The Role of Adaptor Protein Disabled-2 in Maintaining Endothelial Cell Function in Atherosclerosis

项目摘要/摘要 心血管疾病通常与内皮细胞的反应受损有关，这导致 血管内皮细胞功能障碍。内皮细胞功能障碍导致内皮细胞活化和亚内皮化 修饰的低密度脂蛋白(LDL)颗粒的滞留，导致免疫和 炎症细胞进入血管内膜，启动动脉粥样硬化斑块的形成。最重要的是，过渡 从稳定的动脉粥样硬化到脆弱的动脉粥样硬化加剧了心肌梗死和中风，构成了巨大的健康 这是美国发病率和死亡率最高的挑战。迫切需要新的研究来 揭示关键的病理生理机制，并确定限制内皮功能障碍的分子。这 使我们确定了一种称为失能的内吞适配器蛋白的新的、不可或缺的作用 同源蛋白2(DAB2)，除兼职作为肿瘤外，还参与网状蛋白介导的内吞作用 抑制者。奇怪的是，以前几乎没有做过任何工作来确定它在血管内皮细胞中的作用。我们的飞行员 研究表明，动脉粥样硬化血管内皮细胞中DAB2水平显著降低。 老鼠和人类的脂肪条纹--表明在动脉粥样硬化形成中具有保护作用。因为动脉粥样硬化的保护作用 在内皮细胞的背景下，我们创建了内皮特异的诱导物 DAB2基因敲除小鼠(EC-iDab2KO)，并将它们培育到ApoE零背景(EC-Dab2iKO/ApoE-/-)。 西方饮食喂养的EC-iDab2KO/ApoE-/-小鼠动脉炎症加重，斑块更严重 然而，指导DAB2对抗动脉粥样硬化的分子机制和信号通路 炎症是完全未知的。我们的初步研究表明，DAB2的表达在 动脉内皮细胞对动脉粥样硬化保护流的反应和DAB2缺陷抑制 内皮型一氧化氮合酶(ENOS)激活。为了确保我们工作的临床相关性，我们正在 利用创新的纳米技术将DAB2 mRNA传递到动脉粥样硬化的内皮细胞 设计纳米颗粒以恢复DAB2功能。这项技术增加了动脉粥样硬化中DAB2的表达， 抑制载脂蛋白E-/-小鼠的斑块进展。本提案的目标是定义信令 DAB2保护动脉粥样硬化内皮细胞的重要作用的机制。为此， 我们试图确定DAB2抑制动脉炎症和激活eNOS的分子机制。 内皮细胞。我们拥有创新的靶向试剂和新颖的动物模型将极大地促进 我们改变范式的努力。如果富有成效，我们在申请中提出的令人兴奋的工作将提供一个 为开发新的治疗方法，使有心脏病发作和中风风险的患者受益。

PROJECT SUMMARY/ABSTRACT Cardiovascular diseases are often associated with impaired responses from the endothelium, which results from endothelial cell dysfunction. Endothelial cell dysfunction causes endothelial activation and sub-endothelial retention of modified low-density lipoprotein (LDL) particles, leading to the recruitment of immune and inflammatory cells to the intima, which initiate atheromatous plaque build-up. Of major importance, transitioning from a stable to vulnerable atheroma fuels myocardial infarction and stroke, posing enormous health challenges with the highest morbidity and mortality in the United States. New research is urgently needed to uncover critical pathophysiological mechanisms and identify molecules that limit endothelial dysfunction. This has led us to determine a novel and indispensable role for an endocytic adaptor protein called Disabled homolog 2 (Dab2), which participates in clathrin-mediated endocytosis in addition to moonlighting as a tumor suppressor. Curiously, little to no prior work has been done to identify its role in endothelial cells. Our pilot assessment has revealed that Dab2 levels are strikingly decreased in the atherosclerotic endothelium of mouse and human fatty streaks—suggesting a protective role in atherogenesis. As the atheroprotective effects of Dab2 are poorly understood in the context of endothelial cells, we created endothelial-specific inducible Dab2 knockout mice (EC-iDab2KO) and bred them to an ApoE-null background (EC-Dab2iKO/ApoE-/-). Western diet-fed EC-iDab2KO/ApoE-/- mice exhibit heightened arterial inflammation and more severe plaque formation; yet, the molecular mechanisms and signaling pathways that direct Dab2 to combat arterial inflammation are completely unknown. Our initial investigation indicates that Dab2 expression is upregulated in response to atheroprotective flow, and Dab2 deficiency in human aortic endothelial cells suppresses endothelial nitric oxide synthase (eNOS) activation. To ensure the clinical relevance of our work, we are employing an innovative nanotechnology to deliver Dab2 mRNA to the atherogenic endothelium using an engineered nanoparticle to restore Dab2 function. This technology increases Dab2 expression in the atheroma, which restrains plaque progression in ApoE-/- mice. The goal of this proposal is to define the signaling mechanisms underpinning the essential role of Dab2 in protecting the atherogenic endothelium. To this end, we seek to determine molecular mechanisms by which Dab2 curbs arterial inflammation and activates eNOS in endothelial cells. Our possession of innovative targeting reagents and novel animal models will greatly facilitate our paradigm-shifting endeavor. If fruitful, the exciting work proposed in our application will provide a foundation for the development of new treatments to benefit patients at-risk for heart attacks and strokes.