miR-133a-5p and miR-29b-1-5p repress myoblast differentiation. (A,B) Overexpression of miR-133a-5p and miR-29b-1-5p reduced the expression of MYOD and MYOG. (C,D) Inhibition of miR-133a-5p and miR-29b-1-5p accelerated the expression of MYOD and MYOG. (E,F) Immunofluorescence analysis of MyHC-staining cells after overexpression miR-133a-5p or miR-29b-1-5p. (G,H) Immunofluorescence analysis of MyHC-staining cells after down-regulation of miR-133a-5p or miR-29b-1-5p. In all panels, results are expressed as the mean ± S.E.M. of three independent experiments, and statistical significance of differences between means was assessed using an unpaired Student’s t-test (* p < 0.05; ** p < 0.01). NC, negative control.