TY - JOUR A1 - Garcia, A. L. A1 - Steiniger, J. A1 - Reich, S. C. A1 - Weickert, M. O. A1 - Harsch, I. A1 - Machowetz, A. A1 - Mohlig, M. A1 - Spranger, Joachim A1 - Rudovich, N. N. A1 - Meuser, F. A1 - Doerfer, J. A1 - Katz, N. A1 - Speth, M. A1 - Zunft, Hans-Joachim Franz A1 - Pfeiffer, Andreas F. H. A1 - Koebnick, Corinna T1 - Arabinoxylan fibre consumption improved glucose metabolism, but did not affect serum adipokines in subjects with impaired glucose tolerance JF - Hormone and metabolic research N2 - The consumption of arabinoxylan, a soluble fibre fraction, has been shown to improve glycemic control in type 2 diabetic subjects. Soluble dietary fibre may modulate gastrointestinal or adipose tissue hormones regulating food intake. The present study investigated the effects of arabinoxylan consumption on serum glucose, insulin, lipids, leptin, adiponectin and resistin in subjects with impaired glucose tolerance. In a randomized, single-blind, controlled, crossover intervention trial, 11 adults consumed white bread rolls as either placebo or supplemented with 15g arabinoxylan for 6 weeks with a 6-week washout period. Fasting serum glucose, insulin, triglycerides, unesterified fatty acids, apolipoprotein A1 and B, adiponectin, resistin and leptin were assessed before and after intervention. Fasting serum glucose, serum triglycerides and apolipoprotein A-1 were significantly lower during arabinoxylan consumption compared to placebo (p = 0.029, p = 0.047; p = 0.029, respectively). No effects of arabinoxylan were observed for insulin, adiponectin, leptin and resistin as well as for apolipoprotein B, and unesterified fatty acids. In conclusion, the consumption of AX in subjects with impaired glucose tolerance improved fasting serum glucose, and triglycerides. However, this beneficial effect was not accompanied by changes in fasting adipokine concentrations. KW - dietary fibre KW - arabinoxylan KW - adiponectin KW - resistin KW - leptin Y1 - 2006 U6 - https://doi.org/10.1055/s-2006-955089 SN - 0018-5043 VL - 38 IS - 2 SP - 761 EP - 766 PB - Thieme CY - Stuttgart ER - TY - JOUR A1 - Maares, Maria A1 - Keil, Claudia A1 - Koza, Jenny A1 - Straubing, Sophia A1 - Schwerdtle, Tanja A1 - Haase, Hajo T1 - In Vitro Studies on Zinc Binding and Buffering by Intestinal Mucins JF - International Journal of Molecular Sciences N2 - The investigation of luminal factors influencing zinc availability and accessibility in the intestine is of great interest when analyzing parameters regulating intestinal zinc resorption. Of note, intestinal mucins were suggested to play a beneficial role in the luminal availability of zinc. Their exact zinc binding properties, however, remain unknown and the impact of these glycoproteins on human intestinal zinc resorption has not been investigated in detail. Thus, the aim of this study is to elucidate the impact of intestinal mucins on luminal uptake of zinc into enterocytes and its transfer into the blood. In the present study, in vitro zinc binding properties of mucins were analyzed using commercially available porcine mucins and secreted mucins of the goblet cell line HT-29-MTX. The molecular zinc binding capacity and average zinc binding affinity of these glycoproteins demonstrates that mucins contain multiple zinc-binding sites with biologically relevant affinity within one mucin molecule. Zinc uptake into the enterocyte cell line Caco-2 was impaired by zinc-depleted mucins. Yet this does not represent their form in the intestinal lumen in vivo under zinc adequate conditions. In fact, zinc-uptake studies into enterocytes in the presence of mucins with differing degree of zinc saturation revealed zinc buffering by these glycoproteins, indicating that mucin-bound zinc is still available for the cells. Finally, the impact of mucins on zinc resorption using three-dimensional cultures was studied comparing the zinc transfer of a Caco-2/HT-29-MTX co-culture and conventional Caco-2 monoculture. Here, the mucin secreting co-cultures yielded higher fractional zinc resorption and elevated zinc transport rates, suggesting that intestinal mucins facilitate the zinc uptake into enterocytes and act as a zinc delivery system for the intestinal epithelium. KW - intestinal zinc resorption KW - zinc binding KW - mucus layer KW - intestinal mucins KW - in vitro intestinal model KW - goblet cells KW - Caco-2/HT-29-MTX-model Y1 - 2018 U6 - https://doi.org/10.3390/ijms19092662 SN - 1422-0067 VL - 19 IS - 9 ER - TY - GEN A1 - Ponce, Carol Barahona A1 - Scherer, Dominique A1 - Boekstegers, Felix A1 - Garate-Calderon, Valentina A1 - Jenab, Mazda A1 - Aleksandrova, Krasimira A1 - Katzke, Verena A1 - Weiderpass, Elisabete A1 - Bonet, Catalina A1 - Moradi, Tahereh A1 - Fischer, Krista A1 - Bossers, Willem A1 - Brenner, Hermann A1 - Schöttker, Ben A1 - Holleczek, Bernd A1 - Hveem, Kristian A1 - Eklund, Niina A1 - Voelker, Uwe A1 - Waldenberger, Melanie A1 - Bermejo, Justo Lorenzo T1 - Arsenic and gallbladder cancer risk BT - Mendelian randomization analysis of European prospective data T2 - International journal of cancer KW - arsenic KW - gallbladder cancer KW - Mendelian randomization Y1 - 2019 U6 - https://doi.org/10.1002/ijc.32837 SN - 0020-7136 SN - 1097-0215 VL - 146 IS - 9 SP - 2648 EP - 2650 PB - Wiley CY - Hoboken ER - TY - GEN A1 - Henze, Andrea T1 - Proteinoxidation als Indikator des Alterungsphänotyps und Target einer individualisierten Ernährungsintervention (ProAID) T1 - Protein Oxidation as an Indicator of the Aging Phenotype and Target of an individualized Nutritional Intervention (ProAID) T2 - Ernährungs-Umschau : Forschung & Praxis N2 - Oxidative posttranslationale Modifikationen endogener Proteine werden v. a. durch reaktive Sauerstoff- und Stickstoffspezies (engl:. Reactive Oxygen Species, ROS, reactive nitrogen species, RNS) hervorgerufen und können sowohl reversibel (z. B. Disulfidbindungen) als auch irreversibel (z. B. Proteincarbonyle) erfolgen [1–3]. Lange wurde angenommen, dass oxidative posttranslationale Proteinmodifikationen (oxPTPM) nur von untergeordneter Bedeutung für den Metabolismus sind. Tatsächlich handelt es sich jedoch um einen physiologischen Prozess, der über die Modulation der Proteinstruktur auch die Proteinfunktion (z. B. Enzymaktivität, Stabilität) und somit zahlreiche Stoffwechselwege wie den Energiestoffwechsel, die Immunfunktion, die vaskuläre Funktion sowie Apoptose und Genexpression beeinflussen kann. Die Bildung von oxPTPM ist dabei hochreguliert und hängt u. a. von der Proteinstruktur, der Verfügbarkeit von ROS und RNS sowie dem lokalen Mikromilieu der Zelle ab [2, 4]. Y1 - 2018 SN - 0174-0008 VL - 65 IS - 10 SP - M566 EP - M567 PB - Umschau-Zeitschriftenverl. CY - Frankfurt, Main ER - TY - GEN A1 - Kleuser, Burkhard T1 - The enigma of sphingolipids in health and disease T2 - International journal of molecular sciences Y1 - 2018 U6 - https://doi.org/10.3390/ijms19103126 SN - 1422-0067 VL - 19 IS - 10 PB - MDPI CY - Basel ER - TY - JOUR A1 - Groop, Per-Henrik A1 - Cooper, Mark E. A1 - Perkovic, Vlado A1 - Hocher, Berthold A1 - Kanasaki, Keizo A1 - Haneda, Masakazu A1 - Schernthaner, Guntram A1 - Sharma, Kumar A1 - Stanton, Robert C. A1 - Toto, Robert A1 - Cescutti, Jessica A1 - Gordat, Maud A1 - Meinicke, Thomas A1 - Koitka-Weber, Audrey A1 - Thiemann, Sandra A1 - von Eynatten, Maximilian T1 - Linagliptin and its effects on hyperglycaemia and albuminuria in patients with type 2 diabetes and renal dysfunction BT - the randomized MARLINA-T2D trial JF - Diabetes obesity & metabolism : a journal of pharmacology and therapeutics N2 - Aims: The MARLINA-T2D study (ClinicalTrials. gov, NCT01792518) was designed to investigate the glycaemic and renal effects of linagliptin added to standard-of-care in individuals with type 2 diabetes and albuminuria. Methods: A total of 360 individuals with type 2 diabetes, HbA1c 6.5% to 10.0% (48-86 mmol/ mol), estimated glomerular filtration rate (eGFR) >= 30 mL/min/1.73 m(2) and urinary albumin-tocreatinine ratio (UACR) 30-3000 mg/g despite single agent renin-angiotensin-system blockade were randomized to double-blind linagliptin (n = 182) or placebo (n = 178) for 24 weeks. The primary and key secondary endpoints were change from baseline in HbA1c at week 24 and time-weighted average of percentage change from baseline in UACR over 24 weeks, respectively. Results: Baseline mean HbA1c and geometric mean (gMean) UACR were 7.8% +/- 0.9% (62.2 +/- 9.6 mmol/mol) and 126 mg/g, respectively; 73.7% and 20.3% of participants had microalbuminuria or macroalbuminuria, respectively. After 24 weeks, the placebo-adjusted mean change in HbA1c from baseline was -0.60% (-6.6 mmol/mol) (95% confidence interval [CI], -0.78 to -0.43 [-8.5 to -4.7 mmol/mol]; P <.0001). The placebo-adjusted gMean for time-weighted average of percentage change in UACR from baseline was -6.0% (95% CI, -15.0 to 3.0; P =.1954). The adverse-event profile, including renal safety and change in eGFR, was similar between the linagliptin and placebo groups. Conclusions: In individuals at early stages of diabetic kidney disease, linagliptin significantly improved glycaemic control but did not significantly lower albuminuria. There was no significant change in placebo-adjusted eGFR. Detection of clinically relevant renal effects of linagliptin may require longer treatment, as its main experimental effects in animal studies have been to reduce interstitial fibrosis rather than alter glomerular haemodynamics. KW - antidiabetic drug KW - clinical trial KW - diabetic nephropathy KW - DPP-IV inhibitor KW - glycaemic control KW - linagliptin Y1 - 2017 U6 - https://doi.org/10.1111/dom.13041 SN - 1462-8902 SN - 1463-1326 VL - 19 IS - 11 SP - 1610 EP - 1619 PB - Wiley CY - Hoboken ER - TY - GEN A1 - Hocher, Berthold A1 - Tsuprykov, Oleg T1 - Renoprotective effects of GLP1R agonists and SGLT2 inhibitors T2 - Nature reviews nephroloy N2 - New data from the LEADER trial show that the glucagon-like peptide 1 receptor agonist liraglutide protects against diabetic nephropathy in patients with type 2 diabetes mellitus. The renoprotective efficacy of liraglutide is not, however, as great as that reported for the sodium-glucose cotransporter 2 inhibitor emplagiflozin in the EMPA-REG OUTCOME trial. Y1 - 2017 U6 - https://doi.org/10.1038/nrneph.2017.140 SN - 1759-5061 SN - 1759-507X VL - 13 SP - 728 EP - 729 PB - Nature Publ. Group CY - New York ER - TY - JOUR A1 - Wirsching, Jan A1 - Grassmann, Sophie A1 - Eichelmann, Fabian A1 - Harms, Laura Malin A1 - Schenk, Matthew A1 - Barth, Eva A1 - Berndzen, Alide A1 - Olalekan, Moses A1 - Sarmini, Leen A1 - Zuberer, Hedwig A1 - Aleksandrova, Krasimira T1 - Development and reliability assessment of a new quality appraisal tool for cross-sectional studies using biomarker data (BIOCROSS) JF - BMC Medical Research Methodology N2 - Background Biomarker-based analyses are commonly reported in observational epidemiological studies; however currently there are no specific study quality assessment tools to assist evaluation of conducted research. Accounting for study design and biomarker measurement would be important for deriving valid conclusions when conducting systematic data evaluation. Methods We developed a study quality assessment tool designed specifically to assess biomarker-based cross-sectional studies (BIOCROSS) and evaluated its inter-rater reliability. The tool includes 10-items covering 5 domains: ‘Study rational’, ‘Design/Methods’, ‘Data analysis’, ‘Data interpretation’ and ‘Biomarker measurement’, aiming to assess different quality features of biomarker cross-sectional studies. To evaluate the inter-rater reliability, 30 studies were distributed among 5 raters and intraclass correlation coefficients (ICC-s) were derived from respective ratings. Results The estimated overall ICC between the 5 raters was 0.57 (95% Confidence Interval (CI): 0.38–0.74) indicating a good inter-rater reliability. The ICC-s ranged from 0.11 (95% CI: 0.01–0.27) for the domain ‘Study rational’ to 0.56 (95% CI: 0.40–0.72) for the domain ‘Data interpretation’. Conclusion BIOCROSS is a new study quality assessment tool suitable for evaluation of reporting quality from cross-sectional epidemiological studies employing biomarker data. The tool proved to be reliable for use by biomedical scientists with diverse backgrounds and could facilitate comprehensive review of biomarker studies in human research. KW - BIOCROSS KW - Quality appraisal KW - Evaluation tool KW - Cross-sectional studies Y1 - 2018 U6 - https://doi.org/10.1186/s12874-018-0583-x SN - 1471-2288 VL - 18 PB - BMC CY - London ER - TY - JOUR A1 - Werno, Martin Witold A1 - Wilhelmi, Ilka A1 - Kuropka, Benno A1 - Ebert, Franziska A1 - Freund, Christian A1 - Schürmann, Annette T1 - The GTPase ARFRP1 affects lipid droplet protein composition and triglyceride release from intracellular storage of intestinal Caco-2 cells JF - Biochemical and biophysical research communications N2 - Intestinal release of dietary triglycerides via chylomicrons is the major contributor to elevated postprandial triglyceride levels. Dietary lipids can be transiently stored in cytosolic lipid droplets (LDs) located in intestinal enterocytes for later release. ADP ribosylation factor-related protein 1 (ARFRP1) participates in processes of LD growth in adipocytes and in lipidation of lipoproteins in liver and intestine. This study aims to explore the impact of ARFRP1 on LD organization and its interplay with chylomicron-mediated triglyceride release in intestinal-like Caco-2 cells. Suppression of Arfrp1 reduced release of intracellularly derived triglycerides (0.69-fold) and increased the abundance of transitional endoplasmic reticulum ATPase TERA/VCP, fatty acid synthase-associated factor 2 (FAF2) and perilipin 2 (Plin2) at the LD surface. Furthermore, TERA/VCP and FAF2 co-occurred more frequently with ATGL at LDs, suggesting a reduced adipocyte triglyceride lipase (ATGL)-mediated lipolysis. Accordingly, inhibition of lipolysis reduced lipid release from intracellular storage pools by the same magnitude as Arfrp1 depletion. Thus, the lack of Arfrp1 increases the abundance of lipolysis-modulating enzymes TERA/VCP, FAF2 and Plin2 at LDs, which might decrease lipolysis and reduce availability of fatty acids for triglyceride synthesis and their release via chylomicrons. (C) 2018 The Authors. Published by Elsevier Inc. KW - Chylomicron KW - Lipid droplet proteome KW - Triglyceride secretion KW - Lipolysis Y1 - 2018 U6 - https://doi.org/10.1016/j.bbrc.2018.10.092 SN - 0006-291X SN - 1090-2104 VL - 506 IS - 1 SP - 259 EP - 265 PB - Elsevier CY - San Diego ER - TY - THES A1 - Baeseler, Jessica T1 - Trace element effects on longevity and neurodegeneration with focus on C. elegans T1 - Effekte von Spurenelementen auf die Lebensdauer und Neurodegeneration mit Fokus auf C. elegans N2 - The trace elements zinc and manganese are essential for human health, especially due to their enzymatic and protein stabilizing functions. If these elements are ingested in amounts exceeding the requirements, regulatory processes for maintaining their physiological concentrations (homeostasis) can be disturbed. Those homeostatic dysregulations can cause severe health effects including the emergence of neurodegenerative disorders such as Parkinson’s disease (PD). The concentrations of essential trace elements also change during the aging process. However, the relations of cause and consequence between increased manganese and zinc uptake and its influence on the aging process and the emergence of the aging-associated PD are still rarely understood. This doctoral thesis therefore aimed to investigate the influence of a nutritive zinc and/or manganese oversupply on the metal homeostasis during the aging process. For that, the model organism Caenorhabditis elegans (C. elegans) was applied. This nematode suits well as an aging and PD model due to properties such as its short life cycle and its completely sequenced, genetically amenable genome. Different protocols for the propagation of zinc- and/or manganese-supplemented young, middle-aged and aged C. elegans were established. Therefore, wildtypes, as well as genetically modified worm strains modeling inheritable forms of parkinsonism were applied. To identify homeostatic and neurological alterations, the nematodes were investigated with different methods including the analysis of total metal contents via inductively-coupled plasma tandem mass spectrometry, a specific probe-based method for quantifying labile zinc, survival assays, gene expression analysis as well as fluorescence microscopy for the identification and quantification of dopaminergic neurodegeneration.. During aging, the levels of iron, as well as zinc and manganese increased.. Furthermore, the simultaneous oversupply with zinc and manganese increased the total zinc and manganese contents to a higher extend than the single metal supplementation. In this relation the C. elegans metallothionein 1 (MTL-1) was identified as an important regulator of metal homeostasis. The total zinc content and the concentration of labile zinc were age-dependently, but differently regulated. This elucidates the importance of distinguishing these parameters as two independent biomarkers for the zinc status. Not the metal oversupply, but aging increased the levels of dopaminergic neurodegeneration. Additionally, nearly all these results yielded differences in the aging-dependent regulation of trace element homeostasis between wildtypes and PD models. This confirms that an increased zinc and manganese intake can influence the aging process as well as parkinsonism by altering homeostasis although the underlying mechanisms need to be clarified in further studies. N2 - Die Spurenelemente Zink und Mangan sind vor allem aufgrund ihrer enzymatischen und Protein-stabilisierenden Funktionen essentiell für die menschliche Gesundheit. Werden sie allerdings in Mengen aufgenommen, die den Bedarf übersteigen, können regulatorische Prozesse für die Aufrechterhaltung physiologischer Konzentrationen dieser Metalle (Homöostase) aus dem Gleichgewicht geraten. Das kann ernsthafte gesundheitliche Konsequenzen nach sich ziehen, unter anderem die Entstehung neurodegenerativer Krankheiten, wie zum Beispiel der Parkinson’schen Erkrankung. Auch während des Alterungsprozesses verändern sich die Gehalte an lebensnotwendigen Spurenelementen im Körper. Jedoch sind die Zusammenhänge zwischen Ursache und Wirkung einer erhöhten Aufnahme an Zink und Mangan und deren Einfluss auf den Alterungsprozess und die Entstehung der altersassoziierten Parkinson’schen Erkrankung bisher nur unzureichend verstanden. Im Rahmen dieser Doktorarbeit wurde deshalb der Einfluss einer nutritiven Zink- und/oder Manganüberversorgung auf die Metallhomöostase während der Alterung untersucht. Dazu wurde Caenorhabditis elegans (C. elegans) als Modellorganismus verwendet. Diese Fadenwürmer eignen sich aufgrund verschiedener Eigenschaften, wie einem kurzen Lebenszyklus und einem komplett sequenzierten und leicht manipulierbarem Genom, hervorragend als Alters- und Parkinson-Modelle. Es wurden verschiedene Protokolle etabliert, die die Anzucht von Zink- und/oder Mangan-supplementierten jungen, mittelalten bzw. gealterten C. elegans erlaubten. Neben Wildtypen wurden auch Wurmstämme untersucht, die genetische Modifikationen aufweisen, die mit vererbbaren Formen des Parkinsonismus assoziiert werden können. Die Würmer wurden mithilfe verschiedener Methoden, wie der analytischen Bestimmung des Gesamtmetallgehaltes mittels Massenspektrometrie mit induktiv-gekoppeltem Plasma, einer Sonden-spezifischen Methode zur Bestimmung von freiem Zink, Letalitätsassays, Genexpressionsanalysen und der Fluoreszenz-mikroskopischen Untersuchung der dopaminergen Neurodegeneration auf verschiedene Parameter untersucht, die Aufschluss über homöostatische und neurologische Veränderungen geben. Es wurde eine altersbedingte Zunahme von Eisen, sowie Zink und Mangan in den Würmern beobachtet. Weiterhin stellte sich heraus, dass vor allem die simultane Überversorgung mit Zink und Mangan den Gesamtmetallgehalt dieser Metalle in C. elegans in einem Maß steigerte, das das der Einzelmetallsupplementierung überstieg. Dabei konnte vor allem das C. elegans Metallothionein 1 (MTL-1) als wichtiger Faktor in der Regulation der Metallhomöostase identifiziert werden. Außerdem wurde die Wichtigkeit verdeutlicht, zwischen dem Gesamtzinkgehalt und der Konzentration an freiem Zink als Biomarkern für den Zinkstatus eines Organismus zu unterscheiden. Beide Parameter wurden altersabhängig unterschiedlich reguliert. Im Gegensatz zur Alterung, wurde durch die Überversorgung mit Metallen keine zusätzliche Schädigung der dopaminergen Neuronen beobachtet. In nahezu all diesen Ergebnissen verdeutlichten sich weiterhin Unterschiede in der altersabhängigen Regulation der Spurenelementhomöostase zwischen Wildtypen und Parkinson-Modellen. Dies bestätigt die Annahme, dass sich eine erhöhte Aufnahme von Mangan und Zink durch die Beeinflussung der Homöostase sowohl auf die Alterung, als auch den Parkinsonismus auswirken kann, jedoch müssen die mechanistischen Grundlagen dessen in zukünftigen Studien aufgeklärt werden. KW - Caenorhabditis elegans KW - aging KW - trace element KW - zinc KW - manganese KW - Caenorhabditis elegans KW - Alterung KW - Spurenelement KW - Zink KW - Mangan Y1 - 2021 ER - TY - JOUR A1 - Nitezki, Tina A1 - Schulz, Nadja A1 - Krämer, Stephanie T1 - Color matters BT - They would choose if they could (see)! JF - Laboratory animals : the international journal of laboratory animal science and welfare N2 - Concerning standardization of laboratory animal husbandry, only exiguous changes of habitat can potentially influence animal physiology or results of behavioral tests. Routinely, mice chow is dyed when different types of diets are dispensed. Given the fact that the dye itself has no effects on food odor or flavor, we wanted to test the hypothesis that the color of chow has an impact on food uptake in mice. Twelve-week-old male mice of different strains (C57BL/6J, DBA/2J, C3H/HeJ, BALB/cJ; n = 12/strain) were single-housed in PhenoMaster (R) cages. After acclimatization standard mice chow in different colors was administered. Food intake was monitored as a two-alternative choice test of different color combinations. All animals had an average food intake of 3 g/d and no preferences were observed when a combination of identically colored food was offered. Preference tests yielded significant aversion to blue food and significant attraction