microRNA-378b regulates ethanol-induced hepatic steatosis by targeting CaMKK2 to mediate lipid metabolism

Alcoholic liver disease (ALD) has seriously harmed the health of people worldwide, but its underlying mechanisms remain unclear. This study aims to clarify the biological function of microRNA-378b (miR-378b) in ethanol (EtOH)-induced hepatic lipid accumulation. Here, we report miR-378b is over-expressed in EtOH-induced cells and EtOH-fed mice and finally accelerates lipid accumulation. MiR-378b directly targets Ca(2+)/calmodulin-dependent protein kinase kinase 2 (CaMKK2), a kinase of AMP-activated protein kinase (AMPK), and mediates the protein level of CaMKK2. Over-expression of miR-378b exacerbated the lipid accumulation induced by EtOH and inhibited CaMKK2 and the AMPK cascade while inhibition of miR-378b ameliorated lipid metabolism dysfunction in vivo and in vitro. In brief, our results show that miR-378b plays an important role in the regulation of lipid metabolism by directly targeting CaMKK2.