TY - JOUR A1 - Zhou, Ying A1 - Zeng, Lanting A1 - Fu, Xiumin A1 - Mei, Xin A1 - Cheng, Sihua A1 - Liao, Yinyin A1 - Deng, Rufang A1 - Xu, Xinlan A1 - Jiang, Yueming A1 - Duan, Xuewu A1 - Baldermann, Susanne A1 - Yang, Ziyin T1 - The sphingolipid biosynthetic enzyme Sphingolipid delta8 desaturase is important for chilling resistance of tomato JF - Scientific reports N2 - The physiological functions of sphingolipids in animals have been intensively studied, while less attention has been paid to their roles in plants. Here, we reveal the involvement of sphingolipid delta8 desaturase (SlSLD) in the chilling resistance of tomato (Solanum lycopersicum cv. Micro-Tom). We used the virus-induced gene silencing (VIGS) approach to knock-down SlSLD expression in tomato leaves, and then evaluated chilling resistance. Changes in leaf cell structure under a chilling treatment were observed by transmission electron microscopy. In control plants, SlSLD was highly expressed in the fruit and leaves in response to a chilling treatment. The degree of chilling damage was greater in SlSLD-silenced plants than in control plants, indicating that SlSLD knock-down significantly reduced the chilling resistance of tomato. Compared with control plants, SlSLD-silenced plants showed higher relative electrolytic leakage and malondialdehyde content, and lower superoxide dismutase and peroxidase activities after a chilling treatment. Chilling severely damaged the chloroplasts in SlSLD-silenced plants, resulting in the disruption of chloroplast membranes, swelling of thylakoids, and reduced granal stacking. Together, these results show that SlSLD is crucial for chilling resistance in tomato. Y1 - 2016 U6 - https://doi.org/10.1038/srep38742 SN - 2045-2322 VL - 6 PB - Nature Publ. Group CY - London ER - TY - GEN A1 - Woting, Anni A1 - Blaut, Michael T1 - The intestinal microbiota in metabolic disease T2 - Nutrients N2 - Gut bacteria exert beneficial and harmful effects in metabolic diseases as deduced from the comparison of germfree and conventional mice and from fecal transplantation studies. Compositional microbial changes in diseased subjects have been linked to adiposity, type 2 diabetes and dyslipidemia. Promotion of an increased expression of intestinal nutrient transporters or a modified lipid and bile acid metabolism by the intestinal microbiota could result in an increased nutrient absorption by the host. The degradation of dietary fiber and the subsequent fermentation of monosaccharides to short-chain fatty acids (SCFA) is one of the most controversially discussed mechanisms of how gut bacteria impact host physiology. Fibers reduce the energy density of the diet, and the resulting SCFA promote intestinal gluconeogenesis, incretin formation and subsequently satiety. However, SCFA also deliver energy to the host and support liponeogenesis. Thus far, there is little knowledge on bacterial species that promote or prevent metabolic disease. Clostridium ramosum and Enterococcus cloacae were demonstrated to promote obesity in gnotobiotic mouse models, whereas bifidobacteria and Akkermansia muciniphila were associated with favorable phenotypes in conventional mice, especially when oligofructose was fed. How diet modulates the gut microbiota towards a beneficial or harmful composition needs further research. Gnotobiotic animals are a valuable tool to elucidate mechanisms underlying diet-host-microbe interactions. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 448 KW - intestinal microbiota KW - obesity KW - diabetes KW - metabolic syndrome KW - energy harvest KW - diet KW - absorption KW - bile acids KW - low-grade inflammation KW - SCFA Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-407687 ER - TY - JOUR A1 - Wilde, Sandra Catharina A1 - Treitz, Christian A1 - Keppler, Julia Katharina A1 - Koudelka, Tomas A1 - Palani, Kalpana A1 - Tholey, Andreas A1 - Rawel, Harshadrai Manilal A1 - Schwarz, Karin T1 - beta-Lactoglobulin as nanotransporter - Part II: Characterization of the covalent protein modification by allicin and diallyl disulfide JF - Food chemistry N2 - The whey protein beta-lactoglobulin has been proposed as a transporter for covalent bound bioactive compounds in order to enhance their stability and reduce their sensory perception. The garlic derived compounds allicin and diallyl disulfide were bound covalently to the native and heat denatured protein. The binding site and the influence of the modification on the digestibility were determined by mass spectrometric analysis of the modified beta-lactoglobulin. Further, the conformation of the modified protein was assessed by circular dichroism and dynamic light scattering. The free thiol group of Cys(121) turned out to be the major binding site. After proteolysis with trypsin at pH 7 but not with pepsin at pH 2, a limited transfer to other cysteinyl residues was observed. The covalently bound ligands did not mask any proteolytic cleavage sites of pepsin, trypsin or chymotrypsin. The modified beta-lactoglobulin showed a native like conformation, besides a moderate loosening of protein folding. The covalent binding of organosulfur compounds to beta-lactoglobulin provides a bioactive ingredient without impairing the digestibility and functional properties of the protein. (C) 2015 Elsevier Ltd. All rights reserved. KW - Beta-lactoglobulin KW - Covalent modification KW - LC-MS KW - CD, DLS KW - Thiol KW - Allicin KW - Garlic KW - Diallyl disulfide Y1 - 2016 U6 - https://doi.org/10.1016/j.foodchem.2015.11.011 SN - 0308-8146 SN - 1873-7072 VL - 197 SP - 1022 EP - 1029 PB - Elsevier CY - Oxford ER - TY - THES A1 - Weber, Florian Till T1 - In vitro Toxizität von Elektrolytlösungen der Lithium-Ionen Batterie Y1 - 2016 ER - TY - GEN A1 - Walter, Tim A1 - Collenburg, Lena A1 - Japtok, Lukasz A1 - Kleuser, Burkhard A1 - Schneider-Schaulies, Sibylle A1 - Müller, Nora A1 - Becam, Jerome A1 - Schubert-Unkmeir, Alexandra A1 - Kong, Ji Na A1 - Bieberich, Erhard A1 - Seibel, Jürgen T1 - Incorporation and visualization of azido-functionalized N-oleoyl serinol in Jurkat cells, mouse brain astrocytes, 3T3 fibroblasts and human brain microvascular endothelial cells N2 - The synthesis and biological evaluation of azido-N-oleoyl serinol is reported. It mimicks biofunctional lipid ceramides and has shown to be capable of click reactions for cell membrane imaging in Jurkat and human brain microvascular endothelial cells. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 324 Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-394960 ER - TY - JOUR A1 - Walter, T. A1 - Collenburg, Lena A1 - Japtok, Lukasz A1 - Kleuser, Burkhard A1 - Schneider-Schaulies, Sibylle A1 - Mueller, N. A1 - Becam, Jerome A1 - Schubert-Unkmeir, A. A1 - Kong, J. N. A1 - Bieberich, Erhard A1 - Seibel, J. T1 - Incorporation and visualization of azido-functionalized N-oleoyl serinol in Jurkat cells, mouse brain astrocytes, 3T3 fibroblasts and human brain microvascular endothelial cells JF - Chemical communications N2 - The synthesis and biological evaluation of azido-N-oleoyl serinol is reported. It mimicks biofunctional lipid ceramides and has shown to be capable of click reactions for cell membrane imaging in Jurkat and human brain microvascular endothelial cells. Y1 - 2016 U6 - https://doi.org/10.1039/c6cc02879a SN - 1359-7345 SN - 1364-548X VL - 52 SP - 8612 EP - 8614 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Uhr, Linda A1 - Wieland, Phillis A1 - Homann, Thomas A1 - Huschek, Gerd A1 - Rawel, Harshadrai Manilal T1 - Identification and LC-MS/MS-based analyses of technical enzymes in wheat flour and baked products JF - European food research and technology : official organ of the EuCheMS, Division of Food Chemistry N2 - The use of technical enzymes in bakery industry is necessary for a consistent and good quality of baked products. Since the cultivation of cereals leads to low amounts of endogenous enzymes being present, a need of their commercial alternatives is becoming a routine process in order to meet the consumer quality demands. Targeted quantification proteomics-based methods are necessary for their detection to meet the regulatory criteria. Here, we initially report on the identification of Lipase FE-01, a lipase from fungus Thermomyces lanuginosus, as analyzed by SDS-PAGE, in-Gel digestion, and MALDI-TOF-MS. In further experiments, the focus of the study was directed toward an extensive use and optimization of in-solution enzymatic digestion in combination with LC-MS/MS techniques in identification of specific peptide markers and finally in utilization of the latter in delivering reproducible quantification data for several different technical enzymes (alpha-amylases, xylanase, and lipases from microbial origin) in complex matrices such as baked bread and wheat flour. Two digestion protocols (a fast option using thermocycler program and the well-established overnight method) were tested, and both of these can be successfully applied. The application of isotopically labeled analogs of the MRM targeted peptides as internal standards and the addition of an internal protein standard during the extraction/digestion experiment were compared to determine the optimal quantification algorithm of the recovered enzyme concentrations. Thus, a standardized sensitive LC-MS/MS method could be developed to determine technical enzymes as forthcoming ingredients in the prefabricated food formulations in concentrations lower than 10 ppm. KW - Technical enzymes KW - Amylase KW - Xylanase KW - Lipase KW - Baked products KW - Mass spectrometry Y1 - 2016 U6 - https://doi.org/10.1007/s00217-015-2536-5 SN - 1438-2377 SN - 1438-2385 VL - 242 SP - 247 EP - 257 PB - Springer CY - New York ER - TY - THES A1 - Uhr, Linda T1 - Technische Enzyme in Backwaren T1 - Technical enzymes BT - Untersuchung der technologischen Wirkung und Entwicklung eines Multiparameterverfahrens zum quantitativen Nachweis mittels LC-MS/MS im Spurenbereich BT - investigation of technological impact, and development of a multi-parameter method for the quantitative detection by LC/MS/MS in trace concentration N2 - Die sensorisch einwandfreie, konstant gute Qualität von Backprodukten, die beim Verbraucher einen hohen Stellenwert hat, wird maßgeblich durch den Gehalt endogener Getreideenzyme beeinflusst. Seit dem Auftreten züchtungsbedingter Enzymdefizite ist der Einsatz technischer Enzyme zur Gewährleistung dieser geforderten Qualität eine feste Größe in der Backwarenindustrie. Lebensmittelrechtlich werden technische Enzyme nicht als Zutat betrachtet, da sie theoretisch während des Backprozesses umgesetzt werden und im Endprodukt keine technologische Wirkung mehr zeigen. Vor allem in gebackenen Produkten bedarf es der Prüfung, dass die eingesetzten technischen Enzyme nicht mehr als Zutat vorliegen und sich somit einer potentiellen Deklarationspflicht entziehen. Zur Gewährleistung der Wirtschaftlichkeit muss der quantitative Einsatz technischer Enzyme in der Backwarenindustrie gesteuert werden, um optimale Effekte zu erzielen und Kosten zu sparen. Ziel dieser Arbeit war daher die Entwicklung eines Analysenverfahrens, das den simultanen Nachweis verschiedener technischer Enzyme und deren Quantifizierung im Spurenbereich auch in gebackenen Produkten ermöglicht. Für die Einschätzung der Wirkung der technischen Enzyme Fungamyl (Novozymes), Amylase TXL (ASA Spezialenzyme GmbH) sowie Lipase FE-01 (ASA Spezialenzyme GmbH) wurden Backversuche durchgeführt, die zeigten, dass Fungamyl und Amylase TXL zu einer verbesserten Brotqualität (Volumenausbeute, Feuchtegehalt, Sensorik) beitrugen. Die Zugabe der Lipase FE-01 führte zu einer vermehrten Bildung freier Fettsäuren und wirkte sich negativ auf die sensorische Brotqualität aus. Dieser bisher nicht beschriebene Effekt konnte auf die Nutzung eines Spezialöls als Backzutat zurückgeführt werden, welches ausschließlich aus gesättigten Fettsäuren besteht. Dies bestätigt die Bedeutung der Auswahl eines geeigneten Fettes beim Zusatz technischer Lipase zum Backprozess. Um die in Fungamyl und Lipase FE-01 enthaltenen Enzyme zu identifizieren, wurden SDS-PAGE und anschließender In-Gel-Verdau angewendet um die Analyse proteolytisch gespaltener Proteine mit MALDI-TOF-MS zu ermöglichen. Es konnte gezeigt werden, dass Fungamyl ein Gemisch aus 9,8 % alpha-Amylase (Aspergillus oryzae) und 5,2 % Endo-1,4-Xylanase (Thermomyces lanuginosus) enthält. Lipase FE-01 besteht aus der Lipase (Thermomyces lanuginosus), Amylase TXL wurde als alpha-Amylase (Aspergillus oryzae) identifiziert. Zur Analyse der technischen Enzyme in Backwaren wurde aufgrund seiner Robustheit und Sensitivität das Verfahren der LC-MS/MS gewählt. Die Entwicklung einer solchen Methode zur Detektion spezifischer Peptide ermöglichte den qualitativen Nachweis der 3 Enzyme alpha-Amylase (Aspergillus oryzae), Endo-1,4-Xylanase (Thermomyces lanuginosus) und Lipase (Thermomyces lanuginosus). Durch eine lineare Kalibrierung aus synthetisch hergestellten Peptiden unter Einbeziehung eines Protein-Internen-Standards sowie isotopenmarkierter Peptidstandards erfolgte darüber hinaus die quantitative Bestimmung in selbst hergestellten Referenzmaterialien (Weizenmehl, Toastbrot und Biskuitkeks). In weniger als 20 Minuten Messzeit kann das Enzym alpha-Amylase ab einer Konzentration von 2,58 mg/kg (Mehl, Keks), bzw. 7,61 mg/kg (Brot) quantitativ nachgewiesen werden. Zeitgleich können die Enzyme Endo-1,4-Xylanase ab einer Konzentration von 7,75 mg/kg (Brot), 3,64 mg/kg (Keks) bzw. 15,60 mg/kg (Mehl) sowie Lipase ab einer Konzentration von 1,26 mg/kg (Mehl, Keks), bzw. 2,68 mg/kg (Brot) quantifiziert werden. Die Methode wurde nach allgemein verwendeten Richtlinien im Zuge einer Validierung statistisch geprüft und lieferte sehr robuste und reproduzierbare quantitative Werte mit Wiederfindungsraten zwischen 50 % und 122 %. Das primäre Ziel dieser Arbeit, die Entwicklung eines quantitativen Multiparameterverfahrens zum Nachweis technischer Enzyme in Backwaren, wurde somit erfolgreich umgesetzt. N2 - The consistent and good quality of baked products, which is of great importance for