人脐带内皮细胞受到血流剪切应力刺激后表达凋亡蛋白X连锁抑制物

摘要

AIM Physiological levels of laminar shear stress inhibit apoptosis of endothelial cells and exert a potent antiatheroslerotic effect. However, the mechanisms which regulate shear stress-mediated inhibition of apoptosis remain to be fully clarified. METHODS Cultured human umbilical vein endothelial cells (HUVEC) were cultured and exposed to laminar shear stress, X-linked inhibitor of apoptosis protein (XIAP) mRNA and protein expression were observed by real-time polymerase chain reaction and Western blotting analysis respectively. RESULTS Both XIAP mRNA and protein expression were induced in cultured HUVEC after subjected to laminar shear stress 20 dyne*cm-2. XIAP mRNA expression increased from 1-4 h, and reached to the peak at 4 h. XIAP protein expression increased after exposure to shear stress for 6, 12 and 24 h. CONCLUSION The present study provides the first evidence that physiological levels of laminar shear stress induce XIAP expression in cultured endothelial cells, upregulation of XIAP may contribute to the potent antiatherosclerotic effect of shear stress by preventing apoptosis of endothelial cells.%目的生理水平的血流剪切应力有抑制内皮细胞凋亡等作用, 进而发挥抗动脉粥样硬化作用,本研究的目的是阐明血流剪切应力抑制血管内皮细胞凋亡的分子机制.方法人脐静脉内皮细胞培养于DMEM培养液, 当细胞融合时将细胞暴露于20 dyne*cm-2的剪切应力,分别用免疫印迹杂交及实时聚合酶链反应法检测凋亡蛋白X连锁抑制物(X-linked inhibitor of apoptosis protein, XIAP) mRNA 及蛋白的表达.结果 20 dyne*cm-2的剪切应力刺激1～4 h,可诱导内皮细胞产生XIAP mRNA,4 h时表达最多.20 dyne*cm-2剪切应力刺激6, 12和24 h,XIAP蛋白表达明显增加.结论生理水平的剪切应力明显诱导内皮细胞XIAP mRNA和蛋白的表达,这可能是剪切应力抑制内皮细胞凋亡,发挥抗动脉粥样硬化作用的机制之一.