Epigenetic regulation of vascular smooth muscle cell phenotype

描述（由申请人提供）：血管平滑肌细胞表型的表观遗传调节血管平滑肌细胞（SMC）分化是血管发生和血管生成过程中非常重要的过程，并且众所周知SMC表型的改变在几种主要心血管疾病状态（包括动脉粥样硬化、高血压和再狭窄）的进展中起作用。虽然血清反应因子（SRF）和心肌因子是至关重要的SMC分化，最近的研究从我们的实验室和其他人表明，表观遗传机制也是至关重要的SMC特异性基因表达的整体模式。事实上，我们确定了组蛋白去甲基化酶，jmjd1a，作为一种心肌因子相互作用蛋白，并已表明，jmjd1a刺激SMC分化标记基因表达在主动脉SMC培养物附近的SMC特异性去甲基化H3K9。目前的建议的一个主要目标将是仔细检查jmjd1a基因敲除小鼠对SMC表型的影响，我们将在几个SMC表型调节的体外和体内模型中表征H3K9甲基化。H3K9甲基化与DNA甲基化密切相关，有趣的是，SMC特异性启动子内的SRF结合区域嵌入CpG岛内。基于我们的初步数据表明SMC特异性启动子受甲基化调控，目的2的目标是确定所涉及的分子机制。最后，为了更好地了解控制SMC表型的全局染色质变化，我们与Jason Lieb和Terry Furrey建立了合作关系，使用DNA酶超敏反应和甲醛辅助分离调控元件（FAIRE）“映射”SMC中的开放染色质区域。我们已经产生了一个全基因组的人类主动脉平滑肌细胞培养物的地图，并确定了一些以前未检查的启动子区域作为潜在的重要SMC特异性基因表达。目的3的目标是测试这些区域是否驱动体内表达，并确定参与的染色质修饰和转录因子。

DESCRIPTION (provided by applicant): Epigenetic regulation of vascular smooth muscle cell phenotype Vascular smooth muscle cell (SMC) differentiation is a very important process during vasculogenesis and angiogenesis, and it is well recognized that alterations in SMC phenotype play a role in the progression of several prominent cardiovascular disease states including atherosclerosis, hypertension, and restenosis. Although serum response factor (SRF) and the myocardin factors are critical for SMC differentiation, recent studies from our lab and others indicate that epigenetic mechanisms are also critical for the overall pattern of SMC-specific gene expression. Indeed, we identified the histone demethylase, jmjd1a, as a myocardin factor interacting protein and have shown that jmjd1a stimulates SMC differentiation marker gene expression in aortic SMC cultures by demethylating H3K9 near the SMC-specific. A major goal of the current proposal will be to closely examine jmjd1a knock-out mice for effects on SMC phenotype, and we will characterize H3K9 methylation in several in vitro and in vivo models of SMC phenotypic modulation. H3K9 methylation is strongly associated with DNA methylation, and interestingly, the SRF binding regions within the SMC-specific promoters are embedded within CpG islands. Based on our preliminary data indicating that the SMC-specific promoters are regulated by methylation, the goal of Aim 2 is to identify the molecular mechanisms involved. Finally, in an attempt to better understand the global chromatin changes that control SMC phenotype, we have established collaborations with Jason Lieb and Terry Furrey to "map" open chromatin regions in SMC using DNase hypersensitivity and Formaldehyde-Assisted Isolation of Regulatory Elements (FAIRE). We have generated a genome-wide map from human aortic SMC cultures and have identified a number of previously unexamined promoter regions as potentially important for SMC-specific gene expression. The goals of Aim 3 are to test whether these regions drive expression in vivo and to identify the chromatin modifying and transcription factors that are involved.