Integrin-Linked Kinase Regulates Vasomotor Function by Preventing Endothelial Nitric Oxide Synthase Uncoupling Role in Atherosclerosis
Integrin-Linked Kinase Regulates Vasomotor Function by Preventing Endothelial Nitric Oxide Synthase Uncoupling Role in Atherosclerosis
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DOI：
10.1161/circresaha.111.253948
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发表时间：
2012-02-03
影响因子：
20.1
通讯作者：
Saura, Marta
中科院分区：
文献类型：
--
作者：
Herranz, Beatriz;Marquez, Susana;Saura, Marta
理论基础：动脉粥样硬化病变发生在血流紊乱的区域，而层流可以防止动脉粥样硬化的发生；然而，所涉及的机制尚未完全阐明。整合素是内皮细胞剪切应力的机械传感器，整合素连接激酶（ILK）对血管完整性和心血管发育很重要。目的：通过研究条理性ILK缺陷（cKO）小鼠和人动脉粥样硬化动脉，探讨ILK在血管功能中的作用。结果：ILK在非动脉粥样硬化血管内皮细胞层中表达，而在动脉粥样硬化血管内皮细胞层中不表达。实时超声成像显示，乙酰胆碱介导的血管舒张功能在cKO小鼠中受损。这些小鼠表现出激动剂诱导的一氧化氮合酶（NOS）活性降低，环鸟苷单磷酸和亚硝酸盐产量减少。ILK缺失导致内皮细胞NOS （eNOS）解耦，表现为四氢生物蝶呤（BH4）水平降低，BH2水平升高，二氢叶酸还原酶表达降低，eNOS依赖性超氧化物生成增加，同时血管蛋白大量硝化。在cKO细胞中，ILK的再表达阻止了eNOS的解偶联，而在eNOS- ko细胞中，超氧化物的形成不受ILK缺失的影响，这表明eNOS是超氧化物阴离子的主要来源。eNOS和ILK在对照动物的主动脉裂解液中共免疫沉淀，eNOS-ILK-shock蛋白90相互作用在人类正常乳腺动脉中检测到，但在人类动脉粥样硬化性颈动脉中不存在。格尔达霉素可阻止内皮细胞中eNOS-ILK的相互作用，提示热休克蛋白90是其结合伙伴。结论：我们的研究结果确定ILK是体内eNOS的调控伙伴，可以阻止eNOS解偶联，并提示ILK是预防与剪切应力诱导的血管疾病相关的内皮功能障碍的治疗靶点。（Circ Res. 2012;110:439-449.）
Rationale: Atherosclerotic lesions develop in regions of disturbed flow, whereas laminar flow protects from atherogenesis; however, the mechanisms involved are not completely elucidated. Integrins are mechanosensors of shear stress in endothelial cells, and integrin-linked kinase (ILK) is important for blood vessel integrity and cardiovascular development.Objectives: To explore the role of ILK in vascular function by studying conditionally ILK-deficient (cKO) mice and human atherosclerotic arteries.Results: ILK expression was detected in the endothelial cell layer of nonatherosclerotic vessels but was absent from the endothelium of atherosclerotic arteries. Live ultrasound imaging revealed that acetylcholine-mediated vasodilatation was impaired in cKO mice. These mice exhibited lowered agonist-induced nitric oxide synthase (NOS) activity and decreased cyclic guanosine monophosphate and nitrite production. ILK deletion caused endothelial NOS (eNOS) uncoupling, reflected in reduced tetrahydrobiopterin (BH4) levels, increased BH2 levels, decreased dihydrofolate reductase expression, and increased eNOS-dependent generation of superoxide accompanied by extensive vascular protein nitration. ILK reexpression prevented eNOS uncoupling in cKO cells, whereas superoxide formation was unaffected by ILK depletion in eNOS-KO cells, indicating eNOS as a primary source of superoxide anion. eNOS and ILK coimmunoprecipitated in aortic lysates from control animals, and eNOS-ILK-shock protein 90 interaction was detected in human normal mammary arteries but was absent from human atherosclerotic carotid arteries. eNOS-ILK interaction in endothelial cells was prevented by geldanamycin, suggesting heat shock protein 90 as a binding partner.Conclusions: Our results identify ILK as a regulatory partner of eNOS in vivo that prevents eNOS uncoupling, and suggest ILK as a therapeutic target for prevention of endothelial dysfunction related to shear stress-induced vascular diseases. (Circ Res. 2012;110:439-449.)