to yellow and green food in C57BL/6 and DBA/2J mice. In C3H/HeJ and BALB/cJ mice no color-related pattern occurred. Selected mice strains have known differences concerning functionality of their visual sense. C57BL/6 and DBA/2 mice are considered to be normal sighted at testing age, BALB/c is representative for albino strains and C3H mice carry mutations resulting in retinal alterations. Results suggesting that normal-sighted mice would be selective concerning food color when given the choice. Nevertheless, this does not influence overall quantity of food intake when animals were provided solely with food colored with a single dye. Moreover, visually impaired mice showed no color-related food preferences. N2 - Concernant la normalisation des élevages d’animaux de laboratoire, seuls des changements mineurs de leur habitat peuvent potentiellement influencer la physiologie des animaux ou les résultats des tests comportementaux. Habituellement, la nourriture des souris show est colorée en fonction des différents types de régimes administrés. Étant donné que la couleur n’a aucun effet sur l’odeur ou le goût des aliments, nous avons souhaité vérifier l’hypothèse selon laquelle la couleur des aliments a un impact sur la quantité consommée par les souris. Des souris mâles âgés de 12 semaines issus de différentes souches (C57BL/6J, DBA/2J, C3H/HeJ, BALB/cJ; n = 12/souche) ont été hébergés individuellement dans des cages PhenoMaster®. Après une phase d’acclimatation, des aliments normaux de couleurs différentes ont été administrés. La consommation alimentaire a été mesurée dans le cadre d’un test permettant aux souris de choisir entre deux combinaisons de couleurs différentes. Tous les animaux ont consommé en moyenne 3 g de nourriture par jour et aucune préférence n’a été remarquée lorsqu’une combinaison d’aliments de couleur identique était offerte. Les tests de préférence ont révélé une forte aversion aux aliments de couleur bleue et une attirance importante envers les aliments de couleurs jaune et verte chez les souris C57BL/6 et DBA/2J. Chez les souris C3H/HeJ et BALB/cJ, aucune préférence basée sur les couleurs n’a été observée. Les lignées de souris sélectionnées présentent des différences connues en ce qui concerne la fonctionnalité de leur sens visuel. Il est considéré que les souris C57BL/6 et DBA/2 possèdent une vue normale au moment du test. La lignée BALB/c représente les souches de souris albinos et les souris C3H sont porteuses de mutations entraînant des modifications de la rétine. Les résultats suggèrent que les souris possédant une vue normale sont sélectives en ce qui concerne la couleur des aliments lorsqu’on leur donne le choix. De manière générale, ceci n’influence toutefois pas la quantité de nourriture consommée lorsque les animaux reçoivent uniquement des aliments ne présentant qu’une seule couleur. Par ailleurs, les souris malvoyantes n’ont affiché aucune préférence alimentaire associée aux couleurs. N2 - Bei der Standardisierung der Labortierhaltung können schon geringfügige Veränderungen des Habitats die Physiologie des Tieres oder die Ergebnisse von Verhaltenstests beeinflussen. Routinemäßig wird das Futter von Mäusen gefärbt, wenn verschiedene Arten von Diäten verabreicht werden. Angesichts der Tatsache, dass der Farbstoff selbst keine Auswirkungen auf den Lebensmittelgeruch oder -geschmack hat, wollten wir die Hypothese testen, dass die Futterfarbe einen Einfluss auf die Nahrungsaufnahme bei Mäusen hat. 12 Wochen alte männliche Mäuse verschiedener Stämme (C57BL/6J, DBA/2J, C3H/HeJ, BALB/cJ; n = 12/Stamm) wurden einzeln in PhenoMaster® Käfigen untergebracht. Nach der Akklimatisierung wurde Standard-Mäusefutter in verschiedenen Farben verabreicht. Die Nahrungsaufnahme wurde als ein Zwei-Alternativen-Wahltest verschiedener Farbkombinationen überwacht. Alle Tiere nahmen durchschnittlich 3 g/Tag Nahrung auf und es wurden keine Präferenzen beobachtet, wenn eine Kombination von gleichfarbigen Futtermitteln angeboten wurde. Präferenztests ergaben eine signifikante Abneigung gegen blaues Futter und eine signifikante Vorliebe für gelbes und grünes Futter bei C57BL/6- und DBA/2J-Mäusen. Bei C3H/HeJ- und BALB/cJ-Mäusen waren keine farbbezogenen Muster erkennbar. Ausgewählte Stämme von Mäusen weisen bekanntermaßen Unterschiede in der Funktionalität ihres Sehsinns auf. C57BL/6- und DBA/2-Mäuse gelten im Testalter als normalsichtig, BALB/c sind repräsentativ für Albino-Stämme und C3H-Mäuse sind von Mutationen betroffen, die zu Netzhautveränderungen führen. Die Ergebnisse legen nahe, dass normalsichtige Mäuse selektiv in Bezug auf die Futterfarbe sein dürften, sofern sie die Wahl haben. Dies hat jedoch keinen Einfluss auf die Gesamtmenge der Nahrungsaufnahme, wenn die Tiere ausschließlich mit durch einen einzigen Farbstoff gefärbtem Futter versorgt wurden. Außerdem zeigten sehbehinderte Mäuse keine farbbezogenen Futtervorlieben. KW - refinement KW - color vision KW - food choice KW - color preference KW - eating Y1 - 2018 U6 - https://doi.org/10.1177/0023677218766370 SN - 0023-6772 SN - 1758-1117 VL - 52 IS - 6 SP - 611 EP - 620 PB - Sage Publ. CY - Thousand Oaks ER - TY - JOUR A1 - Rohn, Sascha A1 - Petzke, Klaus-Jürgen A1 - Rawel, Harshadrai Manilal A1 - Kroll, Jürgen T1 - Reactions of chlorogenic acid and quercetin with a soy protein isolate - Influence on the in vivo food protein quality in rats JF - Molecular nutrition & food research : bioactivity, chemistry, immunology, microbiology, safety, technology N2 - Plant phenolic compounds are known to interact with proteins producing changes in the food (e.g., biological value (BV), color, taste). Therefore, the in vivo relevance, especially, of covalent phenolprotein reactions on protein quality was studied in a rat bioassay. The rats were fed protein derivatives at a 10% protein level. Soy proteins were derivatized with chlorogenic acid and quercetin (derivatization levels: 0.056 and 0.28 mmol phenolic compound/gram protein). Analysis of nitrogen in diets, urine, and fecal samples as well as the distribution of amino acids were determined. Depending on the degree of derivatization, the rats fed with soy protein derivatives showed an increased excretion of fecal and urinary nitrogen. As a result, true nitrogen digestibility, BV, and net protein utilization were adversely affected. Protein digestibility corrected amino acid score was decreased for lysine, tryptophan, and sulfur containing amino acids. KW - amino acid score KW - plant phenolic compounds KW - protein derivatization KW - protein digestibility KW - soy protein Y1 - 2006 U6 - https://doi.org/10.1002/mnfr.200600043 SN - 1613-4125 VL - 50 SP - 696 EP - 704 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Rawel, Harshadrai Manilal A1 - Frey, Simone K. A1 - Meidtner, Karina A1 - Kroll, Jürgen A1 - Schweigert, Florian J. T1 - Determining the binding affinities of phenolic compounds to proteins by quenching of the intrinsic tryptophan fluorescence JF - Molecular nutrition & food research : bioactivity, chemistry, immunology, microbiology, safety, technology N2 - The noncovalent binding of selected phenolic compounds (chlorogenic-, ferutic-, gallic acid, quercetin, rutin, and isoquercetin) to proteins (HSA, BSA, soy glycinin, and lysozyme) was studied by an indirect method applying the quenching of intrinsic tryptophan fluorescence. From the data obtained, the binding constants were calculated by nonlinear regression (one site binding; y = Bx/k + x). It has been reported that tannins inhibit human salivary amylase and that these complexes may reduce the development of cariogenic plaques. Further, amylase contains two tryptophan residues in its active site. Therefore, in a second part of the study involving 31 human subjects, evidence was sought for noncovalent interactions between the phenols of green tea and saliva proteins as measured by the fluorescence intensity. Amylase activity was determined before and after the addition of green tea to saliva of 31 subjects. Forty percent of the subjects showed an increase in amylase activity contrary to studies reporting only a decrease in activity. The interactions of tannin with amylase result in a decrease of its activity. It still remains to be elucidated why amylase does not react uniformly under conditions of applying green tea to saliva. Further, in terms of using phenols as caries inhibitors this finding should be of importance. KW - amylase activity KW - green tea phenols KW - protein-phenol binding KW - saliva proteins KW - tryptophan quenching Y1 - 2006 U6 - https://doi.org/10.1002/mnfr.200600013 SN - 1613-4125 VL - 50 IS - 8 SP - 705 EP - 713 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Ghaffari, Morteza Hosseini A1 - Bernhoeft, Katrin A1 - Etheve, Stephane A1 - Immig, Irmgard A1 - Hoelker, Michael A1 - Sauerwein, Helga A1 - Schweigert, Florian J. T1 - Technical note: Rapid field test for the quantification of vitamin E, beta-carotene, and vitamin A in whole blood and plasma of dairy cattle JF - Journal of dairy science N2 - Fast and easy tests for quantifying fat-soluble vitamins such as vitamin E and vitamin A, as well as beta-carotene, in whole blood without a need to preprocess blood samples could facilitate assessment of the vitamin status of dairy cattle. The objective of this study was to validate a field-portable fluorometer/spectrophotometer assay for the rapid quantification of these vitamins in whole blood and plasma of dairy cows and calves. We measured the concentrations of vitamin E and beta-carotene in whole blood and plasma from 28 dairy cows and 11 calves using the iCheck test (Bio-Analyt GmbH, Teltow, Germany) and compared the results with the current analytical standard (HPLC) in 2 independent laboratories, one at the University of Potsdam (Germany) and at one at DSM Nutritional Products Ltd. (Kaiseraugst, Switzerland). For vitamin A, the HPLC measurements were done only in the laboratory in Germany. The whole-blood concentrations of vitamin E as determined by iCheck (blood-hematocritcorrected) ranged from 1.82 to 4.99 mg/L in dairy cows and 0.34 to 3.40 mg/L in calves. These findings were moderately correlated (R-2 = 0.66) with the values assessed by HPLC in dairy cattle (cows + calves). When calves were excluded, the correlation was higher (R-2 = 0.961). The beta-carotene and vitamin A values obtained by the reference method HPLC were highly correlated with the iCheck methods in whole blood (R-2 = 0.99 and 0.88, respectively). In plasma, we observed strong correlations between the concentrations assessed by iCheck and those of HPLC for vitamin E (R-2 = 0.97), beta-carotene (R-2 = 0.98), and vitamin A (R-2 = 0.92) in dairy cattle (cows + calves). For vitamin E, beta-carotene, and vitamin A, we compared the relationship between the differences obtained by the iCheck assay and the HPLC measurements, as well as the magnitude of measurements, using Bland-Altman plots to test for systematic bias. For all 3 vitamins, the differences values were not outside the 95% acceptability limits; we found no systematic error between the 2 methods for all 3 analytes. KW - vitamin KW - cow-side assay KW - HPLC KW - method comparison Y1 - 2019 U6 - https://doi.org/10.3168/jds.2019-16755 SN - 0022-0302 SN - 1525-3198 VL - 102 IS - 12 SP - 11744 EP - 11750 PB - Elsevier CY - New York ER - TY - JOUR A1 - Witt, Barbara A1 - Ebert, Franziska A1 - Meyer, Sören A1 - Francesconi, Kevin A. A1 - Schwerdtle, Tanja T1 - Assessing neurodevelopmental effects of arsenolipids in pre-differentiated human neurons JF - Molecular nutrition & food research : bioactivity, chemistry, immunology, microbiology, safety, technology N2 - Scope: In the general population exposure to arsenic occurs mainly via diet. Highest arsenic concentrations are found in seafood, where arsenic is present predominantly in its organic forms including arsenolipids. Since recent studies have provided evidence that arsenolipids could reach the brain of an organism and exert toxicity in fully differentiated human neurons, this work aims to assess the neurodevelopmental toxicity of arsenolipids. Methods and results: Neurodevelopmental effects of three arsenic-containing hydrocarbons (AsHC), two arsenic-containing fatty acids (AsFA), arsenite and dimethylarsinic acid (DMA(V)) were characterized in pre-differentiated human neurons. AsHCs and arsenite caused substantial cytotoxicity in a similar, low concentration range, whereas AsFAs and DMA(V) were less toxic. AsHCs were highly accessible for cells and exerted pronounced neurodevelopmental effects, with neurite outgrowth and the mitochondrial membrane potential being sensitive endpoints; arsenite did not substantially decrease those two endpoints. In fully differentiated neurons, arsenite and AsHCs caused neurite toxicity. Conclusion: These results indicate for a neurodevelopmental potential of AsHCs. Taken into account the possibility that AsHCs might easily reach the developing brain when exposed during early life, neurotoxicity and neurodevelopmental toxicity cannot be excluded. Further studies are needed in order to progress the urgently needed risk assessment. KW - Arsenic-containing fatty acids KW - Arsenic-containing hydrocarbons KW - Arsenite KW - Arsenolipids KW - Neurodevelopmental toxicity Y1 - 2017 U6 - https://doi.org/10.1002/mnfr.201700199 SN - 1613-4125 SN - 1613-4133 VL - 61 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Goetz, Klaus-Peter A1 - Chmielewski, Frank M. A1 - Goedeke, Kristin A1 - Wolf, Kristine A1 - Jander, Elisabeth A1 - Sievers, Steven A1 - Homann, Thomas A1 - Huschek, Gerd A1 - Rawel, Harshadrai Manilal T1 - Assessment of amino acids during winter rest and ontogenetic development in sweet cherry buds (Prunus avium. L.) JF - Scientia horticulturae : an international journal sponsored by the International Society for Horticultural Science N2 - This study examined changes in sweet cherry buds of ‘Summit’ cultivar in four seasons (2011/12–2014/15) with respect to the nitrogen (N) content and the profile of eight free amino acids (asparagine (Asn), aspartic acid (Asp), isoleucine (Ile), glutamine (Gln), glutamic acid (Glu), arginine (Arg), alanine (Ala), histidine (His)). The presented results are to our knowledge the first under natural conditions in fruit tree orchards with a high temporal resolution from the dormant stage until cluster development. The N content in the buds from October, during endo- and ecodormancy until the beginning of ontogenetic development was a relatively stable parameter in each of the four seasons. The N accumulation into the buds began after ‘swollen bud’ and significant differences were visible at ‘green tip’ with an N content of 3.24, 3.12, 3.08, 2.40 which increased markedly to the mean of ‘tight’ and ‘open cluster’ by 3.77%, 3.78%, 3.44% and 3.10% in 2012–2015, respectively. In the buds, levels of asparagine were higher (up to 44 mg g−1 DW−1) than aspartic acid (up to 2 mg g−1 DW−1) and aspartic acid higher than isoleucine (up to 0.83 mg g−1 DW−1). Levels of glutamine were higher (up to 25 mg g−1 DW−1) than glutamic acid (up to 20 mg g−1 DW−1). The course of the arginine content was higher in 2011/12 compared to 2012/13, 2013/14 and 2014/15 which showed only slight differences. The alanine content in the buds was denoted in the four seasons only by relatively minor changes. The histidine content was higher in 2011/12 and 2012/13 compared to 2013/14 and 2014/15 which showed a comparable pattern. For 6 amino acids (Asn, Asp, Ile, Glu, Arg, Ala), the highest content was observed in 2012/13, the warmest period between swollen bud and open cluster. However in 2014/15, the season with the lowest mean temperature of 8.8 °C, only the content of Gln was the lowest. It was not possible to explain any seasonal differences in the amino acid content by environmental factors (air temperature) on the basis of few seasons. From none of the measured free amino acids could a clear determination of the date of endodormancy release (t1) or the beginning of the ontogenetic development (t1*) be derived. Therefore, these amino acids are no suitable markers to improve phenological models for the beginning of cherry blossom. KW - Amino acids KW - Flower buds KW - Prunus avium L. KW - Dormancy KW - Ontogenetic development Y1 - 2017 U6 - https://doi.org/10.1016/j.scienta.2017.05.001 SN - 0304-4238 SN - 1879-1018 VL - 222 SP - 102 EP - 110 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Witt, Barbara A1 - Meyer, Sören A1 - Ebert, Franziska A1 - Francesconi, Kevin A. A1 - Schwerdtle, Tanja T1 - Toxicity of two classes of arsenolipids and their water-soluble metabolites in human differentiated neurons JF - Archives of toxicology : official journal of EUROTOX N2 - Arsenolipids are lipid-soluble organoarsenic compounds, mainly occurring in marine organisms, with arsenic-containing hydrocarbons (AsHCs) and arsenic-containing fatty acids (AsFAs) representing two major subgroups. Recently, toxicity studies of several arsenolipids showed a high cytotoxic potential of those arsenolipids in human liver and bladder cells. Furthermore, feeding studies with Drosophila melanogaster indicated an accumulation of arsenolipids in the fruit fly’s brain. In this study, the neurotoxic potential of three AsHCs, two AsFAs and three metabolites (dimethylarsinic acid, thio/oxo-dimethylarsenopropanoic acid) was investigated in comparison to the toxic reference arsenite (iAsIII) in fully differentiated human brain cells (LUHMES cells). Thereby, in the case of AsHCs both the cell number and cell viability were reduced in a low micromolar concentration range comparable to iAsIII, while AsFAs and the applied metabolites were less toxic. Mechanistic studies revealed that AsHCs reduced the mitochondrial membrane potential, whereas neither iAsIII nor AsFAs had an impact. Furthermore, neurotoxic mechanisms were investigated by examining the neuronal network. Here, AsHCs massively disturbed the neuronal network and induced apoptotic effects, while iAsIII and AsFAs showed comparatively lesser effects. Taking into account the substantial in vitro neurotoxic potential of the AsHCs and the fact that they could transfer across the physiological barriers of the brain, a neurotoxic potential in vivo for the AsHCs cannot be excluded and needs to be urgently characterized. KW - Arsenolipids KW - Neurons KW - Cytotoxicity KW - Neurotoxicity KW - Arsenic-containing hydrocarbons KW - Arsenic-containing fatty acids Y1 - 2017 U6 - https://doi.org/10.1007/s00204-017-1933-x SN - 0340-5761 SN - 1432-0738 VL - 91 SP - 3121 EP - 3134 PB - Springer CY - Heidelberg ER - TY - THES A1 - Ziemann, Vanessa T1 - Toxische Effekte von Arsenolipiden in humanen Kulturzellen und Caenorhabditis elegans Y1 - 2020 ER - TY - JOUR A1 - Garcia, Ada Lizbeth A1 - Raila, Jens A1 - Koebnick, Corinna A1 - Eulenberger, Klaus A1 - Schweigert, Florian J. T1 - Great apes show highly selective plasma carotenoids and have physiologically high plasma retinyl esters compared to humans JF - American journal of physical anthropology N2 - Great apes are the closest living relatives of humans. Physiological similarities between great apes and humans provide clues to identify which biological features in humans are primitive or derived from great apes. Vitamin A (VA) and carotenoid metabolism have been only partially studied in great apes, and comparisons between great apes and humans are not available. We aimed to investigate VA and carotenoid intake and plasma concentrations in great apes living in captivity, and to compare them to healthy humans. Dietary intakes of humans (n = 20) and, among the great apes, chimpanzees (n = 15) and orangutans (n = 5) were calculated. Plasma retinol (ROH), retinol-binding protein (RBP), retinyl esters, and major carotenoids were analyzed. The great ape diet was higher in VA than in humans, due to high intake of provitamin A carotenoids. Plasma ROH concentrations in great apes were similar to those in humans, but retinyl esters were higher in great apes than in humans. Differences in plasma carotenoid concentrations were observed between great apes and humans. Lutein was the main carotenoid in great apes, while P-carotene was the main carotenoid for humans. RBP concentrations did not differ between great apes and humans. The molar ratio of ROH to RBP was close to 1.0 in both great apes and humans. In conclusion, great apes show homeostatic ROH regulation, with high but physiological retinyl esters circulating in plasma. Furthermore, great apes show great selectivity in their plasmatic carotenoid concentration, which is not explained by dietary intake. KW - vitamin A KW - diet KW - retinol-binding protein KW - chimpanzee KW - orangutan Y1 - 2006 U6 - https://doi.org/10.1002/ajpa.20428 SN - 0002-9483 VL - 131 IS - 2 SP - 236 EP - 242 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Eggert, Kai A1 - Rawel, Harshadrai Manilal A1 - Nikfardjam, Martin S. Pour A1 - Kroll, Jürgen T1 - Interactions between lysozyme and wine components JF - Deutsche Lebensmittel-Rundschau : DLR N2 - The addition of lysozyme amounting to 1000 mg/l wine does neither effect its total phenol content (Folin-Ciocalteu-Method), nor wine colour (measured by extinction at 512 nm) nor its antioxidative capacity (TEAC-Assay). No covalent binding of wine phenols to the enzyme was observed during lysozyme addition, although non-covalent interactions are possible. Lysozyme activity is not influenced by the presence of malvidin-3-glucoside and resveratrol in model experiments, whereas pH and ethanol content produce a corresponding alteration in lysozyme activity. With regard to red wine, a significant effect was noted in the presence of wine components. KW - lysozyme KW - red wine KW - total phenol content KW - colour KW - antioxidative capacity KW - lysozyme activity Y1 - 2006 SN - 0012-0413 VL - 102 IS - 10 SP - 472 EP - 478 PB - Behr CY - Stuttgart ER - TY - JOUR A1 - Lossow, Kristina A1 - Schwerdtle, Tanja A1 - Kipp, Anna Patricia T1 - Selen und Jod: essenzielle Spurenelemente für die Schilddrüse T1 - Selenium and iodine - essential trace elements for the thyroid JF - Ernährungs-Umschau : Forschung & Praxis N2 - Selen und Jod sind essenzielle Spurenelemente, die gemeinsam für eine optimale Funktionstüchtigkeit der Schilddrüse erforderlich sind. Der Mangel eines oder beider Elemente führt zu Verschiebungen auf Ebene der Schilddrüsenhormonproduktion mit weitreichenden Konsequenzen für Stoffwechselprozesse, neurologische Entwicklung und Erkrankungen. Auch bei Autoimmunerkrankungen der Schilddrüse