Targeted Demethylation of the TGFβ1 mRNA Promotes Myoblast Proliferation via Activating the SMAD2 Signaling Pathway

Recent evidence suggested that N6-methyladenosine (m(6)A) methylation can determine m(6)A-modified mRNA fate and play an important role in skeletal muscle development. It was well known that transforming growth factor beta 1 (TGF beta 1) is involved in a variety of cellular processes, such as proliferation, differentiation, and apoptosis. However, little is known about the m(6)A-mediated TGF beta 1 regulation in myogenesis. Here, we observed an increase in endogenous TGF beta 1 expression and activity during myotube differentiation. However, the knockdown of TGF beta 1 inhibits the proliferation and induces cell apoptosis of myoblast. Moreover, we found that m(6)A in 5 '-untranslated regions (5 ' UTR) of TGF beta 1 promote its decay and inhibit its expression, leading to the blockage of the TGF beta 1/SMAD2 signaling pathway. Furthermore, the targeted specific demethylation of TGF beta 1 m(6)A using dCas13b-FTO significantly increased the TGF beta 1-mediated activity of the SMAD2 signaling pathway, promoting myoblast proliferation. These findings suggest that TGF beta 1 is an essential regulator of myoblast growth that is negatively regulated by m(6)A. Overall, these results highlight the critical role of m(6)A-mediated post-transcriptional regulation in myogenesis.

Automated summary

Recent evidence suggests that m(6)A methylation plays a crucial role in skeletal muscle development through its regulation of TGF beta 1. Knockdown of TGF beta 1 inhibits myoblast proliferation and induces apoptosis. The presence of m(6)A in the 5 'UTR of TGF beta 1 promotes its decay and inhibits its expression, leading to a blockage in the TGF beta 1/SMAD2 signaling pathway. Targeted demethylation of TGF beta 1 m(6)A enhances the activity of the SMAD2 signaling pathway and promotes myoblast proliferation.