Actions of Estrogen & Environmental Estrogens on Neurons

描述(申请人提供)：拟议研究的广泛长期目标是了解17β-雌二醇(雌激素；E2)和雌激素受体(ER)在发育中的神经系统中的功能，并确定环境雌激素对这些功能的影响程度。雌二醇会影响男性和女性大脑多个区域的发育和功能。因此，其他雌激素化合物可能会影响大脑的发育。环境雌激素，也被称为“内分泌干扰物”，是一组不同的化合物，可以模仿或拮抗E2的正常作用。环境雌激素对发育中的神经系统的影响程度尚不清楚。拟议的实验采用原代培养的新生大鼠小脑神经元和发育中的小脑作为模型，将解决以下特定目的-特定目标1：确定E2是否通过对MAPK信号转导的快速、非基因组作用来调节发育中的小脑神经元的细胞信号；特定目标2：确定其在小脑神经元中的表达受E2调控的雌激素反应基因网络；特定目标3：确定具有代表性的环境雌激素在多大程度上模仿或抑制E2对发育中的小脑神经元的影响。特定的AIMS 1和2验证了这一假设，即E2通过快速调节MAPK信号的活性以及通过基因组ER介导的机制共同调节离散的基因产物网络的表达，从而在发育中的神经元中正常发挥作用。具体目标3将测试这一假设，即环境雌激素通过改变MAPK信号和基因组ER介导的机制来影响发育中的神经元，从而导致表达基因网络的改变。所有这三个特定的目标都将通过使用激活状态特异性抗血清来确定E2介导的信号通路的实验以及通过基因芯片和RT-PCR分析E2反应基因的表达来实现。根据这些结果，将开发一个神经元“E2签名基因阵列”，并将其用于目标3，以确定环境雌激素如何影响这些发育中的神经元中E2反应基因的表达。

DESCRIPTION (provided by applicant): The broad long-term goal of the proposed research is to understand the functions of 17beta-estradiol (estrogen; E2) and estrogen receptors (ERs) in the developing nervous system and to determine to what extent environmental estrogens influence these functions. E2 influences the development and function of many regions of the brain in both males and females. Thus, it is possible that other estrogenic compounds can impact development of the brain. Environmental estrogens, also known as "endocrine disrupters," are a diverse group of compounds that can mimic or antagonize the normal actions of E2. The extent to which environmental estrogens impact the developing nervous system is unclear. Proposed experiments employing primary cultures of neonatal rat cerebellar neurons and the developing cerebellum as models will address the following Specific Aims-Specific Aim 1: Determine whether E2 modulates cellular signaling in developing cerebellar neurons through rapid, non-genomic actions on MAPK signal transduction; Specific Aim 2: Determine the networks of estrogen responsive genes whose expression is modulated by E2 in cerebellar neurons; Specific Aim 3: Determine to what degree representative environmental estrogens mimic or inhibit the effects of E2 in developing cerebellar neurons. Specific Aims 1 & 2 test the hypothesis that E2 normally functions in developing neurons by rapidly modulating the activity of MAPK signaling, and also through genomic ER-mediated mechanisms which together, modify expression of discrete networks of gene products. Specific Aim 3 will test the hypothesis that environmental estrogens influence developing neurons by modifying both MAPK signaling and genomic ER-mediated mechanisms, which results in altered networks of expressed genes. All three Specific Aims will be addressed through experiments using activation-state specific antisera to determine E2-mediated signaling pathways and by cDNA array and RT -PCR analysis of E2-responsive gene expression. From these results a neuronal "E2-signature cDNA array" will be developed and used in Aim 3 to determine how environmental estrogens influence E2-responsive gene expression in these developing neurons.