NO AND ESTRADIOL SUSTAINED NEURONAL DIFFERENTIATION

描述：（由申请人提供）本提案的长期目标 是研究胎儿神经元发育的分子机制， 雌激素雌二醇作用下的神经元分化 （E2）。研究人员假设E2诱导的nNOS是一种重要的 E2介导的维持神经元分化的分子介质 NGF-戒断PCl2细胞。这一假设将在以下条件下进行检验： 具体目标：确定E2维持 PCl2细胞的神经元分化和神经突生长， 最初从大鼠嗜铬细胞瘤，通过确定是否E2诱导的NO 是持续差异化计划所必需的;并确定 nNOS启动子中的顺式作用反应元件，转录因子 反式激活nNOS基因和信号传导途径 所需的雌激素介导的诱导nNOS基因的表达。这些 实验将指导未来的研究，这对理解E2- 介导的胎儿神经元发育和神经元分化， 有助于深入了解神经退行性疾病的治疗方法。 为了实现这些目标，研究设计和方法将包括 PC12细胞系被广泛用作研究NGF的模型系统， 介导的神经元分化。E2介导的分子机制， 参与维持PCl2细胞分化后，神经生长因子撤回 不知道。用一氧化氮（NO）抑制剂阻断NO的产生 NOS，N（ω）-硝基-L-精氨酸甲酯（L-NAME），但不包括D-NAME， 抑制神经突延伸，暗示nNOS参与分化过程。 E2与NGF一样，显著诱导神经细胞nNOS活性和mRNA水平 抗雌激素药物作为纯化的nNOS的强抑制剂，表明 E2可以通过NO-2受体维持神经元的分化和轴突的生长。 中介过程。根据这些观察，研究人员假设 E_2诱导的nNOS是E_2介导细胞凋亡的重要分子介质， 神经元分化的维持在NGF撤除PCl 2细胞中。

DESCRIPTION: (provided by applicant) The long-term objective of this proposal is to study the molecular mechanism(s) of fetal neuronal development and neuronal differentiation under the effects of the female hormone, estradiol (E2). The investigators hypothesize that E2 induced nNOS is an important molecular mediator of E2 mediated sustenance of neuronal differentiation in NGF-withdrawal PCl2 cells. This hypothesis will be tested under the following specific aims: to determine the molecular mechanism by which E2 sustains neuronal differentiation and neurite outgrowth of PCl2 cells, derived originally from a rat pheochromocytoma, by determining whether E2-induced NO is required for the continued differentiation program; and to identify the cis-acting response elements in the nNOS promoter, the transcription factors that transactivate the nNOS gene, and the signaling transduction pathways required for estrogen-mediated induction of nNOS gene expression. These experiments will direct future studies critical to the understanding of E2- mediated fetal neuronal development and neuronal differentiation, that will lend insights into the approach to neurodegenerative diseases. In order to achieve these goals, the research design and methods will include the PC12 cell line, which is widely used as a model system to study NGF- mediated neuronal differentiation. The E2 mediated molecular mechanisms which participate in sustaining PCl2 cell differentiation following NGF-withdrawn are not known. Blocking production of Nitric Oxide (NO) with an inhibitor of NOS, N (omega)-nitro-L-arginine methyl ester (L-NAME), but not D-NAME, inhibits neurite extension, implicating nNOS in the differentiation process. E2, like NGF, markedly induces nNOS activity and mRNA levels in neuronal cells and anti-estrogen drugs act as strong inhibitors of purified nNOS, suggesting that E2 may sustain neuronal differentiation and neurite growth via an NO- mediated process. Based on these observations, the investigators hypothesize that E2 induced nNOS is an important molecular mediator of E2 mediated sustenance of neuronal differentiation in NGFwithdrawal PCl2 cells.