@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{VolckmarHanPuetteretal.2016, author = {Volckmar, Anna-Lena and Han, Chung-Ting and P{\"u}tter, Carolin and Haas, Stefan and Vogel, Carla I. G. and Knoll, Nadja and Struve, Christoph and G{\"o}bel, Maria and Haas, Katharina and Herrfurth, Nikolas and Jarick, Ivonne and Grallert, Harald and Sch{\"u}rmann, Annette and Al- Hasani, Hadi and Hebebrand, Johannes and Sauer, Sascha and Hinney, Anke}, title = {Analysis of genes involved in body weight regulation by targeted re-sequencing}, series = {PLoS ONE}, journal = {PLoS ONE}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-410289}, pages = {16}, year = {2016}, abstract = {Introduction Genes involved in body weight regulation that were previously investigated in genome-wide association studies (GWAS) and in animal models were target-enriched followed by massive parallel next generation sequencing. Methods We enriched and re-sequenced continuous genomic regions comprising FTO, MC4R, TMEM18, SDCCAG8, TKNS, MSRA and TBC1D1 in a screening sample of 196 extremely obese children and adolescents with age and sex specific body mass index (BMI) >= 99th percentile and 176 lean adults (BMI <= 15th percentile). 22 variants were confirmed by Sanger sequencing. Genotyping was performed in up to 705 independent obesity trios (extremely obese child and both parents), 243 extremely obese cases and 261 lean adults. Results and Conclusion We detected 20 different non-synonymous variants, one frame shift and one nonsense mutation in the 7 continuous genomic regions in study groups of different weight extremes. For SNP Arg695Cys (rs58983546) in TBC1D1 we detected nominal association with obesity (p(TDT) = 0.03 in 705 trios). Eleven of the variants were rare, thus were only detected heterozygously in up to ten individual(s) of the complete screening sample of 372 individuals. Two of them (in FTO and MSRA) were found in lean individuals, nine in extremely obese. In silico analyses of the 11 variants did not reveal functional implications for the mutations. Concordant with our hypothesis we detected a rare variant that potentially leads to loss of FTO function in a lean individual. For TBC1D1, in contrary to our hypothesis, the loss of function variant (Arg443Stop) was found in an obese individual. Functional in vitro studies are warranted.}, language = {en} } @misc{HenkelColemanMacGregorofInneregnySchraplauetal.2018, author = {Henkel, Janin and Coleman Mac Gregor of Inneregny, Charles Dominic and Schraplau, Anne and J{\"o}hrens, Korinna and Weiss, Thomas Siegfried and Jonas, Wenke and Sch{\"u}rmann, Annette and P{\"u}schel, Gerhard Paul}, title = {Augmented liver inflammation in a microsomal prostaglandin E synthase 1 (mPGES-1)-deficient diet-induced mouse NASH model}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {483}, issn = {1866-8372}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-420879}, pages = {11}, year = {2018}, abstract = {In a subset of patients, non-alcoholic fatty liver disease (NAFLD) is complicated by cell death and inflammation resulting in non-alcoholic steatohepatitis (NASH), which may progress to fibrosis and subsequent organ failure. Apart from cytokines, prostaglandins, in particular prostaglandin E-2 (PGE(2)), play a pivotal role during inflammatory processes. Expression of the key enzymes of PGE(2) synthesis, cyclooxygenase 2 and microsomal PGE synthase 1 (mPGES-1), was increased in human NASH livers in comparison to controls and correlated with the NASH activity score. Both enzymes were also induced in NASH-diet-fed wild-type mice, resulting in an increase in hepatic PGE(2) concentration that was completely abrogated in mPGES-1-deficient mice. PGE(2) is known to inhibit TNF-alpha synthesis in macrophages. A strong infiltration of monocyte-derived macrophages was observed in NASH-diet-fed mice, which was accompanied with an increase in hepatic TNF-alpha expression. Due to the impaired PGE(2) production, TNF-alpha expression increased much more in livers of mPGES-1-deficient mice or in the peritoneal macrophages of these mice. The increased levels of TNF-alpha resulted in an enhanced IL-1 beta production, primarily in hepatocytes, and augmented hepatocyte apoptosis. In conclusion, attenuation of PGE(2) production by mPGES-1 ablation enhanced the TNF-alpha-triggered inflammatory response and hepatocyte apoptosis in diet-induced NASH.}, language = {en} } @article{HenkelColemanMacGregorofInneregnySchraplauetal.2018, author = {Henkel, Janin and Coleman Mac Gregor of Inneregny, Charles Dominic and Schraplau, Anne and J{\"o}hrens, Korinna and Weiss, Thomas Siegfried and Jonas, Wenke and Sch{\"u}rmann, Annette and P{\"u}schel, Gerhard Paul}, title = {Augmented liver inflammation in a microsomal prostaglandin E synthase 1 (mPGES-1)-deficient diet-induced mouse NASH model}, series = {Scientific Reports}, journal = {Scientific Reports}, number = {8}, publisher = {Nature Research}, address = {London}, issn = {2045-2322}, doi = {10.1038/s41598-018-34633-y}, pages = {1 -- 11}, year = {2018}, abstract = {In a subset of patients, non-alcoholic fatty liver disease (NAFLD) is complicated by cell death and inflammation resulting in non-alcoholic steatohepatitis (NASH), which may progress to fibrosis and subsequent organ failure. Apart from cytokines, prostaglandins, in particular prostaglandin E-2 (PGE(2)), play a pivotal role during inflammatory processes. Expression of the key enzymes of PGE(2) synthesis, cyclooxygenase 2 and microsomal PGE synthase 1 (mPGES-1), was increased in human NASH livers in comparison to controls and correlated with the NASH activity score. Both enzymes were also induced in NASH-diet-fed wild-type mice, resulting in an increase in hepatic PGE(2) concentration that was completely abrogated in mPGES-1-deficient mice. PGE(2) is known to inhibit TNF-alpha synthesis in macrophages. A strong infiltration of monocyte-derived macrophages was observed in NASH-diet-fed mice, which was accompanied with an increase in hepatic TNF-alpha expression. Due to the impaired PGE(2) production, TNF-alpha expression increased much more in livers of mPGES-1-deficient mice or in the peritoneal macrophages of these mice. The increased levels of TNF-alpha resulted in an enhanced IL-1 beta production, primarily in hepatocytes, and augmented hepatocyte apoptosis. In conclusion, attenuation of PGE(2) production by mPGES-1 ablation enhanced the TNF-alpha-triggered inflammatory response and hepatocyte apoptosis in diet-induced NASH.}, language = {en} } @article{HenkelColemanSchraplauetal.2018, author = {Henkel, Janin and Coleman, Charles Dominic and Schraplau, Anne and Joehrens, Korinna and Weiss, Thomas Siegfried and Jonas, Wenke and Sch{\"u}rmann, Annette and P{\"u}schel, Gerhard Paul}, title = {Augmented liver inflammation in a microsomal prostaglandin E synthase 1 (mPGES-1)-deficient diet-induced mouse NASH model}, series = {Scientific reports}, volume = {8}, journal = {Scientific reports}, publisher = {Nature Publ. Group}, address = {London}, issn = {2045-2322}, doi = {10.1038/s41598-018-34633-y}, pages = {11}, year = {2018}, abstract = {In a subset of patients, non-alcoholic fatty liver disease (NAFLD) is complicated by cell death and inflammation resulting in non-alcoholic steatohepatitis (NASH), which may progress to fibrosis and subsequent organ failure. Apart from cytokines, prostaglandins, in particular prostaglandin E-2 (PGE(2)), play a pivotal role during inflammatory processes. Expression of the key enzymes of PGE(2) synthesis, cyclooxygenase 2 and microsomal PGE synthase 1 (mPGES-1), was increased in human NASH livers in comparison to controls and correlated with the NASH activity score. Both enzymes were also induced in NASH-diet-fed wild-type mice, resulting in an increase in hepatic PGE(2) concentration that was completely abrogated in mPGES-1-deficient mice. PGE(2) is known to inhibit TNF-alpha synthesis in macrophages. A strong infiltration of monocyte-derived macrophages was observed in NASH-diet-fed mice, which was accompanied with an increase in hepatic TNF-alpha expression. Due to the impaired PGE(2) production, TNF-alpha expression increased much more in livers of mPGES-1-deficient mice or in the peritoneal macrophages of these mice. The increased levels of TNF-alpha resulted in an enhanced IL-1 beta production, primarily in hepatocytes, and augmented hepatocyte apoptosis. In conclusion, attenuation of PGE(2) production by mPGES-1 ablation enhanced the TNF-alpha-triggered inflammatory response and hepatocyte apoptosis in diet-induced NASH.