TY - JOUR A1 - Vogel, Heike A1 - Kamitz, Anne A1 - Hallahan, Nicole A1 - Lebek, Sandra A1 - Schallschmidt, Tanja A1 - Jonas, Wenke A1 - Jähnert, Markus A1 - Gottmann, Pascal A1 - Zellner, Lisa A1 - Kanzleiter, Timo A1 - Damen, Mareike A1 - Altenhofen, Delsi A1 - Burkhardt, Ralph A1 - Renner, Simone A1 - Dahlhoff, Maik A1 - Wolf, Eckhard A1 - Müller, Timo Dirk A1 - Blüher, Matthias A1 - Joost, Hans-Georg A1 - Chadt, Alexandra A1 - Al-Hasani, Hadi A1 - Schürmann, Annette T1 - A collective diabetes cross in combination with a computational framework to dissect the genetics of human obesity and Type 2 diabetes JF - Human molecular genetics N2 - To explore the genetic determinants of obesity and Type 2 diabetes (T2D), the German Center for Diabetes Research (DZD) conducted crossbreedings of the obese and diabetes-prone New Zealand Obese mouse strain with four different lean strains (B6, DBA, C3H, 129P2) that vary in their susceptibility to develop T2D. Genome-wide linkage analyses localized more than 290 quantitative trait loci (QTL) for obesity, 190 QTL for diabetes-related traits and 100 QTL for plasma metabolites in the out-cross populations. A computational framework was developed that allowed to refine critical regions and to nominate a small number of candidate genes by integrating reciprocal haplotype mapping and transcriptome data. The efficiency of the complex procedure was demonstrated for one obesity QTL. The genomic interval of 35 Mb with 502 annotated candidate genes was narrowed down to six candidates. Accordingly, congenic mice retained the obesity phenotype owing to an interval that contains three of the six candidate genes. Among these the phospholipase PLA2G4A exhibited an elevated expression in adipose tissue of obese human subjects and is therefore a critical regulator of the obesity locus. Together, our broad and complex approach demonstrates that combined- and comparative-cross analysis exhibits improved mapping resolution and represents a valid tool for the identification of disease genes. Y1 - 2018 U6 - https://doi.org/10.1093/hmg/ddy217 SN - 0964-6906 SN - 1460-2083 VL - 27 IS - 17 SP - 3099 EP - 3112 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Saussenthaler, Sophie A1 - Ouni, Meriem A1 - Baumeier, Christian A1 - Schwerbel, Kristin A1 - Gottmann, Pascal A1 - Christmann, Sabrina A1 - Laeger, Thomas A1 - Schürmann, Annette T1 - Epigenetic regulation of hepatic Dpp4 expression in response to dietary protein JF - The journal of nutritional biochemistry N2 - 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. KW - DPP4 KW - DNA methylation KW - Protein restriction KW - Type 2 diabetes KW - NZO Y1 - 2019 U6 - https://doi.org/10.1016/j.jnutbio.2018.09.025 SN - 0955-2863 SN - 1873-4847 VL - 63 SP - 109 EP - 116 PB - Elsevier CY - New York ER - TY - JOUR A1 - Wittenbecher, Clemens A1 - Ouni, Meriem A1 - Kuxhaus, Olga A1 - Jähnert, Markus A1 - Gottmann, Pascal A1 - Teichmann, Andrea A1 - Meidtner, Karina A1 - Kriebel, Jennifer A1 - Grallert, Harald A1 - Pischon, Tobias A1 - Boeing, Heiner A1 - Schulze, Matthias Bernd A1 - Schürmann, Annette T1 - Insulin-Like Growth Factor Binding Protein 2 (IGFBP-2) and the Risk of Developing Type 2 Diabetes JF - Diabetes : a journal of