MG132诱导人血管内皮细胞凋亡及对caspase-3表达的影响

Effect on expression of caspase-3 in the apoptosis of cultured humanumbilical vein endothelial cells induced by proteasome inhibitor MG132

目的 观察蛋白酶体抑制剂MG132对人血管脐静脉内皮细胞(ECV -304)的致凋亡作用及其对凋亡相关的天冬氨酸特异的半胱氨酸蛋白酶3表达的影响。方法 采用两个浓度(2, 5μmol·L-1 )的蛋白酶体抑制剂MG132处理ECV -304细胞;DNA琼脂糖凝胶电泳检测细胞凋亡,流式细胞术检测细胞周期和细胞凋亡率;RT -PCR检测细胞内凋亡相关基因caspase -3的转录水平;免疫细胞化学检测细胞caspase 3蛋白表达。结果 对照组ECV -304细胞凋亡率低于5%,在2μmol·L-1MG132作用下,凋亡率为11. 3%,MG132浓度升至5μmol·L-1,细胞凋亡率增致44 .5%,MG132诱导ECV 304细胞凋亡具有量-效关系;RT -PCR检测发现细胞内凋亡相关基因caspase 3mRNA表达上调;免疫细胞化学检测细胞caspase- 3蛋白表达水平升高。结论:蛋白酶体抑制剂MG132能够诱导血管内皮细胞凋亡,其机制可能与MG132抑制UPP活性,促进caspase- 3基因转录,使细胞内caspase -3增加而促进细胞凋亡。

Aim To study the effect of proteasome inhibitor MG132 on the expression of caspase-3 and apoptosis in cultured human umbilical vein endothelial cells.Methods Human umbilical vein endothelial cells was treated with MG132 (2,5 μmol·L^(-1)) for 24 h. The apoptotic cells were determined by DNA fragment analysis and flow cytometric analysis. The level of caspase-3 mRNA was quantified by reverse transcription-polymerase chain reaction (RT-PCR). The protein contents of caspase-3 were analyzed by immunocytochemistry.Results The results showed that the increase of the degree of human umbilical vein endothelial cells apoptosis was concentration dependent. MG132 could up-regulate the gene/protein expression of caspase-3.Conclusions The results implicated that proteasome inhibitor MG132 induced human umbilical vein endothelial cells apoptosis by accumulation of caspase-3.