Function of a novel molecule ADAR1 in endothelial cells for angiogenesis

 描述(由申请人提供)：心血管疾病(CVD)是全世界以及美国导致死亡和残疾的主要原因2。占34.4% 在美国每年240万人的死亡中，这导致了最大的健康差距和不断上升的医疗成本。众所周知，内皮功能障碍是启动和维持CVD5的关键步骤。尽管研究表明，包括循环炎性细胞因子、活性氧、氧化型低密度脂蛋白、自身抗体和传统危险因素在内的多种因素直接或间接地导致内皮细胞功能障碍，最终导致心血管疾病，但我们对内皮细胞调控的了解仍然不足以开发有效的治疗方法来控制这种疾病。为了改进心血管疾病的治疗，需要更好地了解内皮细胞在生物和病理条件下发挥作用的分子机制。在我们之前的研究中，我们发现了一个新的分子，它在血管生成的内皮细胞中发挥着以前没有描述过的关键作用--作用于RNA1的腺苷脱氨酶(ADAR1)。本研究旨在明确ADAR1在血管内皮细胞中的功能和机制。已知ADAR1是转录后RNA过程中必不可少的蛋白质。它通过改变蛋白质密码子和改变microRNA的生物发生来调节基因的功能。它还调节细胞质RNA信号通路，以抑制先天免疫和应激反应。血管内皮细胞特异的ADAR1基因敲除显著升高了血压，显著损害了后肢缺血动物模型的血管生成。在这项拟议的研究中，我们将分析新产生的内皮特异性ADAR1基因敲除小鼠，确定ADAR1的基因表达模式，并寻找ADAR1表达与内皮细胞功能状态的潜在关联。将测定ADAR1在幼年健康动物、老年和患病动物(如糖尿病动物)中的表达水平。我们还将探讨ADAR1与炎性细胞因子、活性氧物种、氧化型低密度脂蛋白的关系。我们还将通过建立小鼠后肢缺血模型来确定ADAR1在缺血条件下血管生成中的作用。根据我们的初步发现，Coviin-1受ADAR1调控，我们将试图揭示ADAR1调节血管功能并参与血管疾病的机制。

 DESCRIPTION (provided by applicant): Cardiovascular disease (CVD) is the leading cause of death and disabilities worldwide, as well as in the United States2. It accounts for 34.4 percent of the 2.4 million annual deaths in US, and leads to the most health disparities and rising healthcare costs. It is known that endothelial dysfunction represents a key step in the initiation and maintenance of CVD5. Although studies showed that multiple factors, including circulating inflammatory cytokines, reactive oxygen species, oxidized LDL (low density lipoprotein), autoantibodies and traditional risk factors directly and indirectly cause endothelial cell dysfunction, and eventually lead to CVD, our knowledge of endothelial cell regulation is still insufficient for the development of an effective therapeutics to control this disease. Better understanding of the molecular mechanism, by which endothelial cells functions under biological and pathologic conditions, is required to improve the treatment of CVDs. During our previous study we found a new molecule that played a critical role in endothelial cells for angiogenesis that has not be described previously -- adenosine deaminase acting on RNA1 (ADAR1). This proposal is to define the function and mechanism of ADAR1 in endothelial cells. It is known that ADAR1 is an essential protein for posttranscriptional RNA process. It regulates gene functions through changing the protein codon and modifying microRNA biogenesis. It also regulates cytoplasmic RNA signaling pathways to suppress innate immune and stress responses. Knockout ADAR1 specifically in endothelial cells dramatically elevated blood pressure, significantly impaired angiogenesis in hind limb ischemic animal models. In this proposed study, we will analyze the newly generated endothelial specific knockout mice of ADAR1, determine the gene expression pattern of ADAR1 and find the potential association of ADAR1 expression with the functional status of endothelial cells. ADAR1 expression levels in young healthy animal, aged and diseased animal, such as diabetic animals will be determined. We will also look into the relationship of ADAR1 and the inflammatory cytokines, reactive oxygen species, oxidized LDL. We will also determine the effect of ADAR1 in angiogenesis under ischemia condition by using the hind limb ischemic mouse model. Based on our preliminary finding that coviolin-1 is regulated by ADAR1, we will try to reveal the mechanism of ADAR1 by which it regulate blood vessel function and involves in blood vessel diseases.