Fig. 4

The expression of miR-31-5p, CamkIIδ, MyoD, and Myogenin in the differentiation of C2C12 cells treated by RA. a RA treatment impaired the myogenic differentiation of C2C12 cells. After treated with 10 μM RA for 4 days in differentiation medium, immunofluorenscence showed the decrease of myosin and CaMKIIδ expression; correspondingly, the fusion of myotubes was also decreased with RA addition. b, c The effects of RA on the expression of miR-31-5p and CamkIIδ in the differentiation process of C2C12 cells. The relative expression of miR-31-5p was evidently up-regulated, but the CamkIIδ expression was significantly down-regulated by 10 μM RA treatment. d Western blotting and statistical showed the down-regulation of CaMKIIδ, the reduction is 24.8%. e–f The effects of RA on the transcriptions of MyoD and Myogenin. Similar to CamkIIδ, the relative transcriptions of both MyoD (e) and Myogenin (f) were repressed by RA, compared to controls (*P < 0.05 and **P < 0.01)