The Role of Histone Deacetylase 9 in Vascular Calcification

项目摘要 血管钙化是心肌梗死等动脉粥样硬化性心血管疾病的标志 和中风，这是世界上发病率和死亡率的主要原因。尽管主动脉钙化是 心血管疾病的强独立危险因素--主动脉钙化的遗传决定因素 目前尚不清楚，血管钙化的分子机制也不完全阐明。在一个 对9400多名参与者进行的多队列研究中，我们发现了 组蛋白脱乙酰酶9(HDAC9)基因座与腹主动脉钙化相关。在体外实验中 模型，我们的初步实验表明，抑制HDAC9可以阻止 主动脉血管平滑肌细胞(VSMCs)钙化。在两种不同的小鼠模型中，我们发现 全球HDAC9缺乏对血管钙化和动脉粥样硬化的发展具有保护作用。 根据我们的初步证据，结合一项人类全基因组关联研究，体外培养的VSMC 实验和小鼠血管钙化模型，我们已经确定HDAC9是一种新的激活剂 血管钙化。这项建议的总体目标是通过以下方式了解分子机制 哪种HDAC9促进血管钙化和动脉粥样硬化。HDAC9是IIa类的成员 HDAC家族，它们都具有脱乙酰酶催化结构域和心肌细胞增强因子2 (MeF2)结合位点。首先，使用一系列VSMC功能分析，我们建议确定 HDAC9及其下游靶点MEF2在促进VSMC成骨表型转换和钙化方面发挥了重要作用。 第二，检验HDAC9对血管疾病的影响是通过其特异性发挥作用的假设。 在小鼠模型中，我们将确定VSMC特异性的HDAC9缺失是否足以 减轻血管钙化和动脉粥样硬化。最后，我们发现了一种新的相互作用 HDAC9和长的非编码RNA MALAT1。我们将确定HDAC9是否需要MALAT1- MALAT1对VSMC表型及血管钙化和动脉粥样硬化的依赖效应 小鼠基因敲除模型。所提出的实验将提供对功能的重要的机械学见解 HDAC9在血管系统中的表达及血管形成的分子和细胞机制 钙化和动脉粥样硬化。

Project Summary Vascular calcification is a hallmark of atherosclerotic cardiovascular diseases such as myocardial infarction and stroke, which are the leading causes of morbidity and mortality in the world. Although aortic calcification is a strong independent risk factor for cardiovascular disease, the genetic determinants of aortic calcification remain unknown and the molecular mechanisms of vascular calcification are incompletely elucidated. In a multi-cohort study with more than 9400 participants, we identified single nucleotide polymorphisms in the histone deacetylase 9 (HDAC9) locus that are associated with abdominal aortic calcification. In an in vitro model of calcification, our preliminary experiments demonstrated that inhibition of HDAC9 prevented the calcification of aortic vascular smooth muscle cells (VSMCs). In two different mouse models, we found that global HDAC9 deficiency protected against the development of vascular calcification and atherosclerosis. Based on our preliminary evidence, combining a human genome-wide association study, in vitro VSMC experiments, and a murine model of vascular calcification, we have identified HDAC9 as a novel activator of vascular calcification. The overall objective of this proposal is to understand the molecular mechanisms by which HDAC9 promotes vascular calcification and atherosclerosis. HDAC9 is a member of the Class IIa HDAC family, all of which possess both a deacetylase catalytic domain and a myocyte enhancer factor 2 (MEF2) binding site. First, using a series of VSMC functional assays, we propose to determine the role of HDAC9, and its downstream target MEF2, in promoting VSMC osteogenic phenotype switch and calcification. Second, to test the hypothesis that the influence of HDAC9 on vascular disease is exerted through its specific effects on VSMCs, we will determine if VSMC-specific deletion of HDAC9 in a murine model is sufficient to attenuate vascular calcification and atherosclerosis. Lastly, we have uncovered a novel interaction between HDAC9 and the long non-coding RNA MALAT1. We will determine if MALAT1 is required for the HDAC9- dependent effects on VSMC phenotype and on vascular calcification and atherosclerosis using a MALAT1 murine knockout model. The experiments proposed will provide important mechanistic insights into the function of HDAC9 in the vasculature and into the underlying molecular and cellular mechanisms of vascular calcification and atherosclerosis.