}, language = {en} } @misc{WardelmannRathCastroetal.2021, author = {Wardelmann, Kristina and Rath, Michaela and Castro, Jos{\´e} Pedro and Bl{\"u}mel, Sabine and Schell, Mareike and Hauffe, Robert and Schumacher, Fabian and Flore, Tanina and Ritter, Katrin and Wernitz, Andreas and Hosoi, Toru and Ozawa, Koichiro and Kleuser, Burkhard and Weiß, J{\"u}rgen and Sch{\"u}rmann, Annette and Kleinridders, Andr{\´e}}, title = {Central acting Hsp10 regulates mitochondrial function, fatty acid metabolism and insulin sensitivity in the hypothalamus}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {5}, issn = {1866-8372}, doi = {10.25932/publishup-52298}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-522985}, pages = {24}, year = {2021}, abstract = {Mitochondria are critical for hypothalamic function and regulators of metabolism. Hypothalamic mitochondrial dysfunction with decreased mitochondrial chaperone expression is present in type 2 diabetes (T2D). Recently, we demonstrated that a dysregulated mitochondrial stress response (MSR) with reduced chaperone expression in the hypothalamus is an early event in obesity development due to insufficient insulin signaling. Although insulin activates this response and improves metabolism, the metabolic impact of one of its members, the mitochondrial chaperone heat shock protein 10 (Hsp10), is unknown. Thus, we hypothesized that a reduction of Hsp10 in hypothalamic neurons will impair mitochondrial function and impact brain insulin action. Therefore, we investigated the role of chaperone Hsp10 by introducing a lentiviral-mediated Hsp10 knockdown (KD) in the hypothalamic cell line CLU-183 and in the arcuate nucleus (ARC) of C57BL/6N male mice. We analyzed mitochondrial function and insulin signaling utilizing qPCR, Western blot, XF96 Analyzer, immunohistochemistry, and microscopy techniques. We show that Hsp10 expression is reduced in T2D mice brains and regulated by leptin in vitro. Hsp10 KD in hypothalamic cells induced mitochondrial dysfunction with altered fatty acid metabolism and increased mitochondria-specific oxidative stress resulting in neuronal insulin resistance. Consequently, the reduction of Hsp10 in the ARC of C57BL/6N mice caused hypothalamic insulin resistance with acute liver insulin resistance.}, language = {en} } @article{WardelmannRathCastroetal.2021, author = {Wardelmann, Kristina and Rath, Michaela and Castro, Jos{\´e} Pedro and Bl{\"u}mel, Sabine and Schell, Mareike and Hauffe, Robert and Schumacher, Fabian and Flore, Tanina and Ritter, Katrin and Wernitz, Andreas and Hosoi, Toru and Ozawa, Koichiro and Kleuser, Burkhard and Weiß, J{\"u}rgen and Sch{\"u}rmann, Annette and Kleinridders, Andr{\´e}}, title = {Central acting Hsp10 regulates mitochondrial function, fatty acid metabolism and insulin sensitivity in the hypothalamus}, series = {Antioxidants}, volume = {10}, journal = {Antioxidants}, number = {5}, publisher = {MDPI}, address = {Basel}, issn = {2076-3921}, doi = {10.3390/antiox10050711}, pages = {22}, year = {2021}, abstract = {Mitochondria are critical for hypothalamic function and regulators of metabolism. Hypothalamic mitochondrial dysfunction with decreased mitochondrial chaperone expression is present in type 2 diabetes (T2D). Recently, we demonstrated that a dysregulated mitochondrial stress response (MSR) with reduced chaperone expression in the hypothalamus is an early event in obesity development due to insufficient insulin signaling. Although insulin activates this response and improves metabolism, the metabolic impact of one of its members, the mitochondrial chaperone heat shock protein 10 (Hsp10), is unknown. Thus, we hypothesized that a reduction of Hsp10 in hypothalamic neurons will impair mitochondrial function and impact brain insulin action. Therefore, we investigated the role of chaperone Hsp10 by introducing a lentiviral-mediated Hsp10 knockdown (KD) in the hypothalamic cell line CLU-183 and in the arcuate nucleus (ARC) of C57BL/6N male mice. We analyzed mitochondrial function and insulin signaling utilizing qPCR, Western blot, XF96 Analyzer, immunohistochemistry, and microscopy techniques. We show that Hsp10 expression is reduced in T2D mice brains and regulated by leptin in vitro. Hsp10 KD in hypothalamic cells induced mitochondrial dysfunction with altered fatty acid metabolism and increased mitochondria-specific oxidative stress resulting in neuronal insulin resistance. Consequently, the reduction of Hsp10 in the ARC of C57BL/6N mice caused hypothalamic insulin resistance with acute liver insulin resistance.}, language = {en} } @article{KluthStadionGottmannetal.2019, author = {Kluth, Oliver and Stadion, Mandy and Gottmann, Pascal and Aga-Barfknecht, Heja and J{\"a}hnert, Markus and Scherneck, Stephan and Vogel, Heike and Krus, Ulrika and Seelig, Anett and Ling, Charlotte and Gerdes, Jantje and Sch{\"u}rmann, Annette}, title = {Decreased expression of cilia genes in pancreatic islets as a risk factor for type 2 diabetes in mice and humans}, series = {Cell reports}, volume = {26}, journal = {Cell reports}, number = {11}, publisher = {Cell Press}, address = {Maryland Heights}, issn = {2211-1247}, doi = {10.1016/j.celrep.2019.02.056}, pages = {3027 -- 3036}, year = {2019}, abstract = {An insufficient adaptive beta-cell compensation is a hallmark of type 2 diabetes (T2D). Primary cilia function as versatile sensory antennae regulating various cellular processes, but their role on compensatory beta-cell replication has not been examined. Here, we identify a significant enrichment of downregulated, cilia-annotated genes in pancreatic islets of diabetes-prone NZO mice as compared with diabetes-resistant B6-ob/ob mice. Among 327 differentially expressed mouse cilia genes, 81 human orthologs are also affected in islets of diabetic donors. Islets of nondiabetic mice and humans show a substantial overlap of upregulated cilia genes that are linked to cell-cycle progression. The shRNA-mediated suppression of KIF3A, essential for ciliogenesis, impairs division of MINE beta cells as well as in dispersed primary mouse and human islet cells, as shown by decreased BrdU incorporation. These findings demonstrate the substantial role of cilia-gene regulation on islet function and T2D risk.}, language = {en} } @article{LaegerCastanoMartinezWernoetal.2018, author = {Laeger, Thomas and Castano-Martinez, Teresa and Werno, Martin W. and Japtok, Lukasz and Baumeier, Christian and Jonas, Wenke and Kleuser, Burkhard and Sch{\"u}rmann, Annette}, title = {Dietary carbohydrates impair the protective effect of protein restriction against diabetes in NZO mice used as a model of type 2 diabetes}, series = {Diabetologia : journal of the European Association for the Study of Diabetes (EASD)}, volume = {61}, journal = {Diabetologia : journal of the European Association for the Study of Diabetes (EASD)}, number = {6}, publisher = {Springer}, address = {New York}, issn = {0012-186X}, doi = {10.1007/s00125-018-4595-1}, pages = {1459 -- 1469}, year = {2018}, abstract = {Aims/hypothesis Low-protein diets are well known to improve glucose tolerance and increase energy expenditure. Increases in circulating fibroblast growth factor 21 (FGF21) have been implicated as a potential underlying mechanism. Methods We aimed to test whether low-protein diets in the context of a high-carbohydrate or high-fat regimen would also protect against type 2 diabetes in New Zealand Obese (NZO) mice used as a model of polygenetic obesity and type 2 diabetes. Mice were placed on high-fat diets that provided protein at control (16 kJ\%; CON) or low (4 kJ\%; low-protein/high-carbohydrate [LP/HC] or low-protein/high-fat [LP/HF]) levels. Results Protein restriction prevented the onset of hyperglycaemia and beta cell loss despite increased food intake and fat mass. The effect was seen only under conditions of a lower carbohydrate/fat ratio (LP/HF). When the carbohydrate/fat ratio was high (LP/HC), mice developed type 2 diabetes despite the robustly elevated hepatic FGF21 secretion and increased energy expenditure. Conclusion/interpretation Prevention of type 2 diabetes through protein restriction, without lowering food intake and body fat mass, is compromised by high dietary carbohydrates. Increased FGF21 levels and elevated energy expenditure do not protect against hyperglycaemia and type 2 diabetes per se.