Zhang Guo-Min, Deng Ming-Tian, Zhang Yan-Li, Fan Yi-Xuan, Wan Yong-Jie, Nie Hai-Tao, Wang Zi-Yu, Wang Feng, Lei Zhi-Hai
Jiangsu Livestock Embryo Engineering Laboratory, Nanjing Agricultural University, No.1 Weigang, Nanjing, China.
College of veterinary medicine, Nanjing Agricultural University, No.1 Weigang, Nanjing, China.
J Bioenerg Biomembr. 2016 Oct;48(5):493-507. doi: 10.1007/s10863-016-9684-6. Epub 2016 Nov 28.
During goat follicular development, abnormal expression of peroxisome proliferator- activated receptor gamma coactivator-1 alpha (PGC-1α) in granulosa cells (GCs) may contribute to follicular atresia with unknown regulatory mechanisms. In this study, we investigate the effect of ectopic expression or interference of PGC-1α on cell apoptosis of goat first passage granulosa cells (FGCs) in vitro. The results indicate that PGC-1α silencing by short hairpin RNA (shRNA) in goat FGCs significantly reduced mitochondrial DNA (mtDNA) copy number (P < 0.05), changed mitochondria ultrastructure, and induced cell apoptosis (P < 0.05). The transcription and translation levels of the apoptosis-related genes BCL-2-associated X protein (BAX), caspase 3, and caspase 9 were significantly up-regulated (P < 0.05, respectively). Moreover, the ratio of BAX/B-cell lymphoma 2 (BCL-2) was reduced (P < 0.05), and the release of cytochrome c (cyt c) and lactate dehydrogenase (LDH) was significantly enhanced (P < 0.05, respectively) in PGC-1α interference goat FGCs. Furthermore, the expression of anti-oxidative related genes superoxide dismutase 2 (SOD2), glutathione peroxidase (GPx) and catalase (CAT) was down-regulated (P < 0.05, respectively) and the activity of glutathione/glutathione disulfide (GSH/GSSG) was inhibited (P < 0.05). While enforced expression of PGC-1α increased the levels of genes involved in the regulation of mitochondrial function and biogenesis, and enhanced the anti-oxidative and anti-apoptosis capacity. Taken together, our results reveal that lack of PGC-1α may lead to mitochondrial dysfunction and disrupt the cellular redox balance, thus resulting in goat GCs apoptosis through the mitochondria-dependent apoptotic pathway.
在山羊卵泡发育过程中，颗粒细胞（GCs）中过氧化物酶体增殖物激活受体γ共激活因子-1α（PGC-1α）的异常表达可能导致卵泡闭锁，但其调控机制尚不清楚。在本研究中，我们在体外研究了PGC-1α的异位表达或干扰对山羊原代颗粒细胞（FGCs）细胞凋亡的影响。结果表明，通过短发夹RNA（shRNA）沉默山羊FGCs中的PGC-1α可显著降低线粒体DNA（mtDNA）拷贝数（P < 0.05），改变线粒体超微结构，并诱导细胞凋亡（P < 0.05）。凋亡相关基因BCL-2相关X蛋白（BAX）、半胱天冬酶3和半胱天冬酶9的转录和翻译水平显著上调（分别为P < 0.05）。此外，在PGC-1α干扰的山羊FGCs中，BAX/B细胞淋巴瘤2（BCL-2）的比值降低（P < 0.05），细胞色素c（cyt c）和乳酸脱氢酶（LDH）的释放显著增强（分别为P < 0.05）。此外，抗氧化相关基因超氧化物歧化酶2（SOD2）、谷胱甘肽过氧化物酶（GPx）和过氧化氢酶（CAT）的表达下调（分别为P < 0.05），谷胱甘肽/谷胱甘肽二硫化物（GSH/GSSG）的活性受到抑制（P < 0.05）。而PGC-1α的强制表达增加了参与线粒体功能和生物发生调控的基因水平，并增强了抗氧化和抗凋亡能力。综上所述，我们的结果表明，PGC-1α的缺乏可能导致线粒体功能障碍并破坏细胞氧化还原平衡，从而通过线粒体依赖性凋亡途径导致山羊GCs凋亡。
