Aim: 

Myogenesis is a process orchestrated by the basic helix loop helix myogenic regulatory factors (MRFs) of the MyoD family. It is established that the p38-MAPK signaling pathway plays a central role in myogenesis as a regulator of myoblast proliferation and that represent a key step in controlling muscle specific gene expression (MHC). In cell differentiation DNA methylation is associated with a variety of gene regulatory processes. Previous works indicate that treatment of mesenchymal stem cells with the DNA-demethylating agent 5-azacytidine (5-AZA) promotes the MyoD expression. Previous data by us suggest that genetic variants of genes encoding enzymes involved in methylation pathway are present in DNA of athletes.

Methods: 

We studied the effects of demethylating treatment during myogenesis in particular we analyzed: 1) MRFs and muscle specific protein expression, 2) modulation of signaling pathways involved in muscle differentiation. We stimulated C2C12 cells with 5 mM 5-AZA incubated with growth (GM) or differentiation (DM) medium for 4, 24, 48, 72 and 96 hours. Controls were unstimulated cells.

Results: 

MRFs protein contents, evaluated by Western Blot and Immunofluorescence studies, were higher in cells treated with AZA. The positive effect of demethylation was observed by analysis of cellular cycle and p38-JNK pathways. Data, obtained in GM condition, suggest that the AZA action is sufficient to induce myogenesis.

Conclusion: 

Our study indicates the importance of DNA methylation in muscle differentiation.