Objective To investigate the effects of fluid shear stress on the vascular endothelial cell damage and focal adhesion remodeling induced by oxidized low-density lipoprotein(ox-LDL).Methods Human umbilical vein endothelial cells(HUVECs)injury was induced by 100 μg/mL ox-LDL and then we constructed the 5 and 25 dynes/cm2fluid shear stress.The cells were divided into the static group, static plus ox-LDL intervention group,5 dyne/cm2fluid shear stress plus ox-LDL intervention group,and 25 dyne/cm2fluid shear stress plus ox-LDL intervention group.The morphology of the cells was observed by phase contrast microscopy,and the retention rate of the cells was measured.The expression levels of major components of focal adhesions including Integrin-β1,focal adhesion kinase(FAK),and Paxillin were measured by immunofluorescence.Results The morphology of cells in the static group was normal.The endothelial cells in the static plus ox-LDL intervention group lost their typical morphology,with disorder arrangement and shedding.The morphology of cells in the 5 dyne/cm2fluid shear stress plus ox-LDL intervention group was improved, the shedding decreased, but the arrangement was in disorder.The cells in the 25 dyne/cm2fluid shear stress plus ox-LDL intervention group were arranged closely,with less shedding,and more solid adhesion of cell-to-matrix.The cell retention rate of 25 dyne/cm2fluid shear stress plus ox-LDL intervention group was 95.15%±16.20 %,which was higher than that of the static plus ox-LDL group (80.95%±14.72 %)and 5 dyne/cm2fluid shear stress plus LDL intervention group(88.86%±14.23%)(both P<0.05).The fluorescence intensity of Integrin-β1,FAK,and Paxillin in the static plus ox-LDL intervention group,5 and 25 dyne/cm2fluid shear stress plus ox-LDL intervention groups was higher than that of static group(all P<0.05).The fluo-rescence intensity of Integrin-β1,FAK,and Paxillin in the 5 dyne/cm2fluid shear stress plus ox-LDL intervention group was lower than that of the static plus ox-LDL intervention group(all P<0.05).The fluorescence intensity of Integrin-β1, FAK,and Paxillin in the 25 dyne/cm2fluid shear stress plus ox-LDL intervention group was lower than that of the static plus ox-LDL intervention group and 5 dyne/cm2fluid shear stress plus ox-LDL intervention group(all P<0.05).Conclu-sions The ox-LDL can cause vascular endothelial cell injury, shedding, and remodeling of focal adhesions.However, higher levels of laminar shear stress in the physiological range can effectively reduce excessive remodeling of focal adhe -sions,promote adhesion of vascular endothelial cells to matrix,and reduce vascular endothelial cell injury.%目的 探讨流体剪切应力对氧化型低密度脂蛋白(ox-LDL)导致的血管内皮细胞损伤和黏着斑重塑的影响.方法 以100 μg/mL ox-LDL诱导人脐静脉内皮细胞(HUVECs)损伤模型,构建5、25 dyne/cm2流体剪切应力,将细胞随机分为静态组、静态加ox-LDL干预组、5 dyne/cm2流体剪切应力加ox-LDL干预组、25 dyne/cm2流体剪切应力加ox-LDL干预组.采用相差显微镜观察细胞形态,检测细胞留存率,免疫荧光法检测各组黏着斑组成分子整合素-β1(Integrin-β1)、黏着斑激酶(FAK)、桩蛋白(Paxillin)的表达水平.结果 静态组细胞形态正常;静态加ox-LDL干预组内皮细胞失去了典型的形态,排列紊乱,大量脱落,内皮细胞单层完整性受损;5 dyne/cm2流体剪切应力加ox-LDL干预组细胞形态比静态加ox-LDL干预组有所改善,脱落有所减少,但排列仍较紊乱;25 dyne/cm2流体剪切应力加ox-LDL干预组细胞排列紧密,脱落较少,细胞与基质之间的黏附较为牢固.25 dyne/cm2流体剪切应力加ox-LDL干预组细胞留存率为95.15%±16.20 %,高于静态加ox-LDL组(80.95%±14.72 %)、5 dyne/cm2流体剪切应力加ox-LDL干预组(88.86%±14.23 %)(P均<0.05);静态加ox-LDL干预组、5 dyne/cm2流体剪切应力加ox-LDL干预组、25 dyne/cm2流体剪切应力加ox-LDL干预组Integrin-β1、FAK、Paxillin的荧光强度均高于静态组(P均<0.05);5 dyne/cm2流体剪切应力加ox-LDL干预组Integrin-β1、FAK、Paxillin荧光强度低于静态加ox-LDL干预组(P<0.05);25 dyne/cm2流体剪切应力加ox-LDL干预组Integrin-β1、FAK、Paxillin荧光强度低于静态加ox-LDL干预组及5 dyne/cm2流体剪切应力加ox-LDL干预组(P均<0.05).结论 ox-LDL可导致血管内皮细胞损伤、脱落和黏着斑重塑,而生理范围内较高水平的流体剪切应力能够有效地减轻黏着斑过度重塑,促进血管内皮细胞附着于基质,减轻血管内皮细胞损伤.
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