microRNA regulation of endothelial functions

描述(由申请人提供)：miRNAs在血管功能中的具体作用才刚刚开始探索。我们以前的工作表明，通过沉默人内皮细胞(EC)而降低总miRNA水平，可以强烈调控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的生长和形态形成。这些体外实验得到了新的令人兴奋的初步数据的支持，这些数据使用的是在EC中条件缺乏miRNA合成限速酶(Dier)的小鼠。在EC(EC特异性DICER KO)中缺乏DICER的小鼠是存活的，但表现出出生后血管生成反应受损。为了剖析EC中信号转导、基因表达与miRNAs之间的关系，我们证明了VEGF处理EC可以刺激全球miRNA谱随时间的变化，并表明miRNA簇的组成部分miR17-92可以调节血管内皮生长因子诱导的细胞生长和形态发生。此外，我们还鉴定了一种特异的miRNA(miR-155)，它可以调节培养的EC内皮型一氧化氮合酶(ENOS)的水平。因此，我们假设DICER生成的内皮miRNAs通过调节重要蛋白质的mRNA水平和/或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.鉴定和鉴定血管生成因子在EC中调节的miRNAs；2.确定miR 17-92在血管生成模型中的作用；3.确定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miRNAs在EC生物学中的重要性，并有助于深入了解它们作为潜在治疗靶点的作用。 公共卫生相关性：这项研究与公共健康相关，因为内皮功能障碍是大多数心血管疾病的常见表现。我们的研究发现了内皮细胞控制血流和动脉粥样硬化的主要机制。由这笔赠款支持的研究可能有助于确定减少心脏病和改善心血管疾病患者生活质量的新药。

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.