consumers, is significantly influenced by endogenous grain enzymes. Since cereal breeding techniques have caused deficits of endogenous enzymes, the use of technical enzyme alternatives became a routine process in the bakery industry to ensure the expected quality. According to food law, technical enzymes are not listed as ingredients, because theoretically, enzymes are destroyed during the baking process so that there is no more technological activity in the end product. To prevent a potentially required declaration, it has to be verified that technical enzymes are no ingredients in baking products. To secure economic viability, the quantitative application of technical enzymes should be regulated to gain optimal effects and save costs. Therefore, the aim of this thesis was the development of a quantitative analytical method with the potential to analyze several technical enzymes simultaneously and sensitively (ppm concentration) quantify them in baking products. The effects of the use of the technical enzymes Fungamyl (Novozymes), Amylase TXL (ASA Spezialenzyme GmbH) and Lipase FE-01 (ASA Spezialenzyme GmbH) were monitored during baking experiments. The application of Fungamyl and Amylase TXL resulted in a perfect bread quality (high volume, good bread humidity, good sensory grading). The addition of Lipase FE-01 led to an increased release of free fatty acids, resulting in bread with a bad sensory quality. Reason for that previously not described negative effect is the use of an oil consisting only of saturates fatty acids as a baking ingredient. Thereby the importance of the choice of fat as a baking ingredient was demonstrated and confirmed. To identify the enzymes contained in the technical enzymes Fungamyl and Lipase FE-01, SDS-PAGE and in-gel digestion were applied, enabling the analysis of proteolytically splitted proteins by MALDI-TOF-MS. It was shown that Fungamyl contains 9.8 % alpha-Amylase (Aspergillus oryzae) and 5.2 % Endo-1,4-Xylanase (Thermomyces lanuginosus). Lipase FE-01 consists of Lipase (Thermomyces lanuginosus) and Amylase TXL could be qualified as alpha-Amylase (Aspergillus oryzae). Based on its robustness and sensitivity LC/MS/MS was the analytical method of choice. The development of a specific LC/MS/MS method capable of detecting characteristic peptides, allowed for the qualitative determination of the enzymes alpha-Amylase (Aspergillus oryzae), Endo-1,4-Xylanase (Thermomyces lanuginosus) and Lipase (Thermomyces lanuginosus). Quantification of self-made reference material (wheat flour, bread and cookies) was performed by linear calibration with synthetically produced peptide standards and the use of a protein internal standard as well as isotopically labeled peptide standards. Less than 20 minutes are necessary to quantify alpha-Amylase at a minimum concentration of 2.58 mg/kg (flour, cookies) and 7.61 mg/kg (bread). Simultaneously the enzyme Endo-1,4-Xylanase can be quantified at concentrations as low as 3.64 mg/kg (cookies), 7.75 mg/kg (bread) and 15.60 mg/kg (flour) as well as the enzyme Lipase at a minimum concentration of 1.26 mg/kg (flour, cookies) and 2.68 mg/kg (bread). Finally the method was validated in accordance with generally accepted guidelines. It was shown that the method leads to very stable and reproducible quantitative results for the three tested enzymes with recovery rates between 50 % and 122 %. The primary aim of this thesis, developing a quantitative multi parameter method for analyzing technical enzymes in baking products, was successfully implemented. KW - Enzyme KW - LC-MS/MS KW - quantitativ KW - enzymes KW - LC/MS/MS KW - quantitative Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-96432 ER - TY - THES A1 - Töle, Nadine T1 - Molekulare und histologische Untersuchungen zur gustatorischen Fettwahrnehmung des Menschen T1 - Molecular and histological analyses of human gustatory fat perception N2 - Die hohe Energieaufnahme durch Fette ist ein Hauptfaktor für die Entstehung von Adipositas, was zu weltweiten Bestrebungen führte, die Fettaufnahme zu verringern. Fettreduzierte Lebensmittel erreichen jedoch, trotz ihrer Weiterentwicklung, nicht die Schmackhaftigkeit ihrer Originale. Die traditionelle Sichtweise, dass die Attraktivität von Fetten allein durch Textur, Geruch, Aussehen und postingestive Effekte bestimmt wird, wird nun durch das Konzept einer gustatorischen Wahrnehmung ergänzt. Bei Nagetieren zeigte sich, dass Lipide unabhängig von den vorgenannten Eigenschaften erkannt werden, sowie, dass Fettsäuren, freigesetzt durch linguale Lipasen, als gustatorische Stimuli fungieren und Fettsäuresensoren in Geschmackszellen exprimiert sind. Die Datenlage für den Menschen erwies sich jedoch als sehr begrenzt, daher war es Ziel der vorliegenden Arbeit molekulare und histologische Voraussetzungen für eine gustatorische Fettwahrnehmung beim Menschen zu untersuchen. Zunächst wurde humanes Geschmacksgewebe mittels RT-PCR und immunhistochemischen Methoden auf die Expression von Fettsäuresensoren untersucht, sowie exprimierende Zellen in Kofärbeexperimenten charakterisiert und quantifiziert. Es wurde die Expression fettsäuresensitiver Rezeptoren nachgewiesen, deren Agonisten das gesamte Spektrum an kurz- bis langkettigen Fettsäuren abdecken (GPR43, GPR84, GPR120, CD36, KCNA5). Ein zweifelsfreier Nachweis des Proteins konnte für den auf langkettige Fettsäuren spezialisierten Rezeptor GPR120 in Typ-I- und Typ-III-Geschmackszellen der Wallpapillen erbracht werden. Etwa 85 % dieser GPR120-exprimierenden Zellen enthielten keine der ausgewählten Rezeptoren der Geschmacksqualitäten süß (TAS1R2/3), umami (TAS1R1/3) oder bitter (TAS2R38). Somit findet sich in humanen Geschmackspapillen nicht nur mindestens ein Sensor, sondern möglicherweise auch eine spezifische, fettsäuresensitive Zellpopulation. Weitere RT-PCR-Experimente und Untersuchungen mittels In-situ-Hybridisierung wurden zur Klärung der Frage durchgeführt, ob Lipasen in den Von-Ebner-Speicheldrüsen (VED) existieren, die freie Fettsäuren aus Triglyceriden als gustatorischen Stimulus freisetzen können. Es zeigte sich zwar keine Expression der bei Nagetieren gefundenen Lipase F (LIPF), jedoch der eng verwandten Lipasen K, M und N in den serösen Zellen der VED. In-silico-Untersuchungen der Sekundär- und Tertiärstrukturen zeigten die hohe Ähnlichkeit zu LIPF, erwiesen aber auch Unterschiede in den Bindungstaschen der Enzyme, welche auf ein differenziertes Substratspektrum hinweisen. Die Anwesenheit eines spezifischen Signalpeptids macht eine Sekretion der Lipasen in den die Geschmacksporen umspülenden Speichel wahrscheinlich und damit auch eine Bereitstellung von Fettsäuren als Stimuli für Fettsäuresensoren. Die Übertragung des durch diese Stimuli hervorgerufenen Signals von Geschmackszellen auf gustatorische Nervenfasern über P2X-Rezeptormultimere wurde mit Hilfe einer vorherigen Intervention mit einem P2X3 /P2X2/3-spezifischen Antagonisten an der Maus als Modellorganismus im Kurzzeit-Präferenztest untersucht. Es zeigte sich weder eine Beeinträchtigung der Wahrnehmung einer Fettsäurelösung, noch einer zuckerhaltigen Kontrolllösung, wohingegen die Wahrnehmung einer Bitterstofflösung reduziert wurde. Somit ist anhand der Ergebnisse dieser Arbeit eine Beteiligung des P2X3-Homomers bzw. des P2X2/3-Heteromers unwahrscheinlich, jedoch die des P2X2-Homomers und damit der gustatorischen Nervenfasern nicht ausgeschlossen. Die Ergebnisse dieser Arbeit weisen auf die Erfüllung grundlegender Voraussetzungen für die gustatorische Fett(säure)wahrnehmung hin und tragen zum Verständnis der sensorischen Fettwahrnehmung und der Regulation der Fettaufnahme bei. Das Wissen um die Regulation dieser Mechanismen stellt eine Grundlage zur Aufklärung der Ursachen und damit der Bekämpfung von Adipositas und assoziierten Krankheiten dar. N2 - High consumption of energy from fat is considered one of the main factors that evoke obesity which led to a worldwide effort to reduce dietary fat intake. However, despite their continuous improvement, fat-reduced foods do not yet reach the palatability of their originals. The traditional view that the attraction to fats is only determined by texture, odor, appearance as well as postingestive effects is now challenged by the concept of gustatory sensation of fats. After excluding or masking the aforementioned features, rodents showed continuous attraction towards lipid solutions. Also long-chain fatty acids liberated from triglycerides by lingual lipases as the main stimulus and the expression of fatty acid-sensitive receptors in taste buds was shown. In contrast, only little data exists for humans. Therefore, this thesis aimed at elucidating the molecular and cellular prerequisites for a gustatory detection of fat. First, human taste tissue was examined by RT-PCR and immunohistochemical methods for the expression of fatty acid sensors and the expressing cells were characterized and quantified by co-staining procedures. The expression of fatty acid-sensitive receptors was shown whose agonists cover the whole range of short- to long-chain fatty acids (GPR43, GPR84, GPR120, CD36, and KCNA5). Protein expression of the long-chain fatty acid receptor GPR120 in type I and type III taste cells was unambiguously demonstrated. About 85 % of the GPR120-expressing cells did not co-express receptors for sweet (TAS1R2/3), umami (TAS1R1/3) or bitter (TAS2R38) taste. Hence, not only does at least one fatty acid sensor exist in human taste papillae, but possibly also a special fatty acid-sensitive cell population. Additional RT-PCR experiments and in situ hybridization analyses were used to address the question, if lipases in the Von-Ebner-salivary glands (VEG) produce free fatty acids from triglycerides as gustatory stimuli. Unlike mice which express lipase F, lipases K, M and N, which are highly related to lipase F, were found to be expressed in the serous cells of the VEG. In silico approaches confirmed high similarities of the secondary and tertiary structures of these lipases to lipase F. Also a marked difference in the binding pocket of the enzymes was observed, which suggests differential substrate specificity. The presence of a signal peptide sequence proposes that the lipases K, M, and N are secreted into the trenches of gustatory papillae. This would result in lipolysis of dietary triglycerides and generation of stimuli for the fatty acid sensor GPR120. Next the hypothesis was tested whether GPR120-generated signals are conveyed to gustatory nerves via P2X-receptor-multimers. To this end short term preference tests were performed in mice after intervention with a P2X3-/P2X2/3-specific antagonist. However, this treatment did not affect the preference of mice for the fatty acid or for a sweet control solution, whereas recognition of a bitter solution was impaired. Thus, an involvement of the P2X3-homomer or the P2X3-/P2X2/3-heteromer seems unlikely. However, these results do not exclude a contribution of P2X2-receptor-heteromers and in turn gustatory nerves for the preference of fatty acid solutions. In summary, the results of this thesis give new insights into the molecular and cellular prerequisites for a gustatory component for fat detection in humans. They also help understanding fat sensation and the regulation of fat intake which in turn may eventually promote novel concepts for the treatment of obesity and related diseases. KW - Geschmack KW - Fettwahrnehmung KW - Fettsäuren KW - Sensorik KW - Lipasen KW - G-Protein gekoppelte Rezeptoren KW - taste KW - fat perception KW - fatty acids KW - lipases KW - G-protein coupled receptors KW - sensory analysis Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-93180 ER - TY - JOUR A1 - Tsuprykov, Oleg A1 - Ando, Ryotaro A1 - Reichetzeder, Christoph A1 - von Websky, Karoline A1 - Antonenko, Viktoriia A1 - Sharkovska, Yuliya A1 - Chaykovska, Lyubov A1 - Rahnenfuehrer, Jan A1 - Hasan, Ahmed Abdallah Abdalrahman Mohamed A1 - Tammen, Harald A1 - Alter, Markus L. A1 - Klein, Thomas A1 - Ueda, Seiji A1 - Yamagishi, Sho-ichi A1 - Okuda, Seiya A1 - Hocher, Berthold T1 - The dipeptidyl peptidase inhibitor linagliptin and the angiotensin II receptor blocker telmisartan show renal benefit by different pathways in rats with 5/6 nephrectomy JF - Kidney international : official journal of the International Society of Nephrology N2 - Dipeptidyl peptidase (DPP)-4 inhibitors delay chronic kidney disease (CKD) progression in experimental diabetic nephropathy in a glucose-independent manner. Here we compared the effects of the DPP-4 inhibitor linagliptin versus telmisartan in preventing CKD progression in non-diabetic rats with 5/6 nephrectomy. Animals were allocated to 1 of 4 groups: sham operated plus placebo; 5/6 nephrectomy plus placebo; 5/6 nephrectomy plus linagliptin; and 5/6 nephrectomy plus telmisartan. Interstitial fibrosis was significantly decreased by 48% with linagliptin but a non-significant 24% with telmisartan versus placebo. The urine albumin-to-creatinine ratio was significantly decreased by 66% with linagliptin and 92% with telmisartan versus placebo. Blood pressure was significantly lowered by telmisartan, but it was not affected by linagliptin. As shown by mass spectrometry, the number of altered peptide signals for linagliptin in plasma was 552 and 320 in the kidney. For telmisartan, there were 108 peptide changes in plasma and 363 in the kidney versus placebo. Linagliptin up-regulated peptides derived from collagen type I, apolipoprotein C1, and heterogeneous nuclear ribonucleoproteins A2/B1, a potential downstream target of atrial natriuretic peptide, whereas telmisartan up-regulated angiotensin II. A second study was conducted to confirm these findings in 5/6 nephrectomy wild-type and genetically deficient DPP-4 rats treated with linagliptin or placebo. Linagliptin therapy in wild-type rats was as effective as DPP-4 genetic deficiency in terms of albuminuria reduction. Thus, linagliptin showed comparable efficacy to telmisartan in preventing CKD progression in non-diabetic rats with 5/6 nephrectomy. However, the underlying pathways seem to be different. Copyright (C) 2016, International Society of Nephrology. