Environmental Epigenomics and Precision Environmental Health

摘要 生命早期的毒物暴露在一定程度上对动物模型和人类的健康结果都有不利影响。 由于表观遗传机制。积累的研究还表明，暴露对表观基因组的影响 可以是组织甚至细胞特有的。然而，毒理表观遗传动物的研究通常是用单一的 大量和/或有限的表观基因组靶组织(例如DNA甲基化)。此外，表观遗传流行病学 对毒物的分析几乎总是限于生物可用的“代用品”(例如血液)样本。 使用毒理学和流行病学相结合的方法，这两个首要目标中的第一个 革命性的创新、有远见的环境健康研究(河流)应用程序将推动 了解围产期典型暴露(例如，包括铅和内分泌在内的金属)的影响 包括邻苯二甲酸酯在内的活性化合物)对表观基因组和纵向健康风险。为了实现这一目标，我们 将使用与人类生理相关的小鼠模型和纵向人类出生队列样本 评估DNA甲基化、非编码RNA、染色质结构和 不同性别的基因在多个组织中的表达，相关时结合单细胞方法。 最终，我们试图确定导致疾病的暴露的组织特异性表观基因组特征 敏感性以及可用替代组织询问的表观基因组的区域。 虽然对表观基因组的精确修饰很有希望改变环境引起的变化 并降低疾病风险，目前使用通用的全球可用药物(例如氮胞苷)和 目标系统(如TALEN、CRISPR)。因此，我们的第二个首要目标是推动发展 一套工具，基于PIWI-相互作用RNA(PiRNA)系统，将精确的环境 健康，同时避免当前技术的缺陷。在小鼠身上，我们已经证明了piRNA和相关的 与之前的看法相反，处理机制在躯体组织中存在并活跃，特别是在大脑中 PIRNA抑制系统仅限于生殖系。从我们存活的黄色刺鼠身上找到的证据 (Avy)小鼠实验支持体内基于piRNA的DNA甲基化诱导。因此，我们建议使用 这类RNA开发精确的环境健康工具，针对特定的基因和位点进行稳定， 有丝分裂可遗传，在体细胞中沉默。首先，我们将评估体细胞中的piRNA/PIWIL机制 人类组织优先选择具有高内源性piRNA机制的细胞类型，以进行表观遗传编辑。然后，我们 将开发合成的piRNAs，在暴露的啮齿动物和人类细胞系中体外靶向DNA甲基化。这个 研究将扩大人类表观基因组编辑工具的保留范围，从而产生治疗广泛的 一系列环境和表观遗传疾病，包括印记基因紊乱和癌症。的愿景 灵活持续的河流支持是创新环境表观基因组学领域，发展 翻译工具，用于精确的表观基因组编辑，并成为研究和培训的资源。

Abstract Toxicant exposures early in life adversely affect health outcomes in both animal models and humans, in part due to epigenetic mechanisms. Accumulating studies also indicate that exposures' impact on the epigenome can be tissue and even cell specific. Yet, toxicoepigenetic animal studies are often conducted with single tissues in bulk and/or limited epigenomic targets (e.g. DNA methylation). Additionally, epigenetic epidemiology analysis of toxicants is almost always restricted to biologically available, “surrogate” (e.g. blood) samples. Using a combination of toxicological and epidemiological approaches, the first of two overarching goals of this Revolutionizing Innovative, Visionary Environmental Health Research (RIVER) application is to advance the understanding of the effects of representative perinatal exposures (e.g. metals including lead and endocrine active compounds including phthalates) on the epigenome and longitudinal health risks. To accomplish this, we will use human physiologically relevant mouse models and longitudinal human birth cohort samples alongside targeted and unbiased approaches to evaluate DNA methylation, non-coding RNA, chromatin structure, and gene expression in both sexes in multiple tissues, incorporating single cell approaches when relevant. Ultimately, we seek to identify tissue-specific epigenomic signatures of exposures contributing to disease susceptibility as well as regions of the epigenome that may be interrogated with the use of surrogate tissues. While precision modification of the epigenome holds great promise to modify environmentally induced changes and reduce disease risk, it is currently out of reach using common available global (e.g. azacytidine) and targeted (e.g. TALENs, CRISPR) systems. Thus, our second overarching goal is to advance the development of a suite of tools, based on the PIWI-interacting RNA (piRNA) system to transform precision environmental health, while avoiding drawbacks of current technology. In mice, we have shown that piRNA and associated processing machinery are present and active in somatic tissues, especially the brain, in contrast to prior belief that the piRNA suppression system was restricted to the germ-line. Evidence from our viable yellow agouti (Avy) mouse experiments supports piRNA-based DNA methylation induction in vivo. Thus, we propose to use this class of RNA to develop precision environmental health tools to target specific genes and loci for stable, mitotically heritable, silencing in somatic cells. First, we will evaluate piRNA/PIWIL machinery across somatic human tissues to prioritize cell types with high endogenous piRNA machinery for epigenetic editing. Then, we will develop synthetic piRNAs to target DNA methylation in vitro in exposed rodent and human cell lines. The research will expand the repertoire of human epigenome editing tools resulting in therapeutics to treat a broad array of environmental and epigenetic diseases including imprinted gene disorders and cancer. The vision for the flexible and sustained RIVER support is to innovate the field of environmental epigenomics, develop translational tools for precision epigenome editing, and be a resource for research and training.