The intersection of stress and environmental chemicals in germ cell reprogramming

项目摘要 这项提案的目标是确定暴露于无处不在的塑料和产前压力如何相互作用， 赋予发育中的生殖细胞表观遗传变化，以及这些变化如何导致生殖和代谢 表型在以后的生活和潜在的后代。许多研究涉及消费者和 农业化学品显示出在个体的后代甚至孙辈中出现的影响， 在子宫内暴露易感期和表观遗传重编程之间的对应关系表明， 涉及生殖细胞的表观遗传变化。然而，由于大多数研究采用口服管饲法， 剂量，化学品和产前压力的影响是难以解决的。邻苯二甲酸盐是主要的 在加州，100%的孕妇体内都检测到了这种化学物质。我们的初步 对小鼠的研究发现，在生殖细胞表观遗传时期， 在每种情况下，编程都导致逆转录转座子和生殖细胞发育抑制的减少。 缺陷;我们实验室的证据表明，这是通过破坏皮尔纳途径发生的， 通过表观遗传和翻译后机制沉默内源性转座因子。在这 建议，我们将询问生物相关剂量的邻苯二甲酸酯和 妊娠早期应激对小鼠生殖细胞表观遗传状态的影响，并将这些变化与 逆转录转座子活性和后代的生殖表型。目标1中的研究将确定 妊娠应激和邻苯二甲酸酯暴露相互作用，改变胎儿生殖细胞的表观遗传状态， 继承这个国家的潜力。这将解开压力和化学品暴露的影响， 在许多先前的研究中，伴随着可定量的、分子读数以及测试潜力的经口灌胃 直接和多代表观遗传失调的机制。目标2将检查表型 妊娠早期应激和邻苯二甲酸酯暴露对生殖细胞和女性生殖衰老的影响 在下一代。通过将成人生殖表型与胎儿暴露联系起来，这将开始 解开塑料与产前压力的影响。应激关键节点的药理学调节 反应途径将可能为高危妊娠妇女提供适当的治疗方法。 目的3将确定通过转座子插入引起的遗传破坏的程度， 压力和邻苯二甲酸酯直接暴露的生殖细胞和后代。这些研究将确定 对基因组完整性构成最大风险的环境因素和潜在的药物治疗，以减轻 这些影响。

PROJECT ABSTRACT The goal of this proposal is to establish how exposures to ubiquitous plastics and prenatal stress interact to confer epigenetic changes to developing germ cells, and how such changes lead to reproductive and metabolic phenotypes in later life and potentially in subsequent generations. Numerous studies involving consumer and agricultural chemicals demonstrate effects that appear in the progeny and even grandchildren of individuals exposed in utero. Correspondence between period of susceptibility and epigenetic reprogramming suggest that epigenetic changes to germ cells are involved. However, as the majority of studies utilize oral gavage for dosing, the effects of the chemical and prenatal stress are difficult to resolve. Phthalates are the major chemical in household dust and have been detected in 100% of pregnant women in California. Our preliminary studies in mice find that prenatal exposures to two different phthalates during the period of germ cell epigenetic programming leads in each case to decreased repression of retrotransposons and germ cell developmental defects; evidence from our lab suggests that this occurs through disruption of the piRNA pathway, which silences endogenous transposable elements through epigenetic and post-translational mechanisms. In this proposal, we will interrogate the combined and separate effects of biologically relevant doses of phthalate and early gestational stress on the epigenetic state of mouse germ cells and relate these changes to the extent of retrotransposon activity and reproductive phenotypes in the progeny. Studies in Aim 1 will determine how early gestational stress and phthalate exposure interact to alter the epigenetic state of fetal germ cells and the potential for inheritance of that state. This will disentangle the effects of stress and chemical exposure that accompany oral gavage in many prior studies with quantifiable, molecular readouts as well as testing potential mechanisms of direct and multigenerational epigenetic dysregulation. Aim 2 will examine phenotypic consequences of early gestational stress and phthalate exposure on germ cells and female reproductive aging in the next generation. By connecting adult reproductive phenotypes to fetal exposures, this will begin to disentangle the effects of plastics versus prenatal stress. Pharmacologic modulation of key nodes in the stress response pathway will potentially provide insight on appropriate therapies for women in high-risk pregnancies. Aim 3 will determine the extent of genetic disruptions via transposon insertions induced by early gestational stress and phthalates in directly exposed germ cells and subsequent generations. These studies will identify environmental factors that pose greatest risk to genomic integrity and potentially a drug therapy to mitigate those effects.