Critical role of lipid raft redox signaling platforms in endostatin-induced coronary endothelial dysfunction
Critical role of lipid raft redox signaling platforms in endostatin-induced coronary endothelial dysfunction
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DOI：
10.1161/atvbaha.107.159772
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发表时间：
2008-03-01
影响因子：
8.7
通讯作者：
Li, Pin-Lan
中科院分区：
文献类型：
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作者：
Jin, Si;Zhang, Yang;Li, Pin-Lan
目的 - 发现内皮抑素 ( EST) 可以启动与内皮细胞 ( EC) 中 NADPH 氧化酶激活相关的氧化还原信号级联反应。本研究测试了 EST 是否会刺激富含神经酰胺的脂筏 (LR) 聚集，从而组装并激活 NADPH 氧化酶以形成氧化还原信号平台。方法和结果 - 使用共聚焦显微镜，我们首先证明了 LR 簇与 NADPH 氧化酶亚基、gp91(phox) 和 p47(phox) 在 ECs 膜中的共定位 EST 刺激。对漂浮的耐去垢剂膜组分的免疫印迹分析发现，在 LR 组分中，NADPH 氧化酶亚基 gp91phox 和 p47phox 得到富集，并且通过电子自旋共振 (ESR) 光谱测定，该酶的活性显着增加。这种 EST 增加的 LR 平台形成被证明可以通过酸性鞘磷脂酶 (A-SMase) 的抑制或 RNA 干扰而减弱。从功能上讲，EST 预处理显着损害缓激肽或 A23187 诱导的孤立小冠状动脉中的血管舒张，这可以被 LR 干扰物部分逆转。结论 - EST 对血管内皮的早期损伤作用与通过脂筏聚集形成氧化还原信号平台有关。
Objective - Endostatin ( EST) was found to initiate a redox signaling cascade associated with activation of NADPH oxidase in endothelial cells ( ECs). The present study tested whether EST stimulates clustering of ceramide-enriched lipid rafts (LRs), which assembles and activates NADPH oxidase to form redox signaling platforms.Methods and Results - Using confocal microscopy, we first demonstrated a colocalization of LR clusters with NADPH oxidase subunits, gp91(phox) and p47(phox) in the ECs membrane on EST stimulation. Immunoblot analysis of floated detergent-resistant membrane fractions found that in LR fractions NADPH oxidase subunits gp91phox and p47phox are enriched and that the activity of this enzyme increased dramatically, as measured by electron spin resonance (ESR) spectrometry. This EST-increased LR platform formation was shown to be attenuated by inhibition or RNA interference of acid sphingomyelinase (A-SMase). Functionally, EST pretreatment significantly impaired bradykinin or A23187-induced vasodilation in isolated small coronary arteries, which could be partially reversed by LR disruptors.Conclusions - The early injury effect of EST on the vascular endothelium is associated with the formation of redox signaling platforms via lipid raft clustering.