Caspase 9及其相关分子基因表达水平改变对同型半胱氨酸内皮凋亡的影响(英文)

Effect of caspase 9 related signaling molecules on the apoptosis of human vascular endothelial cell induced by homocysteine

目的了解caspase3信号传导通路中上游分子Bcl2、细胞色素c(cytochromec)、caspase9在同型半胱氨酸作用下的人脐静脉血管内皮细胞内的mRNA及蛋白表达水平的改变,揭示线粒体参与信号传导链在caspase3所介导的内皮细胞凋亡过程中的作用。方法培养人脐静脉内皮细胞,用不同浓度同型半胱氨酸作用于细胞后,用逆转录聚合酶链反应及Western印迹分别检测各分子基因及蛋白表达水平的改变。结果Bcl2、cytochromec和caspase9在同型半胱氨酸作用下mRNA及蛋白表达水平下降,并且随同型半胱氨酸浓度的升高而降低。结论Bcl2可能参与了同型半胱氨酸促进细胞凋亡的信号传导途径。Caspase3没有通过上游分子apoptosome和caspase9途径活化。这些研究结果提示,同型半胱氨酸诱导细胞凋亡并不是通过以线粒体凋亡通路为主的信号传导通路。

Objective To understand the role of mitochondria associated signaling pathway in the apoptosis of human vascular endothelial cell induced by homecysteine （Hcy）. Methods The mRNA and protein expression levels of the up-stream signaling molecules of caspase 3, Bcl 2, caspase 9, and cytosolic cytochrome-c, were investigated. The in vitro cultured human umbilical vein endothelial cells with homocysteine at different concentrations were incubated for 24 h. The expressions of Bcl 2 and caspase 9 at mRNA and protein levels were analyzed by reverse transcription-polymerase chain reaction（RT-PCR） and Westem blot. Cytochrome-c in cytoplasm was also detected by Western blot. Resuits The expression levels of three signaling molecules were all down-regulated by homocysteine at both mRNA and protein levels in a dose-dependent mariner. Conclusion Homocysteine could affect the formation of apoptosome through repressing the expression of Bc12 gene and release of cytochrome-c from mitochondria. Decreasing of apoptosome could disturb the activation of caspase 9. The results also indicate that the mitochondria pathway is not the major signaling pathway involved in Hcy-induced apoptosis.