Effects of Phthalates on Trophoblast Differentiation: From Biology to Biomarkers

描述（由申请人提供）：申请人寻求资助，以扩展她在流行病学两个新方向的培训，即人类胎盘生物学和质谱学。学习这些以实验室为基础的方法将使她更接近于实现她的长期目标，即成为一名独立的学术研究者，并为研究低剂量慢性暴露于内分泌干扰化合物及其在妊娠早期引起的健康障碍中的作用提供新的见解和方法。在K99阶段，在Susan Fisher博士的主要指导下，候选人将接受滋养细胞（Tb）干细胞生物学的培训，最先进的基于微阵列的方法用于分析全球水平的基因表达，包括用于数据分析的生物信息学方法。基于她最初的博士后研究结果，这位候选人提出了Tbs（一种执行胎盘许多最重要功能的特化细胞）在怀孕早期暴露于邻苯二甲酸盐中，对胎盘发育和功能产生不利影响的理论。研究人员将测试关于临床结果和生物学参数的假设，包括人类胎盘发育和功能的分子、细胞和形态学测量。具体来说，他们将进行实验来验证这样一种假设，即当培养的人类结核干细胞暴露于环境相关剂量的邻苯二甲酸二（2-乙基己基）和邻苯二甲酸二正丁酯时，它们的基因表达模式将显示出剂量依赖性的变化（目标1）。在R00阶段，候选人将在一项对孕妇的纵向研究中验证这一理论，即由于在体外暴露于邻苯二甲酸盐而差异表达的胎盘基因在体内也以剂量依赖的方式受到类似的调节（目的2）。作为这一目标的一部分，候选人将评估传统的产前暴露剂量计、尿邻苯二甲酸盐代谢物浓度和靶胎盘组织剂量之间的相关性。产科/妇科、质谱学、生物统计学和流行病学的主要导师和共同导师将指导候选人学习完成本提案中设定的目标所需的方法。在这个培训项目结束时，候选人将开发出新的方法和工具，她和其他研究者可以使用这些方法和工具来提出更直接的问题，关于怀孕期间接触邻苯二甲酸盐对胎盘功能改变的影响，从而影响人类发育。这项工作很重要，因为邻苯二甲酸盐可以破坏细胞和组织分化，是啮齿动物生殖和发育的毒物；然而，这些发现与人类的相关性还没有得到很好的理解。有了针对邻苯二甲酸盐引起的胎盘损伤的特异性生物标志物，将有可能识别高危妊娠，并在人群层面提供预防机会，并可能在卫生保健系统层面进行干预，以改善胎盘和胎儿的结局。

DESCRIPTION (provided by applicant): The candidate seeks funding to extend her training in epidemiology in two new directions, namely, human placental biology and mass spectrometry. Learning these laboratory-based methods will move her closer to accomplishing her long-term goals of becoming an independent academic investigator and offering new insights and methods to research on low dose chronic exposures to endocrine disrupting compounds and their role in health disorders that originate in early pregnancy. During the K99 phase, under the primary mentorship of Dr. Susan Fisher, the candidate will receive training in trophoblast (Tb) stem cell biology, state-of-the-art microarray-based methodologies that are used to analyze gene expression at a global level, including bioinformatics approaches for data analysis. Building on the results of her initial postdoctoral research, the candidate theorize that Tbs, the specialized cells that carry out many of the placenta's most important functions, are exposed to phthalates early in pregnancy with adverse consequences on placental development and function. The investigators will test hypotheses regarding clinical outcomes and biological parameters that include molecular, cellular, and morphologic measures of human placental development and function. Specifically, they will conduct experiments to test the hypothesis that cultured human Tb stem cells will show dose-dependent changes in patterns of gene expression when they are exposed to environmentally relevant doses of di-(2-ethylhexyl) phthalate and di-n-butyl phthalate (Aim 1). During the R00 phase, the candidate will test the theory, in a longitudinal study of pregnant women, that placental genes that are differentially expressed as a consequence of phthalate exposure in vitro are similarly regulated, in a dose-dependent manner, in vivo (Aim 2). As part of this aim, the candidate will evaluate the correlation between the conventional dosimeter of prenatal exposure, urinary phthalate metabolite concentrations, and the dose to the target placental tissue. The primary mentor and co-mentors in obstetrics/gynecology, mass spectrometry, biostatistics, and epidemiology will guide the process whereby the candidate learn the methods that are required to accomplish the goals set forth in this proposal. At the conclusion of this training program the candidate will have developed new methodologies and tools that she and other investigators can use to ask more directed questions about the consequences of phthalate exposures during pregnancy in terms of alterations in placental function and consequently, human development. This work is important because phthalates, which can disrupt cell and tissue differentiation, are well established as reproductive and developmental toxicants in rodents; yet the relevance of these finding to humans is not well understood. With biomarkers specific to phthalate-induced placental damage, it will become possible to identify high-risk pregnancies and provide opportunities for prevention, at the population level, and possibly intervention at the level of health care delivery systems to improve placental and fetal outcomes. Public Health Relevance: The goal of this project is to prepare Dr. Jennifer Adibi to transition to a position as an independent academic investigator in environmental health sciences focusing on the consequences of phthalate exposures during human pregnancy. She will conduct experiments using in vitro and in vivo models to test the hypothesis that this toxicant disrupts trophoblast differentiation, and therefore placental development and function, thereby compromising human development in-utero.