}, language = {en} } @article{AgaBarfknechtSoultoukisStadionetal.2022, author = {Aga-Barfknecht, Heja and Soultoukis, George A. and Stadion, Mandy and Garcia-Carrizo, Francisco and J{\"a}hnert, Markus and Gottmann, Pascal and Vogel, Heike and Schulz, Tim Julius and Sch{\"u}rmann, Annette}, title = {Distinct adipogenic and fibrogenic differentiation capacities of mesenchymal stromal cells from pancreas and white adipose tissue}, series = {International journal of molecular sciences}, volume = {23}, journal = {International journal of molecular sciences}, number = {4}, publisher = {Molecular Diversity Preservation International}, address = {Basel}, issn = {1422-0067}, doi = {10.3390/ijms23042108}, pages = {21}, year = {2022}, abstract = {Pancreatic steatosis associates with beta-cell failure and may participate in the development of type-2-diabetes. Our previous studies have shown that diabetes-susceptible mice accumulate more adipocytes in the pancreas than diabetes-resistant mice. In addition, we have demonstrated that the co-culture of pancreatic islets and adipocytes affect insulin secretion. The aim of this current study was to elucidate if and to what extent pancreas-resident mesenchymal stromal cells (MSCs) with adipogenic progenitor potential differ from the corresponding stromal-type cells of the inguinal white adipose tissue (iWAT). miRNA (miRNome) and mRNA expression (transcriptome) analyses of MSCs isolated by flow cytometry of both tissues revealed 121 differentially expressed miRNAs and 1227 differentially expressed genes (DEGs). Target prediction analysis estimated 510 DEGs to be regulated by 58 differentially expressed miRNAs. Pathway analyses of DEGs and miRNA target genes showed unique transcriptional and miRNA signatures in pancreas (pMSCs) and iWAT MSCs (iwatMSCs), for instance fibrogenic and adipogenic differentiation, respectively. Accordingly, iwatMSCs revealed a higher adipogenic lineage commitment, whereas pMSCs showed an elevated fibrogenesis. As a low degree of adipogenesis was also observed in pMSCs of diabetes-susceptible mice, we conclude that the development of pancreatic steatosis has to be induced by other factors not related to cell-autonomous transcriptomic changes and miRNA-based signals.}, language = {en} } @article{GanchevaOuniJeleniketal.2019, author = {Gancheva, Sofiya and Ouni, Meriem and Jelenik, Tomas and Koliaki, Chrysi and Szendroedi, Julia and Toledo, Frederico G. S. and Markgraf, Daniel Frank and Pesta, Dominik H. and Mastrototaro, Lucia and De Filippo, Elisabetta and Herder, Christian and J{\"a}hnert, Markus and Weiss, J{\"u}rgen and Strassburger, Klaus and Schlensak, Matthias and Sch{\"u}rmann, Annette and Roden, Michael}, title = {Dynamic changes of muscle insulin sensitivity after metabolic surgery}, series = {Nature Communications}, volume = {10}, journal = {Nature Communications}, publisher = {Nature Publ. Group}, address = {London}, issn = {2041-1723}, doi = {10.1038/s41467-019-12081-0}, pages = {13}, year = {2019}, abstract = {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.}, language = {en} } @article{OuniSchuermann2020, author = {Ouni, Meriem and Sch{\"u}rmann, Annette}, title = {Epigenetic contribution to obesity}, series = {Mammalian genome}, volume = {31}, journal = {Mammalian genome}, number = {5-6}, publisher = {Springer}, address = {New York, NY ; Berlin ; Heidelberg [u.a.]}, issn = {0938-8990}, doi = {10.1007/s00335-020-09835-3}, pages = {134 -- 145}, year = {2020}, abstract = {Obesity is a worldwide epidemic and contributes to global morbidity and mortality mediated via the development of nonalcoholic fatty liver disease (NAFLD), type 2 diabetes (T2D), cardiovascular (CVD) and other diseases. It is a consequence of an elevated caloric intake, a sedentary lifestyle and a genetic as well as an epigenetic predisposition. This review summarizes changes in DNA methylation and microRNAs identified in blood cells and different tissues in obese human and rodent models. It includes information on epigenetic alterations which occur in response to fat-enriched diets, exercise and metabolic surgery and discusses the potential of interventions to reverse epigenetic modifications.}, language = {en} } @article{SaussenthalerOuniBaumeieretal.2019, author = {Saussenthaler, Sophie and Ouni, Meriem and Baumeier, Christian and Schwerbel, Kristin and Gottmann, Pascal and Christmann, Sabrina and Laeger, Thomas and Sch{\"u}rmann, Annette}, title = {Epigenetic regulation of hepatic Dpp4 expression in response to dietary protein}, series = {The journal of nutritional biochemistry}, volume = {63}, journal = {The journal of nutritional biochemistry}, publisher = {Elsevier}, address = {New York}, issn = {0955-2863}, doi = {10.1016/j.jnutbio.2018.09.025}, pages = {109 -- 116}, year = {2019}, abstract = {Dipeptidyl peptidase 4 (DPP4) is known to be elevated in metabolic disturbances such as obesity, type 2 diabetes and fatty liver disease. Lowering DPP4 concentration by pharmacological inhibition improves glucose homeostasis and exhibits beneficial effects to reduce hepatic fat content. As factors regulating the endogenous expression of Dpp4 are unknown, the aim of this study was to examine whether the Dpp4 expression is epigenetically regulated in response to dietary components. Primary hepatocytes were treated with different macronutrients, and Dpp4 mRNA levels and DPP4 activity were evaluated. Moreover, dietary low-protein intervention was conducted in New Zealand obese (NZO) mice, and subsequently, effects on Dpp4 expression, methylation as well as plasma concentration and activity were determined. Our results indicate that Dpp4 mRNA expression is mediated by DNA methylation in several tissues. We therefore consider the Dpp4 southern shore as tissue differentially methylated region. Amino acids increased Dpp4 expression in primary hepatocytes, whereas glucose and fatty acids were without effect. Dietary protein restriction in NZO mice increased Dpp4 DNA methylation in liver leading to diminished Dpp4 expression and consequently to lowered plasma DPP4 activity. We conclude that protein restriction in the adolescent and adult states is a sufficient strategy to reduce DPP4 which in turn contributes to improve glucose homeostasis. (C) 2018 Published by Elsevier Inc.}, language = {en} } @article{KanzleiterJaehnertSchulzeetal.2015, author = {Kanzleiter, Timo and Jaehnert, Markus and Schulze, Gunnar and Selbig, Joachim and Hallahan, Nicole and Schwenk, Robert Wolfgang and Sch{\"u}rmann, Annette}, title = {Exercise training alters DNA methylation patterns in genes related to muscle growth and differentiation in mice}, series = {American journal of physiology : Endocrinology and metabolism}, volume = {308}, journal = {American journal of physiology : Endocrinology and metabolism}, number = {10}, publisher = {American Chemical Society}, address = {Bethesda}, issn = {0193-1849}, doi = {10.1152/ajpendo.00289.2014}, pages = {E912 -- E920}, year = {2015}, abstract = {The adaptive response of skeletal muscle to exercise training is tightly controlled and therefore requires transcriptional regulation. DNA methylation is an epigenetic mechanism known to modulate gene expression, but its contribution to exercise-induced adaptations in skeletal muscle is not well studied. Here, we describe a genome-wide analysis of DNA methylation in muscle of trained mice (n = 3). Compared with sedentary controls, 2,762 genes exhibited differentially methylated CpGs (P < 0.05, meth diff >5\%, coverage > 10) in their putative promoter regions. Alignment with gene expression data (n = 6) revealed 200 genes with a negative correlation between methylation and expression changes in response to exercise training. The majority of these genes were related to muscle growth and differentiation, and a minor fraction involved in metabolic regulation. Among the candidates were genes that regulate the expression of myogenic regulatory factors (Plexin A2) as well as genes that participate in muscle hypertrophy (Igfbp4) and motor neuron innervation (Dok7). Interestingly, a transcription factor binding site enrichment study discovered significantly enriched occurrence of CpG methylation in the binding sites of the myogenic regulatory factors MyoD and myogenin. These findings suggest that DNA methylation is involved in the regulation of muscle adaptation to regular exercise training.