低氧对大鼠颏舌肌成肌细胞分化的影响

目的:通过观测低氧环境对体外培养大鼠颏舌肌成肌细胞分化及低氧诱导因子1α(HIF-1α)表达的影响,探讨低氧引起颏舌肌损伤的机制以及HIF-1α在其中的作用。方法:根据环境氧浓度不同,将体外培养的原代大鼠颏舌肌成肌细胞分为正常氧浓度组(NC)(21%)和低氧组(HG)(1%),分别诱导分化0 d、1 d、3 d、6 d。采用RT-PCR及Western blotting检测生肌调节因子(MyoD)、肌源性决定因子(myogenin)、肌球蛋白重链(MHC)以及HIF-1α的mRNA及蛋白表达;倒置显微镜下观察成肌细胞分化的形态变化。结果:在颏舌肌成肌细胞分化过程中,两种氧状态下HIF-1αmRNA表达均没有显著变化(P>0.05),但蛋白表达逐渐上调;低氧对MyoD、myogenin、MHC的mRNA(P<0.05)和蛋白表达有显著的抑制作用,致肌管形成延迟;低氧使HIF-1αmRNA(P<0.05)和蛋白显著上调。结论:低氧环境可能是通过上调HIF-1α表达抑制大鼠颏舌肌成肌细胞的分化,从而抑制颏舌肌损伤的修复。

Effect of hypoxia on the differentiation of rat genioglossus myoblast.

Objective:To investigate the effect of hypoxia on the differentiation of rat genioglossus myoblasts.Method:According to the oxygen concentration of culture environment,genioglossus myoblasts were divided into two groups:the normal oxygen concentration group(NC)(21 %) and hypoxia group(HG)(1 %) and medium was changed to 2 % horse serum to induce differentiation.The mRNA levels of MyoD,myogenin and MHC were determined by real-time RT-PCR and the protein contents of which were detected by western blotting analysis;Cellmorphology was observed by inverted microscope.Result:During differentiation the protein levels of HIF-1α were significantly increased,however the mRNA levels stayed unchanged.Hypoxia significantly decreased the mRNA and protein levels of MyoD,myogenin and MHC,which was coincidence with the results of cellular morphology observation.Conclusion:Hypoxia may inhibited the differentiation of rat genioglossus myoblasts through upregulating HIF-1αexpression,which postponed or inhibitedgenioglossus lesion repair.