spielt die Versorgung mit Jod und Selen eine wichtige Rolle. Als Biomarker für den Selenstatus eignet sich der Gehalt des Gesamtselens oder der des Selenoproteins P im Serum. Zur Bestimmung des Jodstatus wird in der Regel der Jodgehalt im Urin herangezogen. Um den Versorgungszustand an diesen und vier weiteren essenziellen Spurenelementen besser zu erfassen, charakterisiert die Forschungsgruppe TraceAge alters- und geschlechtsspezifische Spurenelementprofile und neue funktionelle Biomarker der einzelnen Spurenelemente. Außerdem sollen Interaktionen weiterer Spurenelemente genauer untersucht werden. N2 - Selenium and iodine are essential trace elements that work together to ensure that the thyroid functions optimally. A deficiency in one or both of these elements leads to fluctuations in thyroid hormone production, which have far-reaching consequences in terms of metabolic processes, neurological development, and disease. Iodine and selenium supply also play an important role in autoimmune diseases of the thyroid. Both the total selenium concentration in the serum and the concentration of selenoprotein P are suitable biomarkers for determining selenium status. Iodine concentration in the urine is the most commonly used method of determining iodine status. In order to improve assessment of supply status for these two essential trace elements plus an additional four, the TraceAge research group is identifying age- and sex-specific trace element profiles as well as new functional biomarkers for the individual trace elements. In addition, the research group will investigate interactions with other trace elements in more detail. KW - Selen KW - Jod KW - Schilddrüse KW - Schilddrüsenautoimmunerkrankungen KW - Selenoproteine KW - TraceAge Y1 - 2019 U6 - https://doi.org/10.4455/eu.2019.032 SN - 0174-0008 VL - 66 IS - 9 SP - M531 EP - M536 PB - Umschau-Zeitschriftenverl. CY - Frankfurt, Main ER - TY - JOUR A1 - Gancheva, Sofiya A1 - Ouni, Meriem A1 - Jelenik, Tomas A1 - Koliaki, Chrysi A1 - Szendroedi, Julia A1 - Toledo, Frederico G. S. A1 - Markgraf, Daniel Frank A1 - Pesta, Dominik H. A1 - Mastrototaro, Lucia A1 - De Filippo, Elisabetta A1 - Herder, Christian A1 - Jähnert, Markus A1 - Weiss, Jürgen A1 - Strassburger, Klaus A1 - Schlensak, Matthias A1 - Schürmann, Annette A1 - Roden, Michael T1 - Dynamic changes of muscle insulin sensitivity after metabolic surgery JF - Nature Communications N2 - The mechanisms underlying improved insulin sensitivity after surgically-induced weight loss are still unclear. We monitored skeletal muscle metabolism in obese individuals before and over 52 weeks after metabolic surgery. Initial weight loss occurs in parallel with a decrease in muscle oxidative capacity and respiratory control ratio. Persistent elevation of intramyocellular lipid intermediates, likely resulting from unrestrained adipose tissue lipolysis, accompanies the lack of rapid changes in insulin sensitivity. Simultaneously, alterations in skeletal muscle expression of genes involved in calcium/lipid metabolism and mitochondrial function associate with subsequent distinct DNA methylation patterns at 52 weeks after surgery. Thus, initial unfavorable metabolic changes including insulin resistance of adipose tissue and skeletal muscle precede epigenetic modifications of genes involved in muscle energy metabolism and the long-term improvement of insulin sensitivity. Y1 - 2019 U6 - https://doi.org/10.1038/s41467-019-12081-0 SN - 2041-1723 VL - 10 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Figueroa Campos, Gustavo A. A1 - Sagu Tchewonpi, Sorel A1 - Saravia Celis, Pedro A1 - Rawel, Harshadrai Manilal T1 - Comparison of batch and continuous wet-processing of coffee BT - changes in the main compounds in beans, by-products and wastewater JF - Foods N2 - Many technical challenges still need to be overcome to improve the quality of the green coffee beans. In this work, the wet Arabica coffee processing in batch and continuous modus were investigated. Coffee beans samples as well as by-products and wastewaters collected at different production steps were analyzed in terms of their content in total phenols, antioxidant capacity, caffeine content, organic acids, reducing sugars, free amino group and protein content. The results showed that 40% of caffeine was removed with pulp. Green coffee beans showed highest concentration of organic acids and sucrose (4.96 ± 0.25 and 5.07 ± 0.39 g/100 g DW for the batch and continuous processing). Batch green coffee beans contained higher amount of phenols. 5-caffeoylquinic Acid (5-CQA) was the main constituent (67.1 and 66.0% for the batch and continuous processing, respectively). Protein content was 15 and 13% in the green coffee bean in batch and continuous processing, respectively. A decrease of 50 to 64% for free amino groups during processing was observed resulting in final amounts of 0.8 to 1.4% in the processed beans. Finally, the batch processing still revealed by-products and wastewater with high nutrient content encouraging a better concept for valorization. KW - Arabica coffee beans KW - coffee by-products KW - batch process KW - continuous process KW - nutritional characteristics Y1 - 2020 U6 - https://doi.org/10.3390/foods9081135 SN - 2304-8158 VL - 9 IS - 8 PB - MDPI CY - Basel ER - TY - JOUR A1 - Quiclet, Charline A1 - Dittberner, Nicole A1 - Gaessler, Anneke A1 - Stadion, Mandy A1 - Gerst, Felicia A1 - Helms, Anett A1 - Baumeier, Christian A1 - Schulz, Tim Julius A1 - Schurmann, Annette T1 - Pancreatic adipocytes mediate hypersecretion of insulin in diabetes-susceptible mice JF - Metabolism - Clinical and experimental N2 - Objective: Ectopic fat accumulation in the pancreas in response to obesity and its implication on the onset of type 2 diabetes remain poorly understood. Intermittent fasting (IF) is known to improve glucose homeostasis and insulin resistance. However, the effects of IF on fat in the pancreas and beta-cell function remain largely unknown. Our aim was to evaluate the impact of IF on pancreatic fat accumulation and its effects on islet function. Methods: New Zealand Obese (NZO) mice were fed a high-fat diet ad libitum (NZO-AL) or fasted every other day (intermittent fasting, NZO-IF) and pancreatic fat accumulation, glucose homoeostasis, insulin sensitivity, and islet function were determined and compared to ad libitum-fed B6.V-Lep(ob/ob) (ob/ob) mice. To investigate the crosstalk of pancreatic adipocytes and islets, co-culture experiments were performed. Results: NZO-IF mice displayed better glucose homeostasis and lower fat accumulation in both the pancreas (-32%) and the liver (-35%) than NZO-AL mice. Ob/ob animals were insulin-resistant and had low fat in the pancreas but high fat in the liver. NZO-AL mice showed increased fat accumulation in both organs and exhibited an impaired islet function. Co-culture experiments demonstrated that pancreatic adipocytes induced a hypersecretion of insulin and released higher levels of free fatty adds than adipocytes of inguinal white adipose tissue. Conclusions: These results suggest that pancreatic fat participates in diabetes development, but can be prevented by IF. (C) 2019 Published by Elsevier Inc. Y1 - 2019 U6 - https://doi.org/10.1016/j.metabol.2019.05.005 SN - 0026-0495 SN - 1532-8600 VL - 97 SP - 9 EP - 17 PB - Elsevier CY - Philadelphia ER - TY - JOUR A1 - Abebe, Zeweter A1 - Haki, Gulelat Desse A1 - Schweigert, Florian J. A1 - Henkel, Ina M. A1 - Baye, Kaleab T1 - Low breastmilk vitamin A concentration is prevalent in rural Ethiopia JF - European journal of clinical nutrition N2 - Background There is scant information on the breastmilk vitamin A (BMVA) concentration of lactating women in developing countries, partly due to lack of methods applicable in-field. Objective To assess BMVA concentrations of samples collected from lactating women of children aged 6-23 months, in Mecha district, Ethiopia. Subjects/methods Data on socio-demographic and anthropometric characteristics were collected from randomly selected lactating women (n = 104). Breast milk samples were collected and vitamin A concentrations were analyzed using HPLC and iCheck FLUORO then the two measurements were compared. Results The prevalence of underweight (BMI < 18.5 kg/m(2)) among lactating women was 17%. Seventy six percent of the BMVA values were < 1.05 mu mol/l and 81% were < 8 mu g/g fat. The mean BMVA concentration accounted to 41% of the estimated average value for mothers in developing countries. The BMVA values from HPLC and iCheck were correlated (r = 0.59, p = < 0.001), but it was not strong. Conclusions The result indicates the low vitamin A status of the lactating women and their children. It further indicates that intake assessments should not use average BMVA composition. The possibility of using iCheck for monitoring interventions designed to improve vitamin A status of lactating women with low BMVA requires further investigation. Y1 - 2019 U6 - https://doi.org/10.1038/s41430-018-0334-4 SN - 0954-3007 SN - 1476-5640 VL - 73 IS - 8 SP - 1110 EP - 1116 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Franz, Kristina A1 - Otten, Lindsey A1 - Müller-Werdan, Ursula A1 - Döhner, Wolfram A1 - Norman, Kristina T1 - Severe Weight Loss and Its Association with Fatigue in Old Patients at Discharge from a Geriatric Hospital JF - Nutrients N2 - Although malnutrition is frequent in the old, little is known about its association with fatigue. We evaluated the relation of self-reported severe weight loss with fatigue and the predictors for fatigue in old patients at hospital discharge. Severe weight loss was defined according to involuntary weight loss >= 5% in the last three months. We determined fatigue with the validated Brief Fatigue Inventory questionnaire. The regression analyses were adjusted for age, sex, number of comorbidities, medications/day, and BMI. Of 424 patients aged between 61 and 98 y, 34.1% had severe weight loss. Fatigue was higher in patients with severe weight loss (3.7 +/- 2.3 vs. 3.2 +/- 2.3 points, p = 0.021). In a multinomial regression model, weight loss was independently associated with higher risk for moderate fatigue (OR:1.172, CI:1.026-1.338, p = 0.019) and with increased risk for severe fatigue (OR:1.209, CI:1.047-1.395, p = 0.010) together with the number of medications/day (OR:1.220, CI:1.023-1.455, p = 0.027). In a binary regression model, severe weight loss predicted moderate-to-severe fatigue in the study population (OR:1.651, CI:1.052-2.590, p = 0.029). In summary, patients with self-reported severe weight loss at hospital discharge exhibited higher fatigue levels and severe weight loss was an independent predictor of moderate and severe fatigue, placing these patients at risk for impaired outcome in the post-hospital period. KW - malnutrition KW - involuntary weight loss KW - post-hospital syndrome KW - fatigue KW - old adults Y1 - 2019 U6 - https://doi.org/10.3390/nu11102415 SN - 2072-6643 VL - 11 IS - 10 PB - MDPI CY - Basel ER - TY - JOUR A1 - Warrington, Nicole A1 - Beaumont, Robin A1 - Horikoshi, Momoko A1 - Day, Felix R. A1 - Helgeland, Øyvind A1 - Laurin, Charles A1 - Bacelis, Jonas A1 - Peng, Shouneng A1 - Hao, Ke A1 - Feenstra, Bjarke A1 - Wood, Andrew R. A1 - Mahajan, Anubha A1 - Tyrrell, Jessica A1 - Robertson, Neil R. A1 - Rayner, N. William A1 - Qiao, Zhen A1 - Moen, Gunn-Helen A1 - Vaudel, Marc A1 - Marsit, Carmen A1 - Chen, Jia A1 - Nodzenski, Michael A1 - Schnurr, Theresia M. A1 - Zafarmand, Mohammad Hadi A1 - Bradfield, Jonathan P. A1 - Grarup, Niels A1 - Kooijman, Marjolein N. A1 - Li-Gao, Ruifang A1 - Geller, Frank A1 - Ahluwalia, Tarunveer Singh A1 - Paternoster, Lavinia A1 - Rueedi, Rico A1 - Huikari, Ville A1 - Hottenga, Jouke-Jan A1 - Lyytikäinen, Leo-Pekka A1 - Cavadino, Alana A1 - Metrustry, Sarah A1 - Cousminer, Diana L. A1 - Wu, Ying A1 - Thiering, Elisabeth Paula A1 - Wang, Carol A. A1 - Have, Christian Theil A1 - Vilor-Tejedor, Natalia A1 - Joshi, Peter K. A1 - Painter, Jodie N. A1 - Ntalla, Ioanna A1 - Myhre, Ronny A1 - Pitkänen, Niina A1 - van Leeuwen, Elisabeth M. A1 - Joro, Raimo A1 - Lagou, Vasiliki A1 - Richmond, Rebecca C. A1 - Espinosa, Ana A1 - Barton, Sheila J. A1 - Inskip, Hazel M. A1 - Holloway, John W. A1 - Santa-Marina, Loreto A1 - Estivill, Xavier A1 - Ang, Wei A1 - Marsh, Julie A. A1 - Reichetzeder, Christoph A1 - Marullo, Letizia A1 - Hocher, Berthold A1 - Lunetta, Kathryn L. A1 - Murabito, Joanne M. A1 - Relton, Caroline L. A1 - Kogevinas, Manolis A1 - Chatzi, Leda A1 - Allard, Catherine A1 - Bouchard, Luigi A1 - Hivert, Marie-France A1 - Zhang, Ge A1 - Muglia, Louis J. A1 - Heikkinen, Jani A1 - Morgen, Camilla S. A1 - van Kampen, Antoine H. C. A1 - van Schaik, Barbera D. C. A1 - Mentch, Frank D. A1 - Langenberg, Claudia A1 - Scott, Robert A. A1 - Zhao, Jing Hua A1 - Hemani, Gibran A1 - Ring, Susan M. A1 - Bennett, Amanda J. A1 - Gaulton, Kyle J. A1 - Fernandez-Tajes, Juan A1 - van Zuydam, Natalie R. A1 - Medina-Gomez, Carolina A1 - de Haan, Hugoline G. A1 - Rosendaal, Frits R. A1 - Kutalik, Zoltán A1 - Marques-Vidal, Pedro A1 - Das, Shikta A1 - Willemsen, Gonneke A1 - Mbarek, Hamdi A1 - Müller-Nurasyid, Martina A1 - Standl, Marie A1 - Appel, Emil V. R. A1 - Fonvig, Cilius Esmann A1 - Trier, Caecilie A1 - van Beijsterveldt, Catharina E. M. A1 - Murcia, Mario A1 - Bustamante, Mariona A1 - Bonàs-Guarch, Sílvia A1 - Hougaard, David M. A1 - Mercader, Josep M. A1 - Linneberg, Allan A1 - Schraut, Katharina E. A1 - Lind, Penelope A. A1 - Medland, Sarah Elizabeth A1 - Shields, Beverley M. A1 - Knight, Bridget A. A1 - Chai, Jin-Fang A1 - Panoutsopoulou, Kalliope A1 - Bartels, Meike A1 - Sánchez, Friman A1 - Stokholm, Jakob A1 - Torrents, David A1 - Vinding, Rebecca K. A1 - Willems, Sara M. A1 - Atalay, Mustafa A1 - Chawes, Bo L. A1 - Kovacs, Peter A1 - Prokopenko, Inga A1 - Tuke, Marcus A. A1 - Yaghootkar, Hanieh A1 - Ruth, Katherine S. A1 - Jones, Samuel E. A1 - Loh, Po-Ru A1 - Murray, Anna A1 - Weedon, Michael N. A1 - Tönjes, Anke A1 - Stumvoll, Michael A1 - Michaelsen, Kim Fleischer A1 - Eloranta, Aino-Maija A1 - Lakka, Timo A. A1 - van Duijn, Cornelia M. A1 - Kiess, Wieland A1 - Koerner, Antje A1 - Niinikoski, Harri A1 - Pahkala, Katja A1 - Raitakari, Olli T. A1 - Jacobsson, Bo A1 - Zeggini, Eleftheria A1 - Dedoussis, George V. A1 - Teo, Yik-Ying A1 - Saw, Seang-Mei A1 - Montgomery, Grant W. A1 - Campbell, Harry A1 - Wilson, James F. A1 - Vrijkotte, Tanja G. M. A1 - Vrijheid, Martine A1 - de Geus, Eco J. C. N. A1 - Hayes, M. Geoffrey A1 - Kadarmideen, Haja N. A1 - Holm, Jens-Christian A1 - Beilin, Lawrence J. A1 - Pennell, Craig E. A1 - Heinrich, Joachim A1 - Adair, Linda S. A1 - Borja, Judith B. A1 - Mohlke, Karen L. A1 - Eriksson, Johan G. A1 - Widen, Elisabeth E. A1 - Hattersley, Andrew T. A1 - Spector, Tim D. A1 - Kaehoenen, Mika A1 - Viikari, Jorma S. A1 - Lehtimaeki, Terho A1 - Boomsma, Dorret I. A1 - Sebert, Sylvain A1 - Vollenweider, Peter A1 - Sorensen, Thorkild I. A. A1 - Bisgaard, Hans A1 - Bonnelykke, Klaus A1 - Murray, Jeffrey C. A1 - Melbye, Mads A1 - Nohr, Ellen A. A1 - Mook-Kanamori, Dennis O. A1 - Rivadeneira, Fernando A1 - Hofman, Albert A1 - Felix, Janine F. A1 - Jaddoe, Vincent W. V. A1 - Hansen, Torben A1 - Pisinger, Charlotta A1 - Vaag, Allan A. A1 - Pedersen, Oluf A1 - Uitterlinden, Andre G. A1 - Jarvelin, Marjo-Riitta A1 - Power, Christine A1 - Hypponen, Elina A1 - Scholtens, Denise M. A1 - Lowe, William L. A1 - Smith, George Davey A1 - Timpson, Nicholas J. A1 - Morris, Andrew P. A1 - Wareham, Nicholas J. A1 - Hakonarson, Hakon A1 - Grant, Struan F. A. A1 - Frayling, Timothy M. A1 - Lawlor, Debbie A. A1 - Njolstad, Pal R. A1 - Johansson, Stefan A1 - Ong, Ken K. A1 - McCarthy, Mark I. A1 - Perry, John R. B. A1 - Evans, David M. A1 - Freathy, Rachel M. T1 - Maternal and fetal genetic effects on birth weight and their relevance to cardio-metabolic risk factors JF - Nature genetics N2 - Birth weight variation is influenced by fetal and maternal genetic and non-genetic factors, and has been reproducibly associated with future cardio-metabolic health outcomes. In expanded genome-wide association analyses of own birth weight (n = 321,223) and offspring birth weight (n = 230,069 mothers), we identified 190 independent association signals (129 of which are novel). We used structural equation modeling to decompose the contributions of direct fetal and indirect maternal genetic effects, then applied Mendelian randomization to illuminate causal pathways. For example, both indirect maternal and direct fetal genetic effects drive the observational relationship between lower birth weight and higher later blood pressure: maternal blood pressure-raising alleles reduce offspring birth weight, but only direct fetal effects of these alleles, once inherited, increase later offspring blood pressure. Using maternal birth weight-lowering genotypes to proxy for an adverse intrauterine environment provided no evidence that it causally raises offspring blood pressure, indicating that the inverse birth weight-blood pressure association is attributable to genetic effects, and not to intrauterine programming. Y1 - 2019 SN - 1061-4036 SN - 1546-1718 VL - 51 IS - 5 SP - 804 EP - + PB - Nature Publ. Group CY - New York ER - TY - JOUR A1 - Jonas, Wenke A1 - Schürmann, Annette T1 - Genetic and epigenetic factors determining NAFLD risk JF - Molecular metabolism N2 - Background: Hepatic steatosis is a common chronic liver disease that can progress into more severe stages of NAFLD or promote the development of life-threatening secondary diseases for some of those affected. These include the liver itself (nonalcoholic steatohepatitis or NASH; fibrosis and cirrhosis, and hepatocellular carcinoma) or other organs such as the vessels and the heart (cardiovascular disease) or the islets of Langerhans (type 2 diabetes). In addition to elevated caloric intake and a sedentary lifestyle, genetic and epigenetic predisposition contribute to the development of NAFLD and the secondary diseases. Scope of review: We present data from genome-wide association studies (GWAS) and functional studies in rodents which describe polymorphisms identified in genes relevant for the disease as well as changes caused by altered DNA methylation and gene regulation via specific miRNAs. The review also provides information on the current status of the use of genetic and epigenetic factors as risk markers. Major conclusion: With our overview we provide an insight into the genetic and epigenetic landscape of NAFLD and argue about the applicability of currently defined risk scores for risk stratification and conclude that further efforts are needed to make the scores more usable and meaningful. KW - NAFLD KW - genetic variants KW - epigenetics KW - risk score Y1 - 2020 U6 - https://doi.org/10.1016/j.molmet.2020.101111 SN - 2212-8778 VL - 50 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Vogel, Heike A1 - Kamitz, Anne A1 - Hallahan, Nicole A1 - Lebek, Sandra A1 - Schallschmidt, Tanja A1 - Jonas, Wenke A1 - Jähnert, Markus A1 - Gottmann, Pascal A1 - Zellner, Lisa A1 - Kanzleiter, Timo A1 - Damen, Mareike A1 - Altenhofen, Delsi A1 - Burkhardt, Ralph A1 - Renner, Simone A1 - Dahlhoff, Maik A1 - Wolf, Eckhard A1 - Müller, Timo Dirk A1 - Blüher, Matthias A1 - Joost, Hans-Georg A1 - Chadt, Alexandra A1 - Al-Hasani, Hadi A1 - Schürmann, Annette T1 - A collective diabetes cross in combination with a computational framework to dissect the genetics of human obesity and Type 2 diabetes JF - Human molecular genetics N2 - To explore the genetic determinants of obesity and Type 2 diabetes (T2D), the German Center for Diabetes Research (DZD) conducted crossbreedings of the obese and diabetes-prone New Zealand Obese mouse strain with four different lean strains (B6, DBA, C3H, 129P2) that vary in their susceptibility to develop T2D. Genome-wide linkage analyses localized more than 290 quantitative trait loci (QTL) for obesity, 190 QTL for diabetes-related traits and 100 QTL for plasma metabolites in the out-cross populations. A computational framework was developed that allowed to refine critical regions and to nominate a small number of candidate genes by integrating reciprocal haplotype mapping and transcriptome data. The efficiency of the complex procedure was demonstrated for one obesity QTL. The genomic interval of 35 Mb with 502 annotated candidate genes was narrowed down to six candidates. Accordingly, congenic mice retained the obesity phenotype owing to an interval that contains three of the six candidate genes. Among these the phospholipase PLA2G4A exhibited an elevated expression in adipose tissue of obese human subjects and is therefore a critical regulator of the obesity locus. Together, our broad and complex approach demonstrates that combined- and comparative-cross analysis exhibits improved mapping resolution and represents a valid tool for the identification of disease genes. Y1 - 2018 U6 - https://doi.org/10.1093/hmg/ddy217 SN - 0964-6906 SN - 1460-2083 VL - 27 IS - 17 SP - 3099 EP - 3112 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Gao, Lin-rui A1 - Wang, Guang A1 - Zhang, Jing A1 - Li, Shuai A1 - Chuai, Manli A1 - Bao, Yongping A1 - Hocher, Berthold A1 - Yang, Xuesong T1 - High salt-induced excess reactive oxygen species production resulted in heart tube malformation during gastrulation JF - Journal of Cellular Physiology N2 - An association has been proved between high salt consumption and cardiovascular mortality. In vertebrates, the heart is the first functional organ to be formed. However, it is not clear whether high-salt exposure has an adverse impact on cardiogenesis. Here we report high-salt exposure inhibited basement membrane breakdown by affecting RhoA, thus disturbing the expression of Slug/E-cadherin/N-cadherin/Laminin and interfering with mesoderm formation during the epithelial-mesenchymal transition(EMT). Furthermore, the DiI(+) cell migration trajectory in vivo and scratch wound assays in vitro indicated that high-salt exposure restricted cell migration of cardiac progenitors, which was caused by the weaker cytoskeleton structure and unaltered corresponding adhesion junctions at HH7. Besides, down-regulation of GATA4/5/6, Nkx2.5, TBX5, and Mef2c and up-regulation of Wnt3a/-catenin caused aberrant cardiomyocyte differentiation at HH7 and HH10. High-salt exposure also inhibited cell proliferation and promoted apoptosis. Most importantly, our study revealed that excessive reactive oxygen species(ROS)generated by high salt disturbed the expression of cardiac-related genes, detrimentally affecting