ESTROGENIC REGULATION OF GENE EXPRESSION DURING NEURONAL

最近，在初级感觉神经元中发现了雌激素受体（ER）， 的大鼠背根神经节（DRG）的神经元，这表明，特定的 这些神经元的特性受性腺类固醇的调节 荷尔蒙初步研究结果表明，几个主要的细胞骨架 蛋白质mRNAs以及神经营养因子受体mRNAs是 DRG神经元的雌激素调节。这表明雌激素和ER 可能在调节神经突起生长特性中起重要作用， DRG神经元。该项目的长期目标是确定 受雌激素影响的感觉神经元的分子程序， 了解性腺类固醇如何影响生长和再生 这些神经元。本提案的具体目的是测试 三个假设。第一个假设是，ER表达在 DRG由循环的性腺类固醇激素调节。原位 杂交，RNA印迹;免疫细胞化学将用于评估 雌激素治疗对ER分布和水平的影响， 其编码mRNA在卵巢切除雌性大鼠背根神经节， 确定DRG中ER/ER mRNA表达是否存在性别差异。 逆转录-聚合酶链反应（RT-PCR）将用于 评估ER mRNA的选择性剪接作为激素状态的函数 和性别。第二个假设是，雌激素调节 特定的细胞骨架和神经营养因子受体基因可以调节 DRG神经元的轴突切断反应。原位杂交，RNA酶保护 试验和RNA印迹方法将用于研究 雌激素对稳定状态的mRNA水平的编码特异性 细胞骨架蛋白（β II、β III和α 1-微管蛋白、外周蛋白和 tau）和编码神经营养因子受体（p75，trkA，trkB）的那些在正常 以及再生背根神经节神经元。 第三个假设是， 雌激素影响DRG神经元的再生特性。我们将 确定雌激素是否会改变最快的再生速度， 生长的DRG轴突或生长特性的更缓慢再生 卵巢切除雌性大鼠坐骨神经轴突在 周围神经挤压使用快速轴突运输范例。性别 这些研究将评估再生参数的差异。 这项建议的健康相关性在于潜在的识别 神经元损伤的性别差异， 将获得关于雌激素的潜在治疗作用， 神经元损伤

Recently, estrogen receptors (ER) have been discovered in primary sensory neurons of the rat dorsal root ganglion (DRG), suggesting that specific properties of these neurons are subject to regulation by gonadal steroid hormones. Preliminary findings indicate that several major cytoskeletal protein mRNAs as well as neurotrophin receptor mRNAs are targets of estrogenic regulation in DRG neurons. This suggests that estrogen and ER may have an important role in regulating the neurite growth properties of DRG neurons. The long-term objectives of this project are to define the molecular programs affected by estrogen in sensory neurons and to understand how gonadal steroids influence the growth and regeneration of these neurons. The specific aims of this proposal are to test the following 3 hypotheses. The first hypothesis is that ER expression in the DRG is regulated by circulating gonadal steroid hormones. In situ hybridization, RNA blotting; immunocytochemistry will be used to evaluate the effects of estrogen treatment on the distribution and levels of ER and its encoding mRNA in the DRG of ovariectomized female rats, and to determine if sex differences in ER/ER mRNA expression in the DRG exist. Reverse transcription-polymerase chain reaction (RT-PCR) will be used to evaluate alternative splicing of ER mRNA as a function of hormone state and gender. The second hypothesis is that estrogenic regulation of specific cytoskeletal and neurotrophin receptor genes can modulate the axotomy response of DRG neurons. In situ hybridization, RNase protection assays and RNA blotting methods will be used to study the effects of estrogen on the steady-state levels of mRNAs encoding specific cytoskeletal proteins (BetaII, BetaIII and alpha1-tubulin, peripherin and tau) and those encoding neurotrophin receptors (p75, trkA, trkB) in normal as well as in regenerating DRG neurons. The third hypothesis is that estrogen influences the regenerative properties of DRG neurons. We will determine if estrogen alters the regeneration rate of either the fastest growing DRG axons or the growth properties of the more slowly regenerating axons in the sciatic nerve of ovariectomized female rats after a peripheral nerve crush using the fast axonal transport paradigm. Gender differences in regeneration parameters will be assessed in those studies. The health-relatedness of this proposal is in the potential identification of gender differences in neuronal injury and in the new information that will be gained concerning the potentially therapeutic role of estrogen in neuronal injury.