@article{WirschingGrassmannEichelmannetal.2018, author = {Wirsching, Jan and Grassmann, Sophie and Eichelmann, Fabian and Harms, Laura Malin and Schenk, Matthew and Barth, Eva and Berndzen, Alide and Olalekan, Moses and Sarmini, Leen and Zuberer, Hedwig and Aleksandrova, Krasimira}, title = {Development and reliability assessment of a new quality appraisal tool for cross-sectional studies using biomarker data (BIOCROSS)}, series = {BMC Medical Research Methodology}, volume = {18}, journal = {BMC Medical Research Methodology}, publisher = {BMC}, address = {London}, issn = {1471-2288}, doi = {10.1186/s12874-018-0583-x}, pages = {8}, year = {2018}, abstract = {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.}, language = {en} } @article{WernoWilhelmiKuropkaetal.2018, author = {Werno, Martin Witold and Wilhelmi, Ilka and Kuropka, Benno and Ebert, Franziska and Freund, Christian and Sch{\"u}rmann, Annette}, title = {The GTPase ARFRP1 affects lipid droplet protein composition and triglyceride release from intracellular storage of intestinal Caco-2 cells}, series = {Biochemical and biophysical research communications}, volume = {506}, journal = {Biochemical and biophysical research communications}, number = {1}, publisher = {Elsevier}, address = {San Diego}, issn = {0006-291X}, doi = {10.1016/j.bbrc.2018.10.092}, pages = {259 -- 265}, year = {2018}, abstract = {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.}, language = {en} } @phdthesis{Weiss2018, author = {Weiß, Stefanie}, title = {Contribution of bacterially synthesized folate vitamers to folate status and impact on crohn's Disease}, school = {Universit{\"a}t Potsdam}, pages = {148}, year = {2018}, language = {en} } @phdthesis{Waizenegger2018, author = {Waizenegger, Julia}, title = {Untersuchung der molekularen Toxizit{\"a}t von Pyrrolizidinalkaloiden in der humanen Hepatomzelllinie HepaRG}, school = {Universit{\"a}t Potsdam}, pages = {129, XLI}, year = {2018}, language = {de} } @article{vonWebskyHasanReichetzederetal.2018, author = {von Websky, Karoline and Hasan, Ahmed Abdallah Abdalrahman Mohamed and Reichetzeder, Christoph and Tsuprykov, Oleg and Hocher, Berthold}, title = {Impact of vitamin D on pregnancy-related disorders and on offspring outcome}, series = {The Journal of Steroid Biochemistry and Molecular Biology}, volume = {180}, journal = {The Journal of Steroid Biochemistry and Molecular Biology}, publisher = {Elsevier}, address = {Oxford}, issn = {0960-0760}, doi = {10.1016/j.jsbmb.2017.11.008}, pages = {51 -- 64}, year = {2018}, abstract = {Observational studies from all over the world continue to find high prevalence rates of vitamin D insufficiency and deficiency in many populations, including pregnant women. Beyond its classical function as a regulator of calcium and phosphate metabolism, vitamin D elicits numerous effects in the human body. Current evidence highlights a vital role of vitamin D in mammalian gestation. During pregnancy, adaptations in maternal vitamin D metabolism lead to a physiologic increase of vitamin D levels, mainly because of an increased renal production, although other potential sources like the placenta are being discussed. A sufficient supply of mother and child with calcium and vitamin D during pregnancy ensures a healthy bone development of the fetus, whereas lack of either of these nutrients can lead to the development of rickets in the child. Moreover, vitamin D insufficiency during pregnancy has consistently been associated with adverse maternal and neonatal pregnancy outcomes. In multitudinous studies, low maternal vitamin D status was associated with a higher risk for pre-eclampsia, gestational diabetes mellitus and other gestational diseases. Likewise, several negative consequences for the fetus have been reported, including fetal growth restriction, increased risk of preterm birth and a changed susceptibility for later-life diseases. However, study results are diverging and causality has not been proven so far. Meta-analyses on the relationship between maternal vitamin D status and pregnancy outcomes revealed a wide heterogeneity of studied populations and the applied methodology in vitamin D assessment. Until today, clinical guidelines for supplementation cannot be based on high-quality evidence and it is not clear if the required intake for pregnant women differs from non-pregnant women. Long-term safety data of vitamin D supplementation in pregnant women has not been established and overdosing of vitamin D might have unfavorable effects, especially in mothers and newborns with mutations of genes involved in vitamin D metabolism. Reliable data from large observational and interventional randomized control trials are urgently needed as a basis for any detailed and safe recommendations for supplementation in the general population and, most importantly, in pregnant women. This is of utmost importance, as ensuring a sufficient vitamin D-supply of mother and child implies a great potential for the prevention of birth complications and development of diseases.