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). KW - albuminuria KW - angiotensin receptor blockers KW - chronic kidney disease KW - DPP-4 inhibition KW - proteinuria KW - proteomic analysis Y1 - 2016 U6 - https://doi.org/10.1016/j.kint.2016.01.016 SN - 0085-2538 SN - 1523-1755 VL - 89 SP - 1049 EP - 1061 PB - Nature Publ. Group CY - New York ER - TY - JOUR A1 - Swidsinski, Alexander A1 - Loening-Baucke, Vera A1 - Schulz, Stefan A1 - Manowsky, Julia A1 - Verstraelen, Hans A1 - Swidsinski, Sonja T1 - Functional anatomy of the colonic bioreactor: Impact of antibiotics and Saccharomyces boulardii on bacterial composition in human fecal cylinders JF - Systematic and Applied Microbiology N2 - Sections of fecal cylinders were analyzed using fluorescence in situ hybridization targeting 180 bacterial groups. Samples were collected from three groups of women (N = 20 each) treated for bacterial vaginosis with ciprofloxacin + metronidazole. Group A only received the combined antibiotic regimen, whereas the A/Sb group received concomitant Saccharomyces boulardii CNCM I-745 treatment, and the A.Sb group received S. boulardii prophylaxis following the 14-day antibiotic course. The number of stool cylinders analyzed was 188 out of 228 in group A, 170 out of 228 in group A/Sb, and 172 out of 216 in group Ash. The colonic biomass was organized into a separate mucus layer with no bacteria, a 10-30 mu m broad unstirred transitional layer enriched with bacteria, and a patchy fermentative area that mixed digestive leftovers with bacteria. The antibiotics suppressed bacteria mainly in the fermentative area, whereas abundant bacterial clades retreated to the transitional mucus and survived. As a result, the total concentration of bacteria decreased only by one order. These effects were lasting, since the overall recovery of the microbial mass, bacterial diversity and concentrations were still below pre-antibiotic values 4 months after the end of antibiotic treatment. Sb-prophylaxis markedly reduced antibiotic effects and improved the recovery rates. Since the colon is a sophisticated bioreactor, the study indicated that the spatial anatomy of its biomass was crucial for its function. (C) 2015 The Authors. Published by Elsevier GmbH. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). KW - FISH KW - Colonic microbiota KW - Antibiotics KW - Bioreactor KW - Saccharomyces boulardii KW - Clostridium difficile Y1 - 2016 U6 - https://doi.org/10.1016/j.syapm.2015.11.002 SN - 0723-2020 VL - 39 SP - 67 EP - 75 PB - Nature Publ. Group CY - Jena ER - TY - GEN A1 - Stuetz, Wolfgang A1 - Weber, Daniela A1 - Dollé, Martijn E. T. A1 - Jansen, Eugène A1 - Grubeck-Loebenstein, Beatrix A1 - Fiegl, Simone A1 - Toussaint, Olivier A1 - Bernhardt, Juergen A1 - Gonos, Efstathios S. A1 - Franceschi, Claudio A1 - Sikora, Ewa A1 - Moreno-Villanueva, María A1 - Breusing, Nicolle A1 - Grune, Tilman A1 - Bürkle, Alexander T1 - Plasma carotenoids, tocopherols, and retinol in the age-stratified (35–74 years) general population BT - a cross-sectional study in six European countries T2 - Nutrients N2 - Blood micronutrient status may change with age. We analyzed plasma carotenoids, α-/γ-tocopherol, and retinol and their associations with age, demographic characteristics, and dietary habits (assessed by a short food frequency questionnaire) in a cross-sectional study of 2118 women and men (age-stratified from 35 to 74 years) of the general population from six European countries. Higher age was associated with lower lycopene and α-/β-carotene and higher β-cryptoxanthin, lutein, zeaxanthin, α-/γ-tocopherol, and retinol levels. Significant correlations with age were observed for lycopene (r = −0.248), α-tocopherol (r = 0.208), α-carotene (r = −0.112), and β-cryptoxanthin (r = 0.125; all p < 0.001). Age was inversely associated with lycopene (−6.5% per five-year age increase) and this association remained in the multiple regression model with the significant predictors (covariables) being country, season, cholesterol, gender, smoking status, body mass index (BMI (kg/m2)), and dietary habits. The positive association of α-tocopherol with age remained when all covariates including cholesterol and use of vitamin supplements were included (1.7% vs. 2.4% per five-year age increase). The association of higher β-cryptoxanthin with higher age was no longer statistically significant after adjustment for fruit consumption, whereas the inverse association of α-carotene with age remained in the fully adjusted multivariable model (−4.8% vs. −3.8% per five-year age increase). We conclude from our study that age is an independent predictor of plasma lycopene, α-tocopherol, and α-carotene. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 449 KW - carotenoids KW - plasma KW - age KW - Europe KW - micronutrient KW - lycopene KW - retinol KW - tocopherols Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-407659 ER - TY - THES A1 - Stolzenburg, Antje T1 - Bittergeschmacksrezeptoren des peripheren und zentralen Nervensystems T1 - Bitter taste receptors of the peripheral and central nervous system N2 - Der Bittergeschmack warnt den Organismus vor potentiell verdorbener oder giftiger Nahrung und ist somit ein wichtiger Kontrollmechanismus. Die initiale Detektion der zahlreich vorkommenden Bitterstoffe erfolgt bei der Maus durch 35 Bitterrezeptoren (Tas2rs), die sich im Zungengewebe befinden. Die Geschmacksinformation wird anschließend von der Zunge über das periphere (PNS) ins zentrale Nervensystem (ZNS) geleitet, wo deren Verarbeitung stattfindet. Die Verarbeitung der Geschmacksinformation konnte bislang nicht gänzlich aufgeklärt werden. Neue Studien deuten auf eine Expression von Tas2rs auch im PNS und ZNS entlang der Geschmacksbahn hin. Über Vorkommen und Aufgaben dieser Rezeptoren bzw. Rezeptorzellen im Nervensystem ist bislang wenig bekannt. Im Rahmen dieser Arbeit wurde die Tas2r-Expression in verschiedenen Mausmodellen untersucht, Tas2r-exprimierende Zellen identifiziert und deren Funktionen bei der Übertragung der Geschmacksinformationen analysiert. Im Zuge der Expressionsanalysen mittels qRT-PCR konnte die Expression von 25 der 35 bekannten Bittergeschmacksrezeptoren im zentralen Nervensystem der Maus nachgewiesen werden. Die Expressionsmuster im PNS sowie im ZNS lassen darüber hinaus Vermutungen zu Funktionen in verschiedenen Bereichen des Nervensystems zu. Basierend auf den Ergebnissen der Expressionsanalysen war es möglich, stark exprimierte Tas2rs mittels In-situ-Hybridisierung in verschiedenen Zelltypen zu visualisieren. Des Weiteren konnten immunhistochemische Färbungen unter Verwendung eines genetisch modifizierten Mausmodells die Ergebnisse der Expressionsanalysen bestätigen. Sie zeigten eine Expression von Tas2rs, am Beispiel des Tas2r131-Rezeptors, in cholinergen, dopaminergen, GABAergen, noradrenergen und glycinerg-angesteuerten Projektionsneuronen sowie in Interneuronen. Die Ergebnisse der vorliegenden Arbeit zeigen daher erstmals das Vorkommen von Tas2rs in verschiedenen neuronalen Zelltypen in weiten Teilen des ZNS. Dies lässt den Schluss zu, dass Tas2r-exprimierende Zellen potentiell multiple Funktionen innehaben. Anhand von Verhaltensexperimenten in genetisch modifizierten Mäusen wurde die mögliche Funktion von Tas2r131-exprimierenden Neuronen (Tas2r131-Neurone) bei der Geschmackswahrnehmung untersucht. Die Ergebnisse weisen auf eine Beteiligung von Tas2r131-Neuronen an der Signalweiterleitung bzw. -verarbeitung der Geschmacksinformation für eine Auswahl von Bittersubstanzen hin. Die Analysen zeigen darüber hinaus, dass Tas2r131-Neuronen nicht an der Geschmackswahrnehmung anderer Bitterstoffe sowie Geschmacksstimuli anderer Qualitäten (süß, umami, sauer, salzig), beteiligt sind. Eine spezifische „Tas2r131-Bittergeschmacksbahn“, die mit anderen potentiellen „Bitterbahnen“ teils unabhängige, teils überlappende Signalwege bzw. Verarbeitungsbereiche besitzt, bildet eine mögliche zelluläre Grundlage zur Unterscheidung von Bitterstoffen. Die im Rahmen dieser Arbeit entstandene Hypothese einer potentiellen Diskriminierung von Bitterstoffen soll daher in weiterführenden Studien durch die Etablierung eines Verhaltenstest mit Mäusen geprüft werden. N2 - Bitter taste warns the organism about potentially spoiled or toxic food and is thus an important control mechanism. The initial detection of numerous occurring bitter substances is done in mice by 35 bitter taste receptors (Tas2rs), located in tongue tissue. From the tongue the gustatory information is then passed via the peripheral (PNS) to the central nervous system (CNS), where it is processed. The processing of taste information couldn’t yet be clarified entirely. Recent studies point to an expression of Tas2rs also in the PNS and CNS along the taste transmission pathway. However, little is known concerning occurrence and functions of Tas2rs or Tas2r-expressing cells in the nervous system. In this work the Tas2r expression was examined in different mouse models, Tas2r-expressing cells were identified and their functions in transmission of taste information analyzed. Expression analyses using qRT-PCR showed an expression of 25 of the 35 known murine bitter taste receptors in the central nervous system. The expression patterns in the PNS and CNS suggests functions in different areas of the nervous system. Based on the results of the expression analysis it was possible to visualize highly expressed Tas2rs by in-situ-hybridization in various cell types. Furthermore, immunohistochemical staining using a genetically modified mouse model confirmed the results of the expression analysis. They showed an expression of Tas2rs, on the example of the Tas2r131 receptor, in the cholinergic, dopaminergic, GABAergic, noradrenergic and glycinerg-driven projection neurons and interneurons. The results of the present work show for the first time the presence of Tas2rs in different neuronal cell types in many parts of the CNS. This leads to the conclusion that Tas2r-expressing cells hold potentially multiple functions. Based on behavioral experiments in genetically modified mice, the possible taste function of Tas2r131-expressing neurons (Tas2r131 neurons) was studied. The results showed the involvement of Tas2r131 neurons in signal transduction and processing of gustatory information for a selection of bitter substances. Besides, the analyses show that Tas2r131 neurons aren’t involved in taste perception for another selection of bitter substances and taste stimuli of other qualities (sweet, umami, sour, salty). A specific "Tas2r131-bitter-pathway" which forms partly independent and partly overlapping signaling pathways or processing areas with other potential "bitter-pathways", provides a cellular basis for the distinction of specific bitter compounds. The resulting hypothesis of a potential discrimination of bitter substances should therefore be examined in further studies by establishing a behavioral test with mice. KW - Geschmack KW - Bittergeschmack KW - Bittergeschmacksrezeptoren KW - Tas2r KW - Verhaltensstudien KW - zentrales Nervensystem KW - peripheres Nervensystem KW - Neurone KW - Maus KW - taste KW - bitter taste KW - bitter taste receptors KW - Tas2rs KW - peripheral nervous system KW - central nervous system KW - neuron KW - behavioral experiments KW - expression analysis KW - mouse Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-92397 ER - TY - JOUR A1 - Sievers, Steven A1 - Rawel, Harshadrai Manilal A1 - Ringel, Karl Peter A1 - Niggemann, Bodo A1 - Beyer, Kirsten T1 - Wheat protein recognition pattern in tolerant and allergic children JF - Pediatric Allergy and Immunology N2 - BackgroundWheat is one of the most common food allergens in early childhood. In contrast to other food allergies, wheat-specific IgE correlates badly with clinical symptoms and relevant components have been identified mostly for wheat-depended exercise-induced anaphylaxis. Moreover, a high percentage of patients present with immediate type symptoms but wheat-specific IgE cannot be detected with commercial available systems. ObjectiveWe addressed the question whether the IgE recognition pattern between wheat allergic (WA) and clinically tolerant (WT) children differs in order to identify individual proteins useful for component-resolved diagnostics. MethodsSera of 106 children with suspected wheat allergy, of whom 44 children had clinical relevant wheat allergy and 62 were tolerant upon oral food challenge, were analyzed for wheat-specific IgE using the ImmunoCap system as well as immunoblots against water and salt soluble, and water-insoluble protein fractions. 