microRNA133a Targets Foxl2 and Promotes Differentiation of C2C12 into Myogenic Progenitor Cells

microRNAs are endogenous noncoding RNA molecules of similar to 22 nucleotides that regulate gene function by modification of target mRNAs. Due to tissue specific of miR-133a and miR-1/206 for skeletal muscles, we investigated the role of miR-133a and miR-1/206 in promoting the differentiation of the C2C12 cells. The results show that directly transfecting mature miR-133a, miR-1/206, or combinations (miR-1 and miR-206, miR-1 and miR-133a, and miR-133a and miR-206) into C2C12 cells, respectively, for 5 days induces formation of myogenic progenitor cells. Overexpression of miR-133a and miR-206 in C2C12 cells greatly improved multinucleated myotube formation. microRNA-133a (miR-133a) is highly expressed during human muscle development. Using bioinformatics, we identified one putative miR-133a binding site within the 3 '-untranslated region of the mouse Foxl2 mRNA. The expression of Foxl2 was shown to be downregulated by subsequent western blot analysis.