Transcriptional Regulation by Angiotensin II in Vascular Smooth Muscle Cells

项目摘要 动脉粥样硬化和高血压心血管疾病（CVD）是发病的主要原因 和死亡率以及对我们的医疗系统造成的严重压力。肽激素血管紧张素II (Ang II）由于其血管收缩、促氧化、促生长和促生长作用而在这些病理中起主要作用。 和-靶细胞如血管平滑肌细胞（VSMC）中的炎症性质。 一些研究已经证明了血管紧张素II作用的生化和信号机制 通过VSMC的1型受体（AT 1 R）。然而，精确的核表观遗传机制 参与AngII诱导转录调控的病理基因尚不清楚。是 越来越多的人认识到，染色质结构的深刻变化，包括 组蛋白的表观遗传翻译后修饰（PTM），如组蛋白H3 -赖氨酸 甲基化（H3 Kme）可以调节基因的“活性”或“非活性”状态。最近的证据 也证明了microRNA（miRs）在转录后基因调控中的关键作用， 机制等我们的目标是评估这种表观遗传和miR机制在血管紧张素II的作用， 以揭示新的治疗靶点。我们假设组蛋白的失调 H3 Kme和关键miRs的异常表达参与了Ang II诱导的VSMC功能障碍 与各种心血管疾病有关。这将通过3个特定目标进行测试， 沿着相关小鼠的细胞培养中的全基因组分析和生物信息学方法 模型具体目标1是进行关键染色质组蛋白H3 Kme的表观基因组分析 在血管紧张素Ⅱ处理和不处理的VSMC中， 这些标记，以及它们在VSMC中的功能角色。具体目标2是分析miR 在VSMC中响应Ang II的签名，然后确定关键的功能相关性， 差异表达的miR。具体目标3是评估特定的小鼠模型， 为了确定表观遗传标记和miR的体内相关性， 在目标1和2中发现。完成后，拟议的工作将产生新颖的新数据 描述了血管紧张素II处理条件下VSMC的表观遗传和miR谱， 将新一代基因组测序技术引入血管生物学领域。 这些结果可以增加我们对血管紧张素II作用的理解，并确定可能 作为心血管疾病如高血压和动脉粥样硬化的临床治疗。

Project Summary Atherosclerotic and hypertensive cardiovascular diseases (CVDs) are major causes of morbidity and mortality and a severe strain on our healthcare system. The peptide hormone Angiotensin II (Ang II) plays a major role in these pathologies due to its vasoconstrictive, pro-oxidant, -growth and -inflammatory properties in target cells such as vascular smooth muscle cells (VSMC). Several studies have documented the biochemical and signaling mechanisms of Ang II actions via the type 1 receptor (AT1R) in VSMC. However, the precise nuclear epigenetic mechanisms involved in AngII induced transcriptional regulation of pathological genes are not clear. It is increasingly recognized that profound alterations in chromatin structure, including changes in epigenetic posttranslational modifications (PTMs) of histones, such as Histone H3 -lysine methylation (H3Kme) can regulate the "active" or "inactive" state of genes. Recent evidence has also demonstrated the key roles of microRNAs (miRs) in gene regulation by posttranscriptional mechanisms. Our goal is to evaluate such epigenetic and miR mechanisms in Ang II actions in order to unravel new therapeutic targets. We hypothesize that the dysregulation of histone H3Kme and aberrant expression of key miRs contribute to Ang II induced VSMC dysfunction associated with various CVDs. This will be tested via 3 Specific Aims using state-of-the-art genome-wide profiling and bioinformatics approaches in cell culture along with relevant mouse models. Specific Aim 1 is to perform epigenome profiling of key chromatin histone H3Kme marks in VSMC treated with and without Ang II, evaluate the chromatin enzymes regulating these marks, and then their functional roles in VSMC. Specific Aim 2 is to profile the miR signatures in VSMC in response to Ang II and then determine the functional relevance of key differentially expressed miRs. Specific Aim 3 is to evaluate specific mouse models of increased Ang II action in order to determine the in vivo relevance of the epigenetic marks and miRs uncovered in Aims 1 and 2. When completed, the proposed work will yield novel new data describing the epigenetic and miR profiles of VSMC under Ang II treated conditions, and also bring in new next generation genome sequencing technologies to the field of vascular biology. The results can increase our understanding of Ang II actions, and identify new targets that might be developed as clinical therapies for CVDs such as hypertension and atherosclerosis.