Chromatin regions, genes and pathways that confer susceptibility to chemical-induced DNA damage

染色质区域、基因和途径赋予化学诱导的DNA损伤的易感性 摘要 遗传变异对常见疾病的易感性、对药物和毒物的反应有重大影响， 并影响疾病相关的结果。此外，遗传变异性、毒性结果和 表观遗传学正在积极探索中。然而，基因×环境×表观遗传学的研究是困难的， 它们涉及询问多个个体、暴露剂量/时间、组织类型、组学终点和 各种毒性表型。该提案旨在识别和验证染色质区域、基因和 赋予对环境化学诱导和代谢相关DNA易感性的途径 损害我们将对诱导的DNA损伤之间的相互作用进行一系列的原理验证研究。 1，3-丁二烯，一种遗传毒性致癌物，遗传学和表观遗传学。我们有丰富的经验， 小鼠（Collaborative Cross，CC）和人（1000 Genomes淋巴母细胞系）毒理学研究 人口模型。首先，我们将确定表达和染色质数量性状位点（QTL）， 小鼠组织中丁二烯的遗传毒性。我们将检验以下假设： 丁二烯诱导的DNA损伤受遗传变异依赖的背景状态控制， 染色质和基因表达。我们将使用来自50株CC菌株研究的组织（肝、肺和肾） 暴露于丁二烯，并将评估丁二烯DNA损伤，并确定活性/抑制的区域 增强子和启动子。其次，我们将确定丁二烯诱导的DNA损伤的剂量和时间效应 在背景和治疗诱导的染色质和转录状态的背景下。我们将测试 丁二烯暴露以剂量依赖性方式改变菌株和组织特异性表观遗传状态的假设 方式并且DNA损伤相关的对染色质的影响持续存在。我们将检查菌株间和菌株内 变异性、剂量依赖性和时间依赖性。第三，我们将描述人口规模 在人体外群体模型中对丁二烯代谢物反应的变异性。我们将检验这个假设 人类淋巴母细胞可用于绘制丁二烯遗传毒性的易感基因座。四是 验证应变依赖性DNA损伤的转录和表观遗传介质的发现， 丁二烯在人体外基于群体的模型中。我们将检验遗传背景- 依赖性转录和表观遗传状态赋予对丁二烯诱导的DNA的易感性/抗性 损害我们将评估染色质状态和表达，并结合DNA加合物测定。总体而言，这 工作将证明环境之间的相互作用（即，化学暴露），遗传学和表观遗传学， 研究1，3-丁二烯的影响，丁二烯是一种工业毒物和模型遗传毒性致癌物。人类相关性和 可行性是合理的，重点是毒性和致癌的基本机制，事实上， 丁二烯是一种已知的人类和啮齿动物致癌物，我们以前的工作证明了丁二烯的影响， 染色质、组蛋白修饰和其他表观遗传状态以菌株和组织依赖性方式存在。

Chromatin regions, genes and pathways that confer susceptibility to chemical-induced DNA damage ABSTRACT Genetic variability has a major impact on susceptibility to common diseases, responses to drugs and toxicants, and influences disease-related outcomes. In addition, the links between genetic variability, toxicity outcomes and epigenetics are being actively explored. However, studies of Gene × Environment × Epigenetics are difficult as they involve interrogation of multiple individuals, exposure doses/times, tissue types, -omics endpoints and various toxicity phenotypes. This proposal aims to identify and validate chromatin regions, genes and pathways that confer susceptibility to environmental chemical-induced and metabolism-associated DNA damage. We will perform a series of proof-of-principle studies of the interplay between DNA damage induced by 1,3-butadiene, a genotoxic carcinogen, genetics, and epigenetics. We have extensive experience performing toxicology studies in the mouse (Collaborative Cross, CC) and human (1000 Genomes lymphoblast cell lines) population-based models. First, we will determine expression and chromatin quantitative trait loci (QTL) of butadiene genotoxicity in mouse tissues. We will test the hypothesis that strain- and tissue-specific variation in butadiene-induced DNA damage is controlled by the genetic variability-dependent background states in chromatin and gene expression. We will use tissues (liver, lung and kidney) from a study of 50 CC strains exposed to butadiene and will evaluate butadiene DNA damage and identify regions of active/repressed enhancers and promoters. Second, we will determine dose- and time-effects of butadiene-induced DNA damage in the context of background and treatment-induced chromatin and transcriptional states. We will test the hypothesis that butadiene exposure modifies strain- and tissue-specific epigenetic states in a dose-dependent manner and that DNA damage-associated effects on chromatin persist. We will examine inter- vs intra-strain variability, dose- and time-dependency in select CC strains. Third, we will characterize the extent of population variability in response to butadiene metabolites in a human in vitro population model. We will test the hypothesis that human lymphoblasts can be used to map susceptibility loci for butadiene genotoxicity. Fourth, we will validate the discoveries of the transcriptional and epigenetic mediators of strain-dependent DNA damage by butadiene in a human in vitro population-based model. We will test the hypothesis that genetic background- dependent transcriptional and epigenetic states confer susceptibility/resistance to butadiene-induced DNA damage. We will evaluate chromatin states and expression coupled with assays for DNA adducts. Overall, this work will demonstrate the interplay among environment (i.e., chemical exposure), genetics, and epigenetics by studying effects of 1,3-butadiene, an industrial toxicant and model genotoxic carcinogen. Human relevance and feasibility are justified by the focus on a fundamental mechanism of toxicity and carcinogenesis, the fact that butadiene is a known human and rodent carcinogen, and our previous work demonstrating butadiene effects of chromatin, histone modifications and other epigenetic states in a strain- and tissue-dependent manner.