脱氢表雄酮激活ERK1/2和JNK通路抑制血管内皮细胞内质网应激诱导的凋亡研究

Dehydroepiandrosterone inhibits vascular endothelium cell apoptosis induced by endoplasmic reticulum stress via activation of the ERK1/2 and JNK signal pathway

目的探讨脱氢表雄酮(dehydroepiandrosterone,DHEA)对内皮细胞内质网应激(endoplasmic reticulum stress,ERS)凋亡的影响及可能机制。方法二硫苏糖醇(dithiothreitol,DTT)、脱氢表雄酮(DHEA)、来曲唑、雌/雄激素受体拮抗剂ICI182,780、G15、氟他米特(flutamide)、信号通路阻断剂LY294002、SP600125、U0126处理人类内皮细胞系EA.hy926细胞;流式细胞术检测细胞凋亡率;Western blot检测内质网应激相关蛋白表达。结果 DTT促进内皮细胞内质网应激,与空白组相比,葡萄糖调节蛋白78(glucose-regulated protein 78k Da,GRP78)和CCAAT/增强子结合蛋白同源蛋白(CCAAT/enhancer-binding protein homologous protein,CHOP)分别升高了2.3倍和7.7倍(P均<0.05),细胞凋亡率较对照组增加了2.1倍(P<0.05)。DHEA可抑制血管内皮细胞凋亡,细胞凋亡率较DTT组下降了42%(P<0.05)。DHEA抑制内质网应激相关蛋白表达增加,GRP78和CHOP分别较DTT组下降了36.7%和48.3%(P均<0.05)。给予SP600125、U0126后,DHEA抑制细胞内质网应激凋亡的作用被抑制,与DTT+DHEA组相比,CHOP分别升高了3.6倍和4.5倍(P均<0.05)。结论 DHEA可以通过激活ERK1/2和JNK通路抑制血管内皮细胞ERS引起的凋亡。

Objective To investigate the effect and the possible mechanism of dehydroepiandrosterone on endothelial ceils apoptosis by activating endoplasmic reticulum stress. Methods Vascular endothelium cells were treated with dithiothreitol, DHEA, Letrozole, Estrogen/Androgen receptor inhibitors ICI182,780, G15 and Flutamide, Signal pathway blockers LY294002, SP600125 and U0126. The apoptosis rate of endothelial cells was measured by flow cytometry. Western Blot was used to measure the protein expression of endoplasmic reticulum stress markers. Results Dithiothreitol exacerbated vascular endothelium cells endoplasmic reticulum stress. Compared with the control group, GPR78 and CHOP were increased by 2.3-fold （P 〈 0.01）, 7.7-fold （P 〈 0.01） respectively. The apoptosis rate of vascular endothelial cells was elevated by 2.1-fold （P 〈 0.05）. DHEA decreased the apoptosis of vascular endothelium cells, the apoptosis rate of vascular endothelial cells was reduced by 42% （P 〈 0.05）, compared with DTT group. DHEA decreased the expression of ERS markers. GRP-78 and CHOP were decreased by 36.7% and 48.3% （P 〈 0.05） respectively, compared with DTT group. SP600125 and U0126 inhibited the decrease in ERS related apoptosis which induced by DHEA. Compared with DTT＋DHEA group, CHOP increased 3.6-fold and 4.53-fold respectively （both P 〈 0.01 ）, treated with S P600125 and U0126. Conclusions DHEA could inhibit vascular endothelial cells apoptosis by activating endoplasmic reticulum stress via activation of the ERK1/2 and JNK signal pathway.