}, language = {en} } @article{McNultyGoupilAlbaradoetal.2020, author = {McNulty, Margaret A. and Goupil, Brad A. and Albarado, Diana C. and Casta{\~n}o-Martinez, Teresa and Ambrosi, Thomas H. and Puh, Spela and Schulz, Tim Julius and Sch{\"u}rmann, Annette and Morrison, Christopher D. and Laeger, Thomas}, title = {FGF21, not GCN2, influences bone morphology due to dietary protein restrictions}, series = {Bone Reports}, volume = {12}, journal = {Bone Reports}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2352-1872}, doi = {10.1016/j.bonr.2019.100241}, pages = {1 -- 10}, year = {2020}, abstract = {Background: Dietary protein restriction is emerging as an alternative approach to treat obesity and glucose intolerance because it markedly increases plasma fibroblast growth factor 21 (FGF21) concentrations. Similarly, dietary restriction of methionine is known to mimic metabolic effects of energy and protein restriction with FGF21 as a required mechanism. However, dietary protein has been shown to be required for normal bone growth, though there is conflicting evidence as to the influence of dietary protein restriction on bone remodeling. The purpose of the current study was to evaluate the effect of dietary protein and methionine restriction on bone in lean and obese mice, and clarify whether FGF21 and general control nonderepressible 2 (GCN2) kinase, that are part of a novel endocrine pathway implicated in the detection of protein restriction, influence the effect of dietary protein restriction on bone. Methods: Adult wild-type (WT) or Fgf21 KO mice were fed a normal protein (18 kcal\%; CON) or low protein (4 kcal\%; LP) diet for 2 or 27 weeks. In addition, adult WT or Gcn2 KO mice were fed a CON or LP diet for 27 weeks. Young New Zealand obese (NZO) mice were placed on high-fat diets that provided protein at control (16 kcal\%; CON), low levels (4 kcal\%) in a high-carbohydrate (LP/HC) or high-fat (LP/HF) regimen, or on high-fat diets (protein, 16 kcal\%) that provided methionine at control (0.86\%; CON-MR) or low levels (0.17\%; MR) for up to 9 weeks. Long bones from the hind limbs of these mice were collected and evaluated with micro-computed tomography (mu CT) for changes in trabecular and cortical architecture and mass. Results: In WT mice the 27-week LP diet significantly reduced cortical bone, and this effect was enhanced by deletion of Fgf21 but not Gcn2. This decrease in bone did not appear after 2 weeks on the LP diet. In addition, Fgf21 KO mice had significantly less bone than their WT counterparts. In obese NZO mice dietary protein and methionine restriction altered bone architecture. The changes were mediated by FGF21 due to methionine restriction in the presence of cystine, which did not increase plasma FGF21 levels and did not affect bone architecture. Conclusions: This study provides direct evidence of a reduction in bone following long-term dietary protein restriction in a mouse model, effects that appear to be mediated by FGF21.}, language = {en} } @misc{McNultyGoupilAlbaradoetal.2020, author = {McNulty, Margaret A. and Goupil, Brad A. and Albarado, Diana C. and Casta{\~n}o-Martinez, Teresa and Ambrosi, Thomas H. and Puh, Spela and Schulz, Tim Julius and Sch{\"u}rmann, Annette and Morrison, Christopher D. and Laeger, Thomas}, title = {FGF21, not GCN2, influences bone morphology due to dietary protein restrictions}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, issn = {1866-8372}, doi = {10.25932/publishup-51629}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-516297}, pages = {12}, year = {2020}, abstract = {Background: Dietary protein restriction is emerging as an alternative approach to treat obesity and glucose intolerance because it markedly increases plasma fibroblast growth factor 21 (FGF21) concentrations. Similarly, dietary restriction of methionine is known to mimic metabolic effects of energy and protein restriction with FGF21 as a required mechanism. However, dietary protein has been shown to be required for normal bone growth, though there is conflicting evidence as to the influence of dietary protein restriction on bone remodeling. The purpose of the current study was to evaluate the effect of dietary protein and methionine restriction on bone in lean and obese mice, and clarify whether FGF21 and general control nonderepressible 2 (GCN2) kinase, that are part of a novel endocrine pathway implicated in the detection of protein restriction, influence the effect of dietary protein restriction on bone. Methods: Adult wild-type (WT) or Fgf21 KO mice were fed a normal protein (18 kcal\%; CON) or low protein (4 kcal\%; LP) diet for 2 or 27 weeks. In addition, adult WT or Gcn2 KO mice were fed a CON or LP diet for 27 weeks. Young New Zealand obese (NZO) mice were placed on high-fat diets that provided protein at control (16 kcal\%; CON), low levels (4 kcal\%) in a high-carbohydrate (LP/HC) or high-fat (LP/HF) regimen, or on high-fat diets (protein, 16 kcal\%) that provided methionine at control (0.86\%; CON-MR) or low levels (0.17\%; MR) for up to 9 weeks. Long bones from the hind limbs of these mice were collected and evaluated with micro-computed tomography (mu CT) for changes in trabecular and cortical architecture and mass. Results: In WT mice the 27-week LP diet significantly reduced cortical bone, and this effect was enhanced by deletion of Fgf21 but not Gcn2. This decrease in bone did not appear after 2 weeks on the LP diet. In addition, Fgf21 KO mice had significantly less bone than their WT counterparts. In obese NZO mice dietary protein and methionine restriction altered bone architecture. The changes were mediated by FGF21 due to methionine restriction in the presence of cystine, which did not increase plasma FGF21 levels and did not affect bone architecture. Conclusions: This study provides direct evidence of a reduction in bone following long-term dietary protein restriction in a mouse model, effects that appear to be mediated by FGF21.}, language = {en} } @article{JonasSchuermann2020, author = {Jonas, Wenke and Sch{\"u}rmann, Annette}, title = {Genetic and epigenetic factors determining NAFLD risk}, series = {Molecular metabolism}, volume = {50}, journal = {Molecular metabolism}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2212-8778}, doi = {10.1016/j.molmet.2020.101111}, pages = {14}, year = {2020}, abstract = {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.}, language = {en} } @article{HesseJaschkeKanzleiteretal.2012, author = {Hesse, Deike and Jaschke, Alexander and Kanzleiter, Timo and Witte, Nicole and Augustin, Robert and Hommel, Angela and P{\"u}schel, Gerhard Paul and Petzke, Klaus-J{\"u}rgen and Joost, Hans-Georg and Schupp, Michael and Sch{\"u}rmann, Annette}, title = {GTPase ARFRP1 is essential for normal hepatic glycogen storage and insulin-like growth factor 1 secretion}, series = {Molecular and cellular biology}, volume = {32}, journal = {Molecular and cellular biology}, number = {21}, publisher = {American Society for Microbiology}, address = {Washington}, issn = {0270-7306}, doi = {10.1128/MCB.00522-12}, pages = {4363 -- 4374}, year = {2012}, abstract = {The GTPase ADP-ribosylation factor-related protein 1 (ARFRP1) is located at the trans-Golgi compartment and regulates the recruitment of Arf-like 1 (ARL1) and its effector golgin-245 to this compartment. Here, we show that liver-specific knockout of Arfrp1 in the mouse (Arfrp1(liv-/-)) resulted in early growth retardation, which was associated with reduced hepatic insulin-like growth factor 1 (IGF1) secretion. Accordingly, suppression of Arfrp1 in primary hepatocytes resulted in a significant reduction of IGF1 release. However, the hepatic secretion of IGF-binding protein 2 (IGFBP2) was not affected in the absence of ARFRP1. In addition, Arfrp1(liv-/-) mice exhibited decreased glucose transport into the liver, leading to a 50\% reduction of glycogen stores as well as a marked retardation of glycogen storage after fasting and refeeding. These abnormalities in glucose metabolism were attributable to reduced protein levels and intracellular retention of the glucose transporter GLUT2 in Arfrp1(liv-/-) livers. As a consequence of impaired glucose uptake into the liver, the expression levels of carbohydrate response element binding protein (ChREBP), a transcription factor regulated by glucose concentration, and its target genes (glucokinase and pyruvate kinase) were markedly reduced. Our data indicate that ARFRP1 in the liver is involved in the regulation of IGF1 secretion and GLUT2 sorting and is thereby essential for normal growth and glycogen storage.