}, language = {en} } @article{VogelKamitzHallahanetal.2018, author = {Vogel, Heike and Kamitz, Anne and Hallahan, Nicole and Lebek, Sandra and Schallschmidt, Tanja and Jonas, Wenke and J{\"a}hnert, Markus and Gottmann, Pascal and Zellner, Lisa and Kanzleiter, Timo and Damen, Mareike and Altenhofen, Delsi and Burkhardt, Ralph and Renner, Simone and Dahlhoff, Maik and Wolf, Eckhard and M{\"u}ller, Timo Dirk and Bl{\"u}her, Matthias and Joost, Hans-Georg and Chadt, Alexandra and Al-Hasani, Hadi and Sch{\"u}rmann, Annette}, title = {A collective diabetes cross in combination with a computational framework to dissect the genetics of human obesity and Type 2 diabetes}, series = {Human molecular genetics}, volume = {27}, journal = {Human molecular genetics}, number = {17}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0964-6906}, doi = {10.1093/hmg/ddy217}, pages = {3099 -- 3112}, year = {2018}, abstract = {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.}, language = {en} } @misc{UhligGehreKammereretal.2018, author = {Uhlig, Katja and Gehre, Christian P. and Kammerer, Sarah and K{\"u}pper, Jan-Heiner and Coleman, Charles Dominic and P{\"u}schel, Gerhard Paul and Duschl, Claus}, title = {Real-time monitoring of oxygen consumption of hepatocytes in a microbioreactor}, series = {Toxicology letters}, volume = {295}, journal = {Toxicology letters}, publisher = {Elsevier}, address = {Clare}, issn = {0378-4274}, doi = {10.1016/j.toxlet.2018.06.652}, pages = {S115 -- S115}, year = {2018}, language = {en} } @article{TsuprykovBuseSkobloetal.2018, author = {Tsuprykov, Oleg and Buse, Claudia and Skoblo, Roman and Haq, Afrozul and Hocher, Berthold}, title = {Reference intervals for measured and calculated free 25-hydroxyvitamin D in normal pregnancy}, series = {The Journal of Steroid Biochemistry and Molecular Biology}, volume = {181}, journal = {The Journal of Steroid Biochemistry and Molecular Biology}, publisher = {Elsevier}, address = {Oxford}, issn = {0960-0760}, doi = {10.1016/j.jsbmb.2018.03.005}, pages = {80 -- 87}, year = {2018}, abstract = {The determination of free 25-hydroxyvitamin D (25(OH)D) as compared to the analysis of total 25-hydroxyvitamin D might reflect better the vitamin D status during pregnancy, since vitamin D-binding protein (DBP) concentrations increase throughout pregnancy and the vast majority of 25(OH)D is tightly bound to DBP thus strongly influencing total 25(OH)D. The concentration of the biologically active free 25(OH)D - on the other hand - is much less dependent on the DBP concentrations. The study was conducted in May-June 2016 in 368 Caucasian pregnant healthy women - residents of Northeastern Germany. Free 25(OH)D was either measured directly by commercial ELISA kit or assessed by calculation via total 25(OH)D, DBP, and albumin serum concentrations. Regardless of the detection method, free 25(OH)D lowers in the 3rd trimester comparing to the 1st trimester (by 12\% and 21\%, p < 0.05 and p < 0.001, for measured and calculated free 25(OH)D, respectively), whereas total 25(OH)D was not decreased in late pregnancy. DBP rises with gestational age. Total 25(OH)D was not correlated with serum calcium (p = 0.251), whereas free 25(OH)D was significantly (p = 0.007 for measured free 25(OH)D and p < 0.001 for calculated free 25(OH)D) positively correlated with calcium. All 25(OH) D isoforms were significantly negatively correlated with bone-specific alkaline phosphatase (BSAP), however the correlation strength was the lowest with total 25(OH)D (rho = -0.108, p = 0.038), whereas both measured and calculated free 25(OH)D revealed better associations with BSAP (rho = -0.203 and rho = -0.211 for measured and calculated free 25(OH)D, respectively, p < 0.001 for both). We established pregnancy trimester specific reference intervals for free measured and calculated 25(OH)D and DBP. Both measured and calculated free 25(OH)D showed better correlations with parameters of the endocrine vitamin D system (calcium and BSAP). Both ways of measuring free 25(OH)D in pregnant women are suitable as novel laboratory parameter for vitamin D status monitoring during human pregnancy and might replace in the future the routine total 25(OH)D assessment.