HDL抑制人脐静脉内皮细胞NADPH氧化酶4表达和活性氧生成

目的分析HDL对人脐静脉内皮细胞(human umbilical vein endothelial cells,HUVEC)内NAD-PH氧化酶4(NADPH oxidase4,NOX4)及其亚组分p22phox、p67phox、Rac1与活性氧(reactive oxygen species,ROS)生成的影响,研究HDL对LDL的拮抗作用。方法用Ⅱ型胶原酶消化法分离培养HUVEC;用RT-PCR、Western印迹观察NOX4、p22phox、p67phox、Rac1表达的变化;用流式细胞仪检测细胞内ROS的变化。结果HDL处理HUVEC能下调NOX4和p67phox mRNA和蛋白水平,但不影响p22phox和Rac1的表达。高浓度LDL刺激HUVEC时,NOX4表达上调,细胞内ROS生成增加,但p22phox、p67phox和Rac1的表达没有明显变化。用HDL预处理再加高浓度LDL刺激时,NOX4表达下调,ROS生成量减少;结论HDL可通过下调HUVEC NOX4表达降低ROS水平。

HDL Inhibites the Expression of NADPH Oxidase 4 and Production of ROS in HUVEC

Objective To Investigate the changes of NOX4 expression and ROS generation in HUVEC stimulated by HDL and LDL.Methods The expression of NOX4,p22phox,p67phox and Rac1 in HUVEC was measured by RT-PCR and Western blotting.Intracellular ROS level was detected by flow cytometry.Results High concentration of LDL up-regulated the expression of NOX4 but not p22phox,p67phox and Rac1,and it increased intracellular ROS level in HUVEC.However,the expression of NOX4 and p67phox as well as the level of intracellular ROS were decreased in HUVEC stimulated by HDL before LDL treatent.Conclusions HDL could decrease the level of intracellular ROS in HUVEC by down-regulating the expression of NOX4.