Murine miR-483-3p promotes proliferation and suppresses differentiation of C2C12 cells by targeting SRF

Myogenesis is a complicated process, which is regulated by numerous regulators. MicroRNAs (miRNAs) are conserved non-coding RNAs of ~22 nucleotides, which regulate post-transcriptional gene expression in many physiological and pathophysiological processes. Recent studies have indicated that microRNAs are critical regulators of muscle development. Here, we report miR-483-3p as a new essential regulator of muscle development, mediating myoblast proliferation and myogenic differentiation. miR-483-3p is strongly and almost exclusively expressed in muscle-related tissues such as leg muscle, back muscle, and heart. Its expression is downregulated during mouse development. Overexpression of miR-483-3p in C2C12 cells promotes proliferation and suppresses myogenic differentiation. A dual-luciferase reporter assay demonstrated miR-483-3p direct targets to the 3′-UTR of the SRF gene. Overexpression of miR-483-3p reduced SRF protein levels in C2C12 myoblasts. These results reveal a novel function of miR-483-3p as a positive regulator of C2C12 proliferation and inhibitor of myogenic differentiation via SRF downregulation.