40 randomly selected sera were analyzed for specific IgE to 5-gliadin. ResultsSixty-three percent of the WT and 86% of the WA children were sensitized to wheat with >0.35 kU(A)/l in ImmunoCAP analysis. We could confirm the role of -, ss-, -, and -gliadins, and LMW glutenin subunits as major allergens and found also IgE binding to a broad spectrum of water- and salt-soluble protein bands. It is of great importance that wheat allergic and tolerant patients showed IgE binding to the same protein bands. WT and WA did not significantly differ in levels of 5-gliadin-specific IgE. Conclusions & Clinical RelevanceChildren with challenge proven clinical relevant food allergy and tolerant ones had a similar spectrum of IgE binding to the same protein bands. These findings imply that component-resolved diagnostics might not be helpful in the diagnostic work-up of wheat allergy. KW - wheat KW - IgE KW - 5-gliadin KW - protein pattern KW - immunoblot Y1 - 2016 U6 - https://doi.org/10.1111/pai.12502 SN - 0905-6157 SN - 1399-3038 VL - 27 SP - 147 EP - 155 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Schmiedchen, Bettina A1 - Longardt, Ann Carolin A1 - Loui, Andrea A1 - Buehrer, Christoph A1 - Raila, Jens A1 - Schweigert, Florian J. T1 - Effect of vitamin A supplementation on the urinary retinol excretion in very low birth weight infants JF - European journal of pediatrics : official organ of the Belgian Pediatric Association N2 - Despite high-dose vitamin A supplementation of very low birth weight infants (VLBW, <1500 g), their vitamin A status does not improve substantially. Unknown is the impact of urinary retinol excretion on the serum retinol concentration in these infants. Therefore, the effect of high-dose vitamin A supplementation on the urinary vitamin A excretion in VLBW infants was investigated. Sixty-three VLBW infants were treated with vitamin A (5000 IU intramuscular, 3 times/week for 4 weeks); 38 untreated infants were classified as control group. On days 3 and 28 of life, retinol, retinol-binding protein 4 (RBP4), glomerular filtration rate, proteinuria, and Tamm-Horsfall protein were quantified in urine. On day 3 of life, substantial retinol and RBP4 losses were found in both groups, which significantly decreased until day 28. Notwithstanding, the retinol excretion was higher (P<0.01) under vitamin A supplementation as compared to infants of the control group. On day 28 of life, the urinary retinol concentrations were predictive for serum retinol concentrations in the vitamin A treated (P<0.01), but not in the control group (P=0.570). Conclusion: High urinary retinol excretion may limit the vitamin A supplementation efficacy in VLBW infants. Advanced age and thus postnatal kidney maturation seems to be an important contributor in the prevention of urinary retinol losses. KW - Vitamin A supplementation KW - RBP4 KW - Very low birth weight infant KW - Urine excretion Y1 - 2016 U6 - https://doi.org/10.1007/s00431-015-2647-9 SN - 0340-6199 SN - 1432-1076 VL - 175 SP - 365 EP - 372 PB - Springer CY - New York ER - TY - GEN A1 - Schernthaner, G. A1 - Groop, P. A1 - Cooper, M. A1 - Perkovic, V A1 - Hocher, Berthold A1 - Kanasaki, K. A1 - Sharma, K. A1 - Stanton, R. A1 - Toto, R. A1 - Cescutti, Jessica A1 - Gordat, M. A1 - Meinicke, T. A1 - Koitka-Weber, A. A1 - Woerle, H. A1 - Eynatten, M. T1 - EFFECTS OF LINAGLIPTIN ON GLYCAEMIC CONTROL AND ALBUMINURIA IN TYPE 2 DIABETES - THE MARLINA-T2D (TM) TRIAL T2 - Nephrology Y1 - 2016 U6 - https://doi.org/10.1111/nep.12887 SN - 1320-5358 SN - 1440-1797 VL - 21 SP - 60 EP - 60 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Sandmann, Michael A1 - Garz, Andreas A1 - Menzel, Ralf T1 - Physiological response of two different Chlamydomonas reinhardtii strains to light-dark rhythms JF - Botany N2 - Cells of a cell-wall deficient line (cw15-type) of Chlamydomonas reinhardtii and of the corresponding wild type were grown during repetitive light-dark cycles. In a direct comparison, both lines showed approximately the same relative biomass increase during light phase but the cw-line produced significantly more, and smaller, daughter cells. Throughout the light period the average cellular starch content, the cellular chlorophyll content, the cellular rate of dark respiration, and the cellular rate of photosynthesis of the cw-line was lower. Despite this, several non-cell volume related parameters like the development of starch content per cell volume were clearly different over time between the strains. Additionally, the chlorophyll-based photosynthesis rates were 2-fold higher in the mutant than in the wild-type cells, and the ratio of chlorophyll a to chlorophyll b as well as the light-saturation index were also consistently higher in the mutant cells. Differences in the starch content were also confirmed by single cell analyses using a sensitive SHG-based microscopy approach. In summary, the cw15-type mutant deviates from its genetic background in the entire cell physiology. Both lines should be used in further studies in comparative systems biology with focus on the detailed relation between cell volume increase, photosynthesis, starch metabolism, and daughter cell productivity. KW - cell wall deficient mutant KW - diurnal rhythm KW - nonlinear microscopy KW - photosynthesis KW - single-cell analysis Y1 - 2016 U6 - https://doi.org/10.1139/cjb-2015-0144 SN - 1916-2790 SN - 1916-2804 VL - 94 SP - 53 EP - 64 PB - NRC Research Press CY - Ottawa ER - TY - JOUR A1 - Sahle, Fitsum Feleke A1 - Balzus, Benjamin A1 - Gerecke, Christian A1 - Kleuser, Burkhard A1 - Bodmeier, Roland T1 - Formulation and in vitro evaluation of polymeric enteric nanoparticles as dermal carriers with pH-dependent targeting potential JF - European journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences, EUFEPS N2 - pH-sensitive nanoparticles which release in a controlled fashion on the skin or dissolve in the hair follicle could significantly improve treatment effectiveness and make transfollicular drug delivery a success. Dexamethasone-loaded Eudragit L 100 nanoparticles were prepared by nanoprecipitation from an organic drug-polymer solution. Their toxicity potential was assessed using isolated human fibroblasts. pH-dependent swelling and erosion kinetics of the nanoparticles were investigated by dynamic light scattering and viscosity measurements and its effect on drug release was assessed in vitro with Franz diffusion cells. Stable, 100-550 nm-sized dexamethasone-loaded Eudragit L 100 nanoparticles with drug loading capacity and entrapment efficiency as high as 83% and 85%, respectively, were obtained by using polyvinyl alcohol as a stabilizer and ethanol as organic solvent The nanoparticles showed little or no toxicity on isolated normal human fibroblasts. Dexamethasone existed in the nanoparticles as solid solution or in amorphous form. The nanoparticles underwent extensive swelling and slow drug release in media with a low buffer capacity (as low as 10 mM) and a higher pH or at a pH close to the dissolution pH of the polymer (pH 6) and a higher buffer capacity. In 40 mM buffer and above pH 6.8, the nanoparticles eroded fast or dissolved completely and thus released the drug rapidly. pH-sensitive nanoparticles which potentially release in a controlled manner on the stratum corneum but dissolve in the hair follicle could be prepared. (C) 2016 Elsevier B.V. All rights reserved. KW - Dexamethasone KW - Enteric polymer KW - Eudragit L 100 KW - pH-sensitive nanoparticles KW - Skin nanocarrier KW - Erosion kinetics Y1 - 2016 U6 - https://doi.org/10.1016/j.ejps.2016.07.004 SN - 0928-0987 SN - 1879-0720 VL - 92 SP - 98 EP - 109 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Rosenkranz, Eva A1 - Maywald, Martina A1 - Hilgers, Ralf-Dieter A1 - Brieger, Anne A1 - Clarner, Tim A1 - Kipp, Markus A1 - Pluemaekers, Birgit A1 - Meyer, Sören A1 - Schwerdtle, Tanja A1 - Rink, Lothar T1 - Induction of regulatory T cells in Th1-/Th17-driven experimental autoimmune encephalomyelitis by zinc administration JF - The journal of nutritional biochemistry N2 - The essential trace element zinc is indispensable for proper immune function as zinc deficiency accompanies immune defects and dysregulations like allergies, autoimmunity and an increased presence of transplant rejection. This point to the importance of the physiological and dietary control of zinc levels for a functioning immune system. This study investigates the capacity of zinc to induce immune tolerance. The beneficial impact of physiological zinc supplementation of 6 mu g/day (0.3 mg/kg body weight) or 30 mu g/day (1.5 mg/kg body weight) on murine experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis with a Th1/Th17 (Th, T helper) cell-dominated immunopathogenesis, was analyzed. Zinc administration diminished EAE scores in C57BL/6 mice in vivo (P<.05), reduced Th17 ROR gamma T+ cells (P<.05) and significantly increased inducible iTreg cells (P<.05). While Th17 cells decreased systemically, iTreg cells accumulated in the central nervous system. Cumulatively, zinc supplementation seems to be capable to induce tolerance in unwanted immune reactions by increasing iTreg cells. This makes zinc a promising future tool for treating autoimmune diseases without suppressing the immune system. (C) 2015 Elsevier Inc. All rights reserved. KW - Zinc KW - Regulatory T cells (Treg) KW - Foxp3 KW - Mixed lymphocyte culture (MLC) KW - Experimental autoimmune encephalomyelitis (EAE) KW - Th17 Y1 - 2016 U6 - https://doi.org/10.1016/j.jnutbio.2015.11.010 SN - 0955-2863 SN - 1873-4847 VL - 29 SP - 116 EP - 123 PB - Elsevier CY - New York ER - TY - JOUR A1 - Reyes, Anibal M. A1 - Vazquez, Diego S. A1 - Zeida, Ari A1 - Hugo, Martin A1 - Dolores Pineyro, M. A1 - Ines De Armas, Maria A1 - Estrin, Dario A1 - Radi, Rafael A1 - Santos, Javier A1 - Trujillo, Madia T1 - PrxQ B from Mycobacterium tuberculosis is a monomeric, thioredoxin-dependent and highly efficient fatty acid hydroperoxide reductase JF - Free radical biology and medicine : the official journal of the Oxygen Society, a constituent member of the International Society for Free Radical Research N2 - Mycobacterium tuberculosis (M. tuberculosis) is the intracellular bacterium responsible for tuberculosis disease (TD). Inside the phagosomes of activated macrophages, M. tuberculosis is exposed to cytotoxic hydroperoxides such as hydrogen peroxide, fatty acid hydroperoxides and peroxynitrite. Thus, the characterization of the bacterial antioxidant systems could facilitate novel drug developments. In this work, we characterized the product of the gene Rv1608c from M. tuberculosis, which according to sequence homology had been annotated as a putative peroxiredoxin of the peroxiredoxin Q subfamily (PrxQ B from M. tuberculosis or MtPrxQ B). The protein has been reported to be essential for M. tuberculosis growth in cholesterol-rich medium. We demonstrated the M. tuberculosis thioredoxin B/C-dependent peroxidase activity of MtPrxQ B, which acted as a two-cysteine peroxiredoxin that could function, although less efficiently, using a one-cysteine mechanism. Through steady-state and competition kinetic analysis, we proved that the net forward rate constant of MtPrxQ B reaction was 3 orders of magnitude faster for fatty acid hydroperoxides than for hydrogen peroxide (3x10(6) vs 6x10(3) M-1 s(-1), respectively), while the rate constant of peroxynitrite reduction was (0.6-1.4) x10(6) M-1 s(-1) at pH 7.4. The enzyme lacked activity towards cholesterol hydroperoxides solubilized in sodium deoxycholate. Both thioredoxin B and C rapidly reduced the oxidized form of MtPrxQ B, with rates constants of 0.5x10(6) and 1x10(6) M-1 s(-1), respectively. Our data indicated that MtPrxQ B is monomeric in solution both under reduced and oxidized states. In spite of the similar hydrodynamic behavior the reduced and oxidized forms of the protein showed important structural differences that were reflected in the protein circular dichroism spectra. KW - Mycobacterium tuberculosis KW - Peroxiredoxin KW - Thioredoxin KW - Peroxynitrite KW - Fatty acid hydroperoxides KW - Thiol-dependent peroxidase KW - Peroxidatic and resolving cysteine Y1 - 2016 U6 - https://doi.org/10.1016/j.freeradbiomed.2016.10.005 SN - 0891-5849 SN - 1873-4596 VL - 101 SP - 249 EP - 260 PB - Elsevier CY - New York ER - TY - JOUR A1 - Reinkensmeier, Annika A1 - Steinbrenner, Katrin A1 - Homann, Thomas A1 - Bussler, Sara A1 - Rohn, Sascha A1 - Rawel, Harshadrai Manilal T1 - Monitoring the apple polyphenol oxidase-modulated adduct formation of phenolic and amino compounds JF - Food chemistry N2 - Minimally processed fruit products such as smoothies are increasingly coming into demand. However, they are often combined with dairy ingredients. In this combination, phenolic compounds, polyphenoloxidases, and amino compounds could interact. In this work, a model approach is presented where apple serves as a source for a high polyphenoloxidase activity for modulating the reactions. The polyphenoloxidase activity ranged from 128 to 333 nakt/mL in different apple varieties. From these, ‘Braeburn’ was found to provide the highest enzymatic activity. The formation and stability of resulting chromogenic conjugates was investigated. The results show that such adducts are not stable and possible degradation mechanisms leading to follow-up products formed are proposed. Finally, apple extracts were used to modify proteins and their functional properties characterized. There were retaining antioxidant properties inherent to phenolic compounds after adduct formation. Consequently, such interactions may also be utilized to improve the textural quality of food products. KW - Apple polyphenoloxidase KW - Phenol-amino-adducts KW - Post-translational protein modification KW - Functionality Y1 - 2016 U6 - https://doi.org/10.1016/j.foodchem.2015.07.145 SN - 0308-8146 SN - 1873-7072 VL - 194 SP - 76 EP - 85 PB - Elsevier CY - Oxford ER - TY - THES A1 - Reinke, Julia T1 - The Role of Kallistatin in Energy Metabolism and Glucose Homeostasis in Mice Y1 - 2016 ER - TY - JOUR A1 - Reichetzeder, Christoph A1 - Putra, Sulistyo Emantoko Dwi A1 - Li, Jian A1 - Hocher, Berthold T1 - Developmental Origins of Disease - Crisis Precipitates Change JF - Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry and pharmacology N2 - The concept of developmental origins of diseases has gained a huge interest in recent years and is a constantly emerging scientific field. First observations hereof originated from epidemiological studies, linking impaired birth outcomes to adult chronic, noncommunicable disease. By now there is a considerable amount of both epidemiological and experimental evidence highlighting the impact of early life events on later life disease susceptibility. Albeit far from being completely understood, more recent studies managed to elucidate underlying mechanisms, with epigenetics having become almost synonymous with developmental programming. The aim of this review was to give a comprehensive overview of various aspects and mechanisms of developmental origins of diseases. Starting from initial research foci mainly centered on a nutritionally impaired intrauterine environment, more recent findings such as postnatal nutrition, preterm birth, paternal programming and putative interventional approaches are summarized. The review outlines general underlying mechanisms and particularly discusses mechanistic explanations for sexual dimorphism in developmental