Institute for Human Genetics, Division Epigenetics & Metabolism, University of Lübeck, Lübeck, Germany; Center of Brain, Behaviour and Metabolism (CBBM), University of Lübeck, Lübeck, Germany; German Center for Diabetes Research (DZD), Munich, Germany
Jan H Britsemmer
Institute for Human Genetics, Division Epigenetics & Metabolism, University of Lübeck, Lübeck, Germany; Center of Brain, Behaviour and Metabolism (CBBM), University of Lübeck, Lübeck, Germany; German Center for Diabetes Research (DZD), Munich, Germany
German Center for Diabetes Research (DZD), Munich, Germany; Research Unit NeuroBiology of Diabetes, Institute for Diabetes and Obesity, Helmholtz Centre, Munich, Germany
Anna Molenaar
German Center for Diabetes Research (DZD), Munich, Germany; Research Unit NeuroBiology of Diabetes, Institute for Diabetes and Obesity, Helmholtz Centre, Munich, Germany
Natalie Taege
Institute for Human Genetics, Division Epigenetics & Metabolism, University of Lübeck, Lübeck, Germany; Center of Brain, Behaviour and Metabolism (CBBM), University of Lübeck, Lübeck, Germany; German Center for Diabetes Research (DZD), Munich, Germany
Nuria Lopez-Alcantara
Center of Brain, Behaviour and Metabolism (CBBM), University of Lübeck, Lübeck, Germany; Institute for Experimental Endocrinology, University of Lübeck, Lübeck, Germany
Cathleen Geißler
Institute for Human Genetics, Division Epigenetics & Metabolism, University of Lübeck, Lübeck, Germany; Center of Brain, Behaviour and Metabolism (CBBM), University of Lübeck, Lübeck, Germany
Meike Kaehler
Institute of Experimental and Clinical Pharmacology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
Katharina Iben
Institute for Human Genetics, Division Epigenetics & Metabolism, University of Lübeck, Lübeck, Germany; Center of Brain, Behaviour and Metabolism (CBBM), University of Lübeck, Lübeck, Germany
Anna Judycka
Institute for Human Genetics, Division Epigenetics & Metabolism, University of Lübeck, Lübeck, Germany; Center of Brain, Behaviour and Metabolism (CBBM), University of Lübeck, Lübeck, Germany
Jonas Wagner
Department of General, Visceral and Thoracic Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
Stefan Wolter
Department of General, Visceral and Thoracic Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
Oliver Mann
Department of General, Visceral and Thoracic Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
Paul Pfluger
German Center for Diabetes Research (DZD), Munich, Germany; Research Unit NeuroBiology of Diabetes, Institute for Diabetes and Obesity, Helmholtz Centre, Munich, Germany; Chair of Neurobiology of Diabetes, TUM School of Medicine, Technical University of Munich, Munich, Germany
Institute of Experimental and Clinical Pharmacology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
Hendrik Lehnert
Center of Brain, Behaviour and Metabolism (CBBM), University of Lübeck, Lübeck, Germany; German Center for Diabetes Research (DZD), Munich, Germany; University Hospital of Coventry and Warwickshire, Coventry, United Kingdom
Kerstin Stemmer
German Center for Diabetes Research (DZD), Munich, Germany; Molecular Cell Biology, Institute of Theoretical Medicine, Faculty of Medicine, University of Augsburg, Augsburg, Germany
German Center for Diabetes Research (DZD), Munich, Germany; Research Unit NeuroBiology of Diabetes, Institute for Diabetes and Obesity, Helmholtz Centre, Munich, Germany
Institute for Human Genetics, Division Epigenetics & Metabolism, University of Lübeck, Lübeck, Germany; Center of Brain, Behaviour and Metabolism (CBBM), University of Lübeck, Lübeck, Germany; German Center for Diabetes Research (DZD), Munich, Germany
Background: The development of obesity-associated comorbidities such as type 2 diabetes (T2D) and hepatic steatosis has been linked to selected microRNAs in individual studies; however, an unbiased genome-wide approach to map T2D induced changes in the miRNAs landscape in human liver samples, and a subsequent robust identification and validation of target genes are still missing. Methods: Liver biopsies from age- and gender-matched obese individuals with (n=20) or without (n=20) T2D were used for microRNA microarray analysis. The candidate microRNA and target genes were validated in 85 human liver samples, and subsequently mechanistically characterized in hepatic cells as well as by dietary interventions and hepatic overexpression in mice. Results: Here, we present the human hepatic microRNA transcriptome of type 2 diabetes in liver biopsies and use a novel seed prediction tool to robustly identify microRNA target genes, which were then validated in a unique cohort of 85 human livers. Subsequent mouse studies identified a distinct signature of T2D-associated miRNAs, partly conserved in both species. Of those, human-murine miR-182–5 p was the most associated with whole-body glucose homeostasis and hepatic lipid metabolism. Its target gene LRP6 was consistently lower expressed in livers of obese T2D humans and mice as well as under conditions of miR-182–5 p overexpression. Weight loss in obese mice decreased hepatic miR-182–5 p and restored Lrp6 expression and other miR-182–5 p target genes. Hepatic overexpression of miR-182–5 p in mice rapidly decreased LRP6 protein levels and increased liver triglycerides and fasting insulin under obesogenic conditions after only seven days. Conclusions: By mapping the hepatic miRNA-transcriptome of type 2 diabetic obese subjects, validating conserved miRNAs in diet-induced mice, and establishing a novel miRNA prediction tool, we provide a robust and unique resource that will pave the way for future studies in the field. As proof of concept, we revealed that the repression of LRP6 by miR-182–5 p, which promotes lipogenesis and impairs glucose homeostasis, provides a novel mechanistic link between T2D and non-alcoholic fatty liver disease, and demonstrate in vivo that miR-182–5 p can serve as a future drug target for the treatment of obesity-driven hepatic steatosis. Funding: This work was supported by research funding from the Deutsche Forschungsgemeinschaft (KI 1887/2-1, KI 1887/2-2, KI 1887/3-1 and CRC-TR296), the European Research Council (ERC, CoG Yoyo LepReSens no. 101002247; PTP), the Helmholtz Association (Initiative and Networking Fund International Helmholtz Research School for Diabetes; MB) and the German Center for Diabetes Research (DZD Next Grant 82DZD09D1G).
