Journal
ACTA BIOCHIMICA ET BIOPHYSICA SINICA
Volume 49, Issue 7, Pages 628-634Publisher
OXFORD UNIV PRESS
DOI: 10.1093/abbs/gmx052
Keywords
microRNA; transforming growth factor-beta; Smad4; fibrosis; muscle
Categories
Funding
- National Natural Science Foundation of China [81472142]
Ask authors/readers for more resources
Growing evidence suggests the importance of microRNAs (miRNAs) in stress signaling pathways. Transforming growth factor-beta (TGF-beta) is a potent cytokine that promotes the development of skeletal muscle fibrosis after acute contusion. However, how miRNAs are involved in TGF-beta signaling and confer the robustness of TGF-beta-induced fibrotic response remains to be fully elucidated. Here, we demonstrated that miR-146a-5p (miR-146) levels were reduced in a fibrotic mouse model after acute muscle contusion. It was also found that TGF-beta treatment decreased the expression of miR-146 in vitro in a dose-and time-dependent manner. In addition, overexpression of Smad3 and Samd4, two key players in TGF-beta signaling, suppressed the expression of miR-146 in muscle cells. Overexpression of miR-146 inhibited the expressions of fibrosis markers both in vitro and in vivo. Moreover, increase in the expression of miR-146 in muscle cells was able to attenuate the effect of TGF-beta on the expressions of fibrosis markers. Mechanistic analysis revealed that Smad4 is a direct target of miR-146 in muscle cells. Furthermore, the anti-fibrotic effect of miR-146 could be blocked by overexpression of Smad4 in vivo. These results suggest that Smad4 is down-regulated by miR-146 in skeletal muscle. Taken together, our results indicate that the anti-fibrotic miR-146 is a component of TGF-beta signaling. It is down-regulated by Smad protein, and can inhibit the expression of Smad4. Our study suggests that miR-146 might have a therapeutic potential to reduce skeletal muscle fibrosis after injury.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available