Project 2: Toxicant Activation of Pathways of Preterm Birth in Gestational Tissue

摘要 早产既昂贵又危险，而且很普遍。在波多黎各，早产率是 美国境内的任何司法管辖区，在全球范围内仅低于马拉维。流行病学研究与环境 与早产有关的化学物质暴露。尽管胎盘和胎盘外膜在 怀孕，环境污染物通过采取行动导致早产的可能性 组织几乎没有被探索过。通过对胎盘和胎盘外组织毒性作用的研究， 我们将确定毒理学解释之间的流行病学联系，选择 环境污染和早产。与保护团队密切合作，我们将继续 超级基金站点常见的两种环境污染物邻苯二甲酸二乙基己酯的研究 (DEHP)和三氯乙烯(TCE)。尽管目前流行的早产模型侧重于激活 胎盘和胎盘外膜中导致前列腺素产生的促炎途径 这最终会刺激分娩，最近的报告表明，由于增加了 其中，活性氧(ROS)起着重要作用。这个项目建立在我们令人兴奋和新奇的发现之上 DEHP和TCE的生物活性代谢物刺激氧化应激、炎症介质和细胞死亡 人类胎盘细胞--在人类和动物中与早产和低出生体重相关的行为 模特们。此外，与一种产生细胞内ROS的模型促氧化剂合作，我们已经确定了一个关键 细胞信号通路在这些反应中起重要作用。在怀孕的大鼠身上，三氯乙烯的作用与 体外观察三氯乙烯代谢物的反应。 我们提出的实验的一个重要目标是测量氧化应激和炎症反应。 孕鼠暴露于DEHP和TCE中的生物标志物及其与出生不良的关系 结果使用组织学评估胎盘病理，并使用免疫分析、mRNA分析和IHC 评估胎盘、母血和羊水。此外，我们还将定义ROS敏感机制 这将DEHP和TCE与与早产相关的下游事件联系在一起 各种体外模型，包括人胎盘细胞系、原代人胎盘滋养层细胞、原代 胎盘巨噬细胞和体外培养的人胎盘外膜对DEHP的影响 和三氯乙烯代谢物。在这个项目的一个新目标中，我们将定义感染的毒物-微生物相互作用 体外培养的人胎盘外膜。该项目将提供关于以下机制的新数据 环境毒物增加了妇女早产的风险。作为该协作中心的一部分，我们的 该项目将与接触科学和流行病学研究双向互动。

SUMMARY Preterm birth is expensive, dangerous and prevalent. In Puerto Rico, the preterm birth rate is the highest of any jurisdiction in the U.S. and below only Malawi globally. Epidemiologic studies associate environmental chemical exposures with preterm birth. Although the placenta and extraplacental membranes play vital roles in pregnancy, the potential for environmental contaminants to contribute to preterm birth through actions on these tissues has hardly been explored. Through studies of toxicant actions on placental and extraplacental tissues, we will identify toxicologic explanations for epidemiologic associations between exposure to select environmental contaminants and preterm birth. Working closely with the PROTECT team, we will continue study of two environmental contaminants that are common to Superfund sites, di-2-ethylhexyl phthalate (DEHP) and trichloroethylene (TCE). Although current popular models of preterm birth focus on activation of pro-inflammatory pathways in placenta and extraplacental membranes leading to production of prostaglandins that ultimately stimulate labor, recent reports suggest that oxidative stress due to increased generation of reactive oxygen species (ROS) plays an important role. This project builds on our exciting and novel findings that bioactive metabolites of DEHP and TCE stimulate oxidative stress, inflammatory mediators, and cell death in human placental cells - actions associated with preterm birth and low birth weight in humans and in animal models. Moreover, working with a model pro-oxidant that generates intracellular ROS, we have identified a key cell signaling pathway important in these responses. In pregnant rats, TCE exerted effects consistent with the responses observed in vitro with a TCE metabolite. An important objective of our proposed experiments is to measure oxidative stress and inflammatory response biomarkers in pregnant rats exposed to DEHP and TCE, and associate these biomarkers with adverse birth outcomes using histology to assess placental pathology, and using immunoassay, mRNA analysis, and IHC to assess placenta, maternal blood, and amniotic fluid. In addition, we will define the ROS-sensitive mechanisms that link DEHP and TCE to downstream events associated with preterm birth in experiments conducted with various in vitro models, including a human placental cell line, primary human placental trophoblasts, primary placental macrophages, and transwell cultures of human extraplacental membranes exposed in vitro to DEHP and TCE metabolites. In an aim new to this project, we will define toxicant-microbial interactions for infection of human extraplacental membranes in vitro. This project will provide novel data on mechanisms by which environmental toxicants increase women's risk for preterm birth. As part of this collaborative Center, our project will interact bidirectionally with exposure science and epidemiology studies.