Membrane and intracellular progesterone receptors as determinants of the

项目概述（见说明）：在资助的第一阶段。项目1侧重于解决孕激素受体在介导孕激素细胞保护作用中的作用（P4）。在特定的。项目1通过提出最近描述的膜相关孕酮受体可能同样重要，挑战了经典孕酮受体（PR）是P4在大脑中保护作用的主要介质的教条。主要发现包括观察到经典PR和膜相关孕酮受体，特别是Pgrmcl，确实合作调节关键的细胞保护介质，包括ERK/MAPK通路的效应物（如ERK1/2和ERK5）和BDNF。在这个项目的继续中，我们建议应用这些知识来了解1)在类固醇激素剥夺后，P4对神经保护和细胞保护关键介质的作用是否有一个有限的时期（即治疗窗口），或者随着年龄的增长，P4对神经保护和细胞保护关键介质的作用是否得以维持，以及2)PR和Pgrmcl的相对丰度是否预测P4的持续保护作用。此外，我们将确定黄体酮受体表达的特定模式是否预测P4是否补充或拮抗雌激素的保护作用。我们的假设表明，经典PR和膜孕酮受体Pgrmcl的联合表达是维持大脑对P4的反应所必需的。此外，我们提出这两种受体的相对丰度也可以预测P4是补充雌激素的保护程序还是拮抗雌激素的作用。这些假设将在细胞模型中进行测试，其中PR和Pgrmcl的相对水平可以被操纵（药理学或使用分子工具），以及在类固醇剥夺的动物模型（卵巢切除术）中进行测试，并最终转化为卵巢切除术的人类模型（即手术绝经）。虽然雌激素的有益作用随着卵巢切除术后持续时间的增加而丧失，但对于P4的反应却一无所知。因此，本文提出的研究将通过定义哪些孕激素受体是P4保护作用的关键决定因素来揭示“治疗窗口”之谜的关键部分，重要的是，可能为如何扩大治疗窗口（即通过调节特定的孕激素受体）提供独特的见解。与项目2和项目3中提出的研究一起，我们希望这个研究项目能够促进我们对雌激素和黄体酮治疗机会“关键窗口”的神经生物学基础的理解，这是项目1无法单独实现的目标。

PROJECT SUMMARY (See instructions): During the first period of funding. Project 1 focused on addressing the role of progesterone receptors in mediating the cytoprotective effects of progesterone (P4). In particular. Project 1 challenged the dogma that classical progesterone receptors (PR) are the principal mediators of P4's protective effects in the brain by suggesting that recently described membrane-associated progesterone receptors may be equally important. Major findings included the observation that indeed both the classical PR and membrane-associated progesterone receptors, particularly Pgrmcl, cooperate to regulate key cytoprotective mediators, including effectors of the ERK/MAPK pathway (such as ERK1/2 and ERK5) and BDNF. In the continuation of this project, we propose to apply this knowledge to understand whether 1) there is a finite period (i.e., therapeutic window) following steroid hormone deprivation, or with age, where P4's effects on neuroprotection and key mediators of cytoprotection are maintained, and 2) if the relative abundance of PR and Pgrmcl predict sustained protective effects of P4. Further, we will determine whether specific patterns of progesterone receptor expression predict whether P4 complements or antagonizes estrogen's protective effects. Our hypothesis states that the combined expression of the classical PR and the membrane progesterone receptor, Pgrmcl, is required to maintain responsiveness of the brain to P4. Further, we propose that the relative abundance of these two receptors will also predict whether P4 complements estrogen's protective program or whether it antagonizes estrogen's effects. These hypotheses will be tested in cellular models, where the relative levels of PR and Pgrmcl can be manipulated (pharmacologically or using molecular tools), as well as in an animal model of steroid deprivation (ovariectomy), and finally, translated to a human model of ovariectomy (i.e., the surgical menopause). While the loss of estrogen's beneficial effects with increasing post-ovariectomy duration has been described, nothing is known with respect to the response to P4. Thus, the studies proposed herein will reveal a key piece of the "therapeutic window" puzzle by defining which progesterone receptors are critical determinants of P4's protective effects and importantly, may offer unique insight into how the therapeutic window may be expanded (i.e., through regulation of specific progesterone receptors). Together with the studies proposed in Projects 2 and 3, we expect this program of research to advance our understanding of the neurobiological basis of the "critical window" of therapeutic opportunity for estrogen and progesterone, a goal that could not be achieved by Project 1 alone.