不同剪切力对内皮细胞表面凝集素样氧化低密度脂蛋白受体1表达的影响

Effects of different shear stress on expression of lectin-like oxidized low-density lipoprotein receptor-1 on endothelial cell surface

目的 研究不同剪切力对内皮细胞表面凝集素样氧化低密度脂蛋白受体1（LOX-1）表达的影响.方法 体外培养人脐静脉内皮细胞,将其种植于载玻片上,放入流室系统分别施加以不同的剪切力.按施加剪切力的不同分为实验组和对照组：实验组分为低剪切力组（4.2 dyne/cm2,n=5）、中等剪切力组（8.4 dyne/cm2,n=5）和高剪切力组（15.0 dyne/cm2,n=5）;对照组（n=5）静态条件下培养,不施加剪切力.剪切力加载1、2、4、8 h后RT-PCR测定各组内皮细胞LOX-1 mRNA的表达.结果 低剪切力（4.2 dyne/cm2）作用下,内皮细胞LOX-1表达随时间延长而增加.与对照组比较,中等剪切力（8.4dyne/cm2）作用2、4、8 h内皮细胞LOX-1的表达水平均降低[2 h：0.2346±0.0397比0.2948±0.0128,4 h：0.1747±0.0585比0.2985±0.0204,8 h：0.0256±0.0067比0.2968±0.0175,均P＜0.05].高剪切力（15.0dyne/cm2）作用下,血管内皮细胞LOX-1表达一直维持在极低水平.结论 不同剪切力可以影响内皮细胞的LOX-1表达水平.

Objective To investigate the effects of different shear stress on expression of lectinlike oxidized low-density lipoprotein receptor-1 （LOX-1 ） on endothelial cell surface. Methods The human umbilical vein endothelial cells （HUVECs） were cultured in vitro and implanted on microscopic slides which were then put into a flow chamber system and treated with different shear stress. According to different shear stress, HUVECs were allocated into control group （0 dyne/cm2, n=5） and experimental groups including low shear stress group （4.2 dyne/cm2, n=5）, moderate shear stress group （8.4 dyne/cm2, n=5） and high shear stress group （ 15.0 dyne/cm2, n=5）. The mRNA expression of LOX- 1 of the endothelial cells was detected in all groups with RT-PCR at 1 h, 2 h, 4 h and 8 h after loading of shear stress. Results The expression of LOX- 1 increased over time under low shear stress （4.2 dyne/cm2）. Compared with the control group, the expressions of LOX- 1 in endothelial cells were declined at 2 h, 4 h and 8 h after treatment with moderate shear stress （8.4 dyne/cm2） [2 h： 0.2346 ± 0.0397 vs 0.2948 ± 0.0128; 4 h： 0.1747 ± 0.0585 vs 0.2985 ±0.0204; 8 h： 0.0256±0.0067 vs 0.2968±0.0175, all P〈0.05]. However, the expression of LOX- 1 maintained a very low level under high shear stress （15.0 dyne/cm2）. Conclusion Different shear stress may have varied effects on the expression of LOX-1 in endothelial cells.