Prostaglandin Receptors in Primate Ovulatory Follicles

描述(申请人提供)：排卵是成功繁殖的关键。排卵中黄体生成素的激增刺激排卵周围的卵泡产生前列腺素E2(PGE2)，这是卵丘颗粒细胞扩张、卵泡破裂和卵母细胞释放所必需的。阻断PGE2的产生导致排卵失败，支持研究PGE2作为不孕症的治疗方法，以及抑制PGE2的合成/作用作为潜在的避孕药。为了揭示PGE2刺激排卵周围事件的机制，该建议提出了一个总体假设，即四种PGE2(EP)受体在排卵中都具有独特的功能。首先，我们将确定哪些EP受体是由排卵周围卵泡内功能不同的颗粒细胞亚群表达的。利用激光捕获显微切割技术和免疫荧光EP检测技术，在猴卵巢组织切片上鉴定卵丘、基底壁、胃窦壁颗粒细胞以及位于卵泡顶端的颗粒细胞中存在的EP受体(S)。这些亚群每个都在排卵中扮演着独特的角色，我们预计每个亚群都表达所有EP受体的一个独特亚集。其次，我们将证明每个EP受体介导PGE2刺激的排卵前过程的一个子集。已知PGE2可刺激颗粒细胞孕酮的产生、卵丘扩张和卵泡破裂。颗粒细胞培养和猕猴卵泡内注射将被用来证明针对每个EP受体的激动剂刺激了PGE2介导的颗粒细胞功能中的一部分，但不是全部。最后，我们将确定哪些EP受体可以在灵长类排卵前卵泡的颗粒细胞中转导PGE2信号。颗粒细胞将用四种EP受体的特异性激动剂处理，并将评估通过这些G蛋白偶联受体产生的细胞内信号。每个EP受体可能会通过独特的细胞内反应对激动剂刺激做出反应。拟议的研究可能会证明，每个EP受体在灵长类卵泡内介导对PGE2的排卵前反应的一个特定子集。这些数据将促进有针对性的药理学方法，选择性地刺激或抑制排卵过程的基本特征，并最终可能导致开发新的不孕症治疗方法和新的避孕选择。

DESCRIPTION (provided by applicant): Ovulation is essential for successful reproduction. The ovulatory luteinizing hormone surge stimulates perieovulatory follicles to produce prostaglandin E2 (PGE2), which is required for expansion of the cumulus granulosa cells, follicle rupture, and oocyte release. Blockade of PGE2 production causes ovulation failure, supporting investigation of PGE2 as a treatment for infertility as well as inhibition of PGE2 synthesis/action as a potential contraceptive. To unravel the mechanism by which PGE2 stimulates perieovulatory events, this proposal puts forth the overall hypothesis that each of the four PGE2 (EP) receptors has a unique function in ovulation. First, we will determine which EP receptors are expressed by functionally-distinct subpopulations of granulosa cells within perieovulatory follicles. Using laser capture microdissection as well as immunofluorescent EP detection in monkey ovarian tissue sections, we will identify the EP receptor(s) present in cumulus, basal mural, and antral mural granulosa cells as well as granulosa cells located at the follicle apex. These subpopulations each play a unique role in ovulation, and we anticipate that each subpopulation expresses a unique subset of all EP receptors. Second, we will demonstrate that each EP receptor mediates a subset of all PGE2-stimulated preovulatory processes. PGE2 is known to stimulate granulosa cell progesterone production, cumulus expansion, and follicle rupture. Granulosa cell cultures as well as intrafollicular injection in macaques will be utilized to demonstrate that agonists specific for each EP receptor stimulate some, but not all, of these essential PGE2-mediated granulosa cell functions. Finally, we will determine which EP receptors can transduce the PGE2 signal in granulosa cells of primate preovulatory follicles. Granulosa cells will be treated with agonists specific for each of the four EP receptors, and intracellular signals generated via these G protein coupled receptors will be assessed. Each EP receptor will likely respond to agonist stimulation with a unique intracellular response. The proposed studies will likely demonstrate that each EP receptor mediates a specific subset of the total preovulatory response to PGE2 within the primate follicle. These data will facilitate a targeted pharmacological approach to selectively stimulate or inhibit essential features of the ovulatory process and may ultimately lead to the development of new treatments for infertility and novel contraceptive options.