Abstract
Non-coding genes, such as microRNA and lncRNA, which have been widely studied, play an important role in the regulatory network of skeletal muscle development. However, the functions and mechanisms of most non-coding RNAs in skeletal muscle regulatory networks are unclear. This study investigated the function and mechanism of miR-34b in muscle growth and development. MiR-34b overexpression and interference tests were performed in C2C12 myoblasts and animal models. It was demonstrated that miR-34b significantly promoted mouse muscle growth and development in vivo, while miR-34b inhibited myoblast proliferation and promoted myoblast differentiation in vitro. Bioinformatics prediction using TargetScan for miRNA target identification and Bibiserv2 for potential miRNA-gene interaction analysis revealed a miR-34b binding site in the SYlSL sequence. The molecular mechanism of miR-34b regulating muscle growth and development was studied by co-transfection experiment, luciferase reporter gene detection, RNA immunoprecipitation, and RNA pull-down. MiR-34b can directly bind to SYISL and AGO2 proteins and regulate the expression of SYISL target genes p21 and MyoG by targeting SYISL, thereby regulating muscle growth and development. This study highlights that, as a novel regulator of myogenesis, miR-34b regulates muscle growth and development by targeting SYISL.