Multi-Omics Insights into Functional Alterations of the Liver in Insulin-Deficient Diabetes Mellitus

The liver regulates the availability of insulin to other tissues and is the first line insulin response organ being physiologically exposed to higher insulin concentrations than the periphery. Basal insulin during fasting inhibits hepatic gluconeogenesis and glycogenolysis, whereas postprandial insulin peaks stimulate glycogen synthesis. The molecular consequences of chronic insulin deficiency for the liver have not been studied systematically. We analyzed liver samples of a genetically diabetic pig model (MIDY) and of wild-type (WT) littermate controls by RNA sequencing, proteomics and targeted metabolomics/lipidomics. Cross-omics analyses revealed increased activity in gluconeogenesis, ketogenesis, amino acid metabolism and oxidation of fatty acids in the MIDY samples, whereas pathways related to extracellular matrix and inflammation/pathogen defense response were less active than in the WT samples. Our study identified key drivers of these alterations, such as RDH16 and HMGCS2 for stimulated gluconeogenesis and ketogenesis, in a clinically relevant large animal model for insulin-deficient diabetes mellitus.