programming. Furthermore, novel hypotheses are presented emphasizing a non-mendelian impact of parental genes on the offspring's phenotype. KW - Nutrition KW - Thrifty phenotype KW - Developmental programming KW - Paternal, maternal, sex differences KW - Epigenetics Y1 - 2016 U6 - https://doi.org/10.1159/000447801 SN - 1015-8987 SN - 1421-9778 VL - 39 SP - 919 EP - 938 PB - Karger CY - Basel ER - TY - JOUR A1 - Reichetzeder, Christoph A1 - Putra, S. E. Dwi A1 - Pfab, T. A1 - Slowinski, T. A1 - Neuber, Corinna A1 - Kleuser, Burkhard A1 - Hocher, Berthold T1 - Increased global placental DNA methylation levels are associated with gestational diabetes JF - Clinical epigenetics N2 - Background: Gestational diabetes mellitus (GDM) is associated with adverse pregnancy outcomes. It is known that GDM is associated with an altered placental function and changes in placental gene regulation. More recent studies demonstrated an involvement of epigenetic mechanisms. So far, the focus regarding placental epigenetic changes in GDM was set on gene-specific DNA methylation analyses. Studies that robustly investigated placental global DNA methylation are lacking. However, several studies showed that tissue-specific alterations in global DNA methylation are independently associated with type 2 diabetes. Thus, the aim of this study was to characterize global placental DNA methylation by robustly measuring placental DNA 5-methylcytosine (5mC) content and to examine whether differences in placental global DNA methylation are associated with GDM. Methods: Global DNA methylation was quantified by the current gold standard method, LC-MS/MS. In total, 1030 placental samples were analyzed in this single-center birth cohort study. Results: Mothers with GDM displayed a significantly increased global placental DNA methylation (3.22 +/- 0.63 vs. 3.00 +/- 0.46 %; p = 0.013; +/- SD). Bivariate logistic regression showed a highly significant positive correlation between global placental DNA methylation and the presence of GDM (p = 0.0009). Quintile stratification according to placental DNA 5mC levels revealed that the frequency of GDM was evenly distributed in quintiles 1-4 (2.9-5.3 %), whereas the frequency in the fifth quintile was significantly higher (10.7 %; p = 0.003). Bivariate logistic models adjusted for maternal age, BMI, ethnicity, recurrent miscarriages, and familiar diabetes predisposition clearly demonstrated an independent association between global placental DNA hypermethylation and GDM. Furthermore, an ANCOVA model considering known predictors of DNA methylation substantiated an independent association between GDM and placental DNA methylation. Conclusions: This is the first study that employed a robust quantitative assessment of placental global DNA methylation in over a thousand placental samples. The study provides large scale evidence that placental global DNA hypermethylation is associated with GDM, independent of established risk factors. KW - Placenta KW - Gestational diabetes KW - Insulin resistance KW - LC-MS/MS KW - Global DNA methylation KW - Epigenetics KW - Hypermethylation Y1 - 2016 U6 - https://doi.org/10.1186/s13148-016-0247-9 SN - 1868-7083 VL - 8 PB - BioMed Central CY - London ER - TY - JOUR A1 - Reeg, Sandra A1 - Jung, Tobias A1 - Castro, José Pedro A1 - Davies, Kelvin J. A. A1 - Henze, Andrea A1 - Grune, Tilman T1 - The molecular chaperone Hsp70 promotes the proteolytic removal of oxidatively damaged proteins by the proteasome JF - Free radical biology and medicine : the official journal of the Oxygen Society, a constituent member of the International Society for Free Radical Research N2 - One hallmark of aging is the accumulation of protein aggregates, promoted by the unfolding of oxidized proteins. Unraveling the mechanism by which oxidized proteins are degraded may provide a basis to delay the early onset of features, such as protein aggregate formation, that contribute to the aging phenotype. In order to prevent aggregation of oxidized proteins, cells recur to the 20S proteasome, an efficient turnover proteolysis complex. It has previously been shown that upon oxidative stress the 26S proteasome, another form, dissociates into the 20S form. A critical player implicated in its dissociation is the Heat Shock Protein 70 (Hsp70), which promotes an increase in free 20S proteasome and, therefore, an increased capability to degrade oxidized proteins. The aim of this study was to test whether or not Hsp70 is involved in cooperating with the 20S proteasome for a selective degradation of oxidatively damaged proteins. Our results demonstrate that Hsp70 expression is induced in HT22 cells as a result of mild oxidative stress conditions. Furthermore, Hsp70 prevents the accumulation of oxidized proteins and directly promotes their degradation by the 20S proteasome. In contrast the expression of the Heat shock cognate protein 70 (Hsc70) was not changed in recovery after oxidative stress and Hsc70 has no influence on the removal of oxidatively damaged proteins. We were able to demonstrate in HT22 cells, in brain homogenates from 129/SV mice and in vitro, that there is an increased interaction of Hsp70 with oxidized proteins, but also with the 20S proteasome, indicating a role of Hsp70 in mediating the interaction of oxidized proteins with the 20S proteasome. Thus, our data clearly implicate an involvement of Hsp70 oxidatively damaged protein degradation by the 20S proteasome. c) 2016 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). KW - Protein oxidation KW - Proteasome KW - Chaperone KW - HSP70 Y1 - 2016 U6 - https://doi.org/10.1016/j.freeradbiomed.2016.08.002 SN - 0891-5849 SN - 1873-4596 VL - 99 SP - 153 EP - 166 PB - Elsevier CY - New York ER - TY - THES A1 - Reeg, Sandra T1 - Degradation of oxidized proteins by the proteasome - Involvement of chaperones and the ubiquitin-system Y1 - 2016 ER - TY - JOUR A1 - Rakers, Christin A1 - Schumacher, Fabian A1 - Meinl, Walter A1 - Glatt, Hansruedi A1 - Kleuser, Burkhard A1 - Wolber, Gerhard T1 - In Silico Prediction of Human Sulfotransferase 1E1 Activity Guided by Pharmacophores from Molecular Dynamics Simulations JF - The journal of biological chemistry N2 - Acting during phase II metabolism, sulfotransferases (SULTs) serve detoxification by transforming a broad spectrum of compounds from pharmaceutical, nutritional, or environmental sources into more easily excretable metabolites. However, SULT activity has also been shown to promote formation of reactive metabolites that may have genotoxic effects. SULT subtype 1E1 (SULT1E1) was identified as a key player in estrogen homeostasis, which is involved in many physiological processes and the pathogenesis of breast and endometrial cancer. The development of an in silico prediction model for SULT1E1 ligands would therefore support the development of metabolically inert drugs and help to assess health risks related to hormonal imbalances. Here, we report on a novel approach to develop a model that enables prediction of substrates and inhibitors of SULT1E1. Molecular dynamics simulations were performed to investigate enzyme flexibility and sample protein conformations. Pharmacophores were developed that served as a cornerstone of the model, and machine learning techniques were applied for prediction refinement. The prediction model was used to screen the DrugBank (a database of experimental and approved drugs): 28% of the predicted hits were reported in literature as ligands of SULT1E1. From the remaining hits, a selection of nine molecules was subjected to biochemical assay validation and experimental results were in accordance with the in silico prediction of SULT1E1 inhibitors and substrates, thus affirming our prediction hypotheses. KW - drug design KW - drug metabolism KW - liver metabolism KW - molecular dynamics KW - molecular modeling KW - sulfotransferase Y1 - 2016 U6 - https://doi.org/10.1074/jbc.M115.685610 SN - 0021-9258 SN - 1083-351X VL - 291 SP - 58 EP - 71 PB - American Society for Biochemistry and Molecular Biology CY - Bethesda ER - TY - JOUR A1 - Passlack, Nadine A1 - Schmiedchen, Bettina A1 - Raila, Jens A1 - Schweigert, Florian J. A1 - Stumpff, Friederike A1 - Kohn, Barbara A1 - Neumann, Konrad A1 - Zentek, Juergen T1 - Impact of Increasing Dietary Calcium Levels on Calcium Excretion and Vitamin D Metabolites in the Blood of Healthy Adult Cats JF - PLoS one N2 - Background Dietary calcium (Ca) concentrations might affect regulatory pathways within the Ca and vitamin D metabolism and consequently excretory mechanisms. Considering large variations in Ca concentrations of feline diets, the physiological impact on Ca homeostasis has not been evaluated to date. In the present study, diets with increasing concentrations of dicalcium phosphate were offered to ten healthy adult cats (Ca/phosphorus (P): 6.23/6.02, 7.77/7.56, 15.0/12.7, 19.0/17.3, 22.2/19.9, 24.3/21.6 g/kg dry matter). Each feeding period was divided into a 10-day adaptation and an 8-day sampling period in order to collect urine and faeces. On the last day of each feeding period, blood samples were taken. Results Urinary Ca concentrations remained unaffected, but faecal Ca concentrations increased (P < 0.001) with increasing dietary Ca levels. No effect on whole and intact parathyroid hormone levels, fibroblast growth factor 23 and calcitriol concentrations in the blood of the cats were observed. However, the calcitriol precursors 25(OH)D-2 and 25(OH)D-3, which are considered the most useful indicators for the vitamin D status, decreased with higher dietary Ca levels (P = 0.013 and P = 0.033). Increasing dietary levels of dicalcium phosphate revealed an acidifying effect on urinary fasting pH (6.02) and postprandial pH (6.01) (P < 0.001), possibly mediated by an increase of urinary phosphorus (P) concentrations (P < 0.001). Conclusions In conclusion, calcitriol precursors were linearly affected by increasing dietary Ca concentrations. The increase in faecal Ca excretion indicates that Ca homeostasis of cats is mainly regulated in the intestine and not by the kidneys. Long-term studies should investigate the physiological relevance of the acidifying effect observed when feeding diets high in Ca and P. Y1 - 2016 U6 - https://doi.org/10.1371/journal.pone.0149190 SN - 1932-6203 VL - 11 SP - 47 EP - 67 PB - PLoS CY - San Fransisco ER - TY - THES A1 - Ott, Christiane T1 - Untersuchung der intrazellulären Proteolyse während der Zellalterung BT - Einfluss von Proteinaggregaten und Proteinmodifikationen Y1 - 2016 ER - TY - THES A1 - Nowotny, Kerstin T1 - The impact of collagen modifications by methylglyoxal on fibroblast function and the role in aging Y1 - 2016 ER - TY - GEN A1 - Nojima, Hiroyuki A1 - Konishi, Takanori A1 - Japtok, Lukasz A1 - Kleuser, Burkhard A1 - Edwards, Michael J. A1 - Gulbins, Erich A1 - Lentsch, Alex B. T1 - Chemokine receptors, CXCR1 and CXCR2, differentially regulate exosome release in hepatocytes T2 - Hepatology : official journal of the American Association for the Study of Liver Diseases Y1 - 2016 SN - 0270-9139 SN - 1527-3350 VL - 64 SP - 165A EP - 165A PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Nojima, Hiroyuki A1 - Konishi, Takanori A1 - Freeman, Christopher M. A1 - Schuster, Rebecca M. A1 - Japtok, Lukasz A1 - Kleuser, Burkhard A1 - Edwards, Michael J. A1 - Gulbins, Erich A1 - Lentsch, Alex B. T1 - Chemokine Receptors, CXCR1 and CXCR2, Differentially Regulate Exosome Release in Hepatocytes JF - PLoS one N2 - Exosomes are small membrane vesicles released by different cell types, including hepatocytes, that play important roles in intercellular communication. We have previously demonstrated that hepatocyte-derived exosomes contain the synthetic machinery to form sphingosine-1-phosphate (S1P) in target hepatocytes resulting in proliferation and liver regeneration after ischemia/reperfusion (I/R) injury. We also demonstrated that the chemokine receptors, CXCR1 and CXCR2, regulate liver recovery and regeneration after I/R injury. In the current study, we sought to determine if the regulatory effects of CXCR1 and CXCR2 on liver recovery and regeneration might occur via altered release of hepatocyte exosomes. We found that hepatocyte release of exosomes was dependent upon CXCR1 and CXCR2. CXCR1-deficient hepatocytes produced fewer exosomes, whereas CXCR2-deficient hepatocytes produced more exosomes compared to their wild-type controls. In CXCR2-deficient hepatocytes, there was increased activity of neutral sphingomyelinase (Nsm) and intracellular ceramide. CXCR1-deficient hepatocytes had no alterations in Nsm activity or ceramide production. Interestingly, exosomes from CXCR1-deficient hepatocytes had no effect on hepatocyte proliferation, due to a lack of neutral ceramidase and sphingosine kinase. The data demonstrate that CXCR1 and CXCR2 regulate hepatocyte exosome release. The mechanism utilized by CXCR1 remains elusive, but CXCR2 appears to modulate Nsm activity and resultant production of ceramide to control exosome release. CXCR1 is required for packaging of enzymes into exosomes that mediate their hepatocyte proliferative effect. Y1 - 2016 U6 - https://doi.org/10.1371/journal.pone.0161443 SN - 1932-6203 VL - 11 SP - 6900 EP - + PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Nojima, Hiroyuki A1 - Freeman, Christopher M. A1 - Schuster, Rebecca M. A1 - Japtok, Lukasz A1 - Kleuser, Burkhard A1 - Edwards, Michael J. A1 - Gulbins, Erich A1 - Lentsch, Alex B. T1 - Hepatocyte exosomes mediate liver repair and regeneration via sphingosine-1-phosphate JF - Journal of hepatology N2 - Background & Aims: Exosomes are small membrane vesicles involved in intercellular communication. Hepatocytes are known to release exosomes, but little is known about their biological function. We sought to determine if exosomes derived from hepatocytes contribute to liver repair and regeneration after injury. Methods: Exosomes derived from primary murine hepatocytes were isolated and characterized biochemically and biophysically. Using cultures of primary hepatocytes, we tested whether hepatocyte exosomes induced