丝裂原活化蛋白激酶信号通路对软脂酸培养的肌细胞过氧化物酶体增殖物激活受体γ辅激活子表达的调控作用

Regulation of MAPKs pathway on PGC-1α expression in C2C12 cell induced by palmitic acid

目的研究软脂酸对C2C12细胞过氧化物酶体增殖物激活受体γ辅激活子(PGC-1α)表达的影响,揭示丝裂原活化蛋白激酶(MAPKs)信号通路与PGC-1α表达的关系,寻找软脂酸诱导C2C12细胞PGC-1α表达变化的上游调节通路。方法检测软脂酸培养的C2C12细胞PGC-1α、细胞外信号调节激酶(ERK)、jnk氨基末端激酶(JNK)、p38丝裂原活化蛋白激酶(p38MAPK)及其磷酸化蛋白phosp-38MAPK(P-p38MAPK)的表达变化。寻找发生变化的MAPKs信号通路,用筛选到的p38MAPK抑制剂进行干预,分为对照(Con)组、软脂酸(Palmitate)组、p38MAPK抑制剂组和Palmitate+p38MAPK抑制剂组,测定PGC-1α、p38MAPK总蛋白及其P-p38MAPK的表达。结果软脂酸培养的C2C12细胞PGC-1α蛋白表达下降,呈时间依赖性;ERK、phospho-ERK、JNK、phospho-JNK及p38MAPK表达无变化,P-p38MAPK表达升高。用p38MAPK抑制剂干预C2C12细胞,PGC-1α表达在Palmitate组最低,p38MAPK抑制剂组和Palmitate+p38MAPK抑制剂组较Palmitate组升高,p38MAPK抑制剂组最高。结论软脂酸诱导的PGC-1α表达下降可能由p38MAPK信号通路调控。

Objective To assay the expression of peroxisome proliferator-activated receptorγcoactivator-1α（PGC-1α）in palmitic acid-incubated C2C12 cells,to reveal the relationship between mitogen-activated protein kinase（MAPKs）signaling pathway and PGC-1αexpression,and to investigate the up-stream regulatory pathway of the PGC-1αin C2C12 cells. Methods The expressions of PGC-1α,ERK,JNK,p38MAPK and phosphorylased proteins were detected in C2C12 cells incubated with palmitic acid to determine the expression changes of MAPKs signaling pathways.After being interfered with p38MAPK inhibitor,the expressions of PGC-1α,p38MAPK and P-p38MAPK were assayed.The cells were divided into four groups including control group,palmitic acid group,p38MAPK inhibitor group and palmitic acid plus p38MAPK inhibitor group. Results The protein expression of PGC-1αwas significantly decreased in palmitic acid-incubated C2C12 cells in a time-dependent manner.There were no significant changes in the expressions of ERK,P-ERK,JNK,P-JNK and p38MAPK.However,the expression of P-p38MAPK increased.After being interfered with p38MAPK inhibitor,the expressions of PGC-1α were increased in p38MAPK inhibitor group and palmitic acid plus inhibitor p38MAPK group than those in palmitic acid group,with the highest in p38MAPK inhibitor group.Conclusion The down-expression of PGC-1αinduced by palmitic acid may be regulated by p38MAPK.