Per- and poly-fluoroalkyl substances (PFAS) in pregnancy vascular and placental dysfunction

摘要 妊娠诱导的血管适应、充足的胎盘血管化和最佳的营养素流量 通过胎盘到达胎儿对支持胎儿生长至关重要。其中一个或多个中断 胎儿生长受限（FGR）。FGR影响高达15%的所有新生儿，没有治疗方法是 available. FGR的原因尚不清楚，但环境暴露于全氟烷基和多氟烷基 PFAS及其在胎盘中的生物积累可能是了解 疾病的起源和母体器官功能障碍的根本原因。全氟辛烷磺酸 全氟辛烷磺酸（PFOS）是一种传统的全氟辛烷磺酸，是生产最多、研究最充分的全氟辛烷磺酸。母体全氟辛烷磺酸浓度升高， 与人类母体血管功能障碍和FGR相关。全氟辛烷磺酸的增加是否直接 参与内皮功能障碍和FGR的表现是未知的。我们的初步研究表明， 孕鼠体内的全氟辛烷磺酸会增加母体血压，削弱内皮功能， 胎盘大小、VEGF表达和营养转运。基于这些发现，我们假设， 全氟辛烷磺酸水平升高会损害母体心血管功能并减少胎盘血管化和血流量 导致FGR的营养素。我们将在3个目标中采用体内动物研究、离体动物研究和体外动物研究来研究这一前提。 组织水平的功能分析和体外分子分析。目标1将首先确定 全氟辛烷磺酸对全身血压和子宫动脉血流的影响，并确定全氟辛烷磺酸介导的 发信号。为了测试PFOS介导的血管机制，将研究EDHF、NO和PGI 2舒张途径。 测定此外，eNOS的表达及其活性状态--EDHF和PGI 2的信号成分， 途径以及硝酸盐/亚硝酸盐和PGI 2的生产和膜电位的变化将被测量。 然后，转化研究将测试全氟辛烷磺酸是否会影响内皮细胞的途径和机制， 通过检查离体网膜和胎盘血管的影响，对孕妇进行了研究。目标2将检查 胎盘血管效应我们将确定PFOS浓度升高是否会降低植物的生长、直径和长度， 螺旋动脉、中央动脉管、胎儿胎盘动脉分支和脐动脉。我们还将 测量胎盘中促血管生成因子和抗血管生成因子的表达， 破坏从孕妇分离的内皮细胞中的信号传导机制。目的3将检查胎盘 养分运输效应。我们将确定全氟辛烷磺酸浓度升高是否会降低葡萄糖、氨基酸和脂肪酸 通过胎盘运输到胎儿，并测量胎盘中营养转运蛋白的表达。 然后，通过检查全氟辛烷磺酸对孕妇的影响，确定全氟辛烷磺酸是否会干扰孕妇的营养转运。 滋养层这些成果预计将产生重要影响，因为它们将有助于 对全氟辛烷磺酸在妊娠并发症中的作用有实质性的了解， 环境机构制定政策，减少育龄妇女接触全氟辛烷磺酸。

ABSTRACT Pregnancy-induced vascular adaptations, adequate placental vascularization, and optimal flux of nutrients across the placenta to the fetus are critical to support fetal growth. Disruption in one or more of these processes leads to fetal growth restriction (FGR). FGR affects up to 15% of all newborns, and no treatment is available. The cause of FGR is not known, but the environmental exposure to per- and poly-fluoroalkyl substances (PFAS) and its bioaccumulation in the placenta may hold important keys to understanding the origins of the disease and the underlying causes of maternal organ dysfunction. Perfluorooctane sulfonate (PFOS), a legacy PFAS, is the most produced and well studied PFAS. Elevated maternal PFOS is shown to be associated with maternal vascular dysfunction and FGR in humans. Whether this increase in PFOS is directly involved in endothelial dysfunction and manifestations of FGR is unknown. Our pilot studies show that elevated PFOS in pregnant rats increases maternal blood pressure, blunts endothelial function, and decreases in placental size, VEGF expression, and nutrient transport. Based on these findings, we hypothesize that elevated PFOS levels impair maternal cardiovascular function and reduce placental vascularization and flux of nutrients to lead to FGR. We will examine this premise in 3 aims employing in vivo animal studies, ex vivo tissue-level functional analysis and in vitro molecular analyses. Aim 1 will first establish the functional effects of elevated PFOS on systemic blood pressure and uterine artery blood flow and define the PFOS-mediated signaling. To test the PFOS-mediated vascular mechanisms, EDHF, NO, and PGI2 relaxation pathways will be determined. Also, the expression of eNOS and its activity state—signaling components of EDHF and PGI2 pathways as well as nitrate/nitrite and PGI2 production and changes in membrane potential—will be measured. Then translational studies will test whether PFOS affects the endothelial pathways and mechanisms in pregnant women by examining the effects in isolated omental and placental vessels. Aim 2 will examine placental vascular effects. We will determine if elevated PFOS decreases growth, diameter, and length of spiral arteries, central arterial canals, fetoplacental arterial branches, and umbilical arteries. We will also measure the expression of pro- and anti-angiogenic factors in the placenta, and then determine if PFOS disrupts signaling mechanisms in endothelial cells isolated from pregnant women. Aim 3 will examine placental nutrient transport effects. We will determine if elevated PFOS decreases glucose, amino acid, and fatty acid transport across the placenta to the fetus and measure the expression of nutrient transporters in the placenta. Then, determine if PFOS disrupts nutrient transport in pregnant women by examining the effects in primary trophoblasts. These results are expected to have an important impact because they will contribute substantively to a mechanism-based understanding of PFOS's role in pregnancy complications and alert environmental agencies to devise policies to curtail PFOS exposure to reproductive-age women.