proliferation of hepatocytes in vitro. Using models of ischemia/reperfusion injury and partial hepatectomy, we evaluated whether hepatocyte exosomes promote hepatocyte proliferation and liver regeneration in vivo. Results: Hepatocyte exosomes, but not exosomes from other liver cell types, induce dose-dependent hepatocyte proliferation in vitro and in vivo. Mechanistically, hepatocyte exosomes directly fuse with target hepatocytes and transfer neutral ceramidase and sphingosine kinase 2 (SK2) causing increased synthesis of sphingosine-1-phosphate (S1P) within target hepatocytes. Ablation of exosomal SK prevents the proliferative effect of exosomes. After ischemia/reperfusion injury, the number of circulating exosomes with proliferative effects increases. Conclusions: Our data shows that hepatocyte-derived exosomes deliver the synthetic machinery to form S1P in target hepatocytes resulting in cell proliferation and liver regeneration after ischemia/reperfusion injury or partial hepatectomy. These findings represent a potentially novel new contributing mechanism of liver regeneration and have important implications for new therapeutic approaches to acute and chronic liver disease. (C) 2015 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved. KW - Liver injury KW - Sphingolipids KW - Sphingosine kinase KW - Ischemia/reperfusion KW - Transplantation Y1 - 2016 U6 - https://doi.org/10.1016/j.jhep.2015.07.030 SN - 0168-8278 SN - 1600-0641 VL - 64 SP - 60 EP - 68 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Niehoff, Ann-Christin A1 - Schulz, Jacqueline A1 - Soltwisch, Jens A1 - Meyer, Soren A1 - Kettling, Hans A1 - Sperling, Michael A1 - Jeibmann, Astrid A1 - Dreisewerd, Klaus A1 - Francesconi, Kevin A. A1 - Schwerdtle, Tanja A1 - Karst, Uwe T1 - Imaging by Elemental and Molecular Mass Spectrometry Reveals the Uptake of an Arsenolipid in the Brain of Drosophila melanogaster JF - Analytical chemistry N2 - Arsenic-containing lipids (arsenolipids) are natural products of marine organisms such as fish, invertebrates, and algae, many of which are important seafoods. A major group of arsenolipids, namely, the arsenic-containing hydrocarbons (AsHC), have recently been shown to be cytotoxic to human liver and bladder cells, a result that has stimulated interest in the chemistry and toxicology of these compounds. In this study, elemental laser ablation-inductively coupled plasma mass spectrometry (LA-ICPMS) and molecular matrix-assisted laser desorption/ionization (MALDI-)MS were used to image and quantify the uptake of an AsHC in the model organism Drosophila melanogaster. Using these two complementary methods, both an enrichment of arsenic and the presence of the AsHC in the brain were revealed, indicating that the intact arsenolipid had crossed the blood-brain barrier. Simultaneous acquisition of quantitative elemental concentrations and molecular distributions could allow new insight into organ-specific enrichment and possible transportation processes of arsenic-containing bioactive compounds in living organisms. Y1 - 2016 U6 - https://doi.org/10.1021/acs.analchem.6b00333 SN - 0003-2700 SN - 1520-6882 VL - 88 SP - 5258 EP - 5263 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Marschall, Talke Anu A1 - Bornhorst, Julia A1 - Kuehnelt, Doris A1 - Schwerdtle, Tanja T1 - Differing cytotoxicity and bioavailability of selenite, methylselenocysteine, selenomethionine, selenosugar 1 and trimethylselenonium ion and their underlying metabolic transformations in human cells JF - Applied computing review : the publication of the ACM Special Interest Group on Applied Computing N2 - Scope: The trace element selenium (Se) is an integral component of our diet. However, its metabolism and toxicity following elevated uptake are not fully understood. Since the either adverse or beneficial health effects strongly depend on the ingested Se species, five low molecular weight species were investigated regarding their toxicological effects, cellular bioavailability and species-specific metabolism in human cells. Methods and results: For the first time, the urinary metabolites methyl-2-acetamido-2-deoxy1- seleno-beta-D-galactopyranoside (selenosugar 1) and trimethylselenonium ion (TMSe) were toxicologically characterised in comparison to the food relevant species methylselenocysteine (MeSeCys), selenomethionine (SeMet) and selenite in human urothelial, astrocytoma and hepatoma cells. In all cell lines selenosugar 1 and TMSe showed no cytotoxicity. Selenite, MeSeCys and SeMet exerted substantial cytotoxicity, which was strongest in the urothelial cells. There was no correlation between the potencies of the respective toxic effects and the measured cellular Se concentrations. Se speciation indicated that metabolism of the respective species is likely to affect cellular toxicity. Conclusion: Despite being taken up, selenosugar 1 and TMSe are non-cytotoxic to urothelial cells, most likely because they are not metabolically activated. The absent cytotoxicity of selenosugar 1 and TMSe up to supra-physiological concentrations, support their importance as metabolites for Se detoxification. KW - Cellular bioavailability KW - ICP-QQQ-MS KW - Selenosugar 1 KW - Small selenium species KW - Speciation Y1 - 2016 U6 - https://doi.org/10.1002/mnfr.201600422 SN - 1613-4125 SN - 1613-4133 VL - 60 SP - 2622 EP - 2632 PB - Wiley-Blackwell CY - Hoboken ER - TY - THES A1 - Markova, Mariya T1 - Metabolic and molecular effects of two different isocaloric high protein diets in subjects with type 2 diabetes T1 - Metabolische und molekulare Effekte zweier isokalorischer Hochproteindiäten unterschiedlicher Herkunft bei Probanden mit Typ-2-Diabetes N2 - Ernährung stellt ein wichtiger Faktor in der Prävention und Therapie von Typ-2-Diabetes dar. Frühere Studien haben gezeigt, dass Hochproteindiäten sowohl positive als auch negative Effekte auf den Metabolismus hervorrufen. Jedoch ist unklar, ob die Herkunft des Proteins dabei eine Rolle spielt. In der LeguAN-Studie wurden die Effekte von zwei unterschiedlichen Hochproteindiäten, entweder tierischer oder pflanzlicher Herkunft, bei Typ-2-Diabetes Patienten untersucht. Beide Diäten enthielten 30 EN% Proteine, 40 EN% Kohlenhydrate und 30 EN% Fette. Der Anteil an Ballaststoffen, der glykämischer Index und die Fettkomposition waren in beiden Diäten ähnlich. Die Proteinaufnahme war höher, während die Fettaufnahme niedriger im Vergleich zu den früheren Ernährungsgewohnheiten der Probanden war. Insgesamt führten beide Diätinterventionen zu einer Verbesserung der glykämischen Kontrolle, der Insulinsensitivität, des Leberfettgehalts und kardiovaskulärer Risikomarkern ohne wesentliche Unterschiede zwischen den Proteintypen. In beiden Interventionsgruppen wurden die nüchternen Glukosewerte zusammen mit Indizes von Insulinresistenz in einem unterschiedlichen Ausmaß, jedoch ohne signifikante Unterschiede zwischen beiden Diäten verbessert. Die Reduktion von HbA1c war ausgeprägter in der pflanzlichen Gruppe, während sich die Insulinsensitivität mehr in der tierischen Gruppe erhöhte. Die Hochproteindiäten hatten nur einen geringfügigen Einfluss auf den postprandialen Metabolismus. Dies zeigte sich durch eine leichte Verbesserung der Indizes für Insulinsekretion, -sensitivität und –degradation sowie der Werte der freien Fettsäuren. Mit Ausnahme des Einflusses auf die GIP-Sekretion riefen die tierische und die pflanzliche Testmahlzeit ähnliche metabolische und hormonelle Antworten, trotz unterschiedlicher Aminosäurenzusammensetzung. Die tierische Hochproteindiät führte zu einer selektiven Zunahme der fettfreien Masse und Abnahme der Fettmasse, was nicht signifikant unterschiedlich von der pflanzlichen Gruppe war. Darüber hinaus reduzierten die Hochproteindiäten den Leberfettgehalt um durchschnittlich 42%. Die Reduktion des Leberfettgehaltes ging mit einer Verminderung der Lipogenese, der Lipolyse und des freien Fettsäure Flux einher. Beide Interventionen induzierten einen moderaten Abfall von Leberenzymen im Blut. Die Reduktion des Leberfetts war mit einer verbesserten Glukosehomöostase und Insulinsensitivität assoziiert. Blutlipide sanken in allen Probanden, was eventuell auf die niedrigere Fettaufnahme zurückzuführen war. Weiterhin waren die Spiegel an Harnsäure und Inflammationsmarkern erniedrigt unabhängig von der Proteinquelle. Die Werte des systolischen und diastolischen Blutdrucks sanken nur in der pflanzlichen Gruppe, was auf eine potentielle Rolle von Arginin hinweist. Es wurden keine Hinweise auf eine beeinträchtigte Nierenfunktion durch die 6-wöchige Hochproteindiäten beobachtet unabhängig von der Herkunft der Proteine. Serumkreatinin war nur in der pflanzlichen Gruppe signifikant reduziert, was eventuell an dem geringen Kreatingehalt der pflanzlichen Nahrungsmittel liegen könnte. Jedoch sind längere Studien nötig, um die Sicherheit von Hochproteindiäten vollkommen aufklären zu können. Des Weiteren verursachte keine der Diäten eine Induktion des mTOR Signalwegs weder im Fettgewebe noch in Blutzellen. Die Verbesserung der Ganzkörper-Insulinsensitivität deutete auch auf keine Aktivierung von mTOR und keine Verschlechterung der Insulinsensitivität im Skeletmuskel hin. Ein nennenswerter Befund war die erhebliche Reduktion von FGF21, einem wichtigen Regulator metabolischer Prozesse, um ungefähr 50% bei beiden Proteinarten. Ob hepatischer ER-Stress, Ammoniumniveau oder die Makronährstoffpräferenz hinter dem paradoxen Ergebnis stehen, sollte weiter im Detail untersucht werden. Entgegen der anfänglichen Erwartung und der bisherigen Studienlage zeigte die pflanzlich-betonte Hochproteindiät keine klaren Vorteile gegenüber der tierischen Diät. Der ausgeprägte günstige Effekt des tierischen Proteins auf Insulinhomöostase trotz des hohen BCAA-Gehaltes war sicherlich unerwartet und deutet darauf hin, dass bei dem längeren Verzehr andere komplexe metabolische Adaptationen stattfinden. Einen weiteren Aspekt stellt der niedrigere Fettverzehr dar, der eventuell auch zu den Verbesserungen in beiden Gruppen beigetragen hat. Zusammenfassend lässt sich sagen, dass eine 6-wöchige Diät mit 30 EN% Proteinen (entweder pflanzlich oder tierisch), 40 EN% Kohlenhydraten und 30 EN% Fetten mit weniger gesättigten Fetten zu metabolischen Verbesserungen bei Typ-2-Diabetes Patienten unabhängig von Proteinherkunft führt. N2 - Dietary approaches contribute to the prevention and treatment of type 2 diabetes. High protein diets were shown to exert beneficial as well as adverse effects on metabolism. However, it is unclear whether the protein origin plays a role in these effects. The LeguAN study investigated in detail the effects of two high protein diets, either from plant or animal origin, in type 2 diabetic patients. Both diets contained 30 EN% protein, 40 EN% carbohydrates, and 30 EN% fat. Fiber content, glycemic index, and composition of dietary fats were similar in both diets. In comparison to previous dietary habits, the fat content was exchanged for protein, while the carbohydrate intake was not modified. Overall, both high protein diets led to improvements of glycemic control, insulin sensitivity, liver fat, and cardiovascular risk markers without remarkable differences between the protein types. Fasting glucose together with indices of insulin resistance were ameliorated by both interventions to varying extents but without significant differences between protein types. The decline of HbA1c was more pronounced in the plant protein group, whereby the improvement of insulin sensitivity in the animal protein group. The high protein intake had only slight influence on postprandial metabolism seen for free fatty acids and indices of insulin secretion, sensitivity and degradation. Except for GIP release, ingestion of animal and plant meals did not provoke differential metabolic and hormonal responses despite diverse circulating amino acid levels. The animal protein diets led to a selective increase of fat-free mass and decrease of total fat mass, which was not significantly different from the plant protein diet. Moreover, the high protein diets potently decreased liver fat content by 42% on average which was linked to significantly diminished lipogenesis, free fatty acids flux and lipolysis in adipose tissue. Moderate decline of circulating liver enzymes was induced by both interventions. The liver fat reduction was associated with improved glucose homeostasis and insulin sensitivity which underlines the protective effect of the diets. Blood lipid profile improved in all subjects and was probably related to the lower fat intake. Reductions in uric acid and markers of inflammation further argued for metabolic benefits of both high protein diets. Systolic and diastolic blood pressure declined only in the PP group pointing a possible role of arginine. Kidney function was not altered by high protein consumption over 6 weeks. The rapid decrease of serum creatinine in the PP group was noteworthy and should be further investigated. Protein type did not seem to play a role but long-term studies are warranted to fully elucidate safety of high protein regimen. Varying the source of dietary proteins did not affect the mTOR pathway in adipose tissue and blood cells under neither acute nor chronic settings. Enhancement of whole-body insulin sensitivity suggested also no alteration of mTOR and no impairment of insulin sensitivity in skeletal muscle. A remarkable outcome was the extensive reduction of FGF21, critical regulator of metabolic processes, by approximately 50% independently of protein type. Whether hepatic ER-stress, ammonia flux or rather macronutrient preferences is behind this paradoxical finding remains to be investigated in detail. Unlike initial expectations and previous reports plant protein based diet had no clear advantage over animal proteins. The pronounced beneficial effect of animal protein on insulin homeostasis despite high BCAA and methionine intake was certainly unexpected assuming more complex metabolic adaptations occurring upon prolonged consumption. In addition, the reduced fat intake may have also contributed to