Epigenomic Origins of Overlapping Features of Asthma and COPD

摘要 暴露于香烟烟雾与儿童哮喘和成人COPD有关，可能是一种慢性阻塞性肺疾病。 影响哮喘和COPD患者固定气流阻塞轨迹的关键早期环境环节。的 慢性阻塞性肺病途径和网络的启动可能发生在子宫内和/或生命早期。 哮喘和COPD之间共同表观遗传标记的鉴定及其潜在的胎儿起源 分子易感性可以代表COPD和哮喘的生物标志物和/或易感因子。我们 假设固定气流阻塞与miRNA和DNA甲基化变异相关， 支气管上皮细胞，遗传和表观遗传变异共同作用以确定易感个体， 在哮喘和慢性阻塞性肺病患者的固定气流中， 与暴露于子宫内烟雾的胎儿肺组织相关，支持共同和发育起源， 固定气流阻塞和COPD。我们提出了基因水平和基于网络的miRNA和DNA分析， 甲基化测序数据。在目标1中，我们将使用最先进的下一代测序方法， 来自175名受试者的BE细胞的DNA和RNA，以鉴定基因特异性DNA甲基化和miRNA标记 与哮喘患者和COPD老年吸烟者的固定气流阻塞相关， 评估子宫内烟草烟雾（IUS）暴露的胎儿肺组织中的显著标记。我们将执行 来自哮喘受试者、COPD受试者和哮喘患者的支气管上皮（BE）细胞标记的全基因组分析 没有肺病的成年吸烟者在目标2中，我们将整合遗传和表观遗传变异， 表观遗传标记和表型结果的遗传调节。我们预计这些遗传-表观遗传 签名将识别出一部分有早期不可逆气流阻塞风险的儿童哮喘患者， 慢性阻塞性肺病我们将整合甲基化和miRNA信号与基因表达，以评估潜在的 已识别网络的功能相关性，以及哮喘、COPD和胎儿肺之间的网络保守性 暴露于IUS的组织。在目标3中，我们将评估通过甲基化组鉴定的基因的功能特征。 以及使用BE细胞中的体外基因敲除或过表达进行miRNA测序，以突出显示具有 通过促炎和促纤维化介质通过气道重塑对固定AO的功能影响。在 总之，本项目将研究DNA测序鉴定的甲基化和miRNA标记和网络 与哮喘和COPD相关，并在胎儿肺组织中复制，以确定共同的发病机制途径 和潜在的胎儿起源或表观遗传易感性。整合遗传、表观遗传和基因表达数据 可以确定影响这些主要吸烟相关肺部疾病的关键重叠途径， 可以提供早期生命生物标志物，为哮喘和COPD的一级预防提供信息。

ABSTRACT Exposure to cigarette smoke has been associated with both childhood asthma and adult COPD, and may be a key early-life environmental link impacting trajectories of fixed airflow obstruction in asthmatics and COPD. The initiation of chronic obstructive lung disease pathways and networks may occur in utero and/or during early life. The identification of common epigenetic marks between asthma and COPD and the potential fetal origins of molecular susceptibility may represent biomarkers of and/or susceptibility factors for COPD and asthma. We hypothesize that fixed airflow obstruction is associated with variability in miRNA and DNA methylation in bronchial epithelium, that genetic and epigenetic variation act together to define susceptible individuals and that a subset of genes demonstrating epigenetic perturbations in fixed airflow in asthmatics and COPD will be associated in fetal lung tissue exposed to in utero smoke, supporting common and developmental origins of fixed airflow obstruction and COPD. We propose gene-level and network-based analysis of miRNA and DNA methylation sequencing data. In Aim 1, we will use state-of-the-art next generation sequencing approaches in DNA and RNA from BE cells from 175 subjects to identify gene-specific DNA methylation and miRNA marks associated with fixed airflow obstruction in asthmatics and older smokers with COPD, followed by an assessment of significant marks in utero tobacco smoke (IUS) exposed fetal lung tissue. We will perform genome-wide analysis of bronchial epithelial (BE) cell marks from asthmatic subjects, COPD subjects, and adult smokers without lung disease. In Aim 2 we will integrate genetic and epigenetic variation to assess genetic regulation of epigenetic marks and phenotypic outcomes. We anticipate that these genetic-epigenetic signatures will identify a subset of childhood asthmatics at risk for early irreversible airflow obstruction and COPD. We will integrate methylation and miRNA signals with gene expression to assess for potential functional relevance of identified networks, and network conservation between asthma, COPD and fetal lung tissue exposed to IUS. In Aim 3, we will assess the functional features of genes identified through methylome and miRNA sequencing using in vitro gene knockdown or overexpression in BE cells, to highlight genes with a functional impact on fixed AO through airway remodeling via pro-inflammatory and pro-fibrotic mediators. In summary, this project will investigate DNA sequencing-identified methylation and miRNA marks and networks associated in asthma and COPD and replicated in fetal lung tissue to identify common pathogenesis pathways and potential fetal origins or epigenetic susceptibility. Integrating genetic, epigenetic and gene expression data may identify key overlapping pathways that influence these major smoking-related pulmonary disorders and may provide an early-life biomarker to inform primary prevention of both asthma and COPD.