Prostaglandin Receptors in Primate Ovulatory Follicles

描述（由申请人提供）：排卵是成功繁殖的关键。促黄体生成素激增刺激围排卵卵泡产生前列腺素E2（PGE 2），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。PGE 2产生的阻断导致排卵失败，支持研究PGE 2作为不孕症的治疗以及抑制PGE 2合成/作用作为潜在的避孕药。为了阐明PGE 2刺激围排卵期事件的机制，本研究提出了四种PGE 2（EP）受体中的每一种在排卵中具有独特功能的总体假设。首先，我们将确定哪些EP受体表达的功能不同亚群的颗粒细胞内围排卵卵泡。使用激光捕获显微切割以及免疫荧光EP检测猴卵巢组织切片，我们将确定EP受体（S）存在于卵丘，基底壁，窦壁颗粒细胞以及位于卵泡顶端的颗粒细胞。这些亚群在排卵中发挥独特的作用，我们预计每个亚群表达所有EP受体的独特子集。其次，我们将证明，每个EP受体介导的一个子集的所有PGE 2刺激排卵前的过程。已知PGE 2刺激颗粒细胞孕酮产生、卵丘扩张和卵泡破裂。颗粒细胞培养以及猕猴卵泡内注射将被用来证明，激动剂的每一个EP受体刺激一些，但不是全部，这些必不可少的PGE 2介导的颗粒细胞功能。最后，我们将确定哪些EP受体可以抑制灵长类动物排卵前卵泡颗粒细胞中的PGE 2信号。将用对四种EP受体中的每一种具有特异性的激动剂处理颗粒细胞，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受体将可能以独特的细胞内反应对激动剂刺激作出反应。拟议的研究可能会证明，每个EP受体介导的特定子集的总排卵前的反应，前列腺素E2在灵长类卵泡。这些数据将有助于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，并可能最终导致不孕症的新治疗方法和新的避孕选择的发展。

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.