}, language = {en} } @misc{HauffeRathSchelletal.2022, author = {Hauffe, Robert and Rath, Michaela and Schell, Mareike and Ritter, Katrin and Kappert, Kai and Deubel, Stefanie and Ott, Christiane and J{\"a}hnert, Markus and Jonas, Wenke and Sch{\"u}rmann, Annette and Kleinridders, Andr{\´e}}, title = {HSP60 reduction protects against diet-induced obesity by modulating energy metabolism in adipose tissue}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1866-8372}, doi = {10.25932/publishup-54800}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-548002}, pages = {1 -- 14}, year = {2022}, abstract = {Objective Insulin regulates mitochondrial function, thereby propagating an efficient metabolism. Conversely, diabetes and insulin resistance are linked to mitochondrial dysfunction with a decreased expression of the mitochondrial chaperone HSP60. The aim of this investigation was to determine the effect of a reduced HSP60 expression on the development of obesity and insulin resistance. Methods Control and heterozygous whole-body HSP60 knockout (Hsp60+/-) mice were fed a high-fat diet (HFD, 60\% calories from fat) for 16 weeks and subjected to extensive metabolic phenotyping. To understand the effect of HSP60 on white adipose tissue, microarray analysis of gonadal WAT was performed, ex vivo experiments were performed, and a lentiviral knockdown of HSP60 in 3T3-L1 cells was conducted to gain detailed insights into the effect of reduced HSP60 levels on adipocyte homeostasis. Results Male Hsp60+/- mice exhibited lower body weight with lower fat mass. These mice exhibited improved insulin sensitivity compared to control, as assessed by Matsuda Index and HOMA-IR. Accordingly, insulin levels were significantly reduced in Hsp60+/- mice in a glucose tolerance test. However, Hsp60+/- mice exhibited an altered adipose tissue metabolism with elevated insulin-independent glucose uptake, adipocyte hyperplasia in the presence of mitochondrial dysfunction, altered autophagy, and local insulin resistance. Conclusions We discovered that the reduction of HSP60 in mice predominantly affects adipose tissue homeostasis, leading to beneficial alterations in body weight, body composition, and adipocyte morphology, albeit exhibiting local insulin resistance.}, language = {en} } @article{HauffeRathSchelletal.2021, author = {Hauffe, Robert and Rath, Michaela and Schell, Mareike and Ritter, Katrin and Kappert, Kai and Deubel, Stefanie and Ott, Christiane and J{\"a}hnert, Markus and Jonas, Wenke and Sch{\"u}rmann, Annette and Kleinridders, Andr{\´e}}, title = {HSP60 reduction protects against diet-induced obesity by modulating energy metabolism in adipose tissue}, series = {Molecular Metabolism}, volume = {53}, journal = {Molecular Metabolism}, publisher = {Elsevier}, address = {Amsterdam, Niederlande}, issn = {2212-8778}, doi = {10.1016/j.molmet.2021.101276}, pages = {1 -- 14}, year = {2021}, abstract = {Objective Insulin regulates mitochondrial function, thereby propagating an efficient metabolism. Conversely, diabetes and insulin resistance are linked to mitochondrial dysfunction with a decreased expression of the mitochondrial chaperone HSP60. The aim of this investigation was to determine the effect of a reduced HSP60 expression on the development of obesity and insulin resistance. Methods Control and heterozygous whole-body HSP60 knockout (Hsp60+/-) mice were fed a high-fat diet (HFD, 60\% calories from fat) for 16 weeks and subjected to extensive metabolic phenotyping. To understand the effect of HSP60 on white adipose tissue, microarray analysis of gonadal WAT was performed, ex vivo experiments were performed, and a lentiviral knockdown of HSP60 in 3T3-L1 cells was conducted to gain detailed insights into the effect of reduced HSP60 levels on adipocyte homeostasis. Results Male Hsp60+/- mice exhibited lower body weight with lower fat mass. These mice exhibited improved insulin sensitivity compared to control, as assessed by Matsuda Index and HOMA-IR. Accordingly, insulin levels were significantly reduced in Hsp60+/- mice in a glucose tolerance test. However, Hsp60+/- mice exhibited an altered adipose tissue metabolism with elevated insulin-independent glucose uptake, adipocyte hyperplasia in the presence of mitochondrial dysfunction, altered autophagy, and local insulin resistance. Conclusions We discovered that the reduction of HSP60 in mice predominantly affects adipose tissue homeostasis, leading to beneficial alterations in body weight, body composition, and adipocyte morphology, albeit exhibiting local insulin resistance.}, language = {en} } @article{GohlkeZagoriyInostrozaetal.2019, author = {Gohlke, Sabrina and Zagoriy, Vyacheslav and Inostroza, Alvaro Cuadros and Meret, Michael and Mancini, Carola and Japtok, Lukasz and Schumacher, Fabian and Kuhlow, Doreen and Graja, Antonia and Stephanowitz, Heike and J{\"a}hnert, Markus and Krause, Eberhard and Wernitz, Andreas and Petzke, Klaus-Juergen and Sch{\"u}rmann, Annette and Kleuser, Burkhard and Schulz, Tim Julius}, title = {Identification of functional lipid metabolism biomarkers of brown adipose tissue aging}, series = {Molecular Metabolism}, volume = {24}, journal = {Molecular Metabolism}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2212-8778}, doi = {10.1016/j.molmet.2019.03.011}, pages = {1 -- 17}, year = {2019}, abstract = {Objective: Aging is accompanied by loss of brown adipocytes and a decline in their thermogenic potential, which may exacerbate the development of adiposity and other metabolic disorders. Presently, only limited evidence exists describing the molecular alterations leading to impaired brown adipogenesis with aging and the contribution of these processes to changes of systemic energy metabolism. Methods: Samples of young and aged murine brown and white adipose tissue were used to compare age-related changes of brown adipogenic gene expression and thermogenesis-related lipid mobilization. To identify potential markers of brown adipose tissue aging, non-targeted proteomic and metabolomic as well as targeted lipid analyses were conducted on young and aged tissue samples. Subsequently, the effects of several candidate lipid classes on brown adipocyte function were examined. Results: Corroborating previous reports of reduced expression of uncoupling protein-1, we observe impaired signaling required for lipid mobilization in aged brown fat after adrenergic stimulation. Omics analyses additionally confirm the age-related impairment of lipid homeostasis and reveal the accumulation of specific lipid classes, including certain sphingolipids, ceramides, and dolichols in aged brown fat. While ceramides as well as enzymes of dolichol metabolism inhibit brown adipogenesis, inhibition of sphingosine 1-phosphate receptor 2 induces brown adipocyte differentiation. Conclusions: Our functional analyses show that changes in specific lipid species, as observed during aging, may contribute to reduced thermogenic potential. They thus uncover potential biomarkers of aging as well as molecular mechanisms that could contribute to the degradation of brown adipocytes, thereby providing potential treatment strategies of age-related metabolic conditions.