PGC-1α过表达逆转OGD/R诱导的神经元线粒体功能降低和凋亡

目的:探讨过氧化物酶体增殖物激活受体γ辅助活化因子1α(PGC-1α)基因过表达对氧糖剥夺/复氧(OGD/R)诱导的神经元线粒体功能及细胞凋亡的影响。方法:采用RT-PCR的方法从C57BL/6乳鼠大脑皮层获取PGC-1α的全基因序列,并克隆到真核表达载体p EGFP-N1上,经PCR初步鉴定后转染原代皮层神经元,Western blot鉴定PGC-1α的表达情况,成功构建PGC-1α真核表达载体p EGFP-N1-PGC-1α。分别将转染p EGFP-N1和p EGFP-N1-PGC-1α载体的皮层神经元进行OGD/R处理,分别采用Mito Tracker Red染色、流式细胞术、ATP代谢检测试剂盒和TUNEL细胞凋亡检测试剂盒检测线粒体质量分数、活性氧簇(ROS)和ATP生成、细胞凋亡以及caspase-3激活的变化。结果:PGC-1α过表达可抑制OGD/R诱导的神经元线粒体生成能力的降低和ROS的生成(P0.05),增强ATP的合成能力(P0.01),抑制神经元的凋亡(P0.01)并降低caspase-3的激活(P0.05)。结论:PGC-1α过表达可通过促进线粒体生成、抑制ROS的产生和维护线粒体功能而抑制OGD/R诱导的神经元凋亡。PGC-1α可以作为开发脑缺血再灌注损伤药物的靶标之一。

Over-expression of PGC-1α reverses mitochondrial function reduction and apoptosis in OGD/R-induced neurons

AIM: To investigate the effect of over-expression of peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) on mitochondrial morphology and cell apoptosis in the cortical neurons with oxygen glucose deprivation/reoxygenation (OGD/R). METHODS: The whole gene sequence of PGC-1α was obtained from the cerebral cortex of C57BL/6 mice by RT-PCR and cloned into the eukaryotic expression vector pEGFP-N1. The pEGFP-N1-PGC-1α was identified by PCR, and transfected into cortical neurons. The level of PGC-1α expression was identified by Western blot. The cortical neurons transfected with pEGFP-N1 and pEGFP-N1-PGC-1α vectors were treated with OGD/R. The mitochondrial mass, reactive oxygen species (ROS) and ATP production, cell apoptosis and changes of cleaved caspase-3 were detected by MitoTracker Red staining, flow cytometry, ATP metabolic assay kit and TUNEL. RESULTS: Over-expression of PGC-1α inhibited the decrease in mitochondrial biogenesis capacity and the ROS formation of OGD/R neurons (P<0.05), enhanced the ability of ATP synthesis (P<0.01), inhibited neuronal apoptosis (P<0.01) and decreased the activation of caspase-3 (P<0.01). CONCLUSION: PGC-1α over-expression inhibits neuronal apoptosis with OGD/R treatment by promoting mitochondrial biogenesis, inhibiting the production of ROS and maintaining mitochondrial function. PGC-1α may be used as a target for the development of cerebral ischemia/reperfusion injury drugs.