Endothelin-1 attenuates ω3 fatty acid-induced apoptosis by inhibition of caspase 3
Endothelin-1 attenuates ω3 fatty acid-induced apoptosis by inhibition of caspase 3
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DOI：
10.1161/01.hyp.35.1.287
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发表时间：
2000-01-01
期刊：
影响因子：
8.3
通讯作者：
Schiffrin, EL
中科院分区：
文献类型：
--
作者：
Diep, QN;Intengan, HD;Schiffrin, EL
内皮素-1（ET-1）可能参与了高血压血管肥厚的诱导过程。ET-1还可通过发挥抗凋亡作用来调节血管生长。欧米茄3脂肪酸（欧米茄3脂肪酸）在各种细胞类型中具有抗增殖作用，可能在高血压中发挥有益作用。我们测试的假设，ET-1可以作为一个生存因子对ω 3脂肪酸诱导的细胞凋亡，并试图阐明可能的分子机制，ET-1对二十二碳六烯酸（DHA）诱导的细胞凋亡的保护作用。肠系膜血管平滑肌细胞用DHA（一种代表性的ω 3 FA）刺激。使用流式细胞术评估DHA在不同凋亡阶段的剂量反应曲线：（1）极早期：质膜磷脂酰丝氨酸（PS）易位;（2）早期：线粒体跨膜电位（Δ Psim）的变化;和（3）晚期：细胞周期分析。Western blot检测促凋亡蛋白bax和抗凋亡蛋白bcl-2的表达。Caspase 3作为参与死亡信号通路的关键蛋白水解酶，其活性和表达分别用荧光免疫吸附酶测定和Western印迹分析来评估。细胞凋亡，这是检测PS易位，Δ Psim中断，和细胞周期分析，增加剂量依赖性DHA。在细胞周期分析中，DHA诱导的凋亡通过在DHA之前暴露于ET-1 1 1小时而减弱。ET-1与DHA诱导的细胞凋亡的干扰，检测与细胞周期分析，是不明显的在膜（PS易位）或线粒体（Δ Psim）水平。在DHA刺激的细胞中，Bax/bcl-2比值的增加不受ET-1的影响。然而，DHA增加了caspase 3活性和caspase 3的活性形式（20和17 kDa），导致增强的DNA片段化，如Hoechst染色和荧光显微镜所示，这是由ET-1预处理减弱。总之，DHA，一种ω 3脂肪酸，以剂量依赖性方式诱导血管平滑肌细胞凋亡。ET-1通过减弱DHA诱导的caspase 3激活和随后的凋亡晚期DNA片段化而发挥重要的保护作用。
Endothelin-1 (ET-1) may be involved in the induction of vascular hypertrophy in hypertension. ET-1 may also modulate vascular growth through the exertion of antiapoptotic effects. The omega 3 fatty acids (omega 3 FAs), which have antiproliferative effects in various cell types, may have a beneficial role in hypertension. We tested the hypothesis that ET-1 could act as a survival factor against omega 3 FA-induced apoptosis and attempted to elucidate possible molecular mechanisms underlying the protective action of ET-1 on docosahexaenoic acid (DHA)-induced apoptosis. Mesenteric vascular smooth muscle cells were stimulated with DHA, a representative omega 3 FA. Dose-response curves of DHA at different apoptotic stages were assessed with the use of flow cytometry: (1) very early: plasma membrane phosphatidylserine (PS) translocation; (2) early: change in mitochondrial transmembrane potential (Delta Psi m); and (3) late: cell cycle analysis. Expression of the proapoptotic protein bax and the antiapoptotic protein bcl-2 was determined with Western blot assay. The activity and the expression of caspase 3, which as a critical proteolytic enzyme involved in the death-signaling pathway, were evaluated with a fluorometric immunosorbent enzyme assay and Western blot analysis, respectively. Apoptosis, which was detected with PS translocation, Delta Psi m disruption, and cell cycle analysis, was increased dose dependently by DHA. DHA-induced apoptosis was attenuated through exposure to ET-1 for 1 hour before DHA in cell cycle analysis. The interference of ET-1 with DHA-induced apoptosis, as detected with cell cycle analysis, was not apparent at the membrane (PS translocation) or the mitochondrial (Delta Psi m) level. The increase in bax/bcl-2 ratio in DHA-stimulated cells was not affected by ET-1. However, DHA increased both caspase 3 activity and the active forms of caspase 3 (20 and 17 kDa), resulting in enhanced DNA fragmentation as shown through Hoechst staining and fluorescence microscopy, which were attenuated by ET-1 pretreatment. In conclusion, DHA, an omega 3 FA, induced apoptosis in vascular smooth muscle cells in a dose-dependent manner. ET-1 exerted important protective effects through the attenuation of DHA-induced caspase 3 activation and subsequent DNA fragmentation in the late stages of apoptosis.