the above process including EMT, cell migration, differentiation, cell proliferation and apoptosis, which is the major cause of malformation of heart tubes. KW - cardiac progenitor migration and differentiation KW - chick embryo KW - heart tube KW - high salt KW - reactive oxygen species Y1 - 2018 U6 - https://doi.org/10.1002/jcp.26528 SN - 0021-9541 SN - 1097-4652 VL - 233 IS - 9 SP - 7120 EP - 7133 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Krstic, Jelena A1 - Reinisch, Isabel A1 - Schupp, Michael A1 - Schulz, Tim Julius A1 - Prokesch, Andreas T1 - p53 functions in adipose tissue metabolism and homeostasis JF - International journal of molecular sciences N2 - As a tumor suppressor and the most frequently mutated gene in cancer, p53 is among the best-described molecules in medical research. As cancer is in most cases an age-related disease, it seems paradoxical that p53 is so strongly conserved from early multicellular organisms to humans. A function not directly related to tumor suppression, such as the regulation of metabolism in nontransformed cells, could explain this selective pressure. While this role of p53 in cellular metabolism is gradually emerging, it is imperative to dissect the tissue-and cell-specific actions of p53 and its downstream signaling pathways. In this review, we focus on studies reporting p53's impact on adipocyte development, function, and maintenance, as well as the causes and consequences of altered p53 levels in white and brown adipose tissue (AT) with respect to systemic energy homeostasis. While whole body p53 knockout mice gain less weight and fat mass under a high-fat diet owing to increased energy expenditure, modifying p53 expression specifically in adipocytes yields more refined insights: (1) p53 is a negative regulator of in vitro adipogenesis; (2) p53 levels in white AT are increased in diet-induced and genetic obesity mouse models and in obese humans; (3) functionally, elevated p53 in white AT increases senescence and chronic inflammation, aggravating systemic insulin resistance; (4) p53 is not required for normal development of brown AT; and (5) when p53 is activated in brown AT in mice fed a high-fat diet, it increases brown AT temperature and brown AT marker gene expression, thereby contributing to reduced fat mass accumulation. In addition, p53 is increasingly being recognized as crucial player in nutrient sensing pathways. Hence, despite existence of contradictory findings and a varying density of evidence, several functions of p53 in adipocytes and ATs have been emerging, positioning p53 as an essential regulatory hub in ATs. Future studies need to make use of more sophisticated in vivo model systems and should identify an AT-specific set of p53 target genes and downstream pathways upon different (nutrient) challenges to identify novel therapeutic targets to curb metabolic diseases KW - p53 KW - adipose tissue KW - metabolic syndrome KW - obesity KW - adipogenesis KW - insulin resistance Y1 - 2018 U6 - https://doi.org/10.3390/ijms19092622 SN - 1422-0067 VL - 19 IS - 9 PB - MDPI CY - Basel ER - TY - GEN A1 - Jamnok, Jutatip A1 - Sanchaisuriya, Kanokwan A1 - Yamsri, Supawadee A1 - Fucharoen, Goonnapa A1 - Fucharoen, Supan A1 - Schweigert, Florian J. A1 - Sanchaisuriya, Pattara T1 - Application of a new portable nephelometer for screening thalassemia in countries with limited resources T2 - International Journal of Laboratory Hematology Y1 - 2018 SN - 1751-5521 SN - 1751-553X VL - 40 SP - 62 EP - 62 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Karuwanarint, Piyaporn A1 - Phonrat, Benjaluck A1 - Tungtrongchitr, Anchalee A1 - Suriyaprom, Kanjana A1 - Chuengsamarn, Somlak A1 - Schweigert, Florian J. A1 - Tungtrongchitr, Rungsunn T1 - Vitamin D-binding protein and its polymorphisms as a predictor for metabolic syndrome JF - Biomarkers in medicine N2 - Aim: To investigate the relationship of vitamin D-binding protein (GC) and genetic variation of GC (rs4588, rs7041 and rs2282679) with metabolic syndrome (MetS) in the Thai population. Materials & methods: GCglobulin concentrations were measured by quantitative western blot analysis in 401 adults. All participants were genotyped using TaqMan allelic discrimination assays. Results: GC-globulin levels were significatly lower in MetS subjects than in control subjects, in which significant negative correlations of GC-globulin levels with systolic blood pressure, glucose and age were found. Male participants who carried the GT genotype for rs4588 showed an increased risk of MetS compared with the GG wild-type (odds ratio: 3.25; p = 0.004). Conclusion: GC-globulin concentrations and variation in GC rs4588 were supported as a risk factor for MetS in Thais. KW - GC gene KW - GC-globulin KW - metabolic syndrome KW - polymorphism KW - Thai population KW - vitamin D-binding protein Y1 - 2018 U6 - https://doi.org/10.2217/bmm-2018-0029 SN - 1752-0363 SN - 1752-0371 VL - 12 IS - 5 SP - 465 EP - 473 PB - Future Medicine CY - London ER - TY - JOUR A1 - Erbersdobler, Helmut F. A1 - Barth, Christian A. A1 - Jahreis, Gerhard T1 - Körnerleguminosen in der Humanernährung T1 - Grain Legumes in Human Nutrition Nutrient BT - Nährstoffgehalt und Proteinqualität von Hülsenfrüchten BT - Nutrient Content and Protein Quality of Pulses JF - Ernährungs-Umschau : Forschung & Praxis N2 - Fortsetzung aus Ernährungs Umschau Heft 9/2017 Fettsäurenverteilung Die Gehalte an den wichtigsten Fettsäuren (FS) sind in • Tabelle 4 und 5 aufgeführt, in g/100 g sowie in Prozent des Fettanteils (Etherextrakt bzw. g FS-Methylester pro 100 g der Summe der FS-Methylester). Erbsen und Ackerbohnen spielen als Fett- und FS-Quelle praktisch keine Rolle. Sojabohnen sind eine wesentliche Quelle für Linolsäure, die häufigste n-6-FS. An zweiter Stelle steht die Ölsäure. Aber auch der Gehalt an der n-3-FS α-Linolensäure (ALA) ist hoch, womit sich Sojaöl in die Reihe der Fette mit mittlerem ALA-Gehalt, wie Raps- und Walnussöl einreiht. Im Gegensatz zu Rapsöl entspricht jedoch das Linolsäure/α-Linolensäure- Verhältnis nicht dem empfohlenen Verhältnis von 5:1 in der Gesamt- Diät [13]. Zum Ausgleich für die Fette aus der übrigen Nahrung (Getreide, Lebensmittel tierischer Herkunft) sollten Pflanzenöle besser noch ein engeres Verhältnis als 5:1 aufweisen. Das trifft für Lupinen-Öl schon eher zu, wenngleich der absolute Beitrag an ALA hier eher gering ist. N2 - Continuation from Ernährungs Umschau issue 9/2017 Fatty acid distribution The levels of the most important fatty acids are listed in • Table 4 and 5 in g/100 g, and as a percentage of fat (ether extract or g of fatty acid methyl ester per 100 g of the sum of the fatty acid methylesters). Peas and faba beans provide almost no fats. Soybeans are a good source of linoleic acid, the most common n-6 fatty acid followed by oleic acid. However, the level of the n-3 fatty acid α-linolenic acid (ALA) is also high, which puts soybean oil in the category of fats with medium ALA content, along with oils such as rapeseed oil and walnut oil. However, unlike rapeseed oil, the ratio of linoleic acid to α-linolenic acid is not the recommended ratio for the overall diet of 5:1 [13]. In order to balance out the fats from the rest of the diet (cereals, foods of animal origin), vegetable oils should ideally have a ratio even better than 5:1. Lupine oil has such a ratio, although its absolute ALA content is rather low. Y1 - 2017 UR - https://www.ernaehrungs-umschau.de/fileadmin/Ernaehrungs-Umschau/pdfs/pdf_2017/10_17/EU10_2017_WuF_Erbersdobler_englisch.pdf U6 - https://doi.org/10.4455.eu.2017.034 SN - 0174-0008 VL - 64 IS - 10 SP - 140 EP - 144 PB - Umschau-Zeitschriftenverl. CY - Frankfurt, Main ER - TY - GEN A1 - Hocher, Berthold A1 - Zeng, Shufei T1 - Clear the fog around parathyroid hormone assays BT - what do iPTH assays really measure? T2 - Clinical journal of the American Society of Nephrology KW - Assays KW - Biological Assay KW - CKD KW - oxidative stress KW - PTH Y1 - 2018 U6 - https://doi.org/10.2215/CJN.01730218 SN - 1555-9041 SN - 1555-905X VL - 13 IS - 4 SP - 524 EP - 526 PB - American Society of Nephrology CY - Washington ER - TY - JOUR A1 - Prommer, Hans-Ulrich A1 - Maurer, Johannes A1 - von Websky, Karoline A1 - Freise, Christian A1 - Sommer, Kerstin A1 - Nasser, Hamoud A1 - Samapati, Rudi A1 - Reglin, Bettina A1 - Guimaraes, Pedro A1 - Pries, Axel Radlach A1 - Querfeld, Uwe T1 - Chronic kidney disease induces a systemic microangiopathy, tissue hypoxia and dysfunctional angiogenesis JF - Scientific reports N2 - Chronic kidney disease (CKD) is associated with excessive mortality from cardiovascular disease (CVD). Endothelial dysfunction, an early manifestation of CVD, is consistently observed in CKD patients and might be linked to structural defects of the microcirculation including microvascular rarefaction. However, patterns of microvascular rarefaction in CKD and their relation to functional deficits in perfusion and oxygen delivery are currently unknown. In this in-vivo microscopy study of the cremaster muscle microcirculation in BALB/c mice with moderate to severe uremia, we show in two experimental models (adenine feeding or subtotal nephrectomy), that serum urea levels associate incrementally with a distinct microangiopathy. Structural changes were characterized by a heterogeneous pattern of focal microvascular rarefaction with loss of coherent microvascular networks resulting in large avascular areas. Corresponding microvascular dysfunction was evident by significantly diminished blood flow velocity, vascular tone, and oxygen uptake. Microvascular rarefaction in the cremaster muscle paralleled rarefaction in the myocardium, which was accompanied by a decrease in transcription levels not only of the transcriptional regulator HIF-1 alpha, but also of its target genes Angpt-2, TIE-1 and TIE-2, Flkt-1 and MMP-9, indicating an impaired hypoxia-driven angiogenesis. Thus, experimental uremia in mice associates with systemic microvascular disease with rarefaction, tissue hypoxia and dysfunctional angiogenesis. Y1 - 2018 U6 - https://doi.org/10.1038/s41598-018-23663-1 SN - 2045-2322 VL - 8 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Krstic, Jelena A1 - Galhuber, Markus A1 - Schulz, Tim Julius A1 - Schupp, Michael A1 - Prokesch, Andreas T1 - p53 as a dichotomous regulator of liver disease BT - the dose makes the medicine JF - International journal of molecular sciences N2 - Lifestyle-related disorders, such as the metabolic syndrome, have become a primary risk factor for the development of liver pathologies that can progress from hepatic steatosis, hepatic insulin resistance, steatohepatitis, fibrosis and cirrhosis, to the most severe condition of hepatocellular carcinoma (HCC). While the prevalence of liver pathologies is steadily increasing in modern societies, there are currently no approved drugs other than chemotherapeutic intervention in late stage HCC. Hence, there is a pressing need to identify and investigate causative molecular pathways that can yield new therapeutic avenues. The transcription factor p53 is well established as a tumor suppressor and has recently been described as a central metabolic player both in physiological and pathological settings. Given that liver is a dynamic tissue with direct exposition to ingested nutrients, hepatic p53, by integrating cellular stress response, metabolism and cell cycle regulation, has emerged as an important regulator of liver homeostasis and dysfunction. The underlying evidence is reviewed herein, with a focus on clinical data and animal studies that highlight a direct influence of p53 activity on different stages of liver diseases. Based on current literature showing that activation of p53 signaling can either attenuate or fuel liver disease, we herein discuss the hypothesis that, while hyper-activation or loss of function can cause disease, moderate induction of hepatic p53 within physiological margins could be beneficial in the prevention and treatment of liver pathologies. Hence, stimuli that lead to a moderate and temporary p53 activation could present new therapeutic approaches through several entry points in the cascade from hepatic steatosis to HCC. KW - p53 KW - liver disease KW - insulin resistance KW - non-alcoholic fatty liver disease KW - non-alcoholic steatohepatitis KW - hepatocellular carcinoma KW - liver regeneration KW - mouse models Y1 - 2018 U6 - https://doi.org/10.3390/ijms19030921 SN - 1422-0067 VL - 19 IS - 3 PB - MDPI CY - Basel ER - TY - GEN A1 - Reichetzeder, Christoph A1 - Hocher, Berthold T1 - DPP4 inhibition prevents AKI T2 - Oncotarget KW - acute kidney injury KW - DPP-4 inhibitors KW - ischemia reperfusion injury KW - gliptins KW - Dipeptidyl peptidase IV Y1 - 2017 U6 - https://doi.org/10.18632/oncotarget.20212 SN - 1949-2553 VL - 8 SP - 64655 EP - 64656 PB - Impact Journals LLC CY - Orchard Park ER - TY - JOUR A1 - Kleuser, Burkhard T1 - Divergent role of sphingosine 1-phosphate in liver health and disease JF - International journal of molecular sciences N2 - Two decades ago, sphingosine 1-phosphate (S1P) was discovered as a novel bioactive molecule that regulates a variety of cellular functions. The plethora of S1P-mediated effects is due to the fact that the sphingolipid not only modulates intracellular functions but also acts as a ligand of G protein-coupled receptors after secretion into the extracellular environment. In the plasma, S1P is found in high concentrations, modulating immune cell trafficking and vascular endothelial integrity. The liver is engaged in modulating the plasma S1P content, as it produces apolipoprotein M, which is a chaperone for the S1P transport. Moreover, the liver plays a substantial role in glucose and lipid homeostasis. A dysfunction of glucose and lipid metabolism is connected with the development of liver diseases such as hepatic insulin resistance, non-alcoholic fatty liver disease, or liver fibrosis. Recent studies indicate that S1P is involved in liver pathophysiology and contributes to the development of liver diseases. In this review, the current state of knowledge about S1P and its signaling in the liver is summarized with a specific focus on the dysregulation of S1P signaling in obesity-mediated liver diseases. Thus, the modulation of S1P signaling can be considered as a potential therapeutic target for the treatment of hepatic diseases. KW - sphingolipids KW - sphingosine kinase KW - fibrosis KW - non-alcoholic fatty liver disease KW - insulin resistance KW - liver fibrosis Y1 - 2018 U6 - https://doi.org/10.3390/ijms19030722 SN - 1422-0067 VL - 19 IS - 3 PB - MDPI CY - Basel ER - TY - THES A1 - Henkel, Janin T1 - Modulation der Insulin-abhängigen Regulation des hepatischen Glucose- und Lipidmetabolismus durch Prostaglandin E2 Y1 - 2010 CY - Potsdam 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 - THES A1 - Geisendörfer, Birte T1 - Autologer Ansatz zur Entwicklung von 2D- und 3D-Kokultivierungsmethoden für die Bestimmung des sensibilisierenden Potenzials von Xenobiotika N2 - Die allergische Kontaktdermatitis ist eine immunologisch bedingte Hauterkrankung mit insbesondere in den westlichen Industrienationen hoher und weiter ansteigender Prävalenz. Es handelt sich hierbei um eine Hypersensitivitätsreaktion vom Typ IV, die sich nach Allergenkontakt durch Juckreiz, Rötung, Bläschenbildung und Abschälung der Haut äußert. Zahlreiche Xenobiotika besitzen das Potenzial, Kontaktallergien auszulösen, darunter Konservierungsstoffe, Medikamente, Duftstoffe und Chemikalien. Die wirksamste Maßnahme zur Eindämmung der Erkrankung ist die Expositionsprophylaxe, also die Vermeidung des Kontakts mit den entsprechenden Substanzen. Dies wiederum setzt die Kenntnis des jeweiligen sensibilisierenden Potenzials einer Substanz voraus, dessen Bestimmung aus diesem Grund eine hohe toxikologische Relevanz besitzt. Zu diesem Zweck existieren von der OECD veröffentlichte Testleitlinien, welche auf entsprechend validierten Testmethoden basieren. Goldstandard bei der Prüfung auf hautsensibilisierendes Potenzial war über lange Zeit der murine Lokale Lymphknotentest. Seit der 7. Änderung der EU-Kosmetikrichtlinie, welche Tierversuche für Kosmetika und deren Inhaltsstoffe untersagt, wurden vermehrt Alternativmethoden in die OECD-Testleitlinien implementiert.. Die bestehenden in vitro Methoden sind jedoch alleinstehend nur begrenzt aussagekräftig, da sie lediglich singuläre Mechanismen bei der Entstehung einer Kontaktallergie abbilden. Die Entwicklung von Testmethoden, welche mehrere dieser Schlüsselereignisse berücksichtigen, erscheint daher richtungsweisend. Einen vielversprechenden Ansatz liefert hierbei der Loose-fit coculture-based sensitisation assay (LCSA), welcher eine Kokultur aus primären Keratinozyten und PBMC darstellt. Bei der Kokultivierung von Immunzellen mit anderen Zelltypen stellt sich allerdings die Frage, inwiefern die Nutzung von Zellen derselben Spender*innen (autologe Kokultur) bzw. verschiedener Spender*innen (allogene Kokultur) einen Einfluss nimmt. Zu diesem Zweck wurden im Rahmen dieser Arbeit Hautzellen spenderspezifisch aus gezupften Haarfollikeln isoliert und der LCSA mit den generierten HFDK in autologen und allogenen Ansätzen verglichen. Zusätzlich wurde auch ein Vergleich zwischen der Nutzung von HFDK und NHK, welche aus humaner Vorhaut isoliert wurden, im LCSA durchgeführt. Dabei ergaben sich keine signifikanten Unterschiede zwischen autologen und allogenen Kokulturen bzw. zwischen der Verwendung von HFDK und NHK. Die Verwendung allogener Zellen aus anonymem Spendermaterial sowie die Nutzung von Keratinozyten aus unterschiedlichen Quellen scheint im Rahmen des LCSA problemlos möglich. Einige der getesteten Kontaktallergene, darunter DNCB und NiCl2, erwiesen sich im LCSA jedoch als problematisch und konnten nicht zufriedenstellend als sensibilisierend detektiert werden. Daher wurde eine Optimierung der Kokultur durch Verwendung ex vivo differenzierter Langerhans Zellen (MoLC) angestrebt, welche ein besseres Modell primärer epidermaler Langerhans Zellen darstellen als die dendritischen Zellen aus dem LCSA. Zusätzlich wurden weitere, den Erfolg der Kokultur beeinflussende Faktoren, wie die Art und Zusammensetzung des Mediums und die Kokultivierungsdauer, untersucht und angepasst. Das schlussendlich etablierte Kokultivierungsprotokoll führte zu einer maßgeblich verstärkten Expression von CD207 (Langerin) auf den MoLC, was auf eine wirkungsvolle Interaktion zwischen Haut- und Immunzellen in der Kokultur hindeutete. Des Weiteren konnten DNCB und NiCl2 im Gegensatz zum LCSA durch Verwendung des kostimulatorischen Moleküls CD86 sowie des Reifungsmarkers CD83 als Ausleseparameter eindeutig als Kontaktallergene identifiziert werden. Die Untersuchungen zur Kokultur von MoLC und HFDK wurden jeweils vergleichend in autologen und allogenen Ansätzen durchgeführt. Ähnlich wie beim LCSA kam es aber auch hier zu keinen signifikanten Unterschieden, weder hinsichtlich der Expression von Charakterisierungs- und Aktivierungsmarkern auf MoLC noch hinsichtlich der Zytokinsekretion in den Zellkulturüberstand. Die Hinweise aus zahlreichen Studien im Mausmodell, dass Zellen des angeborenen Immunsystems zur Erkennung von und Aktivierung durch allogene Zellen bzw. Gewebe in der Lage sind, bestätigten sich im Rahmen dieser Arbeit dementsprechend nicht. Aus diesem Grund wurden abschließend CD4+ T-Lymphozyten, die Effektorzellen des adaptiven Immunsystems, in die Kokultur aus MoLC und autologen bzw. allogenen HFDK integriert. Überraschenderweise traten auch hier keine verstärkten Aktivierungen in allogener Kokultur im Vergleich zur autologen Kokultur auf. Die Nutzung autologer Primärzellen scheint im Rahmen der hier getesteten Methoden nicht notwendig zu sein, was die Validierung von Kokulturen und deren Implementierung in die OECD-Testleitlinien erleichtern dürfte. Zuletzt wurde eine Kokultivierung primärer Haut- und Immunzellen auch im 3D-Vollhautmodell durchgeführt, wobei autologe MoLC in die Epidermisäquivalente entsprechender Modelle integriert werden sollten. Obwohl die erstellten Hautmodelle unter Verwendung autologer Haarfollikel-generierter Keratinozyten und Fibroblasten eine zufriedenstellende Differenzierung und Stratifizierung aufwiesen, gestaltete sich die Inkorporation der MoLC als problematisch und konnte im Rahmen dieser Arbeit nicht erreicht werden. KW - Kontaktallergie KW - Langerhans Zellen KW - Alternativmethoden KW - Kokultur KW - Hautmodell Y1 - 2022 ER - TY - THES A1 - Vogel, Heike T1 - Genetics of obesity and type 2 diabetes N2 - By using mouse outcross populations in combination with bioinformatic approaches, it was possible to identify and characterize novel genes regulating body weight, fat mass and β-cell function, which all contribute to the pathogenesis of obesity and T2D. In detail, the presented studies identified 1. Ifi202b/IFI16 as adipogenic gene involved in adipocyte commitment, maintenance of white adipocyte identity, fat cell size and the inflammatory state of adipose tissue. 2. Pla2g4a/PLA2G4A as gene linked to increased body weight and fat mass with a higher expression in adipose tissue of obese mice and pigs as well as in obese human subjects. 3. Ifgga2/IRGM as novel regulator of lipophagy protecting from excess hepatic lipid accumulation. 4. Nidd/DBA as a diabetogenic locus containing Kti12, Osbpl9, Ttc39a and Calr4 with differential expression in pancreatic islets and/or genetic variants. 5. miR-31 to be higher expressed in adipose tissue of obese and diabetic mice and humans targeting PPARy and GLUT4 and thereby involved in adipogenesis and insulin signaling. 