microRNA regulation of endothelial functions

描述（申请人提供）：mirna在血管功能中的具体作用刚刚开始被探索。我们之前的研究表明，通过Dicer沉默降低人内皮细胞（EC）中miRNA的总水平，可以强烈调节血管生成基因的表达，并损害体外血管生成的各个方面，包括EC的生长和形态发生。这些体外实验得到了新的令人兴奋的初步数据的支持，这些数据是在EC中条件缺乏miRNA合成限速酶（Dicer）的小鼠体内进行的。在EC （EC特异性Dicer KO）中缺乏Dicer的小鼠存活，但表现出受损的出生后血管生成反应。为了分析EC中信号转导、基因表达和miRNA之间的关系，我们发现用VEGF治疗EC会刺激全球miRNA谱的时间依赖性变化，并表明miRNA簇的成分miR 17-92可以调节VEGF诱导的细胞生长和形态发生的各个方面。此外，我们已经确定了一种特定的miRNA (miR-155)，可以调节培养EC中内皮型一氧化氮合酶（eNOS）的水平。因此，我们假设Dicer产生的内皮mirna通过调节mRNA水平和/或重要蛋白质的翻译稳定性来调节体内血管生成和血流控制的程度。我们将：1；鉴定和表征EC中血管生成生长因子调节的mirna；2. 2 .明确miR 17-92在血管生成模型中的作用。明确miR-155在体外和体内调节eNOS功能中的作用。总的来说，这项工作将有助于理解mirna在EC生物学中的重要性，并深入了解它们作为潜在治疗靶点的作用。

DESCRIPTION (provided by applicant): The specific roles of miRNAs in vascular function are just beginning to be explored. Our previous work has shown that reduction of overall miRNA levels via Dicer silencing in human endothelial cells (EC) strongly regulates angiogenic gene expression and impairs aspects of in vitro angiogenesis including EC growth and morphogenesis. These in vitro experiments are supported by new exciting preliminary data in vivo data using mice conditionally lacking the rate limiting enzyme (Dicer) in miRNA synthesis in EC. Mice lacking Dicer in EC (EC specific Dicer KO) are viable but exhibit impaired post-natal angiogenic responses. In order to dissect the relationships between signal transduction, gene expression and miRNAs in EC, we show that treatment of EC with VEGF stimulates time-dependent changes in global miRNA profiles and show that components of the miRNA cluster, miR 17-92 can regulate aspects of VEGF induced cell growth and morphogenesis. In addition, we have identified a specific miRNA (miR-155) that regulates the levels of endothelial nitric oxide synthase (eNOS) in cultured EC. Thus, we hypothesize that Dicer generated endothelial miRNAs regulate the extent of angiogenesis and blood flow control in vivo by regulating mRNA levels and/or the translational stability of important proteins. We will: 1. Identify and characterize angiogenic growth factor regulated miRNAs in EC; 2. Define the roles of miR 17-92 in models of angiogenesis and 3. Define the roles of miR-155 in regulating eNOS function in vitro and in vivo. Collectively, this work will facilitate the understanding of the importance of miRNAs in EC biology and shed insights into their role as potential therapeutics targets. PUBLIC HEALTH RELEVANCE: This research is relevant to public health since endothelial dysfunction is a common manifestation of most cardiovascular diseases. Our research has discovered the major mechanisms of how the endothelium control blood flow and atherogenesis. Research supported by this grant may help identify new drugs that reduce heart disease and improve the quality of life of people suffering with cardiovascular disease.