Up-Regulated MicroRNA-27b Promotes Adipocyte Differentiation via Induction of Acyl-CoA Thioesterase 2 Expression

Nonalcoholic fatty liver disease (NAFLD) is characterized by a spectrum of liver pathologies, from simple steatosis to steatohepatitis. Recent studies have increasingly noted the aberrant expression of microRNAs closely related to NAFLD pathologies. We have previously shown the presence of increased levels of microRNA-27b (miR-27b) in patients with NAFLD. In this study, we investigated the role of miR-27b in NAFLD by examining the impact of up-regulated miR-27b on the differentiation of preadipocytes into mature adipocytes. We found that miR-27b-3p remarkably enhances the adipocyte differentiation of 3T3-L1 cells associated with lipid accumulation and intracellular triglyceride contents. Furthermore, we have demonstrated not only that miR-27b-3p induces acyl-CoA thioesterase 2 (ACOT2) expression in 3T3-L1 cells, but also that the knockdown of ACOT2 suppresses lipid accumulation and adipocyte differentiation in both the presence and absence of miR-27b-3p treatment. Our data strongly suggest that the miR-27b-ACOT2 axis is an important pathway in adipocyte differentiation and may play a role in the pathogenesis of NAFLD.