Embryonic inheritance of sperm methylome after adult exposure to phthalates

摘要 邻苯二甲酸酯，一类用于塑料和个人护理产品的内分泌干扰化合物(EDCs)， 是无处不在的环境污染物，导致人类广泛接触。流行病学数据 父性邻苯二甲酸酯与生殖健康不良有关，包括精子质量差等 最近，随着−怀孕时间的延长，后者暗示了一种精子来源的效应。不断增长的 令人信服的数据表明，环境暴露可以体现在发育中的男性体内 生殖细胞通过表观遗传标记，继而可以在受精时传递信息来影响受精轨迹 对后代的健康和发育的影响。已知，出生前雄性生殖细胞的表观遗传重编程 细胞是一个特别容易受到邻苯二甲酸盐等环境暴露的窗口。研究人员现在已经 这表明在生殖细胞发育过程中还存在其他这样的敏感窗口。我们的长- 学期目标是提供一个表观遗传学的理解如何父亲的EDC影响生殖和 后代健康--在胚胎和胎盘组织中。这里的目标是确定以下各项的效果 成人接触邻苯二甲酸二(2-乙基己基)酯(DEHP)对精子DNA甲基化的影响及其持久性 精子来源对胚胎DNA甲基化编程的影响。我们的中心假设是 成年DEHP暴露使精子中的DNA甲基化发生变化，这种变化持续存在于F1胚胎中。成虫 生殖年龄(7-8周龄)雄性PWD小鼠分别给予0、2.5和250 mg/kg体重/天的 DEHP治疗60天。将收集附睾精子，并对其进行全基因组亚硫酸盐分析 测序。使用亲本菌株将允许跨基因组的等位基因特异性分析，我们将 对胚胎和胚胎外(胎盘)进行rna-seq和全基因组亚硫酸盐测序。 E6.5胚胎的组织切片。上述目标中提出的研究有望确定DNA甲基化 成年男性暴露于DEHP对精子和发育中胚胎的影响 老鼠。这些结果是显著推进我们对以下机制理解的第一步 成年期父亲的环境暴露会影响生殖健康、成功发育和 后代健康。

Summary Phthalates, a class of endocrine disrupting compounds (EDCs) used in plastics and personal care products, are ubiquitous environmental contaminants resulting in widespread human exposure. Epidemiologic data implicate paternal phthalates with adverse reproductive health including poor sperm quality, and more recently, with longer time to pregnancy − the latter suggests a sperm-derived effect. A growing body of compelling data demonstrates that environmental exposures can be embodied within the developing male germ cell through epigenetic marks, which in turn, can impart information at fertilization to affect the trajectory of health and development of offspring. It is known that prenatal epigenetic reprogramming of male germ cells is a particularly susceptible window to environmental exposures such as phthalates. Research has now emerged demonstrating that other such susceptible windows exist during germ cell development. Our long- term goal is to provide an epigenetic understanding of how paternal EDC exposure affects reproductive and offspring health – in both embryonic and placental tissue. The objective here is to determine the effects of adult exposure to di(2-ethylhexyl) phthalate (DEHP) on sperm DNA methylation and the persistence of these sperm-derived changes on DNA methylation programming of the conceptus. Our central hypothesis is that adult DEHP exposure confers DNA methylation changes in sperm that persist in F1 conceptus. Adult reproductive age (7-8 wks old) male PWD mice will be treated with 0, 2.5 and 250 mg/kg body weight/day of DEHP for 60 days. Epididymal sperm will be collected and will be analyzed for whole genome bisulfite sequencing. Using parental strains that will allow for allele specific analysis across the genome, we will perform RNA-seq and whole genome bisulfite sequencing in embryonic and extraembryonic (placenta) tissues of E6.5 embryos. The research proposed in the above aims is expected to identify a DNA methylation signature in sperm as well as in the developing conceptus as a consequence of DEHP exposure in adult male mice. Such results are the first step to significantly advance our understanding of the mechanisms by which paternal environmental exposures in adulthood affect reproductive health, successful development and offspring health.