Systems Genetic Analysis of Atherogenic Transcriptional Regulation in Human Cells

描述（由申请人提供）：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。一个主要的引发因素是血管壁中磷脂（OxPL）的氧化修饰。OxPL在病变中积累，诱导血管细胞如内皮细胞中的几种途径的激活，并且是冠状动脉疾病和死亡的生物标志物。全基因组关联研究（GWAS）正在确定赋予风险的遗传位点。然而，大多数位于大的非蛋白质编码区。虽然异常的监管可能会带来风险，但监管机制仍然知之甚少。 该提案旨在1）鉴定指定人内皮细胞（EC）身份及其对OxPL的反应的基因组调控元件，以及2）定义这些调控元件的功能如何受到天然遗传变异的影响。在目标1中，我将测试的假设，少数谱系决定转录因子（LDTF）建立了大多数的EC特异性增强子，赋予转录响应OxPL。基于我最近在巨噬细胞中的发现，这一假设是合理的，该发现表明相对简单的巨噬细胞（LDTF）组合在建立监管格局中起主导作用。先前确定的LDTF的特征将用于在这些研究中确定和验证EC LDTF候选物。初步数据表明ETS、AP-1和FOX转录因子家族的成员介导了大部分EC调节。在目标1中，我还将确定介导内皮细胞对OxPL反应的转录因子。假设这些因子与LDTF紧密结合。目标1将在该奖项的K99阶段完成。在目标2中，我将利用50个遗传多样性的原代EC培养物的明确定义的群体来建立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干扰调节功能和促动脉粥样硬化表达程序的遗传变异。然后，我将涉及非编码调节变异，改变增强子的活动，以人类疾病。我 假设这些变异可能在冠状动脉疾病的GWAS位点富集。在这种情况下，将鉴定介导易感性的功能调节变体和细胞类型。目标2将在R 00阶段完成。 我的长期目标是作为一名独立的研究者阐明使个体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，我努力实现这些目标，通过整合我作为系统遗传学家的培训中获得的技能，以及我正在进行的机械基因调控培训。我将继续利用UCSD研究界的众多机会来加强我的培训。我的出版记录证明了在小鼠和人类群体中使用创新方法将遗传学与复杂性状整合的能力。在这个应用程序中，有来自不同的高技能导师组的支持，我很乐观，我将在我的 通往独立的道路。

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.