MiR-455 enhances adipogenic differentiation of 3T3-L1 cells through targeting uncoupling protein-1

Accumulating evidence suggests that microRNAs (miRNAs) play an important role in regulating the pathways in adipose tissue that control processes such as adipogenesis, insulin resistance, and inflammation. Adipogenic differentiation of preadipocytes is a complex process regulated by various factors including miRNAs and cytokines. MiR-455 is a well-known miRNA that enhances adipogenesis. Uncoupling protein-1 (UCP-1), a heparinbinding growth factor, plays a negative role in adipogenesis. In this investigation, we demonstrate that UCP-1 is a target gene of miR-455 during adipogenic differentiation in 3T3-L1 preadipocytes. MiR-455 downregulates UCP-1 expression through interaction with a target site of miR-455 in the coding region of mouse UCP-1. The rare codons upstream of the target site regulate miR-455-induced translational knockdown of UCP-1, which provides more insight into the mechanism of adipogenic differentiation. Thus, these results suggest that the acceerative adipogenic effect of miR-455 in 3T3-L1 cells is due, at least in part, to suppression of UCP-1.