}, language = {en} } @article{JonasKluthHelmsetal.2022, author = {Jonas, Wenke and Kluth, Oliver and Helms, Anett and Voss, Sarah and Jahnert, Markus and Gottmann, Pascal and Speckmann, Thilo and Knebel, Birgit and Chadt, Alexandra and Al-Hasani, Hadi and Sch{\"u}rmann, Annette and Vogel, Heike}, title = {Identification of novel genes involved in hyperglycemia in mice}, series = {International journal of molecular sciences}, volume = {23}, journal = {International journal of molecular sciences}, number = {6}, publisher = {MDPI}, address = {Basel}, issn = {1661-6596}, doi = {10.3390/ijms23063205}, pages = {13}, year = {2022}, abstract = {Current attempts to prevent and manage type 2 diabetes have been moderately effective, and a better understanding of the molecular roots of this complex disease is important to develop more successful and precise treatment options. Recently, we initiated the collective diabetes cross, where four mouse inbred strains differing in their diabetes susceptibility were crossed with the obese and diabetes-prone NZO strain and identified the quantitative trait loci (QTL) Nidd13/NZO, a genomic region on chromosome 13 that correlates with hyperglycemia in NZO allele carriers compared to B6 controls. Subsequent analysis of the critical region, harboring 644 genes, included expression studies in pancreatic islets of congenic Nidd13/NZO mice, integration of single-cell data from parental NZO and B6 islets as well as haplotype analysis. Finally, of the five genes (Acot12, S100z, Ankrd55, Rnf180, and Iqgap2) within the polymorphic haplotype block that are differently expressed in islets of B6 compared to NZO mice, we identified the calcium-binding protein S100z gene to affect islet cell proliferation as well as apoptosis when overexpressed in MINE cells. In summary, we define S100z as the most striking gene to be causal for the diabetes QTL Nidd13/NZO by affecting beta-cell proliferation and apoptosis. Thus, S100z is an entirely novel diabetes gene regulating islet cell function.}, language = {en} } @article{AgaBarfknechtHallahanGottmannetal.2020, author = {Aga-Barfknecht, Heja and Hallahan, Nicole and Gottmann, Pascal and J{\"a}hnert, Markus and Osburg, Sophie and Schulze, Gunnar and Kamitz, Anne and Arends, Danny and Brockmann, Gudrun and Schallschmidt, Tanja and Lebek, Sandra and Chadt, Alexandra and Al-Hasani, Hadi and Joost, Hans-Georg and Sch{\"u}rmann, Annette and Vogel, Heike}, title = {Identification of novel potential type 2 diabetes genes mediating beta-cell loss and hyperglycemia using positional cloning}, series = {Frontiers in genetics}, volume = {11}, journal = {Frontiers in genetics}, publisher = {Frontiers Media}, address = {Lausanne}, issn = {1664-8021}, doi = {10.3389/fgene.2020.567191}, pages = {11}, year = {2020}, abstract = {Type 2 diabetes (T2D) is a complex metabolic disease regulated by an interaction of genetic predisposition and environmental factors. To understand the genetic contribution in the development of diabetes, mice varying in their disease susceptibility were crossed with the obese and diabetes-prone New Zealand obese (NZO) mouse. Subsequent whole-genome sequence scans revealed one major quantitative trait loci (QTL),Nidd/DBAon chromosome 4, linked to elevated blood glucose and reduced plasma insulin and low levels of pancreatic insulin. Phenotypical characterization of congenic mice carrying 13.6 Mbp of the critical fragment of DBA mice displayed severe hyperglycemia and impaired glucose clearance at week 10, decreased glucose response in week 13, and loss of beta-cells and pancreatic insulin in week 16. To identify the responsible gene variant(s), further congenic mice were generated and phenotyped, which resulted in a fragment of 3.3 Mbp that was sufficient to induce hyperglycemia. By combining transcriptome analysis and haplotype mapping, the number of putative responsible variant(s) was narrowed from initial 284 to 18 genes, including gene models and non-coding RNAs. Consideration of haplotype blocks reduced the number of candidate genes to four (Kti12,Osbpl9,Ttc39a, andCalr4) as potential T2D candidates as they display a differential expression in pancreatic islets and/or sequence variation. In conclusion, the integration of comparative analysis of multiple inbred populations such as haplotype mapping, transcriptomics, and sequence data substantially improved the mapping resolution of the diabetes QTLNidd/DBA. Future studies are necessary to understand the exact role of the different candidates in beta-cell function and their contribution in maintaining glycemic control.}, language = {en} } @article{HenkelColemanSchraplauetal.2017, author = {Henkel, Janin and Coleman, Charles Dominic and Schraplau, Anne and J{\"o}hrens, Korinna and Weber, Daniela and Castro, Jose Pedro and Hugo, Martin and Schulz, Tim Julius and Kr{\"a}mer, Stephanie and Sch{\"u}rmann, Annette and P{\"u}schel, Gerhard Paul}, title = {Induction of Steatohepatitis (NASH) with Insulin Resistance in Wild-type B6 Mice by a Western-type Diet Containing Soybean Oil and Cholesterol}, series = {Molecular medicine}, volume = {23}, journal = {Molecular medicine}, publisher = {Feinstein Inst. for Medical Research}, address = {Manhasset}, issn = {1076-1551}, doi = {10.2119/molmed.2016.00203}, pages = {70 -- 82}, year = {2017}, abstract = {Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) are hepatic manifestations of the metabolic syndrome. Many currently used animal models of NAFLD/NASH lack clinical features of either NASH or metabolic syndrome such as hepatic inflammation and fibrosis (e.g., high-fat diets) or overweight and insulin resistance (e.g., methionine-choline-deficient diets), or they are based on monogenetic defects (e.g., ob/ob mice). In the current study, a Western-type diet containing soybean oil with high n-6-PUFA and 0.75\% cholesterol (SOD + Cho) induced steatosis, inflammation and fibrosis accompanied by hepatic lipid peroxidation and oxidative stress in livers of C57BL/6-mice, which in addition showed increased weight gain and insulin resistance, thus displaying a phenotype closely resembling all clinical features of NASH in patients with metabolic syndrome. In striking contrast, a soybean oil-containing Western-type diet without cholesterol (SOD) induced only mild steatosis but not hepatic inflammation, fibrosis, weight gain or insulin resistance. Another high-fat diet, mainly consisting of lard and supplemented with fructose in drinking water (LAD + Fru), resulted in more prominent weight gain, insulin resistance and hepatic steatosis than SOD + Cho, but livers were devoid of inflammation and fibrosis. Although both LAD + Fru-and SOD + Cho-fed animals had high plasma cholesterol, liver cholesterol was elevated only in SOD + Cho animals. Cholesterol induced expression of chemotactic and inflammatory cytokines in cultured Kupffer cells and rendered hepatocytes more susceptible to apoptosis. In summary, dietary cholesterol in the SOD + Cho diet may trigger hepatic inflammation and fibrosis. SOD + Cho-fed animals may be a useful disease model displaying many clinical features of patients with the metabolic syndrome and NASH.}, language = {en} } @article{WittenbecherOuniKuxhausetal.2019, author = {Wittenbecher, Clemens and Ouni, Meriem and Kuxhaus, Olga and J{\"a}hnert, Markus and Gottmann, Pascal and Teichmann, Andrea and Meidtner, Karina and Kriebel, Jennifer and Grallert, Harald and Pischon, Tobias and Boeing, Heiner and Schulze, Matthias Bernd and Sch{\"u}rmann, Annette}, title = {Insulin-Like Growth Factor Binding Protein 2 (IGFBP-2) and the Risk of Developing Type 2 Diabetes}, series = {Diabetes : a journal of the American Diabetes Association}, volume = {68}, journal = {Diabetes : a journal of the American Diabetes Association}, number = {1}, publisher = {American Diabetes Association}, address = {Alexandria}, issn = {0012-1797}, doi = {10.2337/db18-0620}, pages = {188 -- 197}, year = {2019}, abstract = {Recent studies suggest that insulin-like growth factor binding protein 2 (IGFBP-2) may protect against type 2 diabetes, but population-based human studies are scarce. We aimed to investigate the prospective association of circulating IGFBP-2 concentrations and of differential methylation in the IGFBP-2 gene with type 2 diabetes risk.