}, language = {en} } @article{TaoSuXuetal.2018, author = {Tao, Ting and Su, Qiongli and Xu, Simeng and Deng, Jun and Zhou, Sichun and Zhuang, Yu and Huang, Yanjun and He, Caimei and He, Shanping and Peng, Mei and Hocher, Berthold and Yang, Xiaoping}, title = {Down-regulation of PKM2 decreases FASN expression in bladder cancer cells through AKT/mTOR/SREBP-1c axis}, series = {Journal of cellular physiology}, volume = {234}, journal = {Journal of cellular physiology}, number = {3}, publisher = {Wiley}, address = {Hoboken}, issn = {0021-9541}, doi = {10.1002/jcp.27129}, pages = {3088 -- 3104}, year = {2018}, abstract = {Fatty acid synthase (FASN) catalyzing the terminal steps in the de novo biogenesis of fatty acids is correlated with low survival and high disease recurrence in patients with bladder cancer. Pyruvate kinase M2 (PKM2) regulates the final step of glycolysis levels and provides a growth advantage to tumors. However, it is unclear whether the change of PKM2 has an effect on FASN and what is the mechanisms underlying. Here we describe a novel function of PKM2 in control of lipid metabolism by mediating transcriptional activation of FASN, showing the reduced expression of sterol regulatory element binding protein 1c (SREBP-1c). We first discovered that PKM2 physically interacts with the SREBP-1c using biochemical approaches, and downregulation of PKM2 reduced the expression of SREBP-1c by inactivating the AKT/mTOR signaling pathway, which in turn directly suppressed the transcription of major lipogenic genes FASN to reduce tumor growths. Furthermore, either PKM2 inhibitor-Shikonin or FASN inhibitor-TVB-3166 alone induced a strong antiproliferative and anticolony forming effect in bladder cancer cell line. The combination of both inhibitors exhibits a super synergistic effect on blocking the bladder cancer cells growth. It provides a new target and scientific basis for the treatment of bladder cancer.}, language = {en} } @misc{Steinberg2018, author = {Steinberg, Pablo}, title = {Only one Component of a holistic Nutrition Policy}, series = {Fleischwirtschaft}, volume = {98}, journal = {Fleischwirtschaft}, number = {11}, publisher = {Deutscher Fachverlag GmbH}, address = {Frankfurt am Main}, issn = {0015-363X}, pages = {8 -- 9}, year = {2018}, language = {de} } @article{SchwingshacklRuzanskaAntonetal.2018, author = {Schwingshackl, Lukas and Ruzanska, Ulrike Alexandra and Anton, Verena and Wallroth, Raphael and Ohla, Kathrin and Knueppel, Sven and Schulze, Matthias Bernd and Pischon, Tobias and Deutschbein, Johannes and Schenk, Liane and Warschburger, Petra and Harttig, Ulrich and Boeing, Heiner and Bergmann, Manuela M.}, title = {The NutriAct Family Study: a web-based prospective study on the epidemiological, psychological and sociological basis of food choice}, series = {BMC public health}, volume = {18}, journal = {BMC public health}, publisher = {BMC}, address = {London}, issn = {1471-2458}, doi = {10.1186/s12889-018-5814-x}, pages = {12}, year = {2018}, abstract = {Background: Most studies on food choice have been focussing on the individual level but familial aspects may also play an important role. This paper reports of a novel study that will focus on the familial aspects of the formation of food choice among men and women aged 50-70 years by recruiting spouses and siblings (NutriAct Family Study; NFS). Discussion: Until August 4th 2017, 4783 EPIC-Participants were contacted by mail of which 446 persons recruited 2 to 5 family members (including themselves) resulting in 1032 participants, of whom 82\% had started answering or already completed the questionnaires. Of the 4337 remaining EPIC-participants who had been contacted, 1040 (24\%) did not respond at all, and 3297 (76\%) responded but declined, in 51\% of the cases because of the request to recruit at least 2 family members in the respective age range. The developed recruitment procedures and web-based methods of data collection are capable to generate the required study population including the data on individual and inter-personal determinants which will be linkable to food choice. The information on familial links among the study participants will show the role of familial traits in midlife for the adoption of food choices supporting healthy aging.