Genetic and epigenetic regulation of vascular smooth muscle cell phenotype and contractility

摘要 血管平滑肌细胞(SMC)的分化是血管生成和分化过程中非常重要的过程。 血管生成，众所周知，SMC表型的改变在血管病变的进展中起作用。 几种突出的心血管疾病状态，包括动脉粥样硬化、高血压和再狭窄。 在之前的资助期间，我们使用高通量测序和计算生物学来研究 全基因组水平人主动脉平滑肌细胞染色质结构和转录因子结合。我们的工作 导致了以前未被识别的SMC选择性蛋白的鉴定，从而表征了 调节SMC收缩和血压的遗传机制以及新的转录 调节SMC特异性基因表达的机制。使用我们最近发现的质谱学方法 SMC选择性甲基转移酶，PRDM6，作为一种肌钙蛋白因子相互作用蛋白，并有细胞培养 体内实验数据表明，PRDM6是维持SMC分化和血压所必需的。 重要的是，最近的人类遗传学研究描述了导致导管未闭的PRDM6编码突变 动脉粥样硬化和GWA已经在PRDM中发现了一个与血压调节和颅内相关的基因 动脉瘤。在目标1中，我们将确定转录机制和人类基因变异 PRDM6是PRDM6的SMC特异性表达。由于PRDM6调节基因的机制 表达完全未知，在AIM2中，我们将使用全基因组方法来鉴定直接PRDM6 靶，我们将测试PRDM6是否通过直接甲基化来调节MRTF-A的活性。在《目标3》中，我们将 继续评估PRDM6在血压和SMC表型调节中的作用 体内使用我们的条件性SMC特异性PRDM6基因敲除小鼠。我们还与以下公司建立了合作关系 北卡罗来纳大学的心血管临床研究团队开始检查两者之间的相关性 PRDM6基因与当地人群高血压的关系

Summary 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. During the previous funding period we used high throughput sequencing and computational biology to study chromatin structure and transcription factor binding in human aortic SMCs on a genome-wide level. Our work has led to the identification of previously unrecognized SMC-selective proteins, to the characterization of genetic mechanisms that regulate SMC contractility and blood pressure, and to novel transcription mechanisms that regulate SMC-specific gene expression. Using mass spec approaches we recently identified the SMC-selective methyltransferase, PRDM6, as a myocardin factor interacting protein and have cell culture and in vivo data that PRDM6 is required for the maintenance of SMC differentiation and blood pressure. Importantly recent human genetic study described PRDM6 coding mutations that cause patent ductus arteriosis, and GWAS have identified a locus in PRDM that was associated with BP regulation and intracranial aneurysm. In Aim 1 we will identify the transcription mechanisms and human genetic variations that regulate PRDM6 the SMC-specific expression of PRDM6. Since the mechanisms by which PRDM6 regulates gene expression are completely unknown, in Aim2 we will use genome-wide approaches to identify direct PRDM6 targets, and we will test whether PRDM6 regulates MRTF-A activity by direct methylation. In Aim 3 we will continue to evaluate the contributions of PRDM6 to the regulation of blood pressure and SMC phenotype in vivo using our conditional SMC-specific PRDM6 knockout mice. We have also established collaborations with clinical cardiovascular research teams at the University of North Carolina to begin to examine the correlation between PRDM6 genotype and hypertension in local populations.