}, language = {en} } @article{StadionSchuermann2020, author = {Stadion, Mandy and Sch{\"u}rmann, Annette}, title = {Intermittent fasting}, series = {Psychotherapeut}, volume = {66}, journal = {Psychotherapeut}, number = {1}, publisher = {Springer}, address = {New York}, issn = {0935-6185}, doi = {10.1007/s00278-020-00471-5}, pages = {23 -- 27}, year = {2020}, abstract = {A long-term positive energy balance leads to overweight and obesity. Adiposity is the main risk factor for cardiovascular diseases, type 2 diabetes and cancer and is often accompanied by depression. The increasing prevalence creates a major problem for the healthcare system. The conservative management of obesity strives for weight loss by reducing the daily caloric intake and increasing physical activity as well as an improvement in the quality of life supported by psychological interventions. For reducing body weight, intermittent fasting represents an alternative to continuous calorie restriction as it can be easily integrated into daily life. In this form of diet calorie intake is limited in time, i.e. on 2 days in the week or 6-10 h per day. Animal and human studies provide evidence that intermittent fasting over a longer time period is a suitable method to decrease body fat and to improve many metabolic parameters. Fasting alters metabolism and activates specific cellular pathways. These have not only cardioprotective effects but also neuroprotective and antidepressive effects. In this article the currently discussed mechanisms induced by intermittent fasting are highlighted and the essential observations from randomized controlled human trials are presented.}, language = {de} } @article{StadionSchuermann2020, author = {Stadion, Mandy and Sch{\"u}rmann, Annette}, title = {Intermittierendes Fasten}, series = {Der Diabetologe}, volume = {16}, journal = {Der Diabetologe}, number = {7}, publisher = {Springer Medizin}, address = {Berlin}, issn = {1860-9716}, doi = {10.1007/s11428-020-00666-z}, pages = {641 -- 646}, year = {2020}, abstract = {Obesity increases the risk of metabolic disorders and can lead to type 2 diabetes. Therefore, the treatment and prevention of obesity represent important medical challenges. Increased physical activity and a reduction in daily caloric intake of 25-30\% are often recommended. Another possibility is intermittent fasting, by limiting dietary caloric content over certain times, i.e. one or more days a week or for more than 14 h a day. Animal and human studies provide evidence that intermittent fasting in obesity leads to a reduction in body fat mass as well as to improvements of metabolic parameters and insulin sensitivity. These positive effects are mediated not only by the decrease in body mass, but also by the activation of metabolic pathways and cellular processes that are specific for fasting conditions. In this article, we describe the current knowledge about the mechanisms induced by intermittent fasting and present results from randomized controlled human trials.}, language = {de} } @article{GrajaGarciaCarrizoJanketal.2018, author = {Graja, Antonia and Garcia-Carrizo, Francisco and Jank, Anne-Marie and Gohlke, Sabrina and Ambrosi, Thomas H. and Jonas, Wenke and Ussar, Siegfried and Kern, Matthias and Sch{\"u}rmann, Annette and Aleksandrova, Krasimira and Bluher, Matthias and Schulz, Tim Julius}, title = {Loss of periostin occurs in aging adipose tissue of mice and its genetic ablation impairs adipose tissue lipid metabolism}, series = {Aging Cell}, volume = {17}, journal = {Aging Cell}, number = {5}, publisher = {Wiley}, address = {Hoboken}, issn = {1474-9718}, doi = {10.1111/acel.12810}, pages = {13}, year = {2018}, abstract = {Remodeling of the extracellular matrix is a key component of the metabolic adaptations of adipose tissue in response to dietary and physiological challenges. Disruption of its integrity is a well-known aspect of adipose tissue dysfunction, for instance, during aging and obesity. Adipocyte regeneration from a tissue-resident pool of mesenchymal stem cells is part of normal tissue homeostasis. Among the pathophysiological consequences of adipogenic stem cell aging, characteristic changes in the secretory phenotype, which includes matrix-modifying proteins, have been described. Here, we show that the expression of the matricellular protein periostin, a component of the extracellular matrix produced and secreted by adipose tissue-resident interstitial cells, is markedly decreased in aged brown and white adipose tissue depots. Using a mouse model, we demonstrate that the adaptation of adipose tissue to adrenergic stimulation and high-fat diet feeding is impaired in animals with systemic ablation of the gene encoding for periostin. Our data suggest that loss of periostin attenuates lipid metabolism in adipose tissue, thus recapitulating one aspect of age-related metabolic dysfunction. In human white adipose tissue, periostin expression showed an unexpected positive correlation with age of study participants. This correlation, however, was no longer evident after adjusting for BMI or plasma lipid and liver function biomarkers. These findings taken together suggest that age-related alterations of the adipose tissue extracellular matrix may contribute to the development of metabolic disease by negatively affecting nutrient homeostasis.}, language = {en} } @article{CastanoMartinezSchumacherSchumacheretal.2019, author = {Casta{\~n}o Mart{\´i}nez, Mar{\´i}a Teresa and Schumacher, Fabian and Schumacher, Silke and Kochlik, Bastian and Weber, Daniela and Grune, Tilman and Biemann, Ronald and McCann, Adrian and Abraham, Klaus and Weikert, Cornelia and Kleuse, Burkhard and Sch{\"u}rmann, Annette and Laeger, Thomas}, title = {Methionine restriction prevents onset of type 2 diabetes in NZO mice}, series = {The FASEB journal : the official journal of the Federation of American Societies for Experimental Biology}, volume = {33}, journal = {The FASEB journal : the official journal of the Federation of American Societies for Experimental Biology}, number = {6}, publisher = {Federation of American Societies for Experimental Biology}, address = {Bethesda}, issn = {0892-6638}, doi = {10.1096/fj.201900150R}, pages = {7092 -- 7102}, year = {2019}, abstract = {Dietary methionine restriction (MR) is well known to reduce body weight by increasing energy expenditure (EE) and insulin sensitivity. An elevated concentration of circulating fibroblast growth factor 21 (FGF21) has been implicated as a potential underlying mechanism. The aims of our study were to test whether dietary MR in the context of a high-fat regimen protects against type 2 diabetes in mice and to investigate whether vegan and vegetarian diets, which have naturally low methionine levels, modulate circulating FGF21 in humans. New Zealand obese (NZO) mice, a model for polygenic obesity and type 2 diabetes, were placed on isocaloric high-fat diets (protein, 16 kcal\%; carbohydrate, 52 kcal\%; fat, 32 kcal\%) that provided methionine at control (Con; 0.86\% methionine) or low levels (0.17\%) for 9 wk. Markers of glucose homeostasis and insulin sensitivity were analyzed. Among humans, low methionine intake and circulating FGF21 levels were investigated by comparing a vegan and a vegetarian diet to an omnivore diet and evaluating the effect of a short-term vegetarian diet on FGF21 induction. In comparison with the Con group, MR led to elevated plasma FGF21 levels and prevented the onset of hyperglycemia in NZO mice. MR-fed mice exhibited increased insulin sensitivity, higher plasma adiponectin levels, increased EE, and up-regulated expression of thermogenic genes in subcutaneous white adipose tissue. Food intake and fat mass did not change. Plasma FGF21 levels were markedly higher in vegan humans compared with omnivores, and circulating FGF21 levels increased significantly in omnivores after 4 d on a vegetarian diet. These data suggest that MR induces FGF21 and protects NZO mice from high-fat diet-induced glucose intolerance and type 2 diabetes. The normoglycemic phenotype in vegans and vegetarians may be caused by induced FGF21. MR akin to vegan and vegetarian diets in humans may offer metabolic benefits via increased circulating levels of FGF21 and merits further investigation.