Division of Cardiology, Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Block B, 5A, Shatin, NT, Hong Kong.
Cardiovasc Drugs Ther. 2012 Oct;26(5):383-92. doi: 10.1007/s10557-012-6404-2.
Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of eNOS and it is recognized as a risk factor for endothelial dysfunction in cardiovascular diseases. We investigated the effect of AVE3085, a newly developed transcription enhancer of eNOS, on ADMA-induced endothelial dysfunction in coronary arteries with underlying mechanisms explored.
Porcine coronary small arteries (diameter 600-800 μm) were studied in a myograph for endothelium-dependent relaxation to bradykinin and endothelium-independent relaxation to sodium nitroprusside. Protein expressions of eNOS and phosphorylated-eNOS (p-eNOS(Ser1177) and p-eNOS(Thr495)), and nitrotyrosine formation were determined by Western blot. NO release was directly measured with a NO microsensor. Productions of O(2) (.-) and peroxynitrite (ONOO(-)) were determined by lucigenin- and luminol- enhanced chemiluminescence respectively.
Exposure to ADMA significantly decreased the bradykinin-induced vasorelaxation and reduced the protein expression of p-eNOS(Ser1177) whereas increased the expression of p-eNOS(Thr495) and nitrotyrosine. Pre-incubation with AVE3085 restored the bradykinin-induced relaxation, reversed the decrease of p-eNOS(Ser1177), and lowered the level of p-eNOS(Thr495) and nitrotyrosine. NO release in response to bradykinin was significantly reduced by ADMA and such reduction was restored by AVE3085. AVE3085 also prevented the elevation of O (2) (.-) and ONOO(-) levels in coronary arteries exposed to ADMA.
AVE3085 prevents ADMA-induced endothelial dysfunction in coronary arteries. The protective effect of AVE3085 may be attributed to increased NO production resulting from enhanced eNOS activation, and decreased oxidative stress that involves inhibition of O (2) (.-) generation by eNOS recoupling. The present study suggested the therapeutic potential of AVE3085 in endothelial dysfunction in cardiovascular disorders.
不对称二甲基精氨酸（ADMA）是内皮型一氧化氮合酶（eNOS）的内源性抑制剂，被认为是心血管疾病内皮功能障碍的危险因素。我们研究了新型 eNOS 转录增强剂 AVE3085 对 ADMA 诱导的冠状动脉内皮功能障碍的作用，并探讨了其潜在机制。
在肌动描记器中研究猪冠状动脉小动脉（直径 600-800μm）对缓激肽的内皮依赖性舒张和对硝普钠的内皮非依赖性舒张。通过 Western blot 测定 eNOS 和磷酸化-eNOS（p-eNOS（Ser1177）和 p-eNOS（Thr495））的蛋白表达以及硝基酪氨酸的形成。使用 NO 微传感器直接测量 NO 释放。通过发光素和鲁米诺增强化学发光法分别测定 O₂（.-）和过氧亚硝酸盐（ONOO（.-））的产生。
暴露于 ADMA 可显著降低缓激肽诱导的血管舒张，并降低 p-eNOS（Ser1177）的蛋白表达，而增加 p-eNOS（Thr495）和硝基酪氨酸的表达。AVE3085 预孵育可恢复缓激肽诱导的舒张，逆转 p-eNOS（Ser1177）的降低，并降低 p-eNOS（Thr495）和硝基酪氨酸的水平。ADMA 显著降低了对缓激肽的 NO 释放，而 AVE3085 则恢复了这一降低。AVE3085 还可防止 ADMA 暴露引起的冠状动脉中 O₂（.-）和 ONOO（.-）水平的升高。
AVE3085 可预防 ADMA 诱导的冠状动脉内皮功能障碍。AVE3085 的保护作用可能归因于增强的 eNOS 激活导致的 NO 产生增加，以及涉及 eNOS 再偶联抑制 O₂（.-）生成的氧化应激减少。本研究提示 AVE3085 在心血管疾病内皮功能障碍中的治疗潜力。
