非对称性二甲基精氨酸诱导内皮祖细胞氧化应激损伤及L-精氨酸的保护作用

L-arginine Counteracts Asymmetric Dimethylarginine-Induced Oxidative Stress Injury in Endothelial Progenitor Cells

目的:研究非对称性二甲基精氨酸(ADMA)对人脐带血内皮祖细胞氧化应激影响及观测L-精氨酸对内皮祖细胞的保护作用。方法:从脐带血中分离出内皮祖细胞,细胞随机分5组:对照组,ADMA组,ADMA+L-精氨酸组,ADMA+PDTC(吡咯烷二硫代氨基甲酸酯)组,L-精氨酸组。运用荧光染料检测细胞活性氧的产生。逆转录多聚酶链反应检测还原型辅酶Ⅱ氧化酶亚基及细胞内抗氧化剂超氧化物歧化酶mRNA变化。结果:①ADMA显著增加细胞内活性氧的生成;L-精氨酸和抗氧化剂(PDTC)能抑制ADMA刺激后的细胞内活性氧产生。②ADMA诱导还原型辅酶Ⅱ氧化酶p22phox亚基、gp91phox亚基mRNA的表达明显上调,L-精氨酸和抗氧化剂(PDTC)能阻断这些基因的上调。但ADMA对抗氧化剂超氧化物歧化酶mRNA表达没有影响。结论:ADMA可能通过诱导氧化应激,抑制内皮祖细胞的生物学活性,影响内膜的再生化,而给与外源性L-精氨酸能起到保护作用。

Objective： To explore the effects of asymmetric dimethylarginine （ADMA） on oxidative stress in endothelial progenitor cells （EPCs） of human umbilical cord blood and observe whether L-arginine can protect EPCs. Methods： EPCs were isolated from fresh cord blood and the cells were randomly assigned to five groups： control, ADMA （10μmol/L）, L-arg （1 mmol/L） pre-teatment, intracellular antioxidant pyrollidine dithiocarbama （ PDTC 50μmol/L） pre- teatment and L-arg （1mmol/L）. 2＇7＇-dichlorofluorescein （DCF）was used to measured the cellular reactive oxygen species （ROS）. RT-PCR was employed to detect mRNA expression of NADPH oxidase subunit p22 phox, gp91 phox and the intracellular antioxidative enzymes manganese superoxide dismutase（MnSOD）. Results：①ADMA significantly induced the production of intra--cellular ROS. L-arg and PDTC inhibited ADMA-induced ROS generation. ②ADMA stimulated NADPH oxidase subunit gp91phox and p22phox mRNA expression. L-arg and PDTC inhibited the up-regulation of gp91 phox and p22phox mRNA verexpression. However, ADMA had no effect on the intracellular antioxida- tive enzymes MnSOD mRNA expression. Conclusions ： It is suggested that ADMA can suppress the reendothelialization of EPCs by means of oxidant stress injury.