the overall improvements in both groups. Taking into account the above observed study results, a short-term diet containing 30 EN% protein (either from plant or animal origin), 40 EN% carbohydrates, and 30 EN% fat with lower SFA amount leads to metabolic improvements in diabetic patients, regardless of protein source. KW - type 2 diabetes KW - nutrition KW - protein KW - Typ-2-Diabetes KW - Ernährung KW - high protein diet Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-394310 ER - TY - JOUR A1 - Manowsky, Julia A1 - Camargo, Rodolfo Gonzalez A1 - Kipp, Anna Patricia A1 - Henkel, Janin A1 - Püschel, Gerhard Paul T1 - Insulin-induced cytokine production in macrophages causes insulin resistance in hepatocytes JF - American journal of physiology : Endocrinology and metabolism N2 - Overweight and obesity are associated with hyperinsulinemia, insulin resistance, and a low-grade inflammation. Although hyperinsulinemia is generally thought to result from an attempt of the beta-cell to compensate for insulin resistance, there is evidence that hyperinsulinaemia itself may contribute to the development of insulin resistance and possibly the low-grade inflammation. To test this hypothesis, U937 macrophages were exposed to insulin. In these cells, insulin induced expression of the proinflammatory cytokines IL-1 beta, IL-8, CCL2, and OSM. The insulin-elicited induction of IL-1 beta was independent of the presence of endotoxin and most likely mediated by an insulin-dependent activation of NF-kappa B. Supernatants of the insulin-treated U937 macrophages rendered primary cultures of rat hepatocytes insulin resistant; they attenuated the insulin-dependent induction of glucokinase by 50%. The cytokines contained in the supernatants of insulin-treated U937 macrophages activated ERK1/2 and IKK beta, resulting in an inhibitory serine phosphorylation of the insulin receptor substrate. In addition, STAT3 was activated and SOCS3 induced, further contributing to the interruption of the insulin receptor signal chain in hepatocytes. These results indicate that hyperinsulinemia per se might contribute to the low-grade inflammation prevailing in overweight and obese patients and thereby promote the development of insulin resistance particularly in the liver, because the insulin concentration in the portal circulation is much higher than in all other tissues. KW - metabolic syndrome KW - type 2 diabetes KW - inflammation KW - macrophage KW - insulin KW - cytokines Y1 - 2016 U6 - https://doi.org/10.1152/ajpendo.00427.2015 SN - 0193-1849 SN - 1522-1555 VL - 310 SP - E938 EP - E946 PB - American Chemical Society CY - Bethesda ER - TY - JOUR A1 - Mageney, Vera A1 - Baldermann, Susanne A1 - Albach, Dirk C. T1 - Intraspecific Variation in Carotenoids of Brassica oleracea var. sabellica JF - Journal of agricultural and food chemistry : a publication of the American Chemical Society N2 - Carotenoids are best known as a source of natural antioxidants. Physiologically, carotenoids are part of the photoprotection in plants as they act as scavengers of reactive oxygen species (ROS). An important source of carotenoids in European food is Brassica oleracea. Focusing on the most abundant carotenoids, we estimated the contents of beta-carotene, (9Z)-neoxanthin, zeaxanthin, and lutein as well as those of chlorophylls a and b to assess their variability in Brassica oleracea var. sabellica. Our analyses included more than 30 cultivars categorized in five distinct sets grouped according to morphological characteristics or geographical origin. Our results demonstrated specific carotenoid patterns characteristic for American, Italian, and red-colored kale cultivars. Moreover, we demonstrated a tendency of high zeaxanthin proportions under traditional harvest conditions, which accord to low-temperature regimes. We also compared the carotenoid patterns of self-generated hybrid lines. Corresponding findings indicated that crossbreeding has a high potential for carotenoid content optimization in kale. KW - Brassica oleracea var. sabellica KW - beta-carotene KW - lutein KW - (9Z)-neoxanthin KW - zeaxanthin KW - low temperature Y1 - 2016 U6 - https://doi.org/10.1021/acs.jafc.6b00268 SN - 0021-8561 SN - 1520-5118 VL - 64 SP - 3251 EP - 3257 PB - American Chemical Society CY - Washington ER - TY - THES A1 - Lüttig, Julia T1 - Protektiver Effekt von 6-Shogaol, Ellagsäure und Myrrhe auf die intestinale epitheliale Barriere T1 - Protective effect of 6-shogaol, ellagic acid and myrrh on intestinal epithelial barrier N2 - Viele bioaktive Pflanzeninhaltsstoffe bzw. Pflanzenmetabolite besitzen antiinflammatorische Eigenschaften. Diese versprechen ein hohes Potential für den Einsatz in der Phytotherapie bzw. Prävention von chronisch-entzündlichen Darmerkrankungen (CED). Eine intestinale Barrieredysfunktion ist ein typisches Charakteristikum von CED Patienten, die dadurch an akuter Diarrhoe leiden. In dieser Arbeit werden die Pflanzenkomponenten 6-Shogaol, Ellagsäure und Myrrhe an den intestinalen Kolonepithelzellmodellen HT-29/B6 und Caco-2 auf ihr Potential hin, die intestinale Barriere zu stärken bzw. eine Barrieredysfunktion zu verhindern, untersucht. Hauptschwerpunkt der Analysen ist die parazelluläre Barrierefunktion und die Regulation der dafür entscheidenden Proteinfamilie der Tight Junctions (TJs), der Claudine. Die Barrierefunktion wird durch Messung des transepithelialen Widerstands (TER) und der Fluxmessung in der Ussing-Kammer bestimmt. Dazu werden die HT-29/B6- und Caco-2-Monolayer mit den Pflanzenkomponenten (6-Shogaol, Ellagsäure, Myrrhe), dem proinflammatorischen Zytokin TNF-α oder der Kombination von beiden Subsztanzen für 24 oder 48 h behandelt. Außerdem wurden zur weiteren Charakterisierung die Expression sowie die Lokalisation der für die parazelluläre Barriere relevanten Claudine, die TJ-Ultrastruktur und verschiedene Signalwege analysiert. In Caco-2-Monolayern führten Ellagsäure und Myrrhe, nicht aber 6-Shogaol, allein zu einem TER-Anstieg bedingt durch eine verringerte Permeabilität für Natriumionen. Myrrhe verminderte die Expression des Kationenkanal-bildenden TJ-Proteins Claudin-2 über die Inhibierung des PI3K/Akt-Signalweges, während Ellagsäure die Expression der TJ-Proteine Claudin-4 und -7 reduzierte. Alle Pflanzenkomponenten schützten in den Caco-2-Zellen vor einer TNF-α-induzierten Barrieredysfunktion. An den HT-29/B6-Monolayern änderte keine der Pflanzenkomponenten allein die Barrierefunktion. Die HT-29/B6-Zellen reagierten auf TNF-α mit einer deutlichen Verminderung des TER und einer erhöhten Fluoreszein-Permeabilität. Die TER-Abnahme war durch eine PI3K/Akt-vermittelte gesteigerte Claudin-2-Expression sowie eine NFκB-vermittelte Umverteilung des abdichtenden TJ-Proteins Claudin-1 gekennzeichnet. 6-Shogaol konnte den TER-Abfall partiell hemmen sowie die PI3K/Akt-induzierte Claudin-2-Expression und die NFκB-bedingte Claudin-1-Umverteilung verhindern. Ebenso inhibierte Myrrhe, nicht aber Ellagsäure, den TNF-α-induzierten TER-Abfall. Dabei konnte Myrrhe zwar den Claudin-2-Expressionsanstieg und die Claudin-1-Umverteilung unterbinden, jedoch weder die NFκB- noch die PI3K/Akt-Aktivierung hemmen. Diese Arbeit zeigt, dass auch STAT6 an dem Claudin-2-Expressionsanstieg durch TNF-α in HT-29/B6-Zellen beteiligt ist. So wurde durch Myrrhe die TNF-α-induzierte Phosphorylierung von STAT6 und die erhöhte Claudin-2-Expression inhibiert. Die Ergebnisse deuten darauf hin, dass die Pflanzenkomponenten 6-Shogaol, Ellagsäure und Myrrhe mit unterschiedlichen Mechanismen stärkend auf die Barriere einwirken. Zur Behandlung von intestinalen Erkrankungen mit Barrieredysfunktion könnten daher Kombinationspräparate aus verschiedenen Pflanzen effektiver sein als Monopräparate. N2 - Many bioactive phytonutrients or plant metabolites have anti-inflammatory properties promising a high potential as therapeutic application or preventive medicine in inflammatory bowel disease (IBD). An intestinal barrier dysfunction along with diarrhea is a typical characteristic of IBD patients. In this work the plant components 6-shogaol, ellagic acid and myrrh were examined for their potential to strengthen the intestinal barrier or to prevent a barrier dysfunction in two intestinal colonic epithelial cell models: HT-29/B6 and Caco-2. Focusing on paracellular barrier function the protein family of tight junctions (TJs), especially the claudins and their regulation, was studied. The barrier integrity was evaluated measuring transepithelial resistance (TER) and tracer fluxes in the Ussing chamber. Prior to analyses, HT-29/B6 and Caco-2 monolayers were incubated with plant components (6-shogaol, ellagic acid, myrrh) unchallenged or challenged with the pro-inflammatory cytokine TNF-α for 24 or 48 hours. In addition, the expression and localization of the paracellular barrier-relevant claudins, the TJ-ultrastructure and various signaling pathways were analyzed, in order to elucidate underlying mechanisms. In Caco-2 monolayers ellagic acid and myrrh, but not 6-shogaol, increased TER and reduced permeability for sodium ions. The effect of myrrh was accompanied by a reduced expression of the channel forming TJ protein claudin-2 due to the inhibition of the PI3K/Akt signaling pathway, while ellagic acid decreased the expression of claudin-4 and -7 without affecting any of the analyzed signaling pathways. All employed plant components prevented TNF-α-induced barrier dysfunction in Caco-2 cells. In HT-29/B6 monolayers, none of the plant components changed the basal barrier function. Monolayers challenged by TNF-α showed increased fluorescein permeability and reduction in TER accompanied by a PI3K/Akt-mediated increase in claudin-2 expression and a NFκB-mediated redistribution of sealing TJ protein claudin-1 off the TJ. 6-shogaol could partially inhibit the TNF-α-induced TER decrease by inhibiting the PI3K/Akt-mediated claudin-2 expression and the NFκB-mediated claudin-1 redistribution. Likewise, myrrh, but not ellagic acid, prevented the decrease in TER, increase in claudin-2 expression, and claudin-1 redistribution without affecting the signaling pathways NFκB and PI3K/Akt. Instead, the STAT6 pathway was additionally involved in TNF-α-mediated regulation of claudin-2 expression. Thus, myrrh prevented the TNF-α-induced STAT6 phosphorylation as well as the increase in claudin-2 expression. This work demonstrates that the three plant components strengthen the intestinal barrier in different ways. For the treatment of intestinal diseases with barrier dysfunctions, combination preparations of different plant compounds could be more effective than mono preparations. KW - 6-Shogaol KW - Ellagsäure KW - Darmerkrankung KW - Tight Junction KW - Myrrhe KW - Barriere KW - 6-shogaol KW - barrier KW - intesinal disease KW - ellagic acid KW - myrrh KW - tight junction Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-102571 ER - TY - THES A1 - Luckert, Claudia T1 - Molekulare Mechanismen von hepatotoxischen Pyrrolizidinalkaloiden Y1 - 2016 ER - TY - JOUR A1 - Lu, Yong Ping A1 - Tsuprykov, Oleg A1 - Vignon-Zellweger, Nicolas A1 - Heiden, Susi A1 - Hocher, Berthold T1 - Global Overexpression of ET-1 Decreases Blood Pressure - A Systematic Review and Meta-Analysis of ET-1 Transgenic Mice JF - Naunyn-Schmiedeberg's archives of pharmacology N2 - Background/Aims: ET-1 has independent effects on blood pressure regulation in vivo, it is involved in tubular water and salt excretion, promotes constriction of smooth muscle cells, modulates sympathetic nerve activity, and activates the liberation of nitric oxide. To determine the net effect of these partially counteracting mechanisms on blood pressure, a systematic meta-analysis was performed. Methods: Based on the principles of Cochrane systematic reviews, we searched in major literature databases - MEDLINE (PubMed), Embase, Google Scholar, and the China Biological Medicine Database (CBM-disc) - for articles relevant to the topic of the blood pressure phenotype of endothelin-1 transgenic (ET-1+/+) mice from January 1, 1988 to March 31, 2016. Review Manager Version 5.0 (Rev-Man 5.0) software was applied for statistical analysis. In total thirteen studies reported blood pressure data. Results: The meta-analysis of blood pressure data showed that homozygous ET-1 transgenic mice (ET-1+/+ mice) had a significantly lower blood pressure as compared to WT mice (mean difference:-2.57 mmHg, 95% CI: -4.98 similar to -0.16, P = 0.04), with minimal heterogeneity (P = 0.86). A subgroup analysis of mice older than 6 months revealed that the blood pressure difference between ET-1+/+ mice and WT mice was even more pronounced (mean difference: -6.19 mmHg, 95% CI: -10.76 similar to -1.62, P = 0.008), with minimal heterogeneity (P = 0.91). Conclusion: This meta-analysis provides robust evidence that global ET-1 overexpression in mice lowers blood pressure in an age-dependent manner. Older ET-1+/+ mice have a somewhat more pronounced reduction of blood pressure. (C) 2016 The Author(s) Published by S. Karger AG, Basel KW - Endothelin-1 transgenic mice KW - Blood pressure KW - Kidney weight KW - Heart weight Y1 - 2016 U6 - https://doi.org/10.1159/000450567 SN - 1420-4096 SN - 1423-0143 VL - 41 SP - 770 EP - 780 PB - Karger CY - Basel ER - TY - JOUR A1 - Lohren, Hanna A1 - Bornhorst, Julia A1 - Fitkau, Romy A1 - Pohl, Gabriele A1 - Galla, Hans-Joachim A1 - Schwerdtle, Tanja T1 - Effects on and transfer across the blood-brain barrier in vitro-Comparison of organic and inorganic mercury species JF - BMC pharmacology & toxicology N2 - Background: Transport of methylmercury (MeHg) across the blood-brain barrier towards the brain side is well discussed in literature, while ethylmercury (EtHg) and inorganic mercury are not adequately characterized regarding their entry into the brain. Studies investigating a possible efflux out of the brain are not described to our knowledge. Methods: This study compares, for the first time, effects of organic methylmercury chloride (MeHgCl), EtHg-containing thiomersal and inorganic Hg chloride (HgCl2) on as well as their transfer across a