Cellular and Molecular Mechanisms of Mammalian Ovulation

哺乳动物排卵的细胞和分子机制

• 批准号: 6549355
• 负责人: Ok-Kyong Park-Sarge
• 金额: $ 10万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-01 至 2004-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6549355
• 关键词: SDS polyacrylamide gel electrophoresis; apoptosis; biological signal transduction; cell cycle; egg /ovum; endopeptidases; fluorescence microscopy; gene expression; gene targeting; genetically modified animals; graafian follicles; granulosa cell; laboratory mouse; laboratory rat; ligands; luteinizing hormone; neuropeptides; ovulation; progesterone; progesterone receptors; receptor expression; terminal nick end labeling; tissue /cell culture; western blottings

DESCRIPTION (provided by applicant): The long-term goal of our research is to elucidate the molecular cascades of LH-induced signals within preovulatory follicles, leading to ovulation. The LH surge stimulates the synthesis of progesterone and its intracellular receptors, progesterone receptors (PRs), in the granulosa cells of preovulatory follicles. Interaction between progesterone and PRs in an autocrine/paracrine fashion is essential for ovulation. However, the exact mechanisms by which ligand-dependent activation of PRs controls ovulation and thus normal reproductive cyclicity and fecundity are unknown. To gain insight into the molecular mechanisms underlying PR-mediated ovarian functions, we initiated cloning of PR downstream genes in luteinizing granulosa cells. The two genes we have characterized as PR-downstream are the ligand-receptor system for pituitary adenylate cyclase activating polypeptide (PACAP): PACAP and its receptor type 1 (PAC1). The temporal and spatial pattern of expression and secretion of the ligand PACAP along with the cellular localization of the receptor PAC1 in the ovary advocates the potential significance of this ligand-receptor system for ovulatory processes. Indeed, pharmacological blockade of ligand-dependent activation of PAC1 appears to interfere with the efficacy of LH and progesterone in bringing about ovulatory processes. Thus, our working hypothesis is that PACAP-induced activation of PAC1 mediates, at least in part, PR function critical for follicular rupture with release of a meiotically mature oocyte. The immediate goal of this application is to determine the functional importance of PACAP within preovulatory follicles during the periovulatory period, using in vivo and in vitro approaches. In Aim 1, we will test whether PR-induced PACAP is critical for follicular rupture and for expression of ovulation-related genes, including proteolytic enzymes. In addition, we will identify PAC1-downstream genes that may play an important role in follicular rupture. In Aim 2, we will determine the initial death/survival pathway(s) that is modulated by PR-induced PACAP in luteinizing granulosa cells. In Aim 3, we will test whether PR-induced PACAP regulates the polyadenylation/translation capacity of meiotically maturing oocytes. The proposed studies are designed to provide functional endpoint(s) of interaction between PR-induced PACAP and PAC1 in preovulatory follicles during the periovulatory period. Information derived from our results will allow us to better manage fertility, infertility, and endocrine-based disorders.

描述(申请人提供)：我们研究的长期目标是阐明促黄体生成素诱导的信号在排卵前卵泡内的分子级联，从而导致排卵。黄体生成素高峰刺激排卵前卵泡颗粒细胞孕酮及其细胞内受体的合成。孕酮和孕激素以自分泌/旁分泌的方式相互作用是排卵所必需的。然而，依赖配体的PR激活控制排卵从而控制正常生殖周期和繁殖力的确切机制尚不清楚。 为了深入了解PR介导的卵巢功能的分子机制，我们开始克隆黄体化颗粒细胞中的PR下游基因。我们鉴定为PR下游的两个基因是垂体腺苷环化酶激活多肽(PACAP)的配体-受体系统：PACAP及其1型受体(PAC1)。配体PACAP的表达和分泌的时空模式以及PAC1受体在卵巢中的细胞定位表明这种配体-受体系统在排卵过程中具有潜在的意义。事实上，药物阻断PAC1的配体依赖激活似乎干扰了黄体生成素和黄体酮在导致排卵过程中的功效。因此，我们的工作假设是，PACAP诱导的PAC1的激活至少在一定程度上介导了PR功能，该功能对于卵泡破裂至关重要，伴随着减数分裂成熟卵母细胞的释放。 这项应用的直接目标是通过体内和体外方法，确定PACAP在排卵前卵泡中的功能重要性。在目标1中，我们将测试PR诱导的PACAP是否对卵泡破裂和排卵相关基因的表达至关重要，包括蛋白水解酶。此外，我们还将发现可能在卵泡破裂中起重要作用的PAC1下游基因。在目标2中，我们将确定PR诱导的PACAP在黄体形成颗粒细胞中调控的初始死亡/生存途径(S)。在目标3中，我们将测试PR诱导的PACAP是否调节减数分裂成熟卵母细胞的多聚腺苷/翻译能力。本研究旨在为围排卵期排卵前卵泡中PR诱导的PACAP和PAC1的相互作用提供功能终点(S)。从我们的结果中获得的信息将使我们能够更好地管理生育、不孕和基于内分泌的疾病。