the American Diabetes Association N2 - 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. Y1 - 2019 U6 - https://doi.org/10.2337/db18-0620 SN - 0012-1797 SN - 1939-327X VL - 68 IS - 1 SP - 188 EP - 197 PB - American Diabetes Association CY - Alexandria ER - TY - JOUR A1 - Kluth, Oliver A1 - Stadion, Mandy A1 - Gottmann, Pascal A1 - Aga-Barfknecht, Heja A1 - Jähnert, Markus A1 - Scherneck, Stephan A1 - Vogel, Heike A1 - Krus, Ulrika A1 - Seelig, Anett A1 - Ling, Charlotte A1 - Gerdes, Jantje A1 - Schürmann, Annette T1 - Decreased expression of cilia genes in pancreatic islets as a risk factor for type 2 diabetes in mice and humans JF - Cell reports N2 - 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. Y1 - 2019 U6 - https://doi.org/10.1016/j.celrep.2019.02.056 SN - 2211-1247 VL - 26 IS - 11 SP - 3027 EP - 3036 PB - Cell Press CY - Maryland Heights ER - TY - JOUR A1 - Aga-Barfknecht, Heja A1 - Soultoukis, George A. A1 - Stadion, Mandy A1 - Garcia-Carrizo, Francisco A1 - Jähnert, Markus A1 - Gottmann, Pascal A1 - Vogel, Heike A1 - Schulz, Tim Julius A1 - Schürmann, Annette T1 - Distinct adipogenic and fibrogenic differentiation capacities of mesenchymal stromal cells from pancreas and white adipose tissue JF - International journal of molecular sciences N2 - 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. KW - MSCs KW - fatty pancreas KW - WAT KW - lineage commitment KW - transcriptomics KW - miRNAs Y1 - 2022 U6 - https://doi.org/10.3390/ijms23042108 SN - 1422-0067 VL - 23 IS - 4 PB - Molecular Diversity Preservation International CY - Basel ER - TY - JOUR A1 - Aga-Barfknecht, Heja A1 - Hallahan, Nicole A1 - Gottmann, Pascal A1 - Jähnert, Markus A1 - Osburg, Sophie A1 - Schulze, Gunnar A1 - Kamitz, Anne A1 - Arends, Danny A1 - Brockmann, Gudrun A1 - Schallschmidt, Tanja A1 - Lebek, Sandra A1 - Chadt, Alexandra A1 - Al-Hasani, Hadi A1 - Joost, Hans-Georg A1 - Schürmann, Annette A1 - Vogel, Heike T1 - Identification of novel potential type 2 diabetes genes mediating beta-cell loss and hyperglycemia using positional cloning JF - Frontiers in genetics N2 - 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. KW - type 2 diabetes KW - beta-cell loss KW - insulin KW - positional cloning KW - transcriptomics KW - haplotype Y1 - 2020 U6 - https://doi.org/10.3389/fgene.2020.567191 SN - 1664-8021 VL - 11 PB - Frontiers Media CY - Lausanne ER - TY - THES A1 - Gottmann, Pascal T1 - In silico Analyse zur Klärung der Beteiligung von micro-RNAs, die in QTL lokalisiert sind, an den metabolischen Erkrankungen Adipositas und Typ-2-Diabetes mit Hilfe von Mausmodellen Y1 - 2019 ER - TY - JOUR A1 - Jonas, Wenke A1 - Kluth, Oliver A1 - Helms, Anett A1 - Voss, Sarah A1 - Jahnert, Markus A1 - Gottmann, Pascal A1 - Speckmann, Thilo A1 - Knebel, Birgit A1 - Chadt, Alexandra A1 - Al-Hasani, Hadi A1 - Schürmann, Annette A1 - Vogel, Heike T1 - Identification of novel genes involved in hyperglycemia in mice JF - International journal of molecular sciences N2 - 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. KW - beta-cell KW - diabetes KW - proliferation KW - apoptosis KW - QTL Y1 - 2022 U6 - https://doi.org/10.3390/ijms23063205 SN - 1661-6596 SN - 1422-0067 VL - 23 IS - 6 PB - MDPI CY - Basel ER -