MicroRNA-425 controls lipogenesis and lipolysis in adipocytes

An increasing number of studies have demonstrated that some microRNAs participate in the regulation of growth and development of adipocytes. The present study shows that microRNA-425-5p (miR-425) is a novel strong regulator of adipogenesis and adipolysis in adipocytes. Forced expression of miR-425 in mice promoted body fat accumulation and the development of obesity due to high-fat intake, whereas silencing miR-425 prevented mice from being obese. Mechanically, the expression of miR-425 is controlled by PPARγ during the adipogenesis process in adipocytes. MiR-425 overexpression resulted in a reduction in the proliferation of 3t3-L1 pre-adipocytes but significantly accelerated cellular adipogenic differentiation. Mapk14, a negative regulator of adipogenesis, was predicted and confirmed as a real target gene of miR-425. Moreover, knocking down miR-425 remarkably intensified intracellular lipolysis and promoted lipid oxidation, which is related to the activation of AMPK, a monitor for intracellular energy balance. MiR-425 activated AMPK not only by decreasing cellular ATP concentrations but also by targeting the gene of Cab39, which is an upstream co-activator of AMPK. The findings of the present study suggest that miR-425 could control adipogenesis and adipolysis in adipocytes by simultaneously triggering multidirectional targets.