Mechanical stretch regulates microRNA expression profile via NF-κB activation in C2C12 myoblasts

MicroRNAs (miRNAs/miRs) and nuclear factor (NF)-kappa B activation are involved in mechanical stretch-induced skeletal muscle regeneration. However, there are a small number of miRNAs that have been reported to be associated with NF-kappa B activation during mechanical stretch-induced myogenesis. In the present study, C2C12 myoblasts underwent cyclic mechanical stretch in vitro, to explore the relationship between miRNA expression and NF-kappa B activation during stretch-mediated myoblast proliferation. The results revealed that 10% deformation, 0.125 Hz cyclic mechanical stretch could promote myoblast proliferation. The miRNA expression profile was subsequently altered; miR-500,-1934,-31,-378,-331 and -5097 were downregulated, whereas miR-1941 was upregulated. These miRNAs were all involved in stretch-mediated myoblast proliferation. Notably, the expression of these miRNAs was reversed following treatment of 0.125 Hz mechanically stretched C2C12 cells with NF-kappa B inhibitors, which was accompanied by C2C12 cell growth suppression. Therefore, the present study is the first, to the best of our knowledge, to demonstrate that the NF-kappa B-dependent miRNA profile is associated with mechanical stretch-induced myoblast proliferation.