低氧诱导因子1α对成肌分化中PGC-1β的影响及机制研究

Effects of hypoxia-inducible factor 1α on PGC-1β in myogenesis and the relevant mechanism

目的:研究低氧诱导因子HIF-1α在颏舌肌成肌分化和线粒体生物发生中的作用,探索可能的调控机制。方法:构建HIF-1α敲降质粒,慢病毒载体转染小鼠颏舌肌成肌细胞,设阴性对照组,用含2%马血清的分化培养基在低氧(1%O2)环境下诱导成肌细胞分化,western blot检测成肌细胞分化2、4、6 d,PGC-1β、AMPKα1、p AMPKα1的表达水平,免疫细胞化学染色观察低氧分化4 d时AMPK通道激活剂与阻滞剂对PGC-1β的表达影响,western blot定量分析。结果:1 HIF-1α敲降组的PGC-1β表达量高于对照组(P<0.05),且分化4 d时表达最高(P<0.05);2AMPKα1总蛋白表达量无明显差异,p AMPKα1的表达在HIF-1α敲降组远高于对照组(P<0.05)。3AMPK通路促进剂AICAR增加PGC-1β的表达(P<0.05),抑制剂Compound C明显抑制PGC-1β的表达(P<0.05)。结论:HIF-1α下调了低氧环境中PGC-1β的表达,PGC-1β的表达受AMPK通路的正向调节作用。

Objective：To investigate the effects of HIF-1α on myogenic differentiation and mitochondrial biogenesis and the mechanism involved. Method：HIF-1α shRNA lentivirous was used to infect the myoblasts. Myoblasts was induced differentiation by 2%horse serum in hypoxia condition（1%O2） for 6 days,PGC-1β,AMPKα1 and pAMPKα1 were detect-ed through western-blot. Immunocytochemistry and western-blot were performed to detected the expression of PGC-1β after medication of AICAR or Compound C. Result： ①Compared with control myoblasts,the expression of PGC-1βwas higher in HIF-1α KO myoblasts during myogenesis （P 〈0.05）,and highest in the fourth day. ②There is no significant differences in AMPKα1 （P 〉0.05）. The expression of pAMPKα1 was significantly higher under hypoxia condition in HIF-1α KO group, compared with the control groups（P 〈0.05）.③AICAR（activator of AMPK） increaed the expression of PGC-1β（P 〈0.05）, while Compound C （inhibitor of AMPK） showed opposite effect （P〈0.05）. Conclusion：HIF-1αdecreases the expression of PGC-1βunder hypoxia condition. The expression of PGC-1β is influenced by AMPK,which acts as a positively acting com-ponent.