左卡尼汀通过内质网应激ATF6通路抑制高糖诱导的HAECs凋亡  

Inhibitory effects of L-carnitine on high glucose-induced apoptosis of HAECs by suppressing ATF6 signaling

作　　者：高宏民 李尚俭[2] 朱火兰[2] 杨瑜 刘仲伟[2] GAO Hong-min;LI Shang-jian;ZHU Huo-lan;YANG Yu;LIU Zhong-wei(Department of Cardiology, Dali County Hospital, Dali 715100, China;Department of Cardiology, Shaanxi Provincial People’s Hospital,Xi'an 710000, China;Department of Clinical Medicine, Xi'an Medical College, Xi'an 710000, China)

机构地区：[1]陕西省大蒸县医院心血管内科,陕西大蒸715100 [2]陕西省人民医院心血管内科,陕西西安710000 [3]西安医学院临床医学系,陕西西安710000

出　　处：《中国病理生理杂志》2017年第8期1449-1454,共6页Chinese Journal of Pathophysiology

基　　金：国家自然科学基金资助项目(No.81600646)

摘　　要：目的:探讨左卡尼汀对高糖诱导的人主动脉内皮细胞(HAECs)凋亡的影响及相关分子机制。方法:以高糖培养基培养HAECs并诱导其发生凋亡,同时以不同浓度(50、100和200μmol/L)的左卡尼汀对HAECs进行处理。以MTT法对细胞活力进行检测;Hoechst 33258染色及流式细胞术评估细胞凋亡情况;比色法对HAECs的caspase-3活性进行检测;Western blot法对细胞内质网应激信号通路蛋白及磷酸化水平进行分析。结果:高糖培养诱导HAECs产生凋亡并显著抑制细胞活力。高糖培养的HAECs中产生内质网应激,其蛋白激酶R样内质网激酶(PERK)、肌醇需酶1(IRE1)及活化转录因子6(ATF6)信号通路均被显著激活,能够通过下游caspase-4/3级联瀑布反应诱导细胞凋亡。然而,左卡尼汀能够显著减少高糖诱导的HAECs细胞凋亡,使细胞存活率升高,且呈现出浓度依赖性。左卡尼汀可显著降低高糖培养HAECs诱发的内质网应激,通过下调位点1蛋白酶(S1P)及位点2蛋白酶(S2P)表达降低其对ATF6剪切形成的促凋亡因子ATF6 p50的水平;而左卡尼汀并未对PERK及IRE1信号通路活性表现出抑制作用。结论:左卡尼汀能够抑制高糖对HAECs凋亡的诱导作用,其作用机制可能为抑制内质网应激相关的ATF6信号通路。AIM:To investigate the inhibitory effect of L-carnitine on high glucose-induced apoptosis of human aortic endothelial cells(HAECs)and the molecular mechanisms.METHODS:The apoptosis of HAECs was induced by high-glucose incubation.HAECs were treated with L-carnitine at different concentrations(50,100and200μmol/L).The cell viability was measured by MTT assay.The cell apoptosis was assessed by Hoechst33258staining and flow cytometry.Colorimetric method was employed to detect the caspase-3activity in the HAECs.The protein expression and phosphorylation levels were determined by Western blot.RESULTS:High-glucose incubation dramatically decreased the cell viability and induced apoptosis.The protein kinase R-like endoplasmic reticulum kinase(PERK),inositol-requiring enzyme-1(IRE1)and activating transcription factor6(ATF6)signaling pathways of endoplasmic reticulum stress were activated to induce cell apoptosis via down-stream caspase-4/3cascade.However,L-carnitine treatment significantly attenuated the cell apoptosis and increased the cell viability in a concentration-dependent manner.L-carnitine also significantly suppressed endoplasmic reticulum stress and ATF6signaling in high glucose-incubated HAECs without attenuating PERK and IRE1signaling.The expression of site-1protease(S1P)and site-2protease(S2P)was inhibited by L-carnitine treatment,thus decreasing pro-apoptotic factor ATF6p50produced by ATF6cleavage.CONCLUSION:L-carnitine inhibits high glucose-induced apoptosis of HAECs by inhibiting ATF6signaling.

关 键 词：左卡尼汀 内质网应激 活化转录因子6 细胞凋亡 人主动脉内皮细胞 

分 类 号：R587.1[医药卫生—内分泌] R363[医药卫生—内科学]