Abstract
Insulin resistance (IR) and microRNAs (miRNAs), which regulate cell-to-cell communication between hepatocytes and hepatic stellate cells (HSCs), may intertwine in nonalcoholic fatty liver disease (NAFLD) pathogenesis. The aim of this study was to evaluate whether epigenetics and environmental factors interact to promote progressive NAFLD during IR. We examined the miRNA signature in insulin receptor haploinsufficient (InsR+/-) and wild-type (wt) HSCs by RNAseq (n = 4 per group). Then, we evaluated their impact in an IR-NASH (nonalcoholic steatohepatitis) model (InsR+/- mice fed standard or methionine choline deficient (MCD) diet, n = 10 per group) and in vitro. InsR+/- HSCs displayed 36 differentially expressed miRNAs (p < 0.05 vs. wt), whose expression was then analyzed in the liver of InsR+/- mice fed an MCD diet. We found that miR-101-3p negatively associated with both InsR+/- genotype and MCD (p < 0.05) and the histological spectrum of liver damage (p < 0.01). miR-101-3p was reduced in InsR+/- hepatocytes and HSCs and even more in InsR+/- cells exposed to insulin (0.33 µM) and fatty acids (0.25 mM), resembling the IR-NASH model. Conversely, insulin induced miR-101-3p expression in wt cells but not in InsR+/- ones (p < 0.05). In conclusion, IR combined with diet-induced liver injury favors miR-101-3p downregulation, which may promote progressive NAFLD through HSC and hepatocyte transdifferentiation and proliferation.