Systems Genetic Analysis of Atherogenic Transcriptional Regulation in Human Cells

描述(申请人提供)：动脉粥样硬化是一种复杂的疾病，导致心脏病发作和中风，有遗传和环境原因。一个主要的启动因素是血管壁上磷脂(Oxpls)的氧化修饰。氧化磷脂在病变中积聚，诱导血管细胞(如内皮细胞)中几条途径的激活，是冠心病和死亡的生物标志物。全基因组关联研究(GWAS)正在确定与风险相关的遗传位点。然而，大多数都位于大的非蛋白质编码区。尽管异常监管可能会带来风险，但人们对监管机制仍知之甚少。这项建议的目的是：1)确定确定人类内皮细胞(EC)身份的基因组调控元件及其对Oxpls的反应；2)确定这些调控元件的功能如何受到自然遗传变异的影响。在目标1中，我将测试这样一个假设，即少数谱系决定转录因子(LDTF)建立了大多数EC特异性增强子，这些增强子对Oxpls产生转录反应。根据我最近在巨噬细胞中的发现，这一假设是合理的，这些发现表明，相对简单的巨噬细胞组合(LDTF)在建立调控格局方面发挥了主导作用。在这些研究中，将利用先前确定的最低限度信托基金的特征来确定和验证欧洲最不发达国家信托基金的候选者。初步数据表明，ETS、AP-1和Fox转录因子家族成员参与了很大比例的EC调控。在目标1中，我还将确定介导内皮细胞对Oxpls反应的转录因子。据推测，这些因素与低密度脂蛋白结合在一起。目标1将在本奖项的K99阶段完成。在目标2中，我将利用一个由50个遗传多样性的原代EC培养组成的明确定义的群体来构建一个数据驱动的监管网络。关联作图和转录因子基序突变分析将确定扰乱调节功能和促动脉粥样硬化表达程序的遗传变异。然后，我将把改变增强子活性的非编码调控变体与人类疾病联系起来。我 假设这些变异很可能在冠状动脉疾病的GWA基因座上富含。在这种情况下，功能调节变异体和调节易感性的细胞类型将被确定。目标2将在R00阶段完成。我的长期目标是以独立研究者的身份阐明易患动脉粥样硬化等复杂疾病的遗传机制。在我的职业生涯中，我努力通过将我作为系统遗传学家培训期间获得的技能与我正在进行的机械基因调控培训相结合来实现这些目标。我将继续利用加州大学圣地亚哥分校研究界的众多机会来加强我的培训。我的出版记录展示了在老鼠和人类群体中使用创新方法将遗传学与复杂特征相结合的能力。有了这份申请中不同的高技能导师的支持，我乐观地相信我会在我的 通向独立的道路。

DESCRIPTION (provided by applicant): Atherosclerosis is a complex disease leading to heart attack and stroke that has genetic and environmental causes. A major initiating factor is the oxidative modification of phospholipids (OxPLs) in the vessel wall. OxPLs accumulate in lesions, induce the activation of several pathways in vascular cells such as endothelial cells, and are biomarkers of coronary disease and death. Genome-wide association studies (GWAS) are identifying the genetic loci that confer risk. However, most are located in large non-protein coding regions. Whereas aberrant regulation is likely to confer risk, regulatory mechanisms remain poorly understood. This proposal aims 1) to identify the genomic regulatory elements that specify human endothelial cell (EC) identity and their responses to OxPLs and 2) to define how the functions of these regulatory elements are affected by natural genetic variation. In Aim 1, I will test the hypothesis that a handful of lineage-determining transcription factors (LDTFs) establish the majority of the EC-specific enhancers that confer transcriptional responses to OxPLs. This hypothesis is justified based on my recent findings in macrophages, which demonstrated that relatively simple combinations of macrophage (LDTFs) play dominant roles in establishing the regulatory landscape. Characteristics of LDTFs identified previously will be used to identify and validate EC LDTF candidates in these studies. Preliminary data suggests the members of the ETS, AP-1 and FOX transcription factor families mediate a large proportion of EC regulation. In Aim 1 I will also identify the transcription factors that mediate endothelial responses to OxPLs. These factors are hypothesized to bind in close vicinity to LDTFs. Aim 1 will be completed during the K99 phase of this award. In Aim 2, I will utilize a well-defined population of 50 genetically diverse primary EC cultures to build a data-driven regulatory network. Association mapping and transcription factor motif mutation analysis will identify the genetic variants that perturb regulatory function and pro-atherogenic expression programs. Then, I will relate non-coding regulatory variants that alter enhancer activity to human disease. I hypothesize that these variants are likely to be enriched at GWAS loci for coronary artery disease. In such cases, the functional regulatory variant and cell type mediating susceptibility will be identified. Aim 2 will be completed during the R00 phase. My long-term goal is to elucidate the genetic mechanisms that predispose individuals to develop complex diseases such as atherosclerosis as an independent investigator. In my career, I strive to achieve these goals by integrating the skills acquired during my training as a systems geneticist with my ongoing training in mechanistic gene regulation. I will continue to take advantage of the numerous opportunities in the UCSD research community to enhance my training. My publication record demonstrates the ability to integrate genetics with complex traits using innovative approaches in the mouse and human populations. With support from the diverse group of highly skilled mentors in this application I am optimistic that I will be successful on my pathway to independence.