Ausbildung einer Fettleber beitragen (2018)
Kammel, Anne
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