Epigenetic and Fetal Origins of Hypoxia-Induced Pulmonary Hypertension

项目摘要 肺动脉高压（PH）是一种进行性的、危及生命的疾病，通常继发于肺动脉高压。 慢性缺氧心肺疾病或高海拔（HA）居住（海拔2500米）。过去几 几十年来，PH相关死亡率在所有种族和民族的两性中都有所增加，目前没有 治疗已被证明对缺氧诱导的PH有效。不良宫内状况，包括胎儿生长 胎儿宫内发育迟缓（IUGR）、先兆子痫和围产期缺氧，可引起结构的持久变化， 肺和肺血管系统的功能，并预测受影响的肺血管疾病 后代我们的首要目标是确定胎儿宫内生长受限（IUGR）是否增加 通过改变基因的表观遗传调控对缺氧诱导的肺动脉高压的易感性 属于mTOR通路。为了实现这一目标，我们提出了三个综合科学目标。 在目标1中，我们将确定IUGR对mTOR通路DNAm和基因表达模式的影响， 出生时PBMC和两种代表性血管细胞类型（HUAEC和HUASMC）中的mTOR信号传导 使用主要和外部验证队列的人类。我们的主要队列将是在LA或HA出生的婴儿 在玻利维亚（400和3600米），我们的外部验证队列将包括出生在弗里斯科，科罗拉多的婴儿， 生活在海拔3000米以上的女性。从玻利维亚获得样本用于我们的原始数据集是有益的，因为La 帕兹大都市区包括世界上最大的HA居民人口， 居住在海拔3000米以上的人口以及开展拟议研究所需的现代医疗和研究设施 研究目的;这将提高我们在获得足够数量的受试者方面的效率， 在拟议的时间框架内进行前瞻性研究。在目标2中，我们将建立mTOR与 出生时的DNA m和表达模式以及前瞻性测量的PH超声心动图指数， 出生后第一年（1周、6个月和12个月）。由于DNA标记受环境和 遗传因素，我们还将确定是否差异甲基化的mTOR通路基因的情况下， 婴儿期IUGR和/或PH与a）邻近（< 500 kb）差异甲基化的SNP相关 标记，或B）已知参与PH的编码蛋白质的基因内的SNP。 确定遗传因素、表观遗传标记和IUGR对PH的交互作用。在目标3中，我们将使用 在已建立的缺氧诱导IUGR和PH小鼠模型中， 研究DNAm状态、mTOR信号通路与IUGR的相互作用对发育程序的影响 肺血管功能障碍总之，我们的研究目标1）解决主要的知识差距， 关于宫内暴露影响肺功能的潜在机制， 2）有可能确定新的治疗或预防策略的目标，以减少 肺血管疾病的负担。

PROJECT SUMMARY Pulmonary hypertension (PH) is a progressive, life-threatening disease that often develops secondary to the chronic hypoxia of cardiopulmonary disease or high-altitude (HA) residence ( 2500m). Over the past few decades, PH-associated mortality has increased in both sexes of all race and ethnic groups, and no current therapy has proven effective for hypoxia-induced PH. Adverse intrauterine conditions, including fetal growth restriction (IUGR), preeclampsia and perinatal hypoxia, can induce durable changes to the structure and function of the lung and pulmonary vasculature, and are predictive of pulmonary vascular disease in affected offspring. Our overarching goal is to determine whether intrauterine growth restriction (IUGR) increases susceptibility to hypoxia-induced pulmonary hypertension by altering the epigenetic regulation of genes belonging to the mTOR pathway. To address this goal, we propose to conduct three integrated scientific aims. In Aim 1, we will define the effect of IUGR on mTOR pathway DNAm and gene expression patterns, and mTOR signaling in PBMCs and two representative vascular cell types (HUAECs and HUASMCs) at birth in humans using both primary and external validation cohorts. Our primary cohort will be infants born at LA or HA in Bolivia (400 and 3600 m), and our external validation cohort will consist of infants born in Frisco, Colorado to women living ≥ 3000m. Obtaining samples from Bolivia for our primary data set is beneficial because the La Paz metropolitan region comprises the largest, HA resident population in the world with more than two million persons living ≥ 3000m and the modern medical and research facilities necessary to conduct the proposed study aims; this will improve our efficiency with respect to obtaining a sufficient number of subjects for prospective study over the proposed timeframe. In Aim 2, we will establish the relationship between mTOR DNAm and expression patterns at birth and echocardiographic indices of PH measured prospectively across the first year of life (1 week, 6 and 12 months). Because DNAm marks are influenced by environmental and genetic factors, we will also determine whether differentially methylated mTOR pathway genes in cases of IUGR and/or PH during infancy, are associated with a) SNPs neighboring (< 500 kb) differential methylation marks, or b) SNPs within genes encoding proteins known to be involved in PH. Using this approach, we will determine the interactive effect of genetic factors, epigenetic marks and IUGR for PH. In Aim 3 we will use genetic and pharmacologic approaches in an established murine model of hypoxia-induced IUGR and PH to study the interaction of DNAm state, mTOR pathway signaling and IUGR for the developmental programming of pulmonary vascular dysfunction. Together, our research aims 1) address major knowledge gaps with respect to the mechanisms underlying the effect of intrauterine exposures to compromise the pulmonary circulation and 2) have the potential to identify targets for new therapeutic or preventive strategies to reduce the burden of pulmonary vascular disease across the lifespan.