}, language = {en} } @misc{SchulzeMartinezGonzalezFungetal.2018, author = {Schulze, Matthias Bernd and Martinez-Gonzalez, Miguel A. and Fung, Teresa T. and Lichtenstein, Alice H. and Forouhi, Nita G.}, title = {Food based dietary patterns and chronic disease prevention}, series = {BMJ-British medical journal}, volume = {361}, journal = {BMJ-British medical journal}, publisher = {BMJ Publishing Group}, address = {London}, issn = {1756-1833}, doi = {10.1136/bmj.k2396}, pages = {6}, year = {2018}, abstract = {Matthias B Schulze and colleagues discuss current knowledge on the associations between dietary patterns and cancer, coronary heart disease, stroke, and type 2 diabetes, focusing on areas of uncertainty and future research directions.}, language = {en} } @misc{Schulze2018, author = {Schulze, Matthias Bernd}, title = {Metabolic health in normal-weight and obese individuals}, series = {Diabetologia : journal of the European Association for the Study of Diabetes (EASD)}, volume = {62}, journal = {Diabetologia : journal of the European Association for the Study of Diabetes (EASD)}, number = {4}, publisher = {Springer}, address = {New York}, issn = {0012-186X}, doi = {10.1007/s00125-018-4787-8}, pages = {558 -- 566}, year = {2018}, abstract = {Cardiovascular complications are commonly associated with obesity. However, a subgroup of obese individuals may not be at an increased risk for cardiovascular complications; these individuals are said to have metabolically healthy obesity (MHO). In contrast, metabolically unhealthy individuals are at high risk of cardiovascular disease (CVD), irrespective of BMI; thus, this group can include individuals within the normal weight category (BMI 18.5-24.9kg/m(2)). This review provides a summary of prospective studies on MHO and metabolically unhealthy normal-weight (MUHNW) phenotypes. Notably, there is ongoing dispute surrounding the concept of MHO, including the lack of a uniform definition and the potentially transient nature of metabolic health status. This review highlights the relevance of alternative measures of body fatness, specifically measures of fat distribution, for determining MHO and MUHNW. It also highlights alternative approaches of risk stratification, which account for the continuum of risk in relation to CVD, which is observable for most risk factors. Moreover, studies evaluating the transition from metabolically healthy to unhealthy phenotypes and potential determinants for such conversions are discussed. Finally, the review proposes several strategies for the use of epidemiological research to further inform the current debate on metabolic health and its determination across different stages of body fatness.}, language = {en} } @article{SammoudNevillNegraetal.2018, author = {Sammoud, Senda and Nevill, Alan Michael and Negra, Yassine and Bouguezzi, Raja and Chaabene, Helmi and Hachana, Younes}, title = {100-m Breaststroke Swimming Performance in Youth Swimmers}, series = {Pediatric exercise science}, volume = {30}, journal = {Pediatric exercise science}, number = {3}, publisher = {Human Kinetics Publ.}, address = {Champaign}, issn = {0899-8493}, doi = {10.1123/pes.2017-0220}, pages = {393 -- 401}, year = {2018}, abstract = {This study aimed to estimate the optimal body size, limb segment length, and girth or breadth ratios of 100-m breaststroke performance in youth swimmers. In total, 59 swimmers [male: n= 39, age = 11.5 (1.3) y; female: n= 20, age = 12.0 (1.0) y] participated in this study. To identify size/shape characteristics associated with 100-m breaststroke swimming performance, we computed a multiplicative allometric log-linear regression model, which was refined using backward elimination. Results showed that the 100-m breaststroke performance revealed a significant negative association with fat mass and a significant positive association with the segment length ratio (arm ratio = hand length/forearm length) and limb girth ratio (girth ratio = forearm girth/wrist girth). In addition, leg length, biacromial breadth, and biiliocristal breadth revealed significant positive associations with the 100-m breaststroke performance. However, height and body mass did not contribute to the model, suggesting that the advantage of longer levers was limb-specific rather than a general whole-body advantage. In fact, it is only by adopting multiplicative allometric models that the previously mentioned ratios could have been derived. These results highlighted the importance of considering anthropometric characteristics of youth breaststroke swimmers for talent identification and/or athlete monitoring purposes. In addition, these findings may assist orienting swimmers to the appropriate stroke based on their anthropometric characteristics.