Objective To study the protective effect of epalrestat against endothelial cell injuries induced by high glucose. Methods Human umbilical vein endothelial cells were pretreated with epalrestat (0.1 μmol/L) for 30 min followed by exposure to high glucose for 8 h. NO concentration in the cell culture supernatant was assayed using chemiluminescence method following the exposure. Real-time PCR and Western blotting were used to detect eNOS mRNA and protein expression levels and the protein expressions of AR gene (the target gene of epalrestat) and NOX4 (the upstream gene of NO). Results Compared with mannitol treatment, an 8-h exposure to high glucose caused significantly decreased NO levels and eNOS mRNA and protein expression in the vascular endothelial cells (P<0.05). Pretreatment with epalrestat prior to high glucose exposure resulted in elevated eNOS mRNA and protein expression levels and NO up-regulation in the cell culture as compared with the glucose exposure alone group (P<0.05), causing also decreased expression of AR and NOX4 in the cells. Conclusions High glucose can induce endothelial cell damage characterized by a lowered level of NO secretion. Epalrestat can protect the endothelial cells against high glucose-induced injury by inhibiting the expression of AR and NOX4.%目的 初步研究依帕司他保护高糖诱导的血管内皮细胞损伤的作用.方法 体外培养脐静脉血管内皮细胞HUVEC,高糖刺激8h后利用化学发光法检测细胞培养上清中NO的含量,利用Rcal time PCR和Western blot分别检测细胞中内皮型一氧化氮合酶(eNOS)的mRNA和蛋白表达水平,以同浓度的甘露醇作为对照.给予依帕司他(0.1 μmol/L)预处理30 min,随后再进行高糖培养,检测NO的含量以及eNOS的mRNA和蛋白表达,同时检测依帕司他的靶向基因醛糖还原酶(AR)以及NO的上游基因NADPH氧化酶4(NOX4)的蛋白表达水平.结果 高糖培养8h之后,血管内皮细胞分泌NO下降,eNOS的mRNA和蛋白表达水平下降,与甘露醇对照组相比,具有统计学差异(P＜0.05)；预先给予依帕司他处理后再进行高糖培养,细胞中eNOS的mRNA和蛋白表达水平均升高,NO表达上调,与单独高糖培养组相比,具有统计学差异(P＜0.05).同时,细胞中AR和NOX4的蛋白表达下降.结论 高糖可以诱导内皮细胞损伤,表现为NO的分泌水平降低.依帕司他可能是通过抑制AR和NOX4的表达而发挥对血管内皮细胞损伤的保护作用.
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