p38丝裂素活化蛋白激酶信号通路在应力调控成肌细胞分化中的作用

Effect of p38 mitogen-activated protein kinase signaling pathway during stretch-induced differentiation process of C2C12 myoblasts

目的研究在C2C12细胞成肌分化过程中应力对丝裂原活化蛋白激酶(MAPKs)信号通路中p38丝裂素活化蛋白激酶(p38MAPK)信号通路的影响。方法将6孔Bio Flex培养板上贴壁培养的C2C12细胞,以0.5 Hz的加载频率和10%的细胞拉伸变形幅度,分别进行拉伸培养2、6、12、24 h,应用Western blot免疫印迹检测总p38和磷酸化p-p38(Thr180/Tyr182)蛋白的表达情况。结果周期性机械拉伸在调控C2C12成肌细胞分化过程中,p38MAPK信号通路被激活。p38MAPK信号通路蛋白磷酸化水平在较高水平;而p38MAPK通路总蛋白表达维持在一基线水平,各组之间差异无统计学意义。加入p38MAPK信号通路特异性抑制剂SB203580后再加力,Myogenin的表达明显降低。结论p38MAPK信号通路在应力介导的C2C12成肌细胞分化过程中发挥重要作用,但不是这一调控过程的唯一通路。

Objective To investigate the effect of cyclic stretch on p38 mitogen-activated protein kinase （p38MAPK） signaling pathway during stretch-induced differentiation process of C2C12 myoblasts. Methods C2C12 cells were seeded on Bio Flex 6-well plates, and cells were subsequently subjected to cyclic stretch at an optimal magnitude （10%） and frequency （0.5 Hz）. The effects of cyclic stretch were examined at 2, 6, 12, 24 h. Antibodies specific to p38MAPK phosphorylated forms and the total protein levels of the p38MAPK were examined using Western blot ana- lysis. Results These results indicated that p38MAPK was activated during stretch-induced C2C12 cell differentiation. The level of phosphorylated protein was higher in the p38MAPK signaling pathway. The expression of total protein was maintained at baseline level. There were no significant differences between groups. Treatment of ceils with specific p38MAPK inhibitor SB203580 could decrease the expression of myogentn, but not completely abolish the myogenin ex- pression after stretch. Conclusion p38MAPK signaling pathway plays an important role during stretch-induced diffe- rentiation process of C2C12 myoblasts, but is not activated exclusively in this process.