}, language = {en} } @article{RuszkiewiczdeMacedoMirandaVizueteetal.2018, author = {Ruszkiewicz, Joanna A. and de Macedo, Gabriel Teixeira and Miranda-Vizuete, Antonio and Teixeira da Rocha, Joao B. and Bowman, Aaron B. and Bornhorst, Julia and Schwerdtle, Tanja and Aschner, Michael}, title = {The cytoplasmic thioredoxin system in Caenorhabditis elegans affords protection from methylmercury in an age-specific manner}, series = {Neurotoxicology : the interdisciplinary journal of effects to toxic substances on the nervous system}, volume = {68}, journal = {Neurotoxicology : the interdisciplinary journal of effects to toxic substances on the nervous system}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0161-813X}, doi = {10.1016/j.neuro.2018.08.007}, pages = {189 -- 202}, year = {2018}, abstract = {Methylmercury (MeHg) is an environmental pollutant linked to many neurological defects, especially in developing individuals. The thioredoxin (TRX) system is a key redox regulator affected by MeHg toxicity, however the mechanisms and consequences of MeHg-induced dysfunction are not completely understood. This study evaluated the role of the TRX system in C. elegans susceptibility to MeHg during development. Worms lacking or overexpressing proteins from the TRX family were exposed to MeHg for 1 h at different developmental stage: L1, L4 and adult. Worms without cytoplasmic thioredoxin system exhibited age-specific susceptibility to MeHg when compared to wild-type (wt). This susceptibility corresponded partially to decreased total glutathione (GSH) levels and enhanced degeneration of dopaminergic neurons. In contrast, the overexpression of the cytoplasmic system TRX-1/TRXR-1 did not provide substantial protection against MeHg. Moreover, transgenic worms exhibited decreased protein expression for cytoplasmic thioredoxin reductase (TRXR-1). Both mitochondrial thioredoxin system TRX-2/TRXR-2, as well as other thioredoxin-like proteins: TRX-3, TRX-4, TRX-5 did not show significant role in C. elegans resistance to MeHg. Based on the current findings, the cytoplasmic thioredoxin system TRX-1/TRXR-1 emerges as an important age-sensitive protectant against MeHg toxicity in C. elegans.}, language = {en} } @article{RohnMarschallKroepfletal.2018, author = {Rohn, Isabelle and Marschall, Talke Anu and Kr{\"o}pfl, Nina and Jensen, Kenneth Bendix and Aschner, Michael and Tuck, Simon and Kuehnelt, Doris and Schwerdtle, Tanja and Bornhorst, Julia}, title = {Selenium species-dependent toxicity, bioavailability and metabolic transformations in Caenorhabditis elegans}, series = {Metallomics : integrated biometal science}, volume = {10}, journal = {Metallomics : integrated biometal science}, number = {6}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1756-5901}, doi = {10.1039/c8mt00066b}, pages = {818 -- 827}, year = {2018}, abstract = {The essential micronutrient selenium (Se) is required for various systemic functions, but its beneficial range is narrow and overexposure may result in adverse health effects. Additionally, the chemical form of the ingested selenium contributes crucially to its health effects. While small Se species play a major role in Se metabolism, their toxicological effects, bioavailability and metabolic transformations following elevated uptake are poorly understood. Utilizing the tractable invertebrate Caenorhabditis elegans allowed for an alternative approach to study species-specific characteristics of organic and inorganic Se forms in vivo, revealing remarkable species-dependent differences in the toxicity and bioavailability of selenite, selenomethionine (SeMet) and Se-methylselenocysteine (MeSeCys). An inverse relationship was found between toxicity and bioavailability of the Se species, with the organic species displaying a higher bioavailability than the inorganic form, yet being less toxic. Quantitative Se speciation analysis with HPLC/mass spectrometry revealed a partial metabolism of SeMet and MeSeCys. In SeMet exposed worms, identified