红景天类脂质制剂对缺氧所致PC12细胞凋亡抑制作用及相关机制

Inhibitory effects of Rhodiola lipid on apoptosis of PC12 cells induced by hypoxia and its related mechanisms

目的探讨红景天类脂质制剂(Rho-lip)降低缺氧导致PC12细胞凋亡率的机制。方法采用MTT方法研究PC12细胞凋亡的情况;使用2',7'-二氯荧光素二乙酸酯(DCFH-DA)染色、荧光亲脂性羰花青染料(JC-1)染色以及钙离子荧光探针Fluo-4-AM染色来评判PC12细胞中活性氧簇(ROS)是否累积、线粒体的功能有无受损以及Ca2+含量是否超负荷;Western blotting实验用来进一步研究B淋巴细胞瘤-2(Bcl-2)、特大B淋巴细胞瘤(Bcl-x L)、蛋白激酶B(AKT)、糖原合成酶激酶-3(GSK)等与细胞凋亡密切联系的因子的表达水平,以探究Rholip抑制凋亡的机制。结果 Rho-lip给药后,缺氧诱导的PC12细胞活力提高了28.9%(P<0.01),并可降低细胞内Ca2+的含量,改善线粒体膜电位失衡的状况,避免细胞内ROS的大量累积,同时,细胞内Bcl-2与Bcl-x L的表达水平分别提高了50.1%和19.8%(P<0.05),Rho-lip激活细胞内Akt/GSK3β信号通路(P<0.01),进而缓解了由缺氧诱导的PC12细胞凋亡。结论线粒体依赖通路及Akt/GSK3β通路的激活是Rho-lip保护缺氧所致PC12细胞凋亡的重要分子机制。

Objective To investigate the mechanism of Rhodiola lipid（Rho-lip） on apoptosis of PC12 cells induced by hypoxia. Methods The apoptosis of PC12 was detected by MTT method. To evaluate whether there was accumulation of reactive oxygen species（ROS）, impairment in mitochondria function and Ca2 ＋overload in PC12 cells,2＇,7＇-dichlorodihydrofluorescein diacetate（DCFH-DA）, JC-1 staining, and Fluo-4-AM staining were performed. Western blotting was used to further study the expression level of factors closely related to apoptosis, such as B-cell-lymphoma-2（Bcl-2）, large B-cell-lymphoma（Bcl-x L）, protein kinase B（AKT） and glycogen synthase kinase-3（GSK）,so as to explore the mechanism of Rho-lip＇s inhibition of apoptosis. Results After administration of Rho-lip, the activity of PC12 cells induced by hypoxia was significantly increased by 28.9%（P〈0.01）, which help reduce the content of intracellular Ca2 ＋, improve the imbalance of mitochondrial membrane potential, and avoide the accumulation of intracellular ROS. At the same time, the expression levels of Bcl-2 and Bcl-x L in PC12 cells were significantly increased by 50.1% and 19.8%, respectively（P〈0.05）. Rho-lip activated the intracellular Akt/GSK3β signaling pathway（P〈0.01）, which alleviated the apoptosis of PC12 cells induced by hypoxia. Conclusion Activation of mitochondrial-dependent pathway and Akt/GSK3β pathway is an important molecular mechanism of Rho-lip protection of apoptosis in PC12 cells induced by hypoxia.