左卡尼汀通过内质网应激ATF6通路抑制高糖诱导的HAECs凋亡

发布时间：2018-11-26 20:45

【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。
[Abstract]:Aim: to investigate the effect of L-carnitine on (HAECs) apoptosis induced by high glucose in human aortic endothelial cells and its molecular mechanism. Methods: HAECs was cultured in high glucose medium and induced to apoptosis, and HAECs was treated with different concentrations (50100 渭 mol/L and 200 渭 mol/L). Cell viability was detected by MTT assay, apoptosis was evaluated by Hoechst 33258 staining and flow cytometry, and caspase-3 activity of HAECs was detected by colorimetric assay. The protein and phosphorylation levels of ER stress signaling pathway were analyzed by; Western blot assay. Results: high glucose culture induced HAECs apoptosis and significantly inhibited cell viability. Endoplasmic reticulum stress was produced in HAECs cultured with high glucose. The signal pathways of protein kinase R-like endoplasmic reticulum kinase (PERK),) inositol 1 (IRE1) and activated transcription factor 6 (ATF6) were significantly activated. Apoptosis can be induced by downstream caspase-4/3 cascade waterfall reaction. However, L-carnitine could significantly reduce the apoptosis of HAECs cells induced by high glucose and increase the cell survival rate in a concentration-dependent manner. L-carnitine could significantly reduce endoplasmic reticulum stress induced by high glucose culture HAECs, and down-regulate the expression of site-1 protease (S1P) and locus 2 protease (S2P), and decrease the level of apoptosis-promoting factor ATF6 p50 induced by shearing of ATF6. Levocarnitine did not inhibit the activity of PERK and IRE1 signaling pathway. Conclusion: L-carnitine can inhibit the apoptosis of HAECs induced by high glucose, and its mechanism may be the inhibition of endoplasmic reticulum stress-related ATF6 signaling pathway.
【作者单位】：陕西省大荔县医院心血管内科;陕西省人民医院心血管内科;西安医学院临床医学系;
【基金】：国家自然科学基金资助项目(No.81600646)
【分类号】：R587.1

【参考文献】