活性氧、线粒体通透性转化孔介导肌细胞凋亡在失神经骨骼肌萎缩中的相关性

目的 观察活性氧(ROS)、线粒体通透性转化孔(MPTP)在失神经骨骼肌萎缩后的表达变化且与肌细胞凋亡的相关性,探讨ROS、MPTP参与失神经骨骼肌萎缩的具体分子机制.方法 将30只Vistar大鼠随机分为对照组、失神经2d组、失神经7d组、失神经14d组、失神经28d组,每组6只.制作坐骨神经切断后失神经支配的腓肠肌Vistar大鼠模型.应用流式细胞术(FCM)检测失神经支配后腓肠肌细胞ROS的含量,激光共聚焦显微镜检测MPTP的开放,脱氧核糖核苷酸转移酶介导的缺口末端标记(TUNEL)法检测肌细胞凋亡.结果 大鼠失神经支配后,肌细胞中的ROS、MPTP及凋亡率与正常对照组比较,表达随失神经支配时间的延长(<28d)而持续增加,且各组的表达均显著高于对照组(P<0.05),ROS的表达与MPTP的开放呈正相关(r=0.884,P<0.01),与肌细胞的凋亡率呈正相关(r=0.893,P<0.01),MPTP的开放与肌细胞凋亡率呈正相关(r=0.927,P<0.01)与肌细胞萎缩指标肌湿重比呈负相关(r=-0.907,P<0.01).结论 ROS、MPTP为调控失神经支配后骨骼肌萎缩的重要分子,其具体机制是通过线粒体介导的凋亡通路促进骨骼肌萎缩.

Abstract：

Objective To study the expression of reactive oxygen species (ROS) and mitochondrial permeability transition pore (MPTP) in denervated skeletal muscle atrophy and its correlation with cell apoptosis, and explore specific molecular mechanism in denervated skeletal muscle atrophy. MethodsThirty Vista rats were randomly divided into five group: control group, 2-days group, 7-days group, 14-days group, 28-days group. Standard model of denervated gastrocnemius muscle was established. The content of ROS and the opening of MPTP in the gastrocnemius were detected by flow cytometry (FCM) and fluorescence microscope respectively. The apoptotic cells in atrophic muscle were examined by TdT-mediated dUTP nick end labeling (TUNEL). Results As compared with the control group, the content of ROS, the opening of MPTP and the apoptosis of gastrocnemius were increased continuously (<28 days) in 2-days group, 7-days group, 14-days group, 28-days group (P<0.05). The content of ROS had a positive correlation with the opening of MPTP (r=0.884,P<0.01) and the apoptosis rate (r=0.893,P<0.01), and the opening of MPTP had a positive correlation with the apoptosis rate (r=0.927,P<0.01), but a negtive correlation with the ratio of muscle wet weight (r=-0.907,P<0.01). Conclusion ROS and MPTP are important elements in regulating skeletal muscle atrophy after denervation by the mitochondrial apoptosis pathway.

Muscle cells apoptosis mediated by reactive oxygen species and mitochondrial permeability transition pore in denervated skeletal muscle atrophy

Objective To study the expression of reactive oxygen species (ROS) and mitochondrial permeability transition pore (MPTP) in denervated skeletal muscle atrophy and its correlation with cell apoptosis, and explore specific molecular mechanism in denervated skeletal muscle atrophy. MethodsThirty Vista rats were randomly divided into five group: control group, 2-days group, 7-days group, 14-days group, 28-days group. Standard model of denervated gastrocnemius muscle was established. The content of ROS and the opening of MPTP in the gastrocnemius were detected by flow cytometry (FCM) and fluorescence microscope respectively. The apoptotic cells in atrophic muscle were examined by TdT-mediated dUTP nick end labeling (TUNEL). Results As compared with the control group, the content of ROS, the opening of MPTP and the apoptosis of gastrocnemius were increased continuously (<28 days) in 2-days group, 7-days group, 14-days group, 28-days group (P<0.05). The content of ROS had a positive correlation with the opening of MPTP (r=0.884,P<0.01) and the apoptosis rate (r=0.893,P<0.01), and the opening of MPTP had a positive correlation with the apoptosis rate (r=0.927,P<0.01), but a negtive correlation with the ratio of muscle wet weight (r=-0.907,P<0.01). Conclusion ROS and MPTP are important elements in regulating skeletal muscle atrophy after denervation by the mitochondrial apoptosis pathway.