Epigenomes and Epigenetic Mechanisms in BP-relevant Tissues

项目2项目概要 高血压仍然是多种心血管疾病的最重要的危险因素 全球约54%的中风和47%的缺血性心脏病事件。 尽管我们知道有一个重要的遗传成分决定了血液的水平， 血压（BP; BP的遗传率估计在30-70%之间），我们还远远没有理解无数的 遗传因素导致了人类血压的变化。最重要的挑战之一， 了解BP的遗传控制是绝大多数BP相关的单核苷酸多态性 在人类全基因组关联研究（GWAS）中鉴定的SNP位于非编码区， DNA的区域。许多非编码SNPs（ncSNPs）位于数千个碱基的单倍型区域， 这使得几乎不可能将SNP与蛋白质编码基因联系起来 或者是一种生理途径，它根据序列和我们目前对机制的了解来调节血压 对SNPs的作用。在这个项目中，我们将重点测试特定的假设，许多ncSNPs 在GWAS中鉴定的这些基因通过表观遗传机制影响BP相关基因的表达。Epigenetics 术语“稳定的”是指DNA功能的稳定变化，其不是直接由于DNA序列的变化。 表观基因组学指的是发生在整个基因组中的这种变化。因此，我们将使用国家- 最先进的表观基因组学和表观遗传学方法来探测个体 ncSNPs影响人类GWAS中BP相关基因的表达。使用肾单位片段， 我们将显微解剖新鲜的人类肾脏和从臀部活检分离的人类阻力小动脉 以及将从人类诱导性多能干细胞（iPSC）衍生的相关细胞类型，我们将 以前所未有的组织分辨率创建人类BP相关细胞和组织的表观基因组图谱。 使用该图谱结合我们对人类GWAS SNP数据和来自项目1的数据的生物信息学分析， 这个PPG（BP ncSNPs对基因表达的影响），我们将测试特定的表观遗传机制， 单个SNP。最后，我们将进行验证研究，其中精确的基因组编辑和靶向 表观遗传学分析用于确定假设的机制是否是导致 BP相关细胞类型中的基因表达。该项目与其他项目和核心高度协作 通过共享试剂（细胞和组织）、数据传输和 研究人员及其实验室的知识环境。

PROJECT 2 PROJECT SUMMARY Hypertension remains the most important risk factor for a wide variety of cardiovascular diseases accounting for approximately 54 percent of all strokes and 47 percent of all ischemic heart disease events globally. Despite the fact that we know there is a significant genetic component that determines the level of blood pressure (BP; estimates of heritability of BP range from 30-70%) we are far from understanding the myriad of genetic factors that account for BP variation in humans. One of the most significant challenges for understanding genetic control of BP is that the vast majority of BP-associated single nucleotide polymorphisms (SNPs) that have been identified in human genome wide association studies (GWAS) are located in noncoding regions of DNA. Many of the noncoding SNPs (ncSNPs) are in haplotype regions located thousands of base pairs away from any protein-coding gene making it nearly impossible to link the SNPs to a protein-coding gene or a physiological pathway that regulates BP based on sequence and our current knowledge of the mechanism of action for the SNPs. In this project we will focus on testing the specific hypothesis that many ncSNPs identified in GWAS impact the expression of BP relevant genes through epigenetic mechanisms. Epigenetics refers to stable changes in DNA function that are not directly due to changes in the sequence of DNA. Epigenomics refers to such changes when they occur across the entire genome. Therefore, we will use state- of-the-art epigenomic and epigenetic approaches to probe the epigenetic mechanisms by which individual ncSNPs impact the expression of genes associated with BP in human GWAS. Using nephron segments that we will micro-dissect from fresh human kidney and human resistance arterioles isolated from gluteal biopsies as well as related cell types that will be derived from human inducible pluripotent stem cells (iPSCs), we will create an epigenomic map of human BP related cells and tissues at an unprecedented tissue resolution. Using that map combined with our bioinformatic analysis of human GWAS SNP data and data from Project 1 in this PPG (effects of BP ncSNPs on gene expression) we will then test specific epigenetic mechanisms for individual SNPs. Finally, we will perform validation studies in which precision genome editing and targeted epigenetic analysis are utilized to determine if the hypothesized mechanisms are responsible for changes in gene expression in BP-relevant cell types. This project is highly collaborative with the other projects and cores in this Program Project Grant through the sharing of reagents (cells and tissues), transfer of data, and the intellectual environment of the investigators and their laboratories.