Ligand Pharmacology of Estrogen Receptors

描述（由申请人提供）：该项目的长期目标是阐明非基因组雌激素信号传导的分子机制，并创造新的配体，可以选择性地激活或阻断非基因组雌激素信号传导。雌激素基因组信号包括核雌激素受体（ERoc和ERP）的激活以及随后雌激素靶基因的转录调控。另一方面，雌激素的非基因组信号导致离子通道、酶和第二信使信号级联的快速激活。雌激素的许多非基因组效应发生在中脑，可能与绝经后妇女面临的热调节和情绪不稳定问题有关。这些反应对转录/翻译抑制剂的快速动力学和不敏感排除了核内质网参与经典基因组机制的作用；然而，非基因组信号的新细胞机制尚不清楚。本研究计划是围绕雌激素的一种新的膜相关G蛋白偶联受体（GPCR）介导至少一些非基因组激素信号传导的假设构建的。支持这一假设的证据是，雌激素反应性GPCR快速介导下丘脑神经元中特定钾通道的抑制。此外，这种生理上相关的雌激素反应也由一种新的选择性雌激素受体调节剂（SERM）引起，该调节剂对ERa或ERp都没有结合亲和力。在特定目标1中，一个孤儿GPCR被确定为雌激素的候选受体，并开发了表达该GPCR的稳定细胞系。在具体目标2和3中，开发并开展了配体结合和配体激活试验，以建立和表征GPCR的雌激素反应性。有了这些工具，新的serm将被开发出来，激活（特异性靶4）或阻断雌激素应答性GPCR的激活（特异性靶5）。本研究旨在确定快速、非基因组雌激素信号的分子机制和乌干达激活参数，这可能导致急需的安全治疗更年期症状的方法。

DESCRIPTION (provided by applicant): The long-term objectives of this project are to elucidate the molecular mechanism of non-genomic estrogen signaling and create novel ligands that can either activate or block non-genomic signaling selectively over genomic estrogen signaling. Estrogen genomic signaling involves activation of the nuclear estrogen receptors (ERoc and ERP) and subsequent transcriptional regulation of estrogen target genes. On the other hand, nongenomic signaling by estrogen results in rapid activation of ion channels, enzymes, and second messenger signaling cascades. Many of these non-genomic effects of estrogen occur in the mid-brain and may be linked to the problems of thermal regulation and mood instability that post-menopausal women face. The rapid kinetics and insensitivity of these responses to transcription/translation inhibitors rules out the involvement of the nuclear ERs acting by the classical genomic mechanism; however, the novel cellular mechanism of nongenomic signaling is unclear. This research plan is constructed around the hypothesis that a novel membrane associated G protein-coupled receptor (GPCR) for estrogen mediates at least some of the non-genomic hormone signaling. Support for this hypothesis comes from evidence that an estrogen-responsive GPCR rapidly mediates the inhibition of a specific potassium channel in hypothalamic neurons. Moreover, this physiologically relevant estrogen response is also elicited by a novel selective estrogen receptor modulator (SERM) that has no binding affinity for either ERa or ERp. In specific aim 1, an orphan GPCR is identified as a candidate receptor for estrogen and a stable cell line expressing this GPCR is developed. In specific aims 2 and 3, ligand binding and ligand activation assays are developed and carried out to establish and characterize the estrogen responsiveness of the GPCR. With these tools in place, novel SERMs will be developed that either activate (specific aim 4) or block activation (specific aim 5) of the estrogen-responsive GPCR. This research aims to define the molecular mechanisms and Uganda-activation parameters of rapid, non-genomic estrogen signaling which could lead to much needed safe therapeutics for treating the symptoms of menopause.