植物雌激素α-ZAL对oxLDL诱导人内皮细胞中ET-1基因表达的抑制作用及其抗氧化机制

Phytoestrogen α-Zearalanol inhibition of oxLDL-induced endothelin-1 gene expression and antioxidation

目的通过氧应激信号转导通路探讨植物雌激素αZAL对oxLDL诱导人脐静脉内皮细胞中ET1基因表达的抑制作用。方法用荧光探针DCF检测内皮细胞活性氧的含量;采用RTPCR方法对ET1mRNA的表达进行分析,运用WesternBlot法测定了ERK、pERK和cjun/AP1蛋白的表达;同时测定了内皮细胞上清液中ET1的分泌的变化,利用瞬时转染技术观察了内皮细胞的AP1报告基因的活性。结果实验结果表明αZAL对oxLDL诱导的ET1的分泌有抑制作用(P<0.05),它可能通过抗氧化作用阻断oxLDL诱导的内皮细胞氧应激的产生;并能抑制oxLDL诱导的内皮细胞AP1的激活(P<0.05)。结论研究发现αZAL可能是通过氧应激激活细胞外信号调节激酶,进一步通过调节ET1基因上的核转录因子AP1结合位点来抑制oxLDL诱导内皮细胞的ET1基因表达。

Aim The objective of this study was to explore the inhibitory effect of phytoestrogen α-Zearalanol （α-ZAL） on oxLDL-induced ET-1 gene expression in HUVECs. Methods Using the fluorescent product DCF,the effects of α-ZAL were determined on oxLDLinduced redox level in HUVECs. The influences of α- ZAL on expression of mRNA of ET-1 and expressions of protein of ERK,pERK and c-jun/AP-1 induced by oxLDL in HUVECs were measured using RT-PCR and Western Blotting. The level of ET-1 and the effect ofα- ZAL on ET-1 secretion level determined in HUVECs using induced by oxLDL were enzymatic immunoassay.We performed transient transfection assays and showed that the effects of α-ZAL on transcriptional factor AP-1 induced oxLDL were detected. Results α-ZAL inhibited oxLDL-induced ET-1 secretion and expression and oxLDL-induced oxidative stress, α-ZAL downregulate oxLDL-induced the enhance of AP-1 activity and expression. Conclusion α-ZAL inhibited oxLDL-in- creased expression of ET-1 gene through attenuating ROS formation, inhibiting oxLDL-activated ERK signaling pathway and oxLDL-increased AP-1 transcriptional activation in HUVECs.