The role of PAR2 and HuR in programming atherosclerotic vascular smooth muscle cells

项目概要/摘要 冠状动脉疾病（CAD）是动脉粥样硬化形成的结果，是全球死亡的主要原因 每年造成约 679,000 人死亡，相当于该地区五分之一的死亡人数 美国。随着患者中诊断出的 CAD 合并症持续增加，这一数字预计还会增加。 上升。目前，降低循环脂质量的他汀类药物是预防 CAD 的黄金标准。 同时进行饮食和运动治疗的患者。经过数十年死亡率的稳步下降，总体而言 趋势已开始趋于稳定，目前的药物只能提供适度的绝对增量益处 动脉粥样硬化斑块破裂并导致心肌梗塞、中风和心力衰竭。我们实验室有 先前证明 G 蛋白偶联受体 PAR2 在小鼠和人类中均增强 动脉粥样硬化斑块。此外，研究表明人类抗原 R (HuR) 表达增加 在血管损伤部位，有可能在这些炎症条件下结合并稳定 PAR2 mRNA。 尽管我们知道 PAR2 会导致动脉粥样硬化的形成，但 PAR2 的机制 HuR 介导动脉粥样硬化形成，但其在动脉粥样硬化中的作用尚不清楚。了解 PAR2和HuR促进动脉粥样硬化进展的分子机制可能会提供新的 深入了解可以改善 CAD 患者预后并制止治疗的潜在目标 旧疗法的疗效递减。 该提案的主要目标是研究 PAR2 和 HuR 相互作用的机制及其作用 对动脉粥样硬化发展的独立和依赖性贡献。使用之前的数据 根据我们实验室收集的数据，我们知道 PAR2 在动脉粥样硬化中的贡献源自非造血细胞 细胞类型，例如血管平滑肌细胞（VSMC）。因此，我们假设 PAR2 的激活 VSMC 将 HuR 重新定位到细胞质，结合并稳定 Par2 mRNA，上调 PAR2 表达和进一步进展的动脉粥样硬化。该假设将使用两个具体目标 几种由 PAR2 和 HuR 基因突变体组成的小鼠模型，特别是在 VSMC 中（目标 1 和目标 2 分别）。我们还将使用各种体外实验来观察 HuR 结合 PAR2 mRNA（目标 2）： 以及研究 PAR2 在 VSMC 去分化中的作用（目标 1），最近的文献表明 VSMC去分化对动脉粥样硬化进展的贡献。本次活动的长远目标 该研究旨在进一步阐明 PAR2 在动脉粥样硬化中的作用，如果成功，将增进我们对以下疾病的认识： 这种疾病的发生和发展。这些结果也可能对该领域产生积极影响并给予 寻找潜在目标，为 CAD 患者开发新疗法。

PROJECT SUMMARY/ABSTRACT Coronary artery disease (CAD), the result of atherosclerosis formation, is the leading cause of death globally resulting in approximately 679,000 annual deaths or the equivalent to every one in five deaths occurring in the United States. This number is expected to increase as comorbidities of CAD diagnosed in patients continues to rise. Currently, statins, which lowers the amount of circulating lipids, are the gold standard of preventing CAD in patients with a concomitant diet and exercise regimen. After decades of steadily improving mortality rates, overall trends have begun to plateau and current medications provide only modest absolute incremental benefits from atherosclerotic plaque rupture and resultant myocardial infarction, stoke, and heart failure. Our laboratory has previously demonstrated the G-protein coupled receptor, PAR2, is augmented in both murine and human atherosclerotic plaques. Moreover, studies have demonstrated increased Human Antigen R (HuR) expression at sites of vessel injury, with the potential to bind and stabilize PAR2 mRNA in these inflammatory conditions. Though we know PAR2 contributes to the formation of atherosclerosis, the mechanism(s) in which PAR2 mediates atherosclerosis formation and the role of HuR in atherosclerosis are still unknown. Understanding the molecular mechanisms in which PAR2 and HuR contributes to the progression of atherosclerosis could give new insight into potential targets of therapeutics that could improve the outcomes of CAD patients and put a halt to the diminishing returns of old therapeutics. The primary goal of this proposal is to investigate the mechanisms by which PAR2 and HuR interact and their contributions, both independently and dependently, to atherosclerosis development. Using data previously collected in our lab, we know that the contributions of PAR2 in atherosclerosis derive from a non-hematopoietic cell type, such as vascular smooth muscle cells (VSMCs). Thus, we hypothesize that activation of PAR2 in VSMCs relocates HuR to the cytosol where it binds and stabilizes Par2 mRNA, upregulating PAR2 expression and further progressing atherosclerosis. This hypothesis will be using two specific aims and several mouse models that consist of PAR2 and HuR genetic mutants, specifically in VSMCs (aim 1 and aim 2 respectively). We will also use a variety of in vitro experiments to observe HuR binding PAR2 mRNA (aim 2) as well as investigate the role of PAR2 in VSMC dedifferentiation (aim 1), which recent literature has shown the contributions of VSMC dedifferentiation to the progression of atherosclerosis. The long-term objective of this study is to further elucidate the role of PAR2 in atherosclerosis and, if successful, will advance our knowledge of the development and progression of this disease. These results may also positively impact the field and give sight to potential targets to develop new therapies for CAD patients.