A MAFG-lncRNA axis links systemic nutrient abundance to hepatic glucose metabolism
Marta Pradas-Juni, Nils Rouven Hansmeier, Jenny C. Link, Elena Schmidt, Bjørk Ditlev Larsen, Paul Klemm, Nicola Meola, Hande Topel, Rute Loureiro, Ines Dhaouadi, Christoph Kiefer, Robin Schwarzer, Sajjad Khani, Matteo Oliverio, Motoharu Awazawa, Peter Frommolt, Jöerg Heeren, Ludger Scheja, Markus Heine, Christoph Dieterich, Hildegard Büning, Ling Yang, Haiming Cao, Dario F. De Jesus, Rohit Kulkarni, Branko Zevnik, Simon E. Tröder, Uwe Knippschild, Peter A. Edwards, Richard Lee, Masayuki Yamamoto, Igor Ulitsky, Eduardo Fernández‐Rebollo, Thomas Q. de Aguiar Vallim, Jan‐Wilhelm Kornfeld
Abstract
Obesity and type 2 diabetes mellitus are global emergencies and long noncoding RNAs (lncRNAs) are regulatory transcripts with elusive functions in metabolism. Here we show that a high fraction of lncRNAs, but not protein-coding mRNAs, are repressed during diet-induced obesity (DIO) and refeeding, whilst nutrient deprivation induced lncRNAs in mouse liver. Similarly, lncRNAs are lost in diabetic humans. LncRNA promoter analyses, global cistrome and gain-of-function analyses confirm that increased MAFG signaling during DIO curbs lncRNA expression. Silencing Mafg in mouse hepatocytes and obese mice elicits a fasting-like gene expression profile, improves glucose metabolism, de-represses lncRNAs and impairs mammalian target of rapamycin (mTOR) activation. We find that obesity-repressed LincIRS2 is controlled by MAFG and observe that genetic and RNAi-mediated LincIRS2 loss causes elevated blood glucose, insulin resistance and aberrant glucose output in lean mice. Taken together, we identify a MAFG-lncRNA axis controlling hepatic glucose metabolism in health and metabolic disease.