MicroRNA‑23a‑5p mediates the proliferation and differentiation of C2C12 myoblasts.

Skeletal myogenesis is a highly ordered and complex biological process that is mediated by numerous regulatory factors. In previous studies, it has been demonstrated that microRNAs (miRs) and long non-coding RNAs (lncRNAs) serve key roles in skeletal myogenesis. The present study showed that the expression levels ofmiR-23a-5pshowed a dynamic change from decrease to increase during C2C12 myoblast proliferation and differentiation. Functional analysis using 5-ethynyl-2 '-deoxyuridine proliferation and Cell Counting Kit-8 detection assays indicated that overexpression ofmiR-23a-5psignificantly promoted C2C12 myoblast proliferation compared with the negative control. In addition, in C2C12 myoblasts transfected withmiR-23a-5pmimics, increased expression levels of regulators associated with cell proliferation (Cyclin E, CCND1andCyclin B) were observed compared with the negative control. By contrast, overexpression ofmiR-23a-5pdecreased the expression levels of specific-myogenesis factors (MyoD, MyoGandMyf5) and decreased C2C12 myoblast differentiation. Luciferase activity assays indicated thatmiR-23a-5psuppressed the luciferase activity oflncDum. Further analysis demonstrated thatmiR-23a-5pnot only showed an opposite expression level pattern compared withlncDum, which was first increased and then decreased, but also had an opposite effect on the proliferation and differentiation of C2C12 myoblasts compared withlncDumwhich inhibited cell proliferation and promoted cell differentiation. Taken together, these results indicated thatmiR-23a-5pmay mediate the proliferation and differentiation of C2C12 myoblasts, which may be involved in lncDum regulation.