metabolites were Se-adenosylselenomethionine (AdoSeMet) and Se-adenosylselenohomocysteine (AdoSeHcy), while worms exposed to MeSeCys produced Se-methylselenoglutathione (MeSeGSH) and -glutamyl-MeSeCys (-Glu-MeSeCys). Moreover, the possible role of the sole selenoprotein in the nematode, thioredoxin reductase-1 (TrxR-1), was studied comparing wildtype and trxr-1 deletion mutants. Although a lower basal Se level was detected in trxr-1 mutants, Se toxicity and bioavailability following acute exposure was indistinguishable from wildtype worms. Altogether, the current study demonstrates the suitability of C. elegans as a model for Se species dependent toxicity and metabolism, while further research is needed to elucidate TrxR-1 function in the nematode.}, language = {en} } @phdthesis{Ring2018, author = {Ring, Christiane}, title = {The role of the commensal gut bacterium Akkermansia muciniphila in acute and chronic intestinal inflammation}, year = {2018}, abstract = {Microbiota analyses of patients suffering from various diseases suggest a beneficial role of Akkermansia muciniphila in the maintenance of health, whereas several studies in animal models of intestinal inflammation report that this organism may aggravate inflammation. Therefore, it is important to clarify under which circumstances A. muciniphila exerts negative effects in the intestine of its host. The previously reported observation that A. muciniphila aggravates acute intestinal inflammation in the Salmonella enterica serovar Typhimurium infection mouse model colonized with a simplified human intestinal microbiota was investigated in this study. To unravel the underlying mechanism that led to the observed phenomenon, the time course of events following the infection was analyzed. In mice colonized with a simplified human intestinal microbiota, Salmonella infection induced clear signs of intestinal inflammation three days post infection. The inflammatory response was similar in mice colonized with A. muciniphila before Salmonella infection. These observations were independent of the time when colonization with the simplified human intestinal microbiota occurred, right after birth or only after weaning, and contradict the previous report. To find out whether A. muciniphila influences the development of chronic intestinal inflammation in a genetically predisposed host, mono-associated interleukin-10-deficient (Il10-/-) mice, Il10-/- mice dual-associated with A. muciniphila and colitogenic Escherichia coli NC101, as well as Il10-/- mice associated with A. muciniphila and a simplified human intestinal microbiota were compared to the respective mice without A. muciniphila. The data clearly show that in these gnotobiotic Il10-/- mice, A. muciniphila neither induces intestinal inflammation itself nor modulates it after induction by a colitogenic bacterium or by a simplified human intestinal microbiota. The experiments lead to the conclusion that the promotion of intestinal inflammation is not an intrinsic feature of this bacterium. The results of this study encourage the proposed use of A. muciniphila for the prevention or treatment of metabolic disorders.}, language = {en} } @article{ReichelRheinHofmannetal.2018, author = {Reichel, Martin and Rhein, Cosima and Hofmann, Lena M. and Monti, Juliana and Japtok, Lukasz and Langgartner, Dominik and F{\"u}chsl, Andrea M. and Kleuser, Burkhard and Gulbins, Erich and Hellerbrand, Claus and Reber, Stefan O. and Kornhuber, Johannes}, title = {Chronic Psychosocial Stress in Mice Is Associated With Increased Acid Sphingomyelinase Activity in Liver and Serum and With Hepatic C16:0-Ceramide Accumulation}, series = {Frontiers in Psychiatry}, volume = {9}, journal = {Frontiers in Psychiatry}, publisher = {Frontiers Research Foundation}, address = {Lausanne}, issn = {1664-0640}, doi = {10.3389/fpsyt.2018.00496}, pages = {8}, year = {2018}, abstract = {Chronic psychosocial stress adversely affects human morbidity and is a risk factor for inflammatory disorders, liver diseases, obesity, metabolic syndrome, and major depressive disorder (MDD). In recent studies, we found an association of MDD with an increase of acid sphingomyelinase (ASM) activity. Thus, we asked whether chronic psychosocial stress as a detrimental factor contributing to the emergence of MDD would also affect ASM activity and sphingolipid (SL) metabolism. To induce chronic psychosocial stress in male mice we employed the chronic subordinate colony