primary porcine in vitro model of the blood-brain barrier. Results: With respect to the barrier integrity, the barrier model exhibited a much higher sensitivity towards HgCl2 following basolateral incubation (brain-facing side) as compared to apical application (blood-facing side). These HgCl2 induced effects on the barrier integrity after brain side incubation are comparable to that of the organic species, although MeHgCl and thiomersal exerted much higher cytotoxic effects in the barrier building cells. Hg transfer rates following exposure to organic species in both directions argue for diffusion as transfer mechanism. Inorganic Hg application surprisingly resulted in a Hg transfer out of the brain-facing compartment. Conclusions: In case of MeHgCl and thiomersal incubation, mercury crossed the barrier in both directions, with a slight accumulation in the basolateral, brain-facing compartment, after simultaneous incubation in both compartments. For HgCl2, our data provide first evidence that the blood-brain barrier transfers mercury out of the brain. KW - Organic mercury KW - Inorganic mercury KW - Methylmercury KW - Thiomersal KW - Mercuric mercury KW - In vitro blood-brain barrier model Y1 - 2016 U6 - https://doi.org/10.1186/s40360-016-0106-5 SN - 2050-6511 VL - 17 SP - 422 EP - 433 PB - BioMed Central CY - London ER - TY - JOUR A1 - Li, Jian A1 - Tsuprykov, Oleg A1 - Yang, Xiaoping A1 - Hocher, Berthold T1 - Paternal programming of offspring cardiometabolic diseases in later life JF - Journal of hypertension KW - cardiometabolic diseases KW - epigenetics KW - offspring KW - paternal programming KW - spermatogenesis KW - transgenerational effects Y1 - 2016 U6 - https://doi.org/10.1097/HJH.0000000000001051 SN - 0263-6352 SN - 1473-5598 VL - 34 SP - 2111 EP - 2126 PB - Wiley-Blackwell CY - Philadelphia ER - TY - JOUR A1 - Li, Jian A1 - Lu, Yong Ping A1 - Reichetzeder, Christoph A1 - Kalk, Philipp A1 - Kleuser, Burkhard A1 - Adamski, Jerzy A1 - Hocher, Berthold T1 - Maternal PCaaC38:6 is Associated With Preterm Birth - a Risk Factor for Early and Late Adverse Outcome of the Offspring JF - Journal of European public policy N2 - Background/Aims: Preterm birth (PTB) and low birth weight (LBW) significantly influence mortality and morbidity of the offspring in early life and also have long-term consequences in later life. A better understanding of the molecular mechanisms of preterm birth could provide new insights regarding putative preventive strategies. Metabolomics provides a powerful analytic tool to readout complex interactions between genetics, environment and health and may serve to identify relevant biomarkers. In this study, the association between 163 targeted maternal blood metabolites and gestational age was investigated in order to find candidate biomarkers for PTB. Methods: Five hundred twenty-three women were included into this observational study. Maternal blood was obtained before delivery. The concentration of 163 maternal serum metabolites was measured by flow injection tandem mass spectrometry. To find putative biomarkers for preterm birth, a three-step analysis was designed: bivariate correlation analysis followed by multivariable regression analysis and a comparison of mean values among gestational age groups. Results: Bivariate correlation analysis showed that 2 acylcarnitines (C16:2, C2), 1 amino acids (xLeu), 8 diacyl-PCs (PCaaC36:4, PCaaC38:4, PCaaC38:5, PCaaC38:6, PCaaC40:4, PCaaC40:5, PCaaC40:6, PCaaC42:4), and 1 Acylalkyl-PCs (PCaeC40:5) were inversely correlated with gestational age. Multivariable regression analysis confounded for PTB history, maternal body mass index (BMI) before pregnancy, systolic blood pressure at the third trimester, and maternal body weight at the third trimester, showed that the diacyl-PC PCaaC38:6 was the only metabolite inversely correlated with gestational age. Conclusions: Maternal blood concentrations of PCaaC38:6 are independently associated with gestational age. (C) 2016 The Author(s) Published by S. Karger AG, Basel KW - Metabolomics KW - PCaaC38:6 KW - Biomarker KW - Preterm birth Y1 - 2016 U6 - https://doi.org/10.1159/000443428 SN - 1420-4096 SN - 1423-0143 VL - 41 SP - 250 EP - 257 PB - Karger CY - Basel ER - TY - GEN A1 - Kühn, Tilman A1 - Floegel, Anna A1 - Sookthai, Disorn A1 - Johnson, Theron A1 - Rolle-Kampczyk, Ulrike A1 - Otto, Wolfgang A1 - von Bergen, Martin A1 - Boeing, Heiner A1 - Kaaks, Rudolf T1 - Higher plasma levels of lysophosphatidylcholine 18:0 are related to a lower risk of common cancers in a prospective metabolomics study T2 - BMC medicine N2 - Background: First metabolomics studies have indicated that metabolic fingerprints from accessible tissues might be useful to better understand the etiological links between metabolism and cancer. However, there is still a lack of prospective metabolomics studies on pre-diagnostic metabolic alterations and cancer risk. Methods: Associations between pre-diagnostic levels of 120 circulating metabolites (acylcarnitines, amino acids, biogenic amines, phosphatidylcholines, sphingolipids, and hexoses) and the risks of breast, prostate, and colorectal cancer were evaluated by Cox regression analyses using data of a prospective case-cohort study including 835 incident cancer cases. Results: The median follow-up duration was 8.3 years among non-cases and 6.5 years among incident cases of cancer. Higher levels of lysophosphatidylcholines (lysoPCs), and especially lysoPC a C18:0, were consistently related to lower risks of breast, prostate, and colorectal cancer, independent of background factors. In contrast, higher levels of phosphatidylcholine PC ae C30:0 were associated with increased cancer risk. There was no heterogeneity in the observed associations by lag time between blood draw and cancer diagnosis. Conclusion: Changes in blood lipid composition precede the diagnosis of common malignancies by several years. Considering the consistency of the present results across three cancer types the observed alterations point to a global metabolic shift in phosphatidylcholine metabolism that may drive tumorigenesis. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 437 KW - metabolomics KW - epidemiology KW - breast cancer KW - prostate cancer KW - colorectal cancer Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-407258 ER - TY - THES A1 - Kamitz, Anne T1 - Identification and positional cloning of Ltg/NZO; a novel susceptibility locus associated with fatty liver disease Y1 - 2016 ER - TY - THES A1 - Jäger, Susanne T1 - Genetic variants and metabolic pathways of type 2 diabetes within the EPIC-Potsdam study Y1 - 2016 ER - TY - JOUR A1 - Islam, Khan Shaiful A1 - Khalil, Mahmoud A1 - Männer, K. A1 - Raila, Jens A1 - Rawel, Harshadrai Manilal A1 - Zentek, J. A1 - Schweigert, Florian J. T1 - Effect of dietary alpha-tocopherol on the bioavailability of lutein in laying hen JF - Journal of animal physiology and animal nutrition N2 - Lutein and its isomer zeaxanthin have gained considerable interest as possible nutritional ingredient in the prevention of age-related macular degeneration (AMD) in humans. Egg yolk is a rich source of these carotenoids. As an oxidative sensitive component, antioxidants such as -tocopherol (T) might contribute to an improved accumulation in egg yolk. To test this, chickens were fed lutein esters (LE) with and without -tocopherol as an antioxidant. After depletion on a wheat-soya bean-based lutein-poor diet for 21days, laying hens (n=42) were equally divided into three groups and fed the following diets for 21days: control (basal diet), a LE group (40mg LE/kg feed) and LE+T group (40mg LE plus 100mg T/kg feed). Eggs and blood were collected periodically. Carotenoids and -tocopherol in yolk and blood plasma were determined by HPLC. Egg yolk was also analysed for total carotenoids using a one-step spectrophotometric method (iCheck(())). Lutein, zeaxanthin, -tocopherol and total carotenoids in egg yolk were highest after 14days of feeding and decreased slightly afterwards. At the end of the trial, eggs of LE+T group contained higher amount of lutein (13.72), zeaxanthin (0.65), -tocopherol (297.40) and total carotenoids (21.6) compared to the LE group (10.96, 0.55, 205.20 and 18.0mg/kg, respectively, p<0.05). Blood plasma values of LE+T group contain higher lutein (1.3), zeaxanthin (0.06) and tocopherol (20.1) compared to LE group (1.02, 0.04 and 14.90mg/l, respectively, p<0.05). In conclusion, dietary -tocopherol enhances bioavailability of lutein reflecting higher content in egg yolk and blood plasma. Improved bioavailability might be due to increased absorption of lutein in the presence of tocopherol and/or a greater stability of lutein/zeaxanthin due to the presence of -tocopherol as an antioxidant. KW - carotenoids KW - tocopherol KW - egg yolk KW - bioavailability KW - HPLC KW - iCheck Y1 - 2016 U6 - https://doi.org/10.1111/jpn.12464 SN - 0931-2439 SN - 1439-0396 VL - 100 SP - 868 EP - 875 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Hönzke, Stefan A1 - Gerecke, Christian A1 - Elpelt, Anja A1 - Zhang, Nan A1 - Unbehauen, Michael A1 - Kral, Vivian A1 - Fleige, Emanuel A1 - Paulus, Florian A1 - Haag, Rainer A1 - Schäfer-Korting, Monika A1 - Kleuser, Burkhard A1 - Hedtrich, Sarah T1 - Tailored dendritic core-multishell nanocarriers for efficient dermal drug delivery: A systematic top-down approach from synthesis to preclinical testing JF - Journal of controlled release N2 - Drug loaded dendritic core-multishell (CMS) nanocarriers are of especial interest for the treatment of skin diseases, owing to their striking dermal delivery efficiencies following topical applications. CMS nanocarriers are composed of a polyglycerol core, connected by amide-bonds to an inner alkyl shell and an outer methoxy poly(ethylene glycol) shell. Since topically applied nanocarriers are subjected to biodegradation, the application of conventional amide-based CMS nanocarriers (10-A-18-350) has been limited by the potential production of toxic polyglycerol amines. To circumvent this issue, three tailored ester-based CMS nanocarriers (10-E-12-350, 10-E-15-350, 10-E-18-350) of varying inner alkyl chain length were synthesized and comprehensively characterized in terms of particle size, drug loading, biodegradation and dermal drug delivery efficiency. Dexamethasone (DXM), a potent drug widely used for the treatment of inflammatory skin diseases, was chosen as a therapeutically relevant test compound for the present study. Ester-and amide-based CMS nanocarriers delivered DXM more efficiently into human skin than a commercially available DXM cream. Subsequent in vitro and in vivo toxicity studies identified CMS (10-E-15-350) as the most biocompatible carrier system. The anti-inflammatory potency of DXM-loaded CMS (10-E-15-350) nanocarriers was assessed in TNF alpha supplemented skin models, where a significant reduction of the pro-inflammatory cytokine IL-8 was seen, with markedly greater efficacy than commercial DXM cream. In summary, we report the rational design and characterization of tailored, biodegradable, ester-based CMS nanocarriers, and their subsequent stepwise screening for biocompatibility, dermal delivery efficiency and therapeutic efficacy in a top-down approach yielding the best carrier system for topical applications. (C) 2016 Elsevier B.V. All rights reserved. KW - Dendritic core-multishell nanocarriers KW - Biocompatibility KW - Dexamethasone KW - Inflammatory skin disease KW - Dermal drug delivery KW - Skin model Y1 - 2016 U6 - https://doi.org/10.1016/j.jconrel.2016.06.030 SN - 0168-3659 SN - 1873-4995 VL - 242 SP - 50 EP - 63 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Huston, Joseph P. A1 - Kornhuber, Johannes A1 - Muehle, Christiane A1 - Japtok, Lukasz A1 - Komorowski, Mara A1 - Mattern, Claudia A1 - Reichel, Martin A1 - Gulbins, Erich A1 - Kleuser, Burkhard A1 - Topic, Bianca A1 - Silva, Maria A. De Souza A1 - Mueller, Christian P. T1 - A sphingolipid mechanism for behavioral extinction JF - Journal of neurochemistry N2 - Reward-dependent instrumental behavior must continuously be re-adjusted according to environmental conditions. Failure to adapt to changes in reward contingencies may incur psychiatric disorders like anxiety and depression. When an expected reward is omitted, behavior undergoes extinction. While extinction involves active re-learning, it is also accompanied by emotional behaviors indicative of frustration, anxiety, and despair (extinction-induced depression). Here, we report evidence for a sphingolipid mechanism in the extinction of behavior. Rapid extinction, indicating efficient re-learning, coincided with a decrease in the activity of the enzyme acid sphingomyelinase (ASM), which catalyzes turnover of sphingomyelin to ceramide, in the dorsal hippocampus of rats. The stronger the decline in ASM activity, the more rapid was the extinction. Sphingolipid-focused lipidomic analysis showed that this results in a decline of local ceramide species in the dorsal hippocampus. Ceramides shape the fluidity of lipid rafts in synaptic membranes and by that way can control neural plasticity. We also found that aging modifies activity of enzymes and ceramide levels in selective brain regions. Aging also changed how the chronic treatment with corticosterone (stress) or intranasal dopamine modified regional enzyme activity and ceramide levels, coinciding with rate of extinction. These data provide first evidence for a functional ASM-ceramide pathway in the brain involved in the extinction of learned behavior. This finding extends the known cellular mechanisms underlying behavioral plasticity to a new class of membrane-located molecules, the sphingolipids, and their regulatory enzymes, and may offer new treatment targets for extinction- and learning-related psychopathological conditions. KW - acid sphingomyelinase KW - ceramide KW - extinction KW - hippocampus KW - operant behavior KW - sphingomyelin Y1 - 2016 U6 - https://doi.org/10.1111/jnc.13537 SN - 0022-3042 SN - 1471-4159 VL - 137 SP - 589 EP - 603 PB - Wiley-Blackwell CY - Hoboken ER -