miR-22 regulates C2C12 myoblast proliferation and differentiation by targeting TGFBR1
miR-22 regulates C2C12 myoblast proliferation and differentiation by targeting TGFBR1
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miR-22通过靶向TGFBR1调节C2C12成肌细胞增殖和分化
DOI：
10.1016/j.ejcb.2018.03.006
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发表时间：
2018-05-01
影响因子：
6.6
通讯作者：
Huang, Ruihua
中科院分区：
文献类型：
--
作者：
Wang, Han;Zhang, Qian;Huang, Ruihua
近年来发现miR-22在骨骼肌生长的不同阶段有差异表达，提示其可能在骨骼肌成肌过程中发挥作用。在本研究中，我们发现miR-22在骨骼肌中表达最多，并在小鼠成肌细胞（C2 C12成肌细胞系）分化过程中逐渐上调。过表达miR-22可抑制C2 C12成肌细胞增殖并促进成肌细胞分化为肌管，而抑制miR-22则显示相反的结果。在肌形成过程中，我们预测并验证了TGF-β/Smad信号通路的关键受体转化生长因子β受体1（TGF-β R 1）是miR-22的靶基因。结果发现，miR-22可以调控TGF-β R 1的表达，下调Smad 3信号通路。通过siRNA敲低TGF β R 1抑制C2 C12细胞的增殖，但诱导其分化。相反，TGFBR 1的过表达显着促进成肌细胞的增殖，但抑制其分化。此外，当用不同浓度的转化生长因子β 1（TGF-β 1）处理C2 C12细胞时，C2 C12细胞中的miR-22水平降低。在用TGF-β 1处理的C2 C12细胞中，TGF-β 1蛋白水平显著升高。此外，miR-22能够抑制C2 C12细胞中TGF-β 1诱导的TGFBR 1表达。总之，我们证明了TGF-β 1抑制C2 C12细胞中miR-22的表达，miR-22通过靶向TGF β 1调节C2 C12细胞的肌生成。
Recently, miR-22 was found to be differentially expressed in different skeletal muscle growth period, indicated that it might have function in skeletal muscle myogenesis. In this study, we found that the expression of miR-22 was the most in skeletal muscle and was gradually up-regulated during mouse myoblast cell (C2C12 myoblast cell line) differentiation. Overexpression of miR-22 repressed C2C12 myoblast proliferation and promoted myoblast differentiation into myotubes, whereas inhibition of miR-22 showed the opposite results. During myogenesis, we predicted and verified transforming growth factor beta receptor 1 (TGFBR1), a key receptor of the TGF-beta/Smad signaling pathway, was a target gene of miR-22. Then, we found miR-22 could regulate the expression of TGFBR1 and down-regulate the Smad3 signaling pathway. Knockdown of TGFBR1 by siRNA suppressed the proliferation of C2C12 cells but induced its differentiation. Conversely, overexpression of TGFBR1 significantly promoted proliferation but inhibited differentiation of the myoblast. Additionally, when C2C12 cells were treated with different concentrations of transforming growth factor beta 1 (TGF-beta 1), the level of miR-22 in C2C12 cells was reduced. The TGFBR1 protein level was significantly elevated in C2C12 cells treated with TGF-beta 1. Moreover, miR-22 was able to inhibit TGF-beta 1-induced TGFBR1 expression in C2C12 cells. Altogether, we demonstrated that TGF-beta 1 inhibited miR-22 expression in C2C12 cells and miR-22 regulated C2C12 cell myogenesis by targeting TGFBR1.