housing (CSC) paradigm and compared them to non-stressed single housed control (SHC) mice. We determined Asm activity in liver and serum, hepatic SL concentrations as well as hepatic mRNA expression of genes involved in SL metabolism. We found that hepatic Asm activity was increased by 28\% (P = 0.006) and secretory Asm activity by 47\% (P = 0.002) in stressed mice. C16:0-Cer was increased by 40\% (P = 0.008). Gene expression analysis further revealed an increased expression of tumor necrosis factor (TNF)-alpha (P = 0.009) and of several genes involved in SL metabolism (Cers5, P = 0.028; Cers6, P = 0.045; Gba, P = 0.049; Gba2, P = 0.030; Ormdl2, P = 0.034; Smpdl3B; P = 0.013). Our data thus provides first evidence that chronic psychosocial stress, at least in mice, induces alterations in SL metabolism, which in turn might be involved in mediating the adverse health effects of chronic psychosocial stress and peripheral changes occurring in mood disorders.}, language = {en} } @phdthesis{Radloff2018, author = {Radloff, Katrin}, title = {The role of the fatty acid profile and its modulation by cytokines in the systemic inflammation in cancer cachexia}, school = {Universit{\"a}t Potsdam}, pages = {156}, year = {2018}, abstract = {Systemic inflammation is a hallmark of cancer cachexia. Among tumor-host interactions, the white adipose tissue (WAT) is an important contributor to inflammation as it suffers morphological reorganization and lipolysis, releasing free fatty acids (FA), bioactive lipid mediators (LM) and pro-inflammatory cytokines, which accentuate the activation of pro-inflammatory signaling pathways and the recruitment of immune cells to the tissue. This project aimed to investigate which inflammatory factors are involved in the local adipose tissue inflammation and what is the influence of such factors upon enzymes involved in FA or LM metabolism in healthy individuals (Control), weight stable gastro-intestinal cancer patients (WSC) and cachectic cancer patients (CC). The results demonstrated that the inflammatory signature of systemic inflammation is different from local adipose tissue inflammation. The systemic inflammation of the cachectic cancer patients was characterized by higher levels of circulating saturated fatty acids (SFA), tumor-necrosis-factor-α (TNF-α), interleukins IL-6, IL-8 and CRP while levels of polyunsaturated fatty acids (PUFAs), especially n3-PUFAs, were lower in CC than in the other groups. In vitro and in adipose tissue explants, pro-inflammatory cytokines and SFAs were shown to increase the chemokines IL-8 and CXCL10 that were found to be augmented in adipose tissue inflammation in CC which was more profound in the visceral adipose tissue (VAT) than in subcutaneous adipose tissue (SAT). Systemic inflammation was negatively associated with the expression of PUFA synthesizing enzymes, though gene and protein expression did hardly differ between groups. The effects of inflammatory factors on enzymes in the whole tissue could have been masked by differentiated modulation of the diverse cell types in the same tissue. In vitro experiments showed that the expression of FA-modifying enzymes such as desaturases and elongases in adipocytes and macrophages was regulated into opposing directions by TNF-α, IL-6, LPS or palmitate. The higher plasma concentration of the pro-resolving LM resolvin D1 in CC cannot compensate the overall inflammatory status and the results indicate that inflammatory cytokines interfere with synthesis pathways of pro-resolving LM. In summary, the data revealed a complex inter-tissue and inter-cellular crosstalk mediated by pro-inflammatory cytokines and lipid compounds enhancing inflammation in cancer cachexia by feed-forward mechanisms.}, language = {en} } @article{PrommerMaurervonWebskyetal.2018, author = {Prommer, Hans-Ulrich and Maurer, Johannes and von Websky, Karoline and Freise, Christian and Sommer, Kerstin and Nasser, Hamoud and Samapati, Rudi and Reglin, Bettina and Guimaraes, Pedro and Pries, Axel Radlach and Querfeld, Uwe}, title = {Chronic kidney disease induces a systemic microangiopathy, tissue hypoxia and dysfunctional angiogenesis}, series = {Scientific reports}, volume = {8}, journal = {Scientific reports}, publisher = {Nature Publ. Group}, address = {London}, issn = {2045-2322}, doi = {10.1038/s41598-018-23663-1}, pages = {14}, year = {2018}, abstract = {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.}, language = {en} }