6. Gjb4 as novel gene triggering the development of T2D by reducing insulin secretion, inducing apoptosis and inhibiting proliferation. The performed studies confirmed the complexity and strong genetic heritability character of obesity and T2D. A high number of genetic variations, each with a small effect, are collectively influencing the degree and severity of the disease. The use of mouse outcross populations is a valid tool for disease gene identification; however, to facilitate and accelerate the process of gene identification the combination of mouse cross data with advanced sequencing resources and the publicly available data sets are essential. The main goal for future studies should be the translation of these novel molecular discoveries to useful treatment therapies. More recently, several classes of novel unimolecular combination therapeutics have emerged with superior efficacy than currently prescribed options and pose the potential to reverse obesity and T2D (Finan et al., 2015). The glucagon-like peptide-1 (GLP-1)- estrogen conjugate, which targets estrogen into cells expressing GLP-1 receptors, was shown to improve energy, glucose and lipid metabolism as well as to reduce food reward (Finan et al., 2012; Schwenk et al., 2014; Vogel et al., 2016). Another possibility is the development of miRNA-based therapeutics to prevent obesity and T2D, such as miRNA mimetics, anti-miRNA oligonucleotides and exosomes loaded with miRNAs (Ji and Guo, 2019; Gottmann et al., 2020). As already described, genome-wide association studies for polygenic obesity and T2D traits in humans have also led to the identification of numerous gene variants with modest effect, most of them having an unknown function (Yazdi et al., 2015). These discoveries resulted in novel animal models and have illuminated new biologic pathways. Therefore, the integration of mouse-human genetic approaches and the utilization of the synergistic effects have the potential to lead to the identification of more genes responsible for common Mendelian forms of obesity and T2D, as well as gene × gene and gene × environment interactions (Yazdi et al., 2015; Ingelsson and McCarthy, 2018). This combination may help to unravel the missing heritability of obesity and T2D, to identify novel drug targets and to design more efficient and personalized obesity prevention and management programs. Y1 - 2021 CY - Potsdam ER - TY - THES A1 - Finke, Hannah T1 - Toxicological Characterization of Arsenolipids in vitro and Analysis of Global DNA (Hydroxy)methylation in the Context of Aging, Trace Element Status, and Genomic Stability Y1 - 2020 ER - TY - JOUR A1 - Epp, Laura Saskia A1 - Stoof-Leichsenring, Kathleen Rosemarie A1 - Trauth, Martin H. A1 - Tiedemann, Ralph T1 - Molecular profiling of diatom assemblages in tropical lake sediments using taxon-specific PCR and Denaturing High-Performance Liquid Chromatography (PCR-DHPLC) JF - Molecular ecology resources N2 - Here we present a protocol to genetically detect diatoms in sediments of the Kenyan tropical Lake Naivasha, based on taxon-specific PCR amplification of short fragments (approximately 100 bp) of the small subunit ribosomal (SSU) gene and subsequent separation of species-specific PCR products by PCR-based denaturing high-performance liquid chromatography (DHPLC). An evaluation of amplicons differing in primer specificity to diatoms and length of the fragments amplified demonstrated that the number of different diatom sequence types detected after cloning of the PCR products critically depended on the specificity of the primers to diatoms and the length of the amplified fragments whereby shorter fragments yielded more species of diatoms. The DHPLC was able to discriminate between very short amplicons based on the sequence difference, even if the fragments were of identical length and if the amplicons differed only in a small number of nucleotides. Generally, the method identified the dominant sequence types from mixed amplifications. A comparison with microscopic analysis of the sediment samples revealed that the sequence types identified in the molecular assessment corresponded well with the most dominant species. In summary, the PCR-based DHPLC protocol offers a fast, reliable and cost-efficient possibility to study DNA from sediments and other environmental samples with unknown organismic content, even for very short DNA fragments. KW - diatoms KW - environmental DNA KW - lake sediments KW - PCR-DHPLC Y1 - 2011 U6 - https://doi.org/10.1111/j.1755-0998.2011.03022.x SN - 1755-098X VL - 11 IS - 5 SP - 842 EP - 853 PB - Wiley-Blackwell CY - Hoboken ER - TY - THES A1 - Schatz, Daniela T1 - LNA-clamp-PCR zum sensitiven Nachweis von Punktmutationen im Rahmen der Entwicklung eines Darmkrebsfrüherkennungstests T1 - LNA-clamp-PCR as a method for sensitive detection of point mutations as part of the development of an assay for the early diagnosis of colon cancer N2 - Darmkrebs ist die zweithäufigste malignombedingte Todesursache in den westlichen Industrieländern. Durch eine frühzeitige Diagnose besteht jedoch eine hohe Chance auf Heilung. Der Goldstandard zur Darmkrebsfrüherkennung ist gegenwärtig die Koloskopie. Eine Darmspiegelung ist jedoch invasiv und mit Unannehmlichkeiten für den Patienten verbunden. Die Akzeptanz in der Bevölkerung ist daher gering. Ziel des BMBF- Projektes „Entwicklung eines nichtinvasiven Nachweissystems zur Früherkennung von humanem Darmkrebs“, in dessen Rahmen diese Arbeit entstand, ist die Bereitstellung eines nichtinvasiven Nachweisverfahrens zur Darmkrebsfrüherkennung. Der Nachweis soll über die Detektion von aus neoplastischen Zellen stammender DNA in Stuhl erfolgen. Die Entartung dieser Zellen beruht auf Veränderungen im Erbgut, welches unter anderem Mutationen sind. Im ersten Teil des BMBF-Projektes wurde ein Set von Mutationen zusammengestellt, welches eine hohe Sensitivität für Vorstufen von Darmkrebs aufweist. Ziel dieser Arbeit war es, eine Nachweismethode für die zuvor identifizierten Punktmutationen zu entwickeln. Das Nachweisverfahren musste dabei unempfindlich gegen einen hohen Hintergrund nichtmutierter DNA sein, da im Stuhl geringe Mengen DNA aus neoplastischen Zellen bei einem hohen Hintergrund von DNA aus gesunden Zellen vorliegen. Hierzu wurden Plasmidmodellsysteme für die aus dem Marker-Set stammenden Genfragmente BRAF und dessen Mutante V600E, CTNNB1 und T41I, T41A, S45P und K-ras G12C hergestellt. Mit Hilfe dieser Plasmidmodellsysteme wurde dann das Nachweissystem entwickelt. Der entscheidende Schritt für die Detektion von Punktmutationen bei hohem Wildtypüberschuss ist eine vorhergehende Anreicherung. In der vorliegenden Arbeit wurde dazu die Methode der LNA-clamp-PCR (locked nucleic acid) etabliert. Die Bewertung der erzielten Anreicherung erfolgte über das relative Detektionslimit. Zur Bestimmung des Detektionslimits wurde die Schmelzkurvenanalyse von Hybridisierungssonden eingesetzt; diese wurde im Rahmen dieser Arbeit für die drei oben genannten Genfragmente und ihre Mutanten entwickelt. Die LNA-clamp-PCR wird in Anwesenheit eines LNA-Blockers durchgeführt. Das Nukleotidanalogon LNA weist im Vergleich zu DNA eine erhöhte Affinität zu komplementären DNA-Strängen auf. Gleichzeitig kommt es bei Anwesenheit einer Basenfehlpaarung zu einer größeren Destabilisierung der Bindung. Als Blocker werden kurze LNA-DNA-Hybridoligonukleotide eingesetzt, die den mutierten Sequenzbereich überspannen und selbst der Wildtypsequenz entsprechen. Durch Bindung an die Wildtypsequenz wird deren Amplifikation während der PCR verhindert (clamp = arretieren, festklemmen). Der Blocker selbst wird dabei nicht verlängert. Der Blocker bindet unter optimalen Bedingungen jedoch nicht an die mutierte Sequenz. Die Mutante wird daher ungehindert amplifiziert und somit gegenüber dem Wildtyp-Fragment angereichert. Die Position des Blockers kann im Bindungsbereich eines der Primer sein und hier dessen Hybridisierung an dem Wildtyp-Fragment verhindern oder zwischen den beiden Primern liegen und so die Synthese durch die Polymerase inhibieren. Die Anwendbarkeit beider Systeme wurde in dieser Arbeit gezeigt. Die LNA-clamp-PCR mit Primerblocker wurde für BRAF etabliert. Es wurde ein Detektionslimit von mindestens 1:100 erzielt. Die LNA-clamp-PCR mit Amplifikationsblocker wurde erfolgreich für BRAF, K-ras und CTNNB1: T41I, T41A mit einem Detektionslimit von 1:1000 bis 1:10 000 entwickelt. In Stuhlproben liegt DNA aus neoplastischen Zellen nach Literaturangaben zu einem Anteil von 1% bis 0,1% vor. Die LNA-clamp-PCR weist also mit Amplifikationsblockern ein ausreichend hohes Detektionslimit für die Analyse von Stuhlproben auf. Durch die erfolgreiche Etablierung der Methode auf drei verschiedenen Genfragmenten und vier unterschiedlichen Punktmutationen konnte deren universelle Einsetzbarkeit gezeigt werden. Für die Ausweitung der LNA-clamp-PCR auf die übrigen Mutationen des Marker-Sets wurden Richtlinien ausgearbeitet und die Blockereffizienz als Kennzahl eingeführt. Die LNA-clamp-PCR ist ein schnelles, kostengünstiges Verfahren, welches einen geringen Arbeitsaufwand erfordert und wenig fehleranfällig ist. Sie ist somit ein geeignetes Anreicherungsverfahren für Punktmutationen in einem diagnostischen System zur Darmkrebsfrüherkennung. Darüber hinaus kann die LNA-clamp-PCR auch in anderen Bereichen, in denen die Detektion von Punktmutationen in einem hohen Wildtyphintergrund erforderlich ist, eingesetzt werden. N2 - Colon cancer is the second leading cause of cancer related deaths in the western world. However if diagnosed early there is a great chance curing the disease. Coloscopy is the gold standard for early detection of colorectal cancer today. Its greatest disadvantage is the fact that it is an invasive technique and provides some discomfort for the patients. Therefore, the compliance to undergo such a procedure is extremely low. This work was generated in the context of the BMBF-project „Development of a non-invasive assay for the early detection of preneoplastic and neoplastic lesions in the human colon“. The aim of the work described here is the development of a non-invasive assay for the early detection of colon cancer. The assay should detect DNA from neoplastic cells in feces samples. The transformation of these cells is based on alterations in the genome predominantly mutations. In the first part of the BMBF-project a mutation panel with high sensitivity for preneoplastic lesions of colon cancer was determined. The aim of this work was to develop a detection method for the point mutations of the determined mutation panel. The rare mutant DNA needs to be detected in the presence of a great amount of wild-type DNA shed from healthy tissue. The assay system needs to be insensitive to this high background of healthy DNA. Therefore a model system of plasmid DNA containing gene fragments of BRAF and its mutation V600E, CTNNB1 and T41I, T41A, S45P and K-ras G12C obtained from the marker panel was established. Using these plasmid system the detection method was developed. The most critical parameter for the detection of rare point mutations is an enrichment of these rare DNA molecules. In this work LNA-clamp-PCR (locked nucleic acid) technology was used to enrich the mutant DNA.. For the estimation of the achieved enrichment the relative detection limit was used. The detection limit was determined by melting curve analysis of hybridization probes. These assays were established in the present work for the three above mentioned gene fragments. LNA-clamp-PCR is performed in the presence of an LNA blocker. LNA is a synthetic DNA analog. LNA nucleotide analog bind to complementary DNA strands with higher affinity. In addition a single mismatch in the LNA-DNA duplex causes a much greater destabilization compared to a DNA-DNA duplex. Short LNA-DNA-hybrids were used as clamp, which cover the mutated region and represent the wild-type sequence. Within an appropriate temperature range, LNA can specifically bind to wild type template and can inhibit its amplification. The clamp itself will not be elongated. Under optimal conditions the LNA clamp will not interfere with the amplification of the mismatched template. Therefore the mutated gene fragment will be enriched in comparison to the wild-type. The position of the LNA clamp can either be at the primer binding site inhibiting primer hybridization on the wild-type fragment or the LNA clamp is positioned between the two primer binding sites inhibiting chain elongation of the perfectly matched template. In the present work both systems were applied. For the gene fragment BRAF the LNA was used at the primer binding site. The achieved detection limit was at least 1:100. The LNA-clamp-PCR with LNA inhibiting the chain elongation were developed successfully for BRAF, K-ras and CTNNB1: T41I, T41A achieving a detection limit of 1:1000 to 1:10 000. According to the literature 1% to 0.1% of the DNA in feces derives from neoplastic cells. Therefore the detection limit achieved by LNA-clamp-PCR with LNA inhibiting chain elongation would be sufficient for analyzing feces samples. LNA-clamp-PCR protocols were established for three different gene fragments and four diverse point mutations indicating that the technology can generally be used for high sensitive detection of DNA mutations. For the development of LNA-clamp-PCR protocols for the other mutations of the marker panel development guidelines were established. Clamp efficiency was identified as a quantitative parameter for protocol optimization. The LNA-clamp-PCR is a robust, fast and cost-saving technique which needs low labor input. Therefore the method is adequate for enriching point mutated gene fragments in a diagnostic assay for the detection of early colon cancer stages. In addition LNA-clamp-PCR can be applied in other fields where rare sequence variations need to be detected in the presence of high wild-type DNA background. KW - LNA-clamp-PCR KW - Darmkrebsdiagnostik KW - Punktmutation KW - BRAF KW - K-ras KW - LNA- clamp-PCR KW - colon cancer diagnosis KW - point mutation KW - BRAF KW - K-ras Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-52308 ER - TY - THES A1 - Löwinger, Maria T1 - Sulforaphan und Selen : Einfluss auf Phase II Enzyme und Selenoproteine sowie deren Effekt auf die entzündungsvermittelte Dickdarmkanzerogenese T1 - Sulforaphane and Selenium : impact on phase II enzymes and selenoproteins, and the effect on the inflammation triggered colon carcinogenesis N2 - Das ITC SFN und der Mikronährstoff Se sind bekannt als chemopräventive Inhaltsstoffe von Gemüse der Brassica-Familie, welcher auch Brokkoli angehört. Die Wirkungen von sowohl SFN als auch Se beruhen auf zahlreichen verschiedenen Mechanismen. Es existieren jedoch Schnittstellen, an welchen Interaktionen beider Substanzen möglich sind. Basierend auf diesem Wissen wurden in dieser Arbeit Wechselwirkungen zwischen SFN und Se auf die Aktivität sowie Expression von Phase II Enzymen und Selenoproteinen untersucht. Der Einfluss der Kombination von SFN und Se auf die unter physiologischen Bedingungen stattfindende Proliferation und Apoptose war ebenso Gegenstand der Arbeit wie die Modulation von Entzündungsprozessen sowie der Tumorentstehung während der entzündungsverstärkten Colonkanzerogenese im Mausmodell. Das hinsichtlich seiner Wirksamkeit mit aus GRA hydrolysiertem SFN zunächst als vergleichbar befundene synthetische SFN wurde für die Untersuchung im AOM/DSS-induzierten Colontumormodell gewählt und in Kombination mit 3 verschiedenen Selendiäten verabreicht. Der Einfluss von SFN und Se auf Phase II Enzyme und Selenoproteine entlang des GIT war organabhängig und nach 4 Wochen geringer als nach 7 Tagen. Die schwächere Induktion deutet auf eine Anpassung des Organismus hin. Ein SFN-vermittelter Effekt auf NQO1 war im Selenmangel am deutlichsten. Die Aktivität des Selenoproteins TrxR wurde hingegen erst bei ausreichender Selenversorgung durch SFN beeinflusst. Die als Nrf2-Zielgen bekannte und in der Hierarchie der Selenoproteine einen hohen Rang einnehmende GPx2 konnte in bestimmten Organen bereits unter selenarmen Bedingungen durch SFN induziert werden. Eine Überexpression des Enzyms war jedoch nicht möglich. SFN steigerte, unabhängig vom Selenstatus, im oberen Abschnitt des GIT und im Colon die Aktivität der GST. Eine Induktion des eigenen Metabolismus wäre somit denkbar. Im Falle eines Mangels an GPx2 wurde GPx1 bei hinreichender Selenversorgung stärker exprimiert, allerdings konnte sie die Funktion von GPx2 nicht völlig erset-zen. Im Selenmangel kann die Aktivitätssteigerung der TrxR im Dünndarm, dem Ab-schnitt der Selenabsorption, als ein Versuch der GPx2-Kompensation angesehen werden. SFN war nicht in der Lage, über eine Aktivierung des Nrf2/ARE-Signalweges kompensatorische Effekte zu induzieren. Apoptotische Prozesse wurden unter physiologischen Bedingungen nur marginal durch SFN und Se moduliert. Das elektrophile ITC konnte lediglich im Selenmangel Apoptose im luminalen Bereich der Colonkrypten induzieren. Die durch supranutritive Selenkonzentration induzierte Apoptose im Kryptengrund wurde nicht durch SFN beeinflusst. Einer bei Abwesenheit der GPx2 erhöhten Apoptoserate im Kryptengrund wirkte SFN bei adäquater Selenversorgung entgegen, war indessen proapoptotisch unter selendefizienten Konditionen. Der Einfluss von SFN auf die Entzündung war deutlich abhängig vom Selenstatus. Während SFN im Selenmangel anscheinend prooxidative Prozesse induzierte und die Entzündungssymptome verschlimmerte, wirkte es unter adäquatem Selenstatus an-tiinflammatorisch. Den vergleichsweise milden Grad der Entzündung im selensupplementierten Status konnte SFN nicht zusätzlich beeinflussen. SFN veränderte die Inzi-denz colorektaler Tumore nicht. Ein, die Tumorinitiation blockierender SFN-Effekt durch direkte Hemmung der metabolischen Aktivierung des Prokanzerogens im selenadäquaten Zustand scheint offensichtlich. Eine Überversorgung mit Se kann protektiv im Hinblick auf Entzündung oder Colonkanzerogenese sein, jedoch bewirkt SFN keinen zusätzlichen Schutz. Kombinationseffekte von SFN und Se in Bezug auf Phase II Enzyme, Selenoproteine und Apoptose sowie die entzündungsverstärkte Colonkanzerogenese sind nicht eindeutiger Natur und können, abhängig vom Endpunkt, synergistische oder antagonistische Züge aufweisen. Eine bei Selendefizienz deutlichere Wirkung von SFN kann mit Hilfe der gesteigerten Aktivierung von Nrf2 erklärt werden, dies muss jedoch nicht von Vorteil sein. Bei adäquater Selenversorgung kann SFN kurzfristig antiinflammatorische und antikanzerogene Prozesse induzieren. Von einer längerfristigen ständigen SFN-Aufnahme in Form von GRA-reichen Brassicacea ist jedoch abzuraten, da von einer Adaptation auszugehen ist. Die Wirkung von SFN innerhalb der komplexen Pflanzenmatrix bleibt Gegenstand zukünftiger Untersuchungen. N2 - Sulforaphane (SFN), a versatile actor derived from broccoli or other brassicaceae, is proposed to be a dietary anticarcinogen. Together with an adequate selenium status, it has been associated with a decreased risk for developing certain forms of cancer. In our mouse model, we investigate the influence of SFN and Se on the expression and activity of selenoproteins and phase II enzymes as well as the effects on inflammation triggered colon carcinogenesis. SFN increased NQO1 activity and protein expression significantly in the ileum, in both, Se-deficiently and Se-adequately fed animals. TrxR activity was increased in Se-adequately compared to Se-deficiently fed mice, SFN positively affected TrxR activity only in the former ones. An increase of GPx2 protein expression by SFN was observed in the ileum of mice of both diets. GPx1 reacts sensitively on Se supply. GST was the only enzyme analyzed being significantly increased by SFN on activity level in the colon. All AOM/DSS treated animals showed an inflammation, which was attenuated by SFN within Se-adequacy. In contrast, Se-deficient animals showed a more severe inflammation. The administration of SFN therefore seemed to enhance this even more and to be not beneficial in this case. SFN inhibited colon carcinogenesis in Se-adequate mice when being administered together with AOM. To summarize, both, GPx2 and TrxR, require selenium in order to be synthesized. In contrast to TrxR, the SFN-mediated induction of GPx2, the highest ranking selenoprotein, does not depend on additional selenium supply. Whereas distinct effects by SFN were observed in the ileum, only GST was influenced by SFN in the colon. SFN seems to induce its own metabolism. In conclusion, SFN and Se attenuate inflammation and colon carcinogenesis, preferably by means of up-regulating the endogenous defense system and inhibiting the metabolic activation of AOM. KW - Sulforaphan KW - Selen KW - Dickdarmkanzerogenese KW - Phase II Enzyme KW - Selenoproteine KW - sulforaphane KW - selenium KW - colon carcinogenesis KW - phase II enzymes KW - selenoproteins Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-51862 ER - TY - THES A1 - Loßow, Kristina T1 - Erzeugung und Charakterisierung von Mausmodellen mit lichtsensitivem Geschmackssystem zur Aufklärung der neuronalen Geschmackskodierung T1 - Generation and characterization of transgenic lines of mice to elucidate neuralnetworks engaged in processing of gustatory information N2 - Die Wahrnehmung von Geschmacksempfindungen beruht auf dem Zusammenspiel verschiedener Sinneseindrücke wie Schmecken, Riechen und Tasten. Diese Komplexität der gustatorischen Wahrnehmung erschwert die Beantwortung der Frage wie Geschmacksinformationen vom Mund ins Gehirn weitergeleitet, prozessiert und kodiert werden. Die Analysen zur neuronalen Prozessierung von Geschmacksinformationen erfolgten zumeist mit Bitterstimuli am Mausmodell. Zwar ist bekannt, dass das Genom der Maus für 35 funktionelle Bitterrezeptoren kodiert, jedoch war nur für zwei unter ihnen ein Ligand ermittelt worden. Um eine bessere Grundlage für tierexperimentelle Arbeiten zu schaffen, wurden 16 der 35 Bitterrezeptoren der Maus heterolog in HEK293T-Zellen exprimiert und in Calcium-Imaging-Experimenten funktionell charakterisiert. Die Daten belegen, dass das Funktionsspektrum der Bitterrezeptoren der Maus im Vergleich zum Menschen enger ist und widerlegen damit die Aussage, dass humane und murine orthologe Rezeptoren durch das gleiche Ligandenspektrum angesprochen werden. Die Interpretation von tierexperimentellen Daten und die Übertragbarkeit auf den Menschen werden folglich nicht nur durch die Komplexität des Geschmacks, sondern auch durch Speziesunterschiede verkompliziert. Die Komplexität des Geschmacks beruht u. a. auf der Tatsache, dass Geschmacksstoffe selten isoliert auftreten und daher eine Vielzahl an Informationen kodiert werden muss. Um solche geschmacksstoffassoziierten Stimuli in der Analyse der gustatorischen Kommunikationsbahnen auszuschließen, sollten Opsine, die durch Licht spezifischer Wellenlänge angeregt werden können, für die selektive Ersetzung von Geschmacksrezeptoren genutzt werden. Um die Funktionalität dieser angestrebten Knockout-Knockin-Modelle zu evaluieren, die eine Kopplung von Opsinen mit dem geschmacksspezifischen G-Protein Gustducin voraussetzte, wurden Oozyten vom Krallenfrosch Xenopus laevis mit dem Zwei-Elektroden-Spannungsklemm-Verfahren hinsichtlich dieser Interaktion analysiert. Der positiven Bewertung dieser Kopplung folgte die Erzeugung von drei Mauslinien, die in der kodierenden Region eines spezifischen Geschmacksrezeptors (Tas1r1, Tas1r2, Tas2r114) Photorezeptoren exprimierten. Durch RT-PCR-, In-situ-Hybridisierungs- und immunhistochemische Experimente konnte der erfolgreiche Knockout der Rezeptorgene und der Knockin der Opsine belegt werden. Der Nachweis der Funktionalität der Opsine im gustatorischen System wird Gegenstand zukünftiger Analysen sein. Bei erfolgreichem Beleg der Lichtempfindlichkeit von Geschmacksrezeptorzellen dieser Mausmodelle wäre ein System geschaffen, dass es ermöglichen würde, gustatorische neuronale Netzwerke und Hirnareale zu identifizieren, die auf einen reinen geschmacks- und qualitätsspezifischen Stimulus zurückzuführen wären. N2 - Taste impression is based on the interaction of taste, smell and touch. To evaluate the nutritious content of food mammals possess five distinct taste qualities: sweet, bitter, umami (taste of amino acids), sour and salty. For bitter, sweet, and umami compounds taste signaling is initiated by binding of tastants to G protein-coupled receptors. The interactions of taste stimuli, usually watersoluble chemicals, with their cognate receptors lead to the activation of the G protein gustducin, which, in turn, initiates a signal resulting in the activation of gustatory afferents. However, details of gustatory signal transmission and processing as well as neural coding are only incompletely understood. This is partly due to the property of some tastants to elicit several sensations simultaneously, unspecific effects caused by the temperature, viscosity, osmolarity, and pH of the solvents, as well as by mechanical stimulation of the tongue during stimulus application. The analysis of gustatory processing of taste information are mainly based on mouse models after stimulation with bitter taste stimuli. Even though it is known that the mouse genome codes for 35 bitter taste receptor genes only few of them had been analysed so far. For better understanding and interpretation of animal experiments 16 mouse bitter receptors had been analysed by Calcium Imaging experiments with HEK293T cells. The data reveal that mouse bitter taste receptors are more narrow tuned than human bitter taste receptors, proving that the ligand spectra of murine and human orthologous receptors are not complient. In order to avoid the disturbing effects of solvents and stimulus application on the analysis of gustatory information transfer and processing, I employ an optogenetical approach to address this problem. For this purpose I generated three strains of gene-targeted mice in which the coding regions of the genes for the umami receptor subunit Tas1r1, the sweet receptor subunit Tas1r2 or the bitter taste receptor Tas2r114 have been replaced by the coding sequences of different opsins (photoreceptors of visual transduction) that are sensitive to light of various wavelengths. In these animals I should be able to activate sweet, bitter, or umami signalling by light avoiding any solvent effects. In initial experiments of this project I demonstrated that the various visual opsins indeed functionally couple to taste signal transduction pathway in oocyte expression system, generating basic knowledge and foundation for the generation of the gene-targeted animals. The knockout-knockin strategies have been successfully realized in the case of all three mouse models, revealed by RT-PCR, in situ hybridization and immunohistochemical analysis of taste papillae. All data confirm that the particular taste receptors have been replaced by the different opsins in taste cells. Further analysis concerning the functional consequences of opsin knockin and taste receptor knockout are part of prospective work. KW - Geschmack KW - G-Protein-gekoppelte Rezeptoren KW - Bitterrezeptoren KW - Optogenetik KW - taste KW - G protein-coupled receptors KW - bitter taste receptors KW - optogenetic Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-58059 ER - TY - THES A1 - Rothe, Monique T1 - Response of intestinal Escherichia coli to dietary factors in the mouse intestine T1 - Anpassung von Escherichia coli an Ernährungsfaktoren im Intestinaltrakt der Maus N2 - Diet is a major force influencing the intestinal microbiota. This is obvious from drastic changes in microbiota composition after a dietary alteration. Due to the complexity of the commensal microbiota and the high inter-individual variability, little is known about the bacterial response at the cellular level. The objective of this work was to identify mechanisms that enable gut bacteria to adapt to dietary factors. For this purpose, germ-free mice monoassociated with the commensal Escherichia coli K-12 strain MG1655 were fed three different diets over three weeks: a diet rich in starch, a diet rich in non-digestible lactose and a diet rich in casein. Two dimensional gel electrophoresis and electrospray tandem mass spectrometry were applied to identify differentially expressed proteins of E. coli recovered from small intestine and caecum of mice fed the lactose or casein diets in comparison with those of mice fed the starch diet. Selected differentially expressed bacterial proteins were characterised in vitro for their possible roles in bacterial adaptation to the various diets. Proteins belonging to the oxidative stress regulon oxyR such as alkyl hydroperoxide reductase subunit F (AhpF), DNA protection during starvation protein (Dps) and ferric uptake regulatory protein (Fur), which are required for E. coli’s oxidative stress response, were upregulated in E. coli of mice fed the lactose-rich diet. Reporter gene analysis revealed that not only oxidative stress but also carbohydrate-induced osmotic stress led to the OxyR-dependent expression of ahpCF and dps. Moreover, the growth of E. coli mutants lacking the ahpCF or oxyR genes was impaired in the presence of non-digestible sucrose. This indicates that some OxyR-dependent proteins are crucial for the adaptation of E. coli to osmotic stress conditions. In addition, the function of two so far poorly characterised E. coli proteins was analysed: 2 deoxy-D gluconate 3 dehydrogenase (KduD) was upregulated in intestinal E. coli of mice fed the lactose-rich diet and this enzyme and 5 keto 4 deoxyuronate isomerase (KduI) were downregulated on the casein-rich diet. Reporter gene analysis identified galacturonate and glucuronate as inducers of the kduD and kduI gene expression. Moreover, KduI was shown to facilitate the breakdown of these hexuronates, which are normally degraded by uronate isomerase (UxaC), altronate oxidoreductase (UxaB), altronate dehydratase (UxaA), mannonate oxidoreductase (UxuB) and mannonate dehydratase (UxuA), whose expression was repressed by osmotic stress. The growth of kduID-deficient E. coli on galacturonate or glucuronate was impaired in the presence of osmotic stress, suggesting KduI and KduD to compensate for the function of the regular hexuronate degrading enzymes under such conditions. This indicates a novel function of KduI and KduD in E. coli’s hexuronate metabolism. Promotion of the intracellular formation of hexuronates by lactose connects these in vitro observations with the induction of KduD on the lactose-rich diet. Taken together, this study demonstrates the crucial influence of osmotic stress on the gene expression of E. coli enzymes involved in stress response and metabolic processes. Therefore, the adaptation to diet-induced osmotic stress is a possible key factor for bacterial colonisation of the intestinal environment. N2 - Sowohl Humanstudien als auch Untersuchungen an Tiermodellen haben gezeigt, dass die Ernährung einen entscheidenden Einfluss auf die Zusammensetzung der Darmmikrobiota hat. Aufgrund der Komplexität der Mikrobiota und der inter individuellen Unterschiede sind die zellulären Mechanismen, die dieser Beobachtung zugrunde liegen, jedoch weitgehend unbekannt. Das Ziel dieser Arbeit war deshalb, Anpassungsmechanismen von kommensalen Darmbakterien auf unterschiedliche Ernährungsfaktoren mittels eines simplifizierten Modells zu untersuchen. Dazu wurden keimfreie Mäuse mit Escherichia coli MG1655 besiedelt und drei Wochen mit einer stärkehaltigen, einer laktosehaltigen oder einer kaseinhaltigen Diät gefüttert. Mittels zwei dimensionaler Gelelektrophorese und Elektrospray Ionenfallen-Massenspektrometrie wurde das Proteom der intestinalen E. coli analysiert und differentiell exprimierte bakterielle Proteine in Abhängigkeit der gefütterten Diät identifiziert. Die Funktion einiger ausgewählter Proteine bei der Anpassung von E. coli auf die jeweilige Diät wurde im Folgenden in vitro untersucht. E. coli Proteine wie z.B. die Alkylhydroperoxid Reduktase Untereinheit F (AhpF), das DNA Bindeprotein Dps und der eisenabhängige Regulator Fur, deren Expression unter der Kontrolle des Transkriptionsregulators OxyR steht, wurden stärker exprimiert, wenn die Mäuse mit der laktosehaltigen Diät gefüttert wurden. Reportergenanalysen zeigten, dass nicht nur oxidativer Stress, sondern auch durch Kohlenhydrate ausgelöster osmotischer Stress zu einer OxyR abhängigen Expression der Gene ahpCF and dps führte. Weiterhin wiesen E. coli Mutanten mit einer Deletion der ahpCF oder oxyR Gene ein vermindertes Wachstum in Gegenwart von nicht fermentierbarer Saccharose auf. Das spricht dafür, dass OxyR abhängige Proteine eine wichtige Rolle bei der Anpassung von E. coli an osmotischen Stress spielen. Weiterhin wurde die Funktion von zwei bisher wenig charakterisierten E. coli Proteinen untersucht: die 2 Deoxy D Glukonate 3 Dehydrogenase (KduD) wurde im Darm von Mäusen, die mit der laktosehaltigen Diät gefüttert wurden, induziert, während dieses Protein und die 5 Keto 4 Deoxyuronate Isomerase (KduI) nach Fütterung der kaseinhaltigen Diät herunterreguliert wurden. Mittels Reportergenanalysen wurde gezeigt, dass Galakturonat und Glukuronat die kduD und kduI Expression induzierten. KduI begünstigte die Umsetzung dieser Hexuronate. In E. coli wird die Umsetzung von Galakturonat und Glukuronat typischerweise von den Enzymen Uronate Isomerase (UxaC), Altronate Oxidoreduktase (UxaB), Altronate Dehydratase (UxaA), Mannonate Oxidoreduktase (UxuB) und Mannonate Dehydratase (UxuA) katalysiert. Weitere Experimente verdeutlichten, dass osmotischer Stress die Expression der Gene uxaCA, uxaB und uxuAB verminderte. Darüber hinaus zeigten kduID defiziente E. coli Mutanten in Gegenwart von Galakturonat oder Glukuronat und durch Saccharose ausgelösten osmotischen Stress eine Verlangsamung des Wachstums. Das deutet darauf hin, dass KduI und KduD die durch osmotischen Stress bedingten Funktionseinschränkungen der regulären hexuronatabbauenden Enzyme kompensieren. Die beobachtete Bildung von intrazellulären Hexuronaten während des Laktosekatabolismus in vitro stellt eine Verbindung zu dem ursprünglichen Tierexperiment her und deutet darauf hin, dass der Ernährungsfaktor Laktose die Verfügbarkeit von Hexuronat für intestinale E. coli beeinflusst. Diese Studie weist somit den Einfluss von osmotischem Stress auf die Expression von OxyR abhängigen Genen, die für Stressantwortproteine sowie für metabolische Enzymen kodieren, in E. coli nach. Durch Nahrungsfaktoren entstandener osmotischer Stress stellt demnach einen entscheidenden Faktor für die bakterielle Kolonisation des Darmes dar. KW - Mikrobiota KW - Escherichia coli KW - Proteom KW - Ernährungsfaktoren KW - OxyR KW - microbiota KW - Escherichia coli KW - proteome KW - dietary factors KW - OxyR Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-66387 ER - TY - THES A1 - Töle, Jonas Claudius T1 - Über die Arc-catFISH-Methode als neues Werkzeug zur Charakterisierung der Geschmacksverarbeitung im Hirnstamm der Maus T1 - The arc catFISH method as a new tool to characterize taste processing in the mouse hind brain N2 - Intensive Forschung hat in den vergangenen Jahrzehnten zu einer sehr detaillierten Charakterisierung des Geschmackssystems der Säugetiere geführt. Dennoch sind mit den bislang eingesetzten Methoden wichtige Fragestellungen unbeantwortet geblieben. Eine dieser Fragen gilt der Unterscheidung von Bitterstoffen. Die Zahl der Substanzen, die für den Menschen bitter schmecken und in Tieren angeborenes Aversionsverhalten auslösen, geht in die Tausende. Diese Substanzen sind sowohl von der chemischen Struktur als auch von ihrer Wirkung auf den Organismus sehr verschieden. Während viele Bitterstoffe potente Gifte darstellen, sind andere in den Mengen, die mit der Nahrung aufgenommen werden, harmlos oder haben sogar positive Effekte auf den Körper. Zwischen diesen Gruppen unterscheiden zu können, wäre für ein Tier von Vorteil. Ein solcher Mechanismus ist jedoch bei Säugetieren nicht bekannt. Das Ziel dieser Arbeit war die Untersuchung der Verarbeitung von Geschmacksinformation in der ersten Station der Geschmacksbahn im Mausgehirn, dem Nucleus tractus solitarii (NTS), mit besonderem Augenmerk auf der Frage nach der Diskriminierung verschiedener Bitterstoffe. Zu diesem Zweck wurde eine neue Untersuchungsmethode für das Geschmackssystem etabliert, die die Nachteile bereits verfügbarer Methoden umgeht und ihre Vorteile kombiniert. Die Arc-catFISH-Methode (cellular compartment analysis of temporal activity by fluorescent in situ hybridization), die die Charakterisierung der Antwort großer Neuronengruppen auf zwei Stimuli erlaubt, wurde zur Untersuchung geschmacksverarbeitender Zellen im NTS angewandt. Im Zuge dieses Projekts wurde erstmals eine stimulusinduzierte Arc-Expression im NTS gezeigt. Die ersten Ergebnisse offenbarten, dass die Arc-Expression im NTS spezifisch nach Stimulation mit Bitterstoffen auftritt und sich die Arc exprimierenden Neurone vornehmlich im gustatorischen Teil des NTS befinden. Dies weist darauf hin, dass Arc-Expression ein Marker für bitterverarbeitende gustatorische Neurone im NTS ist. Nach zweimaliger Stimulation mit Bittersubstanzen konnten überlappende, aber verschiedene Populationen von Neuronen beobachtet werden, die unterschiedlich auf die drei verwendeten Bittersubstanzen Cycloheximid, Chininhydrochlorid und Cucurbitacin I reagierten. Diese Neurone sind vermutlich an der Steuerung von Abwehrreflexen beteiligt und könnten so die Grundlage für divergentes Verhalten gegenüber verschiedenen Bitterstoffen bilden. N2 - Intense research in the past decades has led to a detailed understanding of the mammalian taste system. Some important issues, however, have remained unanswered with the established methods that have been applied so far. One of these questions is whether different bitter substances can be distinguished. There are thousands of compounds which taste bitter to humans and elicit innate aversive behavior in animals. Moreover, these bitter substances are very heterogeneous regarding their structure as well as their effect on the organism. While many bitter tastants are potent poisons, others are harmless or even have beneficial effects in the amounts that are typically ingested. The ability to discriminate between those groups of bitter tastants could be an evolutionary advantage. Such a mechanism, however, is not known for mammals. The aim of this thesis was to study the processing of taste information in the first station of gustatory processing in the mouse brain, the nucleus of the solitary tract (NTS). Of particular interest was the question concerning discrimination of bitter tastants. To this end a new method was established for the taste system combining the advantages of methods used before while circumventing their disadvantages. The Arc catFISH method (cellular compartment analysis of temporal activity by fluorescent in situ hybridization), which allows the characterization of responses of large neuron populations to two stimuli, was used to analyze taste-processing cells in the NTS. In the course of this project a stimulus-induced Arc expression in the NTS was shown for the first time. The results demonstrated that Arc expression in the NTS appears specifically after stimulation with bitter tastants and that the Arc expressing neurons are located primarily in the gustatory part of the NTS. This indicates that Arc expression is a marker for bitter-processing gustatory neurons in the NTS. Upon stimulating twice with bitter compounds, distinct, yet overlapping neuron populations were identified, that reacted differently to the three bitter substances cycloheximide, quinine hydrochloride, and cucurbitacin I. Presumably these neurons are involved in the regulation of aversive reflexes and could form a basis for divergent behavior towards different bitter substances. KW - Geschmack KW - bitter KW - Nucleus tractus solitarii KW - Immediate-early-Gen KW - activity-regulated cytoskeleton-associated protein KW - catFISH KW - taste KW - bitter KW - nucleus of the solitary tract KW - immediate early gene KW - activity-regulated cytoskeleton-associated protein KW - catFISH Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-70491 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 - THES A1 - Kipp, Anna Patricia T1 - Physiologische und Tumor-Assoziierte Funktionen von Selen und Selenoproteinen Y1 - 2014 ER - TY - THES A1 - Meyer, Sören T1 - Toxicity and toxicokinetics of arsenolipids and their metabolites Y1 - 2015 ER - TY - THES A1 - Prandi, Simone T1 - Characterization of the expression and function of bitter taste receptor genes in gastrointestinal tissues Y1 - 2015 ER - TY - THES A1 - Scherwinski, Ann-Christin T1 - Die Phyllosphäre BT - eine Reservoir für humaneffektive Bakterien Y1 - 2015 ER - TY - THES A1 - Jacobs, Simone T1 - Biological mechanisms of the association between proportions of fatty acids in erythrocyte membranes and type 2 diabetes risk in the EPIC-Potsdam-Study Y1 - 2015 ER - TY - THES A1 - Frenzel, Sabine T1 - Die Rolle der Umamirezeptoruntereinheit Tas1r1 jenseits ihrer gustatorischen Bedeutung T1 - The role of the umami receptor subunit Tas1r1 beyond its gustatory importance BT - Analyse ihrer Expression und Funktion in nichtgustatorischen Geweben gentechnisch modifizierter Mauslinien N2 - Aminosäuren sind lebensnotwendige Moleküle für alle Organismen. Ihre Erkennung im Körper ermöglicht eine bedarfsgerechte Regulation ihrer Aufnahme und ihrer Verwertung. Welcher Chemosensor für diese Erkennung jedoch hauptverantwortlich ist, ist bisher unklar. In der vorliegenden Arbeit wurde die Rolle der Umamigeschmacksrezeptoruntereinheit Tas1r1 jenseits ihrer gustatorischen Bedeutung für die Aminosäuredetektion in der Mundhöhle untersucht. In der histologischen Tas1r1-Expressionsanalyse nichtgustatorischer Gewebe der Mauslinie Tas1r1-Cre/ROSA26-tdRFP wurde über die Detektion des Reporterproteins tdRFP die Expression des Tas1r1 in allen untersuchten Geweben (Speiseröhre, Magen, Darm, Bauchspeicheldrüse, Leber, Niere, Muskel- und Fettgewebe, Milz, Thymus, Lymphknoten, Lunge sowie Hoden) nachgewiesen. Mit Ausnahme von Dünndarm und Hoden gelang hierbei der Nachweis erstmals spezifisch auf zellulärer Ebene. Caecum und Lymphknoten wurden zudem neu als Expressionsorte des Tas1r1 identifiziert. Trotz der beobachteten weiten Verbreitung des Tas1r1 im Organismus – unter anderem auch in Geweben, die für den Proteinstoffwechsel besonders relevant sind – waren im Zuge der durchgeführten Untersuchung potentieller extraoraler Funktionen des Rezeptors durch phänotypische Charakterisierung der Mauslinie Tas1r1-BLiR nur schwache Auswirkungen auf Aminosäurestoffwechsel bzw. Stickstoffhaushalt im Falle eines Tas1r1-Knockouts detektierbar. Während sich Ernährungsverhalten, Gesamtphysiologie, Gewebemorphologie sowie Futterverdaulichkeit unverändert zeigten, war die renale Stickstoffausscheidung bei Tas1r1-Knockout-Mäusen auf eiweißarmer sowie auf eiweißreicher Diät signifikant verringert. Eine Überdeckung der Auswirkungen des Tas1r1-Knockouts aufgrund kompensatorischer Effekte durch den Aminosäuresensor CaSR oder den Peptidsensor Gpr93 war nicht nachweisbar. Es bleibt offen, ob andere Mechanismen oder andere Chemosensoren an einer Kompensation beteiligt sind oder aber Tas1r1 in extraoralem Gewebe andere Funktionen als die der Aminosäuredetektion übernimmt. Unterschiede im extraoralen Expressionsmuster der beiden Umamirezeptor-untereinheiten Tas1r1 und Tasr3 lassen Spekulationen über andere Partner, Liganden und Funktionen zu. N2 - Amino acids are important nutrients for each organism. Recognition of amino acids in the body enables an adequate regulation of their absorption and use. Until now, it is ambiguous which chemosensor is mainly responsible for this recognition. In the present work, the role of the umami taste receptor subunit Tas1r1 was examined beyond its gustatory importance for the amino acid detection in the oral cavity. By a histological expression analysis of non-gustatory tissues of the mouse strain Tas1r1-Cre/ROSA26-tdRFP, Tas1r1 expression has been proven in all of the analysed tissues (oesophagus, stomach, intestine, pancreas, liver, kidney, muscle and fat tissues, spleen, thymus, lymph nodes, lung and testes) via the detection of the reporter protein tdRFP. With the exception of small intestine and testes, the proof succeeded for the first time specifically at the cellular level. Moreover, caecum and lymph nodes were newly identified as expression sites of Tas1r1. Despite the observed widespread distribution of Tas1r1 in the organism – including tissues which are particularly relevant in protein metabolism – only slight effects on amino acid metabolism and nitrogen balance respectively were detectable in the course of examinations of potentially extraoral functions of the receptor by a phenotypical characterization of the mouse strain Tas1r1-BLiR. The renal nitrogen excretion of Tas1r1 knockout mice on low protein and also high protein diet was significantly reduced, whereas dietary habit, overall physiology, tissue morphology and food digestibility remained unchanged. A superposition of the Tas1r1 knockout impact due to compensatory effects by the amino acid sensor CaSR or the peptide sensor Gpr93 was unverifiable. It remains open whether other mechanisms or chemosensors are involved in compensation or whether Tas1r1 takes over other functions in extraoral tissues than the amino acid detection. Differences in the extraoral expression pattern of the two umami receptor subunits Tas1r1 and Tas1r3 leave room for speculations about other partners, ligands and functions. KW - Tas1r1 KW - Geschmacksrezeptor KW - taste receptor KW - umami KW - umami KW - Tas1r1 Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-79502 ER - TY - THES A1 - Bernhardt, Ulrike T1 - Untersuchung zur Rolle von Adapterprotein-Komplexen im Targeting der Glucosetransporter GLUT8 und GLUT4 Y1 - 2008 ER - TY - THES A1 - Hanske, Laura T1 - Der Einfluss der Darmbakterien des Menschen auf die Bioverfügbarkeit von Flavonoiden Y1 - 2008 CY - Potsdam ER - TY - THES A1 - Hommel, Angela T1 - Die Rolle der GTPase ARFRP1 in der Embryonal- und Fettgewebsentwicklung Y1 - 2007 CY - Potsdam ER - TY - THES A1 - Voigt, Anja T1 - Beziehung zwischen dem mitochondrialen Stoffwechsel und der Lebenserwartung in mammalen Knock-out-Modellen Y1 - 2007 CY - Potsdam ER - TY - THES A1 - Schmidt, Stefan T1 - Die Rolle von Glucosetransportern der GLUT-Familie für die Glucosehomöostase und als Glucosesensor Y1 - 2007 CY - Potsdam ER - TY - THES A1 - Kuhlow, Doreen T1 - Mitochondriale Dysfunktion aufgrund Frataxinmangels induziert ernährungsabhängig Symptome des Metabolischen Syndroms in der Maus Y1 - 2007 CY - Potsdam ER - TY - THES A1 - Henderson, Gemma T1 - Development of bacterial food preparations with tumour-prophylactic potential Y1 - 2007 CY - Potsdam ER - TY - THES A1 - Scherneck, Stephan T1 - Identifizierung eines diabetogenen Allels im Suszeptibilitätslocus Nidd/SJL der Maus Y1 - 2007 CY - Potsdam ER - TY - JOUR A1 - Rauk, Erika A1 - Kotzev, Anton A1 - Laschewsky, André A1 - Palmer, Christopher P. T1 - Cationic and perfluorinated polymeric pseudostationary phases for electrokinetic chromatography N2 - Separation selectivity in electrokinetic chromatography (EKC) is directly affected by the chemistry and solvent characteristics of the pseudostationary phase (PSP). The chemical selectivity of micellar PSPs has been previously demonstrated to vary significantly between anionic and cationic surfactants as well as between hydrocarbon and fluorocarbon surfactants. Polymeric PSPs have also been demonstrated to provide unique selectivity. In the current study, four cationic polymeric pseudo-stationary phases, two of which have perfluorinated pendant groups, are introduced and characterized as PSPs in EKC. Their performance and selectivity is compared to conventional micellar PSPs with similar structure. The solvation characteristics and selectivity of the four polymers most closely resemble those observed for cationic micelles. The polymers are all more cohesive and more polar than their hydrocarbon micellar counterparts. The fluorocarbon PSPs did show preferential interaction with fluorocarbon solutes, were somewhat more cohesive, and were stronger hydrogen bond donors. However, the presence of fluorocarbon moieties did not have as dramatic an effect on selectivity as was observed and published previously for fluorocarbon micelles. This may result from the selectivity being dominated by the presence of the cationic head groups or from the fluorocarbon character of the pendant groups being moderated by the presence of hydrocarbon functionality on the polymer back-bones. Y1 - 2006 UR - http://www.sciencedirect.com/science/journal/00219673 U6 - https://doi.org/10.1016/j.chroma.2005.07.114 SN - 0021-9673 ER - TY - THES A1 - Müller, Susanne T1 - Einfluss von Alter und Ernährung auf die Zusammensetzung der intestinalen Mikrobiota und auf ausgewählte Parameter der Darmfunktion bei vier europäischen Studiengruppen (Querschnittstudie) Y1 - 2006 CY - Potsdam ER - TY - THES A1 - Mohan, Ruchika T1 - Microbial colonization of the gastrointestinal tract of preterm infants: Microbial diversity and new ways of prevention of infections Y1 - 2006 CY - Potsdam ER - TY - THES A1 - Clavel, Thomas T1 - Metabolism of the dietary lignan secoisolariciresinol diglucoside by human intestinal bacteria Y1 - 2006 SN - 3-8325-1192-X PB - Logos-Verl. CY - Berlin ER - TY - JOUR A1 - Forterre, Simone A1 - Raila, Jens A1 - Kohn, Barbara A1 - Brunnberg, Leo A1 - Schweigert, Florian J. T1 - Protein profiling of organic stone matrix and urine from dogs with urolithiasis N2 - Two-thirds of the organic matrix in urinary stones consists of proteins. Their relationship to calculogenesis remains controversial with regard to their effect as inhibitors or promoters during stone formation. The purpose of the present study was to determine the differences in peptide and protein pattern between the urine of stone formers (n = 23) and control dogs (n = 12), as well as between organic matrix of different urinary stones (struvite n = 11, calcium oxalate n = 8, uric acid n = 4) using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry. Specific differences in protein and peptide profiles were found in the organic matrix of different mineral compositions. Characteristic differences were also found in urinary peptide and protein pattern especially in molecular masses below 20 kDa between affected and healthy dogs. Based on the obtained molecular masses they were in some cases tentatively identified as proteins that are known to be involved in stone formation in humans. The study shows that in dogs, specific-urinary peptides and proteins might be associated with urolithiasis. It indicates the importance to further characterize those proteins for possible diagnostic purposes in prognosis and therapy Y1 - 2006 UR - http://www3.interscience.wiley.com/journal/122630496/grouphome/home.html U6 - https://doi.org/10.1111/j.1439-0396.2005.00590.x SN - 0931-2439 ER - TY - JOUR A1 - Koch, Christin A1 - Brovkina, Lioudmila A1 - Rühl, Ralph A1 - Worm, Margitta T1 - Immunomodulation by dietary n3-polyunsaturated fatty acids (PUFA) in vitro Y1 - 2006 SN - 0091-6749 ER - TY - JOUR A1 - Barth, Christian A. T1 - Ein Vitamin mit zwei Gesichtern : Folat in der Vorsorge Y1 - 2009 UR - http://www.dlr-online.de/ SN - 0012-0413 ER - TY - JOUR A1 - Ruhl, R. A1 - Fritzsche, Britta A1 - Vermot, J. A1 - Niederreither, K. A1 - Neumann, U. A1 - Schmidt, A. A1 - Schweigert, Florian J. A1 - Dolle, P. T1 - Regulation of expression of the retinoic acid-synthesising enzymes retinaldehyde dehydrogenases in the uteri of ovariectomised mice after treatment with oestrogen, gestagen and their combination N2 - The active metabolite of vitaminA, retinoic acid (RA), plays an important role in the female reproductive system. The synthesis of RA is tightly regulated by the activity of retinaldehyde dehydrogenases (Raldh). Among these, Raldh1 and Raldh2 exhibit specific temporal and spatial expression patterns in the mouse uterus, both during the oestrous cycle and early pregnancy. In the present study, we have assessed whether oestradiol and progesterone directly influence the uterine expression of Raldh1 and Raldh2 in ovariectomised mice. We investigated the effect of gestagen (promegestone 0.3 mg kg(-1) bodyweight), oestrogen (oestradiol 3 mu g kg(-1) bodyweight) and their combination on the uterine expression of Raldh2. Expression was analysed using in situ hybridisation and quantified using real-time detection reverse transcription-polymerase chain reaction. The results show that the expression of Raldh2 is rapidly (within 1-4 h) induced in stromal cells by oestrogen, but not by gestagen, treatment, whereas combined oestrogen + gestagen treatment leads to a more prolonged (48 h) response. In contrast, oestrogen, but not progesterone, treatment downregulates (within 4 - 24 h) Raldh1 expression in the uterine glandular epithelium. We conclude that the uterine RA concentrations are regulated by oestrogens via an effect on the expression of the Raldh synthesising enzymes. Such a regulation is consistent with the natural fluctuations of Raldh expression during the oestrous cycle, early pregnancy and blastocyst implantation Y1 - 2006 ER - TY - JOUR A1 - Rufer, CE A1 - Glatt, Hansruedi A1 - Kulling, Sabine E. T1 - Structural elucidation of hydroxylated metabolites of the isoflavan equol by gas chromatography-mass spectrometry and high-performance liquid chromatography-mass spectrometry N2 - Equol has, as have other isoflavonoids, recently gained considerable interest due to its possible health effects. However, detailed studies on the metabolism of equol are scarce. Therefore, we investigated the phase I metabolism of equol using liver microsomes from Aroclor-treated male Wistar rats as well as from a male human. The identification of the metabolites formed was elucidated using high performance liquid chromatography ( HPLC) with diode array detection, HPLC/atmospheric pressure ionization electrospray mass spectrometry, and gas chromatography-mass spectrometry, as well as reference compounds. ( +/-)-Equol was converted to 11 metabolites by the liver microsomes from Aroclorpretreated rats comprising three aromatic monohydroxylated and four aliphatic monohydroxylated as well as four dihydroxylated products. The main metabolite was identified as 3'-hydroxy-equol. Using human liver microsomes, equol was converted to six metabolites with 3'-hydroxy- and 6-hydroxy-equol as main products. Furthermore, the aliphatic hydroxylated metabolite 4-hydroxyequol, which was recently detected in human urine after soy consumption, was formed. On the basis of these findings, it is suggested that phase I metabolism of equol is part of a complex biotransformation of the soy isoflavone daidzein in humans in vivo Y1 - 2006 U6 - https://doi.org/10.1124/dmd.105.004929 ER - TY - JOUR A1 - Forterre, Simone A1 - Raila, Jens A1 - Forterre, Franck A1 - Brunnberg, Leo A1 - Schweigert, Florian J. T1 - Characterisation of transthyretin and retinol-binding protein in plasma and cerebrospinal fluid of dogs N2 - The aim of this study was to investigate differences in concentrations of vitamin A, transthyretin (TTR) and retinol-binding protein (RBP) between plasma and cerebrospinal fluid (CSF) in dogs. RBP was detected using ELISA, and both RBP and TTR by Western blot analysis after separation on SDS-PAGE. Vitamin A was determined by high performance liquid chromatography. RBP and TTR as well as vitamin A were detected in all samples but at substantially lower concentrations in CSF compared to plasma. RBP in dog plasma showed a similar molecular mass to that of humans, whereas canine TTR had a lower molecular mass. Comparison between plasma and CSF showed that both RBP and TTR were of lower molecular mass in CSF. In CSF, RBP and retinol were present at 10-100-fold lower concentrations compared to plasma. Retinyl esters were present only in minute amounts in 5/17 samples. In conclusion, the CSF of dogs compared to humans is significantly different in terms of both quality and quantity of transport proteins for vitamin A. Y1 - 2006 UR - http://www.sciencedirect.com/science/journal/10900233 U6 - https://doi.org/10.1016/j.tvjl.2004.11.017 SN - 1090-0233 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 - 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 - THES A1 - Bojahr, Juliane T1 - Aktivierung des humanen Süßgeschmacksrezeptors im zellbasierten Testsystem T1 - Human sweet taste receptor activation in cell based assay N2 - Zellbasierte heterologe Expressionssysteme bieten ein einfaches und schnelles Verfahren, um neue Süßstoffe oder Süßverstärker zu finden. Unter Verwendung eines solchen Testsystems, konnte ich in Zusammenarbeit mit der Symrise AG, Holzminden und dem Institut für Pflanzenbiochemie in Halle/Saale die vietnamesische Pflanze Mycetia balansae als Quelle eines neuen Süßstoffs identifizieren. Deren Hauptkomponenten, genannt Balansine, aktivieren spezifisch den humanen Süßrezeptor. Chimäre Rezeptoren zeigten, dass die amino-terminalen Domänen der Süßrezeptoruntereinheiten, welche ein Großteil der Liganden des Süßrezeptors binden, für dessen Aktivierung durch Balansin A nicht notwendig sind. Voraussetzung für die Anwendung zellbasierter Testsysteme zum Auffinden neuer Süßstoffe ist jedoch, dass süße Substanzen gesichert identifiziert werden, während nicht süße Substanzen zuverlässig keine Rezeptoraktivierung aufweisen. Während in HEK293 TAS1R2 TAS1R3To Galpha15i3-Zellen Süßrezeptoraktivierung gegenüber nicht süß schmeckenden Substanzen beobachtet wurde, konnte mit den HEK293PEAKrapid Galpha15-Zellen ein zuverlässiges Testsystem identifiziert, welches den Süßgeschmack der untersuchten Substanzen widerspiegelte. Es fanden sich keine Hinweise, dass akzessorische Proteine oder verwandte Rezeptoren des Süßrezeptors das unterschiedliche Verhalten der Zellen verursachen. Es konnte gezeigt werden, dass die Verwendung unterschiedlicher G-Proteine die Signalamplituden des Süßrezeptors beeinflusst, die Unterschiede zwischen den Zellsystemen jedoch nicht vollständig erklärt. Keine der untersuchten Galpha-Proteinchimären spiegelte die intrinsische Süße der Substanzen wider. Wenn auch nicht ursächlich für die Diskrepanz zwischen Süßrezeptoraktivierung in vitro und Süßgeschmack in vivo, so weisen die Ergebnisse dieser Arbeit auf eine Interaktion der Süßrezeptoruntereinheiten mit dem humanen Calcium-sensing Rezeptor hin. Vanillin und Ethylvanillin konnten als neue Agonisten des Calcium-sensing Rezeptors identifiziert werden. Wie die vorliegende Arbeit zeigt, können sich kleine Unterschiede im Zellhintergrund deutlich auf die Funktionsweise heterolog exprimierter Rezeptoren auswirken. Dies zeigt wie wichtig die Wahl der Zellen für solche Screeningsysteme ist. N2 - Screening for new sweeteners or sweet taste modulators by the use of heterologous expression systems is an easy and fast way without time- and cost-intensive sensory studies. Using such cell based expression systems we could show that the main components of the so far undescribed Vietnamese plant Mycetia balansae activate specifically the human sweet taste receptor TAS1R2-TAS1R3. Analysis of chimeric receptors revealed that the TAS1R2-TAS1R3 amino-terminal domain is not involved in the sweet taste receptor activation by balansin A, one of the main components of Mycetia balansae. The usage of such heterologous expression systems strongly depends on their predictive value, e.g. neither false-positives nor false-negatives shall occur when screening for new sweeteners. However, HEK293 TAS1R2 TAS1R3To Galpha15i3 cells showed sweet taste receptor activation for substances that were not perceived as sweet by a sensory panel. The analysis of further cell based systems revealed the HEK293PEAKrapid Galpha15 cell line as a reliable test system that reflected the sweet taste of the analyzed test compounds. These cell systems differ in their heterologously expressed G protein. Nevertheless, this does not explain the different responses of the cell systems. Although the G protein influences their signal amplitudes, none of the analyzed G protein chimeras showed an activation pattern that reflected the sweet taste of the test compounds. No indication was found that accessory proteins or related receptors like the calcium sensing receptor or the GPRC6A are responsible for the different behavior of these cell systems. First hints for an interaction of the human calcium sensing receptor and the sweet taste receptor subunits were observed. Vanillin and Ethylvanillin were identified as new calcium sensing receptor agonists. It appears as small differences in cellular background can strongly influence on the function of heterologously expressed receptors. KW - Süßrezeptor KW - Süßgeschmack KW - Süßstoff KW - Rezeptorscreening KW - sweet taste KW - sweet taste receptor KW - sweetener KW - taste receptor screening KW - HEK293 Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-93331 ER - TY - THES A1 - Brachs, Maria T1 - Genome wide expression analysis and metabolic mechanisms predicting body weight maintenance T1 - Genomweite Expressions-Analyse und metabolische Mechanismen bestimmen den Körpergewichtserhalt N2 - Obesity is a major health problem for many developing and industrial countries. Increasing rates reach almost 50 % of the population in some countries and related metabolic diseases including cardiovascular events and T2DM are challenging the health systems. Adiposity, an increase in body fat mass, is a major hallmark of obesity. Adipose tissue is long known not only to store lipids but also to influence whole-body metabolism including food intake, energy expenditure and insulin sensitivity. Adipocytes can store lipids and thereby protect other tissue from lipotoxic damage. However, if the energy intake is higher than the energy expenditure over a sustained time period, adipose tissue will expand. This can lead to an impaired adipose tissue function resulting in higher levels of plasma lipids, which can affect other tissue like skeletal muscle, finally leading to metabolic complications. Several studies showed beneficial metabolic effects of weight reduction in obese subjects immediately after weight loss. However, weight regain is frequently observed along with potential negative effects on cardiovascular risk factors and a high intra-individual response. We performed a body weight maintenance study investigating the mechanisms of weight maintenance after intended WR. Therefore we used a low caloric diet followed by a 12-month life-style intervention. Comprehensive phenotyping including fat and muscle biopsies was conducted to investigate hormonal as well as metabolic influences on body weight regulation. In this study, we showed that weight reduction has numerous potentially beneficial effects on metabolic parameters. After 3-month WR subjects showed significant weight and fat mass reduction, lower TG levels as well as higher insulin sensitivity. Using RNA-Seq to analyse whole fat and muscle transcriptome a strong impact of weight reduction on adipose tissue gene expression was observed. Gene expression alterations over weight reduction included several cellular metabolic genes involved in lipid and glucose metabolism as well as insulin signalling and regulatory pathways. These changes were also associated with anthropometric parameters assigning body composition. Our data indicated that weight reduction leads to a decreased expression of several lipid catabolic as well as anabolic genes. Long-term body weight maintenance might be influenced by several parameters including hormones, metabolic intermediates as well as the transcriptional landscape of metabolic active tissues. Our data showed that genes involved in biosynthesis of unsaturated fatty acids might influence the BMI 18-month after a weight reduction phase. This was further supported by analysing metabolic parameters including RQ and FFA levels. We could show that subjects maintaining their lost body weight had a higher RQ and lower FFA levels, indicating increased metabolic flexibility in subjects. Using this transcriptomic approach we hypothesize that low expression levels of lipid synthetic genes in adipose tissue together with a higher mitochondrial activity in skeletal muscle tissue might be beneficial in terms of body weight maintenance. N2 - Die Adipositas hat sich in den letzten Jahren zu einem deutlichen Gesundheitsproblem in Industrie- und Entwicklungsländern entwickelt. So sind in einigen Länder bis zu 50 % der Bevölkerung übergewichtig und Begleiterkrankungen wie Herzkreislauferkrankungen und Typ 2 Diabetes belasten das Gesundheitssystem. Ein Anstieg der Körperfettmasse spielt bei der Adipositas eine große Rolle. Mittlerweile ist bekannt, dass Fettgewebe nicht nur Lipide speichert, sondern auch den Gesamtmetabolismus wie Nahrungsaufnahme, Energieumsatz und Insulinsensitivität beeinflusst. Lipide werden in Adipozyten gespeichert und verhindern so eine vermehrte Fetteinlagerung in andere Gewebe. Somit stellt das Fettgewebe ein wichtiges Organ dar, das andere periphere Gewebe vor dem toxischen Effekt erhöhter Lipidspiegel schütz. Ist über einen längeren Zeitraum die Energiezufuhr höher als der Energieverbrauch, kommt es zu einer Expansion des Fettgewebes. Dies kann im weiteren Verlauf zu einer Dysfunktion der Adipozyten und des Fettgewebes führen. Erhöhte Lipidspiegel können dann nicht mehr im Fettgewebe gespeichert werden und es kommt zu einer Anreicherung in der Peripherie. Vor allem das Muskelgewebe und die Leber sind hiervon betroffen, was zu weiteren metabolischen Komplikationen führt. Eine Gewichtsreduktion führt in adipösen Personen zu einer Verbesserung zahlreicher metabolischer Parameter. Diverse Studien zeigten jedoch, dass nur ein geringer Anteil dieser Personen in der Lage waren, das reduzierte Körpergewicht zu erhalten. Diese Wiederzunahme des Körpergewichts führt unter anderem zu einer Erhöhung des kardiovaskulären Risikos. Im Allgemeinen ist eine hohe Variabilität bei der Gewichtsreduktion und der Wiederzunahme zu beobachten. Diese Arbeit basiert auf Daten einer Studie, die Effekte einer Gewichtsreduktion auf den Gewichtserhalt untersucht. Nach einer 3-monatigen Gewichtsreduktion mittels einer niederkalorischen Diät wurden die Probanden in Kontroll- und Interventionsgruppe eingeteilt. Anthropometrische sowie metabolische Parameter inklusive Muskel- und Fettgewebsbiopsien wurden erfasst. In dieser Studie konnte gezeigt werden, dass eine Gewichtsreduktion verschiedenste positive Auswirkungen auf den Metabolismus der Teilnehmer hat. Die Probanden zeigten nach 3-monatiger Gewichtsreduktion eine signifikante Reduktion des Körpergewichts und der Fettmasse, erniedrigte Triglyzerid Spiegel und eine verbesserte Insulinsensitivität. Mittels RNA-Seq konnten wir zusätzlich zeigen, dass eine Gewichtsreduktion deutliche Auswirkungen auf das Transkriptom des Fettgewebes besitzt. Unter anderem wurden Genexpressionsveränderungen im Bereich zell-metabolischer Gene wie Lipid- und Glukosestoffwechsel als auch im Bereich des Insulinsignalweges und regulatorischer Gene ermittelt. Diese Expressionsveränderungen zeigten auch einen Zusammenhang mit dem BMI. Unsere Daten weisen darauf hin, dass eine Gewichtsreduktion zu einer Erniedrigung der Expression von Genen im Fettstoffwechsel führt. Ein langfristiger Gewichtserhalt wird durch zahlreiche Parameter wie Hormone, Stoffwechselintermediate und vermutlich auch den transkriptionellen Zustand im metabolisch aktiven Gewebe beeinflusst. Die hier gezeigten Daten deuten darauf hin, dass Gene beteiligt in der Biosynthese von ungesättigten Fettsäuren den BMI 18 Monate nach einer Gewichtsreduktion beeinflussen. Weitere Analysen in Bezug auf den RQ und die FFA Spiegel bestätigen diese Daten. Wir konnten zeigen, dass der Gewichtserhalt mit einem erhöhten RQ und niedrigen FFA Spiegel korrelierten. Dies könnte auf eine erhöhte metabolische Flexibilität in Personen mit Gewichtserhalt hinweisen. Aufgrund dieser Daten spekulieren wir, dass eine niedrige Expression von Lipidsynthese-Genen im Fettgewebe zusammen mit einer erhöhten mitochondrialen Aktivität im Skeletmuskel einen positiven Einfluss auf einen langfristigen Gewichtserhalt besitzt. KW - obesity KW - body weight loss KW - RNA Sequencing KW - body weight maintenance KW - Adipositas KW - Körpergewichtsverlust KW - RNA Sequenzierung KW - Körpergewichsterhalt Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-100767 ER - TY - JOUR A1 - Menendez, Orquidea A1 - Rawel, Harshadrai Manilal A1 - Schwarzenbolz, Uwe A1 - Henle, Thomas T1 - Structural changes of microbial transglutaminase during thermal and high-pressure treatment N2 - The activity of microbial transglutaminase (MTG) and the corresponding secondary structure, measured by circular dichroism (CID), was analyzed before and after treatment at different temperatures (40 and 80 degrees C) and pressures (0.1, 200, 400, 600 MPa). Irreversible enzyme inactivation was achieved after 2 min at 80 degrees C and 0.1 MPa. Enzyme inactivation at 0.1, 200, 400, and 600 MPa and 40 degrees C followed first-order kinetics. The enzyme showed residual activity of 50% after 12 min at 600 MPa and 40 degrees C. Mobility of aromatic side chains of the enzyme molecule was observed in all temperature- and/or pressure-treated samples; however, high-pressure treatment at 600 MPa induced a loss of tertiary structure and a significant decrease in the alpha-helix content. The relative content of beta- strand substructures was significantly increased after 30 min at 600 MPa and 40 degrees C or 2 min at 0.1 MPa and 80 degrees C. We conclude that the active center of MTG, which is located in an expanded 8-strand domain, is resistant to high hydrostatic pressure and pressure-induced inactivation is caused by destruction of cc-helix elements with a corresponding influence on the enzyme stability in solution Y1 - 2006 UR - http://pubs.acs.org/journal/jafcau U6 - https://doi.org/10.1021/Jf0522863 ER - TY - JOUR A1 - Garcia, Ada A1 - Wagner, Karen A1 - Einig, Christiana A1 - Trippo, Ulrike A1 - Koebnick, Corinna A1 - Zunft, Hans-Joachim Franz T1 - Evaluation of body fat changes during weight loss by using improved anthropometric predictive equations N2 - Background/Aim: Skinfold-based equations are widely used to evaluate body fat (BF), but over-/underestimation is often reported. We evaluate the capacity of improved skinfold-based equations to estimate BF changes during weight reduction and compare them against well-established equations. Methods: Overweight adults (n = 44) participated in a 4- month weight reduction intervention. Dual-energy X-ray absorptiometry (DXA) and anthropometric measurements were taken at baseline and after intervention. The BF% was calculated using Garcia, Peterson, and Durnin and Womersley (DW) equations. Results: Baseline and postintervention BF% measured by DXA correlated highest with BF% predicted according to Garcia (r = 0.934 and r = 0.948, respectively), followed by Peterson (r = 0.941 and r = 0.932, respectively) and DW (r = 0.557 and r = 0.402, respectively); only a slight systematic error in overestimating the BF% was observed in estimates according to Garcia (r = 0.147 and r = 0.104, respectively; p < 0.001), while increasing errors occurred using the Peterson (r = 0.624 and r = 0.712, respectively; p < 0.001) and DW (r = 0.767 and r = 0.769, respectively; p < 0.001) equations. Moderate correlations between BF changes (kg) measured by DXA and predicted by DW (r = 0.7211), Peterson (r = 0.697), and Garcia (r = 0.645) were observed. Conclusion: Improved skin-fold equations cannot accurately measure changes in BF after weight reduction Y1 - 2006 UR - http://content.karger.com/ProdukteDB/produkte.asp?Aktion=JournalHome&ProduktNr=223977 U6 - https://doi.org/10.1159/000092601 SN - 0250-6807 ER - TY - JOUR A1 - Simchen, U A1 - Koebnick, Corinna A1 - Hoyer, Stephan W. A1 - Issanchou, S A1 - Zunft, Hans-Joachim Franz T1 - Odour and taste sensitivity is associated with body weight and extent of misreporting of body weight N2 - Background: Sensory factors are important determinants of appetite and food choices but little is known about the relationship between body weight and sensory capabilities. Objective: To investigate the relationship between measured body weights, misreporting of body weight and sensory capabilities. Design: In a cross-sectional sensory study, body weight was assessed by measured and self-reported body weight in healthy men ( n = 130) and women ( n = 181). Sensory capabilities were assessed as odour detection and identification, and detection for salty, sweet, sour and bitter taste. Results: Odour detection, odour identification and taste perception scores were lower in subjects with a BMI >= 28 kg/m(2) than in subjects with a BMI < 28 kg/m(2) in the age group < 65 years whereas in subjects >= 65 years scores were higher in subjects with a BMI >= 28 kg/m(2) than in subjects with a BMI < 28 kg/m(2) ( BMI*age group: P = 0.015, 0.053 and 0.015, respectively). Independent of age, scores were highest in under reporters of body weight ( P = 0.008, 0.001 and 0.017). Differences in taste perception could be attributed to sour ( P 0.015) and bitter ( P = 0.026) perception, but not to salty or sweet perception. Conclusion: Relationship between sensory capabilities and body mass is age dependent. Compared to overweight subjects, the sensory capabilities of normal weight individuals appear to be higher ( < 65 years) and lower ( >= 65 years). At any age, however, subjects who under reported their body weight show higher sensory capabilities Y1 - 2006 ER - TY - JOUR A1 - Andert, Christoph U. A1 - Sanchaisuriya, Pattara A1 - Sanchaisuriya, Kanokwan A1 - Schelp, Frank P. A1 - Schweigert, Florian J. T1 - Nutritional status of pregnant women in Northeast Thailand N2 - A comparative study on the nutritional status of primiparous and multiparous women in the first trimester of pregnancy was conducted in the northeastern province of Thailand, Khon Kaen, to investigate differences in protein- energy-mal nutrition, iron deficiency anaemia, vitamin A deficiency and carotenoid status between both parity groups. 94 subjects were recruited at first attendance of antenatal clinic. Data about weight, height, haemoglobin and haematocrit were obtained from hospital records. Anthropometric measurements of mid-upper arm circumference and triceps skinfold were done on a sub sample. Retinol, carotenoids and alpha-tocopherol were analysed using a reversed-phase high- performance liquid chromatography method. Ferritin, transthyretin and retinol-binding protein were determined by enzyme- linked immunosorbent assay. Primiparous women showed lower body mass index, mid-upper arm circumference, corrected arm muscle area (P <0.001) as well as lower retinol, cholesterol and triceps skinfold (P <0.05). After adjusting for age and socio-economical status the significant difference persisted for all parameters but triceps skinfold. No significant differences of alpha-tocopherol, serum proteins, carotenoids and iron indices could be observed, even though a tendency to higher values for ferritin, haemoglobin and haematocrit was shown in multiparous women. Prevalence of protein-energy- malnutrition (body mass index <18.5 kg/m(2)) in the primiparous group was significantly higher compared to the multiparous group (P<0.05). Prevalence of protein-energy-malnutrition, iron deficiency anaemia and vitamin A deficiency were 15.1%, 6.3% and 3.3%, respectively, in the total study population. No differences between parity groups could be observed for prevalence of iron deficiency anaemia and vitamin A deficiency Y1 - 2006 UR - http://www.healthyeatingclub.com/APJCN/ SN - 0964-7058 ER - TY - THES A1 - Winnig, Marcel T1 - Struktur-Wirkungsbeziehungen der Süßgeschmachsrezeptoren des Menschen und der Ratte Y1 - 2006 CY - Potsdam ER - TY - JOUR A1 - Raila, Jens A1 - Forterre, Simone A1 - Schweigert, Florian J. T1 - Markerproteine im Harn von Hunden Y1 - 2005 SN - 3-8304-1051-4 ER - TY - THES A1 - Brune, Nicole Erna Irene T1 - Charakterisierung der intrazellulären Transportmechanismen von Somatostatinrezeptoren der Subtypen 1 und 3 der Ratte Y1 - 2005 CY - Potsdam ER - TY - THES A1 - Fritzsche, Britta T1 - Einfluss Retinsäure-metabolisierender Enzyme auf die Implanttion und die frühe Gestation in den Modelltieren Maus und Ratte Y1 - 2005 ER - TY - JOUR A1 - Garcia, Ada A1 - Wagner, Karen A1 - Hothorn, T. A1 - Koebnick, Corinna A1 - Zunft, Hans-Joachim Franz A1 - Trippo, Ulrike T1 - Improved prediction of body fat by measuring skinfold thickness, circumferences, and bone breadths N2 - Objective: To develop improved predictive regression equations for body fat content derived from common anthropometric measurements. Research Methods and Procedures: 117 healthy German subjects, 46 men and 71 women, 26 to 67 years of age, from two different studies were assigned to a validation and a cross-validation group. Common anthropornetric measurements and body composition by DXA were obtained. Equations using anthropometric measurements predicting body fat mass (BFM) with DXA as a reference method were developed using regression models. Results: The final best predictive sex-specific equations combining skinfold thicknesses (SF), circumferences, and bone breadth measurements were as follows: BFMNew (kg) for men = -40.750 + {(0.397 x waist circumference) + [6.568 x (log triceps SF + log subscapular SF + log abdominal SF)]} and BFMNew (kg) for women = -75.231 + {(0.512 x hip circumference) + [8.889 x (log chin SF + log triceps SF + log subscapular SF)] + (1.905 x knee breadth)}. The estimates of BFM from both validation and cross-validation had an excellent correlation, showed excellent correspondence to the DXA estimates, and showed a negligible tendency to underestimate percent body fat in subjects with higher BFM compared with equations using a two-compartment (Durnin and Womersley) or a four-compartment (Peterson) model as the reference method. Discussion: Combining skinfold thicknesses with circumference and/or bone breadth measures provide a more precise prediction of percent body fat in comparison with established SF equations. Our equations are recommended for use in clinical or epidemiological settings in populations with similar ethnic background Y1 - 2005 SN - 1071-7323 ER - TY - THES A1 - Lehner-Wieternik, Angelika T1 - Die Bedeutung des Instruktionsdesigns für die Entwicklung und Gestaltung computerbasierter Lehr- und Lernsysteme Y1 - 2005 ER - TY - JOUR A1 - Banning, Anja A1 - Deubel, S. A1 - Kluth, Dirk A1 - Zhou, Z. W. A1 - Brigelius-Flohé, Regina T1 - The GI-GPx gene is a target for Nrf2 N2 - The gastrointestinal glutathione peroxidase (GI-GPx, GPx2) is a selenoprotein that was suggested to act as barrier against hydroperoxide absorption but has also been implicated in the control of inflammation and malignant growth. In CaCo-2 cells, GI-GPx was induced by t-butyl hydroquinone (tBHQ) and sulforaphane (SFN), i.e., "antioxidants" known to activate the "antioxidant response element" (ARE) via electrophilic thiol modification of Keap1 in the Nrf2/ Keap1 system. The functional significance of a putative ARE in the GI-GPx promoter was validated by transcriptional activation of reporter gene constructs upon exposure to electrophiles (tBHQ, SFN, and curcumin) or overexpression of Nrf2 and by reversal of these effects by mutation of the ARE in the promoter and by overexpressed Keap1. Binding of Nrf2 to the ARE sequence in authentic gpx2 was corroborated by chromatin immunoprecipitation. Thus, the presumed natural antioxidants sulforaphane and curcumin may exert their anti-inflammatory and anticarcinogenic effects not only by induction of phase 2 enzymes but also by the up-regulation of the selenoprotein GI-GPx Y1 - 2005 SN - 0270-7306 ER - TY - JOUR A1 - Schweigert, Florian J. A1 - Sehouli, Jalid T1 - Transthyretin, a biomarker for nutritional status and ovarian cancer Y1 - 2005 SN - 0008-5472 ER - TY - JOUR A1 - Koebnick, Corinna A1 - Wagner, K. A1 - Thielecke, F. A1 - Dieter, G. A1 - Hohne, A. A1 - Franke, A. A1 - Garcia, Ada A1 - Meyer, H. A1 - Hoffmann, I. A1 - Leitzmann, P. A1 - Trippo, U. A1 - Zunft, Hans-Joachim Franz T1 - An easy-to-use semiquantitative food record validated for energy intake by using doubly labelled water technique N2 - Background: Estimating dietary intake is important for both epidemiological and clinical studies, but often lacks accuracy. Objective: To investigate the accuracy and validity of energy intake estimated by an easy-to-use semiquantitative food record (EISQFR) compared to total energy expenditure ( TEE) estimated by doubly labelled water technique (EEDLW). Design: TEE was measured in 29 nonobese subjects using the doubly labelled water method over a period of 14 days. Within this period, subjects reported their food consumption by a newly developed semiquantitative food record for 4 consecutive days. Energy intake was calculated using the German Food Code and Nutrition Data Base BLS II.3. Results: A good correlation was observed between EISQFR and EEDLW (r = 0.685, P<0.001). The mean difference between EISQFR and EEDLW was - 1.7 +/- 2.6 MJ/ day ( - 14 +/- 21%, P = 0.002). An underestimation of EISQFR <10% was observed in nine subjects (31%), of 10 - 20% in six subjects (21%), and of >20% in nine subjects (31%). In five subjects (17%), an overestimation of EISQFR was observed. Conclusions: The easy-to-use semiquantitative food record provided good estimates of EI in free-living and nonobese adults without prior detailed verbal instructions. The presented food record has limitations regarding accuracy at the individual level Y1 - 2005 SN - 0954-3007 ER - TY - JOUR A1 - Koebnick, Corinna A1 - Wagner, K. A1 - Thielecke, F. A1 - Moeseneder, Jutta A1 - Hoehne, A. A1 - Franke, A. A1 - Meyer, H. A1 - Garcia, Ada A1 - Trippo, U. A1 - Zunft, Hans-Joachim Franz T1 - Validation of a simplified physical activity record by doubly labeled water technique N2 - INTRODUCTION: For obtaining reliable information about physical activity in epidemiological studies, validated and easy-to-use instruments are required. Therefore, a new simplified physical activity record based on 15-min recording intervals was developed and validated. SUBJECTS: Nonobese volunteers (n = 31). MEASUREMENTS: Physical activity was recorded over a 7-day period without detailed instructions. Energy expenditure was calculated (EEsPAR) and compared to energy expenditure measured by doubly labelled water technique (EEDLW). RESULTS: A good agreement between EEsPAR (12.1 +/ 3.0) and EEDLW (11.7 +/- 3.3) with a mean difference of 0.33 +/- 1.55 MJ (r = 0.880, P < 0.001) was observed. The absolute difference between EEsPAR and EEDLW was <10% in 65% of the subjects. The difference between EEsPAR and EEDLW was independent of gender, age, body weight, and body mass index. A weak positive association between the difference and total body fat was observed (r = 0.618, P < 0.001), suggesting a slight tendency to overestimate EEsPAR with increasing total body fat. CONCLUSION: The new simplified physical activity protocol needs no detailed instructions, provides valid estimates of physical activity in nonobese free-living adults and can be used in epidemiological studies to assess total daily energy expenditure and physical activity level Y1 - 2005 SN - 0307-0565 ER - TY - JOUR A1 - Hoie, Lars H. A1 - Morgenstern, E. C. A. A1 - Grünwald, Jörg A1 - Graubaum, Hans-Joachim A1 - Busch, R. A1 - Luder, W. A1 - Zunft, Hans-Joachim Franz T1 - A double-blind placebo-controlled clinical trial compares the cholesterollowering effects of two different soy protein preparations in hypercholesterolemic subjects N2 - Background Soy protein is effective in lowering plasma cholesterol, LDL cholesterol and triglyceride concentrations. It has not been conclusively answered, whether and to what extent other soy constituents may also contribute to this effect. Objective To investigate the change in blood lipid levels after application of two soy-based supplements containing soy protein either without (SuproSoy(R)) or with (Abacor(R)) soy fiber and phospholipids in a randomized placebo-controlled triple-armed study. Methods 121 hypercholesterolemic adults ( 66 females, 55 males) were recruited and randomly assigned to one of three treatments. Over 8 weeks they received daily either 25 g soy protein ( as a component of the supplements Abacor(R) or SuproSoy(R)) or 25 g milk protein ( as a component of placebo). Serum lipids were measured at baseline and after 4, 6 and 8 weeks. Results After 8 weeks of supplementation total cholesterol levels were reduced by 8.0 +/- 9.6% (Abacor(R)) and 3.4 +/- 8.3% (SuproSoy(R)); LDL cholesterol levels by 9.7 +/- 11.7% ( Abacor(R)) and 5.4 +/- 11.6% ( SuproSoy(R)); and Apolipoprotein B levels by 6.9 +/- 14.6% (Abacor(R)) and 4.0 +/- 12.4 % (SuproSoy(R)). Serum levels of HDL cholesterol and triglycerides remained unchanged. Conclusions A preparation combining isolated soy protein with soy fibers and phospholipids showed twice the lipid-lowering effect of a preparation containing isolated soy protein alone. Therefore, such soy-based supplements can be useful in reducing the cardiovascular risk Y1 - 2005 SN - 1436-6207 ER - TY - JOUR A1 - Jurrmann, Nadine A1 - Brigelius-Flohé, Regina A1 - Böl, Gaby Fleur T1 - Curcumin blocks interleukin-1 (IL-1) signaling by inhibiting the recruitment of the IL-1 receptor-associated kinase IRAK in murine thymoma EL-4 cells N2 - Curcumin is a dietary compound with diverse anti-inflammatory and anticarcinogenic effects in several experimental models. A mechanism by which curcumin exerts these actions might be the direct modification of protein thiols, thereby altering the activity of the affected proteins. An early event in inflammatory signaling cascades is the recruitment of the interleukin-1 (IL-1) receptor-associated kinase (IRAK) to the IL-1 receptor (IL-1 RI) upon stimulation with IL-1. IRAK recruitment was shown recently to be inhibited by agents that modify thiols of IRAK. We asked, therefore, whether IRAK is also a target for curcumin. Curcumin indeed blocked IRAK thiols in a murine T-cell line stably overexpressing IRAK (EL-4(IRAK)), which resulted in the inhibition of IRAK recruitment to the IL-1RI and phosphorylation of IRAK and IL-1RI-associated proteins. Inhibitory effects were not reversible by thiol-reducing agents. Thus, modification by curcumin did not occur by oxidation but rather by alkylation, as is typical for electrophilic compounds reacting as Michael addition acceptors. The block in one of the earliest events in the IL-1 signaling cascade can explain the often observed inhibition of IL-1-mediated signaling steps by curcumin further downstream. Hence, thiol modification might be a crucial step in the anti-inflammatory functions of curcumin Y1 - 2005 SN - 0022-3166 ER - TY - JOUR A1 - Kotz, S. A. A1 - Gunter, T. C. A1 - Wonneberger, S. T1 - The basal ganglia are receptive to rhythmic compensation during auditory syntactic processing : ERP patient data Y1 - 2005 SN - 0093-934X ER - TY - JOUR A1 - Schweigert, Florian J. A1 - Raila, Jens T1 - Inadequate attempts to measure the microheterogeneity of transthyretin by low-resolution mass spectrometry : Response Y1 - 2005 SN - 0009-9147 ER - TY - JOUR A1 - Hammes, Annette A1 - Andreassen, Thomas K. A1 - Spoelgen, Robert A1 - Raila, Jens A1 - Hubner, Norbert A1 - Schulz, Herbert A1 - Metzger, Jochen A1 - Schweigert, Florian J. A1 - Luppa, Peter B. A1 - Nykjaer, Andreas A1 - Willnow, Thomas E. T1 - Role of endocytosis in cellular uptake of sex steroids N2 - Androgens and estrogens are transported bound to the sex hormone binding globulin (SHBG). SHBG is believed to keep sex steroids inactive and to control the amount of free hormones that enter cells by passive diffusion. Contrary to the free hormone hypothesis, we demonstrate that megalin, an endocytic receptor in reproductive tissues, acts as a pathway for cellular uptake of biologically active androgens and estrogens bound to SHBG. In line with this function, lack of receptor expression in megalin knockout mice results in impaired descent of the testes into the scrotum in males and blockade of vagina opening in females. Both processes are critically dependent on sex-steroid signaling, and similar defects are seen in animals treated with androgen- or estrogen-receptor antagonists. Thus, our findings uncover the existence of endocytic pathways for protein bound androgens and estrogens and their crucial role in development of the reproductive organs Y1 - 2005 SN - 0092-8674 ER - TY - JOUR A1 - Singh, Jasbir A1 - Singh, S. A1 - Dani, H. M. A1 - Sharma, Reeta A1 - Steinberg, Pablo T1 - Interactions of aflatoxin B-1 with SRP components can disrupt protein targeting N2 - Spectrofluorimetric studies have revealed that aflatoxin B-1 (AFB(1)) interacts with signal recognition particle (SRP), which acts as an escort for polyribosomes with signal peptides to be transported and bound to the cytoplasmic face of the endoplasmic reticulum (ER). We further report that the binding of AFB(1) to SRP is selective as it only binds to two (SRP9 and 14) out of its three constituent polypeptides studied. Binding of AFB(1) to proteins is known to alter their conformations. Interactions of AFB(1) with SRP polypeptides may generate structural and functional alterations in this particle and hinder secretory protein synthesis. Copyright (C) 2004 John Wiley Sons, Ltd Y1 - 2005 SN - 0263-6484 ER - TY - JOUR A1 - Rohn, Sascha A1 - Rawel, Harshadrai Manilal A1 - Rober, M. A1 - Kroll, Jürgen T1 - Reactions with phenolic substances can induce changes in some physico-chemical properties and activities of bromelain - the consequences for supplementary food products N2 - Bromelain was allowed to react with phenolic compounds. The activity and selected physico-chemical properties of the resulting derivatives were characterized. In vitro experiments showed that the proteolytic activity of bromelain was inhibited. Bromelain also serves as a food protein, because food stuffs based on pineapple contain relatively high concentrations of bromelain. In vitro digestion of bromelain derivatives with the main proteolytic enzymes of the gastrointestinal tract was also adversely affected. A covalent attachment of the phenolic compounds was identified at the tryptophan, free amino (lysines and N-terminal) and thiol groups of bromelain. A decrease in solubility of the derivatives was observed. The isoelectric point was shifted to lower pH values and high molecular weight fractions were identified. All effects observed depended on the reactivity of the phenolic substances. Two supplementary food products containing both bromelain and quercetin were also tested in terms of their proteolytic activity and digestibility Y1 - 2005 SN - 0950-5423 ER -