In Vitro Analysis of the Effects of Acute and Chronic Phthalate Exposures on Leydig Cell Testosterone Production, and the Molecular Mechanisms Involved

项目摘要 通过干扰激素的功能和作用，内分泌干扰化学品（EDCs），如增塑剂， 邻苯二甲酸二（2-乙基己基）酯（DEHP）可能对发育和生殖产生负面影响。与支撑 当他还是伊丽莎白城州立大学的一名教员时， 博士Traore发现，妊娠期间体内接触DEHP对睾酮（T）有负面影响。 早期暴露加剧了随后暴露的影响。现在在 迪克讷大学医学院的Traore博士建议对这两种药物进行体外机制研究 DEHP对Leydig细胞产生T的急性和慢性影响。直到最近，Leydig细胞分离和培养 通过现有的方法已经能够生产并维持高水平的T生产仅3-5天。 因此，在体外使用原代细胞来检查细胞因子的直接、长期作用还不可行。 环境相关的内分泌干扰物浓度或严格评估其作用机制 睾丸间质细胞然而，Zirkin博士在约翰霍普金斯彭博公共卫生学院（JHSPH）的实验室已经 最近开发了一种方法，通过该方法，来自Leydig干细胞分化的Leydig细胞能够 生产和维持高水平的T生产更长的时间，几个月。Zirkin博士曾在 SC2奖的导师职位，继续与Traore博士和他的学生合作。的 能够维持高水平T产生的初级Leydig细胞的可用性将具有重要价值， 我们提出的研究环境相关的邻苯二甲酸酯浓度的慢性影响， 高度受控的条件，以及它们发挥作用的机制。有了这些 细胞，我们将在体外研究MEHP对干细胞形成Leydig细胞的直接影响， MEHP暴露对成年Leydig细胞的影响，以及早期暴露对 后续曝光。我们还将对邻苯二甲酸酯的急性和长期影响进行机制研究- 诱导氧化应激对T产生的影响。迪克讷大学拥有必要的设备和设施， 拟议的研究，以及优秀的医学生，研究生和本科生谁将 参与这个研究项目。有了这笔REAP赠款的资金，Traore博士将能够支持和扩大 他在迪克讷大学的实验室里正在进行的研究， 宾夕法尼亚约翰霍普金斯公共卫生学院和迪克讷之间的广泛合作 大学将不仅有助于激发迪克讷大学的学生，但也增加了他们的兴趣，考虑 从事基础科学或临床研究。此外，该项目无疑将吸引其他迪克讷 大学教师寻求资金来发展他们的研究。

Project Summary By interfering with hormone function and action, endocrine-disrupting chemicals (EDCs) such as the plasticizer di-(2-ethylhexyl) phthalate (DEHP) can have negative effects on development and reproduction. With the support of a Research Enhancement (SC2) Award, when he was a faculty member at Elizabeth City State University, Dr. Traore found that in vivo exposure to DEHP during gestation had negative effects on testosterone (T) production in the adult, and that early exposure exacerbated the effects of subsequent exposures. Now at Duquesne University School of Medicine, Dr. Traore is proposing to conduct in vitro mechanistic studies of both acute and chronic DEHP effects on T production by Leydig cells. Until recently, Leydig cells isolated and cultured by available methods have been able to produce and maintain high levels of T production for only 3-5 days. Therefore, it has not yet been feasible to use primary cells in vitro to examine the direct, long-term effects of environmentally relevant concentrations of EDCs or to critically evaluate mechanisms involved in their actions on Leydig cells. However, Dr. Zirkin’s lab at the Johns Hopkins Bloomberg School of Public Health (JHSPH) has recently developed a method by which Leydig cells derived from the differentiation of Leydig stem cells are able to produce and sustain high levels of T production for longer periods, several months. Dr. Zirkin, who served in a mentorship position for the SC2 Award, is continuing to collaborate with Dr. Traore and his students. The availability of primary Leydig cells able to sustain high levels of T production will be of great value for our proposed studies of the chronic effects of environmentally relevant phthalate concentrations under highly controlled conditions, and the mechanisms by which they function. With the availability of these cells, we will conduct in vitro studies of the direct effects of MEHP on Leydig cell formation from stem cells, the effects of MEHP exposure on the adult Leydig cells, and the effects of early exposures on the consequences of subsequent exposures. We also will conduct mechanistic studies of acute and long-term effects of phthalate- induced oxidative stress on T production. Duquesne University has the equipment and facilities necessary for the proposed studies, as well as outstanding medical students, graduate students and undergraduates who will be involved in this research project. With funds of this REAP grant, Dr. Traore will be able to support and expand ongoing research in his lab at Duquesne University, an institution located in an underserved area of Pennsylvania. The extensive collaboration between the Johns Hopkins School of Public Health and Duquesne University will not only help excite Duquesne University students but also increase their interest in considering careers in basic science or clinical research. Moreover, the project undoubtedly will attract other Duquesne University faculty to seek funding to develop their research.