Role of miR-200c in Myogenic Differentiation Impairment via p66Shc: Implication in Skeletal Muscle Regeneration of Dystrophic mdx Mice

Figure 5

miR-200c and p66Shc phosphorylation in Ser-36 increase in dystrophic muscles of mdx mice. (a) The mRNA of quadriceps (Q), gastrocnemius (GA), tibialis anterior (TA), extensor digitorum longus (EDL), and soleus (SOL) muscles isolated from 3 young (4-week-old (4 w)) mdx mice were assayed for miR-200c expression. miR-200c increased in young mdx mice compared to young wt mice ( for each muscle; ; the bar graphs are average results of miR-200c expression levels of 3 different mice for each muscle). (b) The mRNA of quadriceps (Q), gastrocnemius (GA), tibialis anterior (TA), extensor digitorum longus (EDL), and soleus (SOL) muscles isolated from 3 old (36-week-old (36 w)) mdx mice were assayed for miR-200c expression. miR-200c increased in old mdx mice compared to old wt mice ( for each muscle; ; ; the bar graphs are average results of miR-200c expression levels of 3 different mice for each muscle). (c) The mRNA of human myoblasts derived from muscle biopsies of healthy donors or DMD patients and differentiated in vitro were assayed for miR-200c expression. miR-200c increased in DMD myoblasts compared to control myoblasts (; ; the bar graphs are average results of miR-200c expression levels of 3 different cell populations for control or DMD samples). (d) A representative Western blot of GA and Q protein extracts of both young (4 w) and old mdx (36 w) compared to young and old wt mice showed that p66 protein was induced in mdx mice compared to wt mice. Moreover, the phosphorylation in Ser-36 was induced in mdx mice compared to wt mice in both young and old mice (the experiment was performed on 3 biological replicates; 3 wt mice and 3 mdx mice of 4 weeks and 36 weeks, resp.). Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was used as loading control.

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