中文摘要：

目的探讨视黄醇类X受体激动剂能否对抗高糖环境诱导人血管内皮细胞产生的氧化应激反应及Rac-1蛋白在黄醇类X受体激动剂抗氧化应激过程中的作用。方法体外培养人脐静脉血管内皮细胞，以葡萄糖（33mmol／L）干预模拟糖尿病患者体内环境，通过流式细胞学和激光共聚焦显微镜的方法检测细胞内的活性氧离子水平，化学发光法检测还原型烟酰胺腺嘌呤二核苷酸磷酸氧化酶的活性。用GST pull-down和免疫杂交的方法检测Rac-1蛋白的激活。结果（1）高糖干预显著增加内皮细胞内活性氧离子水平及还原型烟酰胺腺嘌呤二核苷酸磷酸氧化酶的活性；（2）Rac-1蛋白抑制剂NSC23766显著降低高糖诱导下内皮细胞活性氧离子的生成及还原型烟酰胺腺嘌呤二核苷酸磷酸氧化酶的活性；（3）视黄醇类X受体激动剂9顺维甲酸和SR11237显著下调高糖环境下内皮细胞内活性氧离子水平及还原型烟酰胺腺嘌呤二核苷酸磷酸氧化酶的活性；（4）视黄醇类X受体激动剂9顺维甲酸和SR11237抑制高糖干预对内皮细胞Rac-1蛋白的激活。结论视黄醇类X受体激动剂通过抑制Rac-1蛋白的激活对抗高糖诱导内皮细胞产生的氧化应激反应。

英文摘要：

Aim To explore the effects and mechanism of Retinoid X receptor （RXR） agonists 9-cis-RA and SR11237 on high-glucose-induced oxidative stress in human endothelial cells and to determine whether Rac-1 is involved in the effect of RXR agonists on oxidative stress. Methods Using human umbilical vein endothelial cells （ HUVEC ） , we evaluated the effect of high glucose levels on reactive oxygen species （ ROS ） production by dihydrodichlorofluorescein and flowcytometry. Rac-1 activity was assessed by both immunoprecipitation of the Rac-p21-activated kinase complex and analysis of Rac-1 translocation to the membrane. Nicotinamide-adenine dinucleotide phosphate （NADPH） oxidase activity in endothelial cells was detected by lucigenin assay. Results ROS production and NADPH activity were increased by high glucose. Treatment of endothelial cells with RXR agonists and Rac-1 inhibitor resulted in significant inhibition of high-glucose-induced ROS production and NADPH activation. Meanwhile, Rac-1 activity and Rac-1 translocation to membrane elevated by high glucose were inhibited by RXR agonists. Conclusion RXR ligands rapidly inhibit high-glucose-induced oxidative stress by antagonizing high-glucose-induced Rac-1 activation.