MiR-204-5p regulates C2C12 myoblast differentiation by targeting MEF2C and ERRγ

Myogenic differentiation, which occurs in the process of muscle development, is a highly ordered process. Increasing evidence indicates that microRNAs (miRNAs) are important regulators in myogenic processes. In this study, we found that miR-204-5p expression gradually decreased when myoblasts were induced to differentiate. Our results suggested that miR-204-5p blunted myoblast differentiation, which was accompanied with a decreased proportion of myosin heavy chain (MyHC)-positive cells in myoblasts with augmented expression of miR-204-5p. Furthermore, overexpression of miR-204-5p significantly decreased the MyHC composition of slow-twitch fibers in myoblasts. Luciferase activity assays confirmed that miR-204-5p directly targeted the 3'-untranslated region (3'-UTR) of myocyte enhancer factor 2C (MEF2C) and estrogen-related receptor gamma (ERR gamma). Small interfering RNA (siRNA) technology successfully inhibited the expression of MEF2C and ERR gamma. Interference with MEF2C or ERR gamma inhibited myoblast differentiation and the formation of slow-twitch fibers. Meanwhile, co-transfection of either si-MEF2C or si-ERR gamma with miR-204-5p mimics resulted in a more severe attenuation of myogenic differentiation. In summary, this study demonstrates that miR-204-5p inhibits myoblast differentiation by targeting MEF2C and ERR gamma. Our findings suggest that miR-204-5p is a potential regulator that could influence myogenesis.