-Castano-Martinez, T., Schumacher, F., Schumacher, S., Kochlik, B., Weber, D., Grune, T., Biemann, R., McCann, A., Abraham, K., Weikert, C., Kleuser, B., Schurmann, A., Laeger, T. Methionine restriction prevents onset of type 2 diabetes in NZO mice.}, language = {en} } @article{KehmJaehnertDeubeletal.2020, author = {Kehm, Richard and J{\"a}hnert, Markus and Deubel, Stefanie and Flore, Tanina and K{\"o}nig, Jeannette and Jung, Tobias and Stadion, Mandy and Jonas, Wenke and Sch{\"u}rmann, Annette and Grune, Tilman and H{\"o}hn, Annika}, title = {Redox homeostasis and cell cycle activation mediate beta-cell mass expansion in aged, diabetes-prone mice under metabolic stress conditions: role of thioredoxin-interacting protein (TXNIP)}, series = {Redox Biology}, volume = {37}, journal = {Redox Biology}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2213-2317}, doi = {10.1016/j.redox.2020.101748}, pages = {11}, year = {2020}, abstract = {Overnutrition contributes to insulin resistance, obesity and metabolic stress, initiating a loss of functional beta-cells and diabetes development. Whether these damaging effects are amplified in advanced age is barely investigated. Therefore, New Zealand Obese (NZO) mice, a well-established model for the investigation of human obesity-associated type 2 diabetes, were fed a metabolically challenging diet with a high-fat, carbohydrate restricted period followed by a carbohydrate intervention in young as well as advanced age. Interestingly, while young NZO mice developed massive hyperglycemia in response to carbohydrate feeding, leading to beta-cell dysfunction and cell death, aged counterparts compensated the increased insulin demand by persistent beta-cell function and beta-cell mass expansion. Beta-cell loss in young NZO islets was linked to increased expression of thioredoxin-interacting protein (TXNIP), presumably initiating an apoptosis-signaling cascade via caspase-3 activation. In contrast, islets of aged NZOs exhibited a sustained redox balance without changes in TXNIP expression, associated with higher proliferative potential by cell cycle activation. These findings support the relevance of a maintained proliferative potential and redox homeostasis for preserving islet functionality under metabolic stress, with the peculiarity that this adaptive response emerged with advanced age in diabetesprone NZO mice.}, language = {en} } @article{HenkelFredeSchanzeetal.2012, author = {Henkel, Janin and Frede, Katja and Schanze, Nancy and Vogel, Heike and Sch{\"u}rmann, Annette and Spruß, Astrid and Bergheim, Ina and P{\"u}schel, Gerhard Paul}, title = {Stimulation of fat accumulation in hepatocytes by PGE(2)-dependent repression of hepatic lipolysis, beta-oxidation and VLDL-synthesis}, series = {Laboratory investigation : the basic and translational pathology research journal ; an official journal of the United States and Canadian Academy of Pathology}, volume = {92}, journal = {Laboratory investigation : the basic and translational pathology research journal ; an official journal of the United States and Canadian Academy of Pathology}, number = {11}, publisher = {Nature Publ. Group}, address = {New York}, issn = {0023-6837}, doi = {10.1038/labinvest.2012.128}, pages = {1597 -- 1606}, year = {2012}, abstract = {Hepatic steatosis is recognized as hepatic presentation of the metabolic syndrome. Hyperinsulinaemia, which shifts fatty acid oxidation to de novo lipogenesis and lipid storage in the liver, appears to be a principal elicitor particularly in the early stages of disease development. The impact of PGE(2), which has previously been shown to attenuate insulin signaling and hence might reduce insulin-dependent lipid accumulation, on insulin-induced steatosis of hepatocytes was studied. The PGE(2)-generating capacity was enhanced in various obese mouse models by the induction of cyclooxygenase 2 and microsomal prostaglandin E-synthases (mPGES1, mPGES2). PGE(2) attenuated the insulin-dependent induction of SREBP-1c and its target genes glucokinase and fatty acid synthase. Nevertheless, PGE(2) enhanced incorporation of glucose into hepatic triglycerides synergistically with insulin. This was most likely due to a combination of a PGE(2)-dependent repression of (1) the key lipolytic enzyme adipose triglyceride lipase, (2) carnitine-palmitoyltransferase 1, a key regulator of mitochondrial beta-oxidation, and (3) microsomal transfer protein, as well as (4) apolipoprotein B, key components of the VLDL synthesis. Repression of PGC1 alpha, a common upstream regulator of these genes, was identified as a possible cause. In support of this hypothesis, overexpression of PGC1 alpha completely blunted the PGE(2)-dependent fat accumulation. PGE(2) enhanced lipid accumulation synergistically with insulin, despite attenuating insulin signaling and might thus contribute to the development of hepatic steatosis. Induction of enzymes involved in PGE(2) synthesis in in vivo models of obesity imply a potential role of prostanoids in the development of NAFLD and NASH. Laboratory Investigation (2012) 92, 1597-1606; doi:10.1038/labinvest.2012.128; published online 10 September 2012}, language = {en} } @article{WilhelmiGrunwaldGimberetal.2020, author = {Wilhelmi, Ilka and Grunwald, Stephan and Gimber, Niclas and Popp, Oliver and Dittmar, Gunnar and Arumughan, Anup and Wanker, Erich E. and Laeger, Thomas and Schmoranzer, Jan and Daumke, Oliver and Sch{\"u}rmann, Annette}, title = {The ARFRP1-dependent Golgi scaffolding protein GOPC is required for insulin secretion from pancreatic 13-cells}, series = {Molecular metabolism}, volume = {45}, journal = {Molecular metabolism}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2212-8778}, doi = {10.1016/j.molmet.2020.101151}, pages = {13}, year = {2020}, abstract = {Objective: Hormone secretion from metabolically active tissues, such as pancreatic islets, is governed by specific and highly regulated signaling pathways. Defects in insulin secretion are among the major causes of diabetes. The molecular mechanisms underlying regulated insulin secretion are, however, not yet completely understood. In this work, we studied the role of the GTPase ARFRP1 on insulin secretion from pancreatic 13-cells.
Methods: A 13-cell-specific Arfrp1 knockout mouse was phenotypically characterized. Pulldown experiments and mass spectrometry analysis were employed to screen for new ARFRP1-interacting proteins. Co-immunoprecipitation assays as well as super-resolution microscopy were applied for validation.
Results: The GTPase ARFRP1 interacts with the Golgi-associated PDZ and coiled-coil motif-containing protein (GOPC). Both proteins are co localized at the trans-Golgi network and regulate the first and second phase of insulin secretion by controlling the plasma membrane localization of the SNARE protein SNAP25. Downregulation of both GOPC and ARFRP1 in Min6 cells interferes with the plasma membrane localization of SNAP25 and enhances its degradation, thereby impairing glucose-stimulated insulin release from 13-cells. In turn, overexpression of SNAP25 as well as GOPC restores insulin secretion in islets from 13-cell-specific Arfrp1 knockout mice.
Conclusion: Our results identify a hitherto unrecognized pathway required for insulin secretion at the level of trans-Golgi sorting. (c) 2020 The Authors. Published by Elsevier GmbH. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).}, 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} } @misc{SchwerbelKamitzJaehnertetal.2018, author = {Schwerbel, Kristin and Kamitz, Anne and Jaehnert, Markus and Gottmann, P. and Schumacher, Fabian and Kleuser, Burkhard and Haltenhof, T. and Heyd, F. and Roden, Michael and Chadt, Alexandra and Al-Hasani, Hadi and Jonas, W. and Vogel, Heike and Sch{\"u}rmann, Annette}, title = {Two immune-related GTPases prevent from hepatic fat accumulation by inducing autophagy}, series = {Diabetologia : journal of the European Association for the Study of Diabetes (EASD)}, volume = {61}, journal = {Diabetologia : journal of the European Association for the Study of Diabetes (EASD)}, publisher = {Springer}, address = {New York}, issn = {0012-186X}, pages = {S259 -- S259}, year = {2018}, language = {en} }