The MMP system in human ovulation: localization, regulation, and function

描述(申请人提供)：在许多物种的卵泡破裂之前，排卵前促黄体生成素激增刺激卵巢基质金属蛋白酶(MMPs)及其相关抑制物TIMPs(统称为MMPs系统)的增加。基质金属蛋白酶系统在排卵中的重要作用来自许多实验，在这些实验中，卵母细胞的释放被基质金属蛋白酶抑制剂阻断。然而，除了我们的初步数据外，还没有关于人类排卵过程中MMPs和TIMP的进展和时间模式的已知信息。这个问题将在第一个具体目标中通过使用一个独特的模型来解决，在该模型中，将在hCG之前和之后的三个指定时间(早期、晚期和排卵后)收集人排卵周围卵泡的颗粒、膜和基质。与人类卵泡破裂相关的基质金属蛋白酶和组织基质金属蛋白酶家族的关键成员的表达模式将被阐明。具体目标#2将建立在这些观察结果的基础上，并利用啮齿动物和人类中具有良好特征的模型，探索已知的促黄体生成素刺激的信号通路对这些MMPs和TIMPs的调节。然而，一个关键的问题仍然是MMPs和TIMP在卵泡破裂过程中到底起着什么作用？我们认为，卵巢基质金属蛋白酶系统引导排卵所必需的蛋白分解或“降解性”改变。因此，特殊目的#3将通过蛋白质组学分析阐明基质金属蛋白酶作用的特定蛋白质靶点，使我们能够表征基质金属蛋白酶和金属基质金属蛋白酶在排卵过程中的功能。这一建议的一个主要优势是我们在基质金属蛋白酶系统方面的广泛专业知识，这使得我们能够通过一种综合的方法来了解基质金属蛋白酶系统在卵泡破裂中的细胞表达、调节和影响。这项研究的一个新的方面是使用特征良好的人排卵前卵泡作为基础来探索基质金属蛋白酶系统在人类排卵过程中的作用，这是从未完成的。因此，建议的研究非常及时地阐明这一精致的蛋白分解系统在卵泡破裂和卵母细胞释放的协调过程中所起的作用，这是正常人类卵巢生理的关键方面。与公共卫生相关：拟议的研究将调查人类排卵的潜在机制，排卵是卵子从卵巢中的卵泡释放出来的过程。这些研究将集中在一类蛋白水解酶上，我们认为这种酶可以破坏卵泡的壁，使卵子得以释放。只有充分了解卵巢功能的这些基本原理，我们才能促进或抑制排卵过程中与金属蛋白酶作用相关的事件，从而促进和提高生育力或采取避孕措施降低生育率。

DESCRIPTION (provided by applicant): The preovulatory LH surge stimulates an increase in ovarian matrix metalloproteinases (MMPs) and their associated inhibitors, the TIMPs, (collectively referred to as the MMP system) prior to follicular rupture in many species. The paramount role of the MMP system in ovulation is forthcoming from numerous experiments where oocyte release is blocked by MMP inhibitors. Yet other than our preliminary data, nothing is known as to progression and temporal patterns of the MMPs and TIMPs involved in the ovulatory process in the human. This question will be addressed in the first Specific Aim by using a unique model where the granulosa, theca, and stroma from human periovulatory follicles will be collected prior to and at three designated times after hCG (early, late and postovulatory). The expression patterns of key members of the MMP and TIMP family associated with follicular rupture in the human will be illuminated. Specific Aim #2 will build upon these observational findings and explore the regulation of these MMPs and TIMPs by known LH stimulated signaling pathways using well characterized models in the rodent and human. However, one of the key questions remains as to what are the MMPs and TIMPs actually doing during the process of follicular rupture? We propose that the ovarian MMP system directs the requisite proteolytic or "degradomic" changes necessary for ovulation. Thus, Specific Aim #3 will elucidate specific protein targets of MMP action by proteomic profiling allowing us to characterize the function of the MMPs and TIMPs in the ovulatory process. A major strength of this proposal is our extensive expertise with the MMP system that allows an integrated approach to understand the cellular expression, regulation, and impact of the MMP system on follicular rupture. One novel aspect of this study is the use of well characterized human preovulatory follicles as a foundation to explore the role of the MMP system in the process of human ovulation, which has never been accomplished. As such the proposed studies are extremely timely to elucidate the role that this exquisite proteolytic system plays in the coordinated processes of follicular rupture and oocyte release which are key aspects of normal human ovarian physiology. PUBLIC HEALTH RELEVANCE: The proposed studies will investigate the underlying mechanism involved in human ovulation, which is a process where the egg is released from the follicle in the ovary. These studies will focus on a family of proteolytic enzymes, known as metalloproteinases, that we believe breakdown the wall of the ovarian follicle to allow the egg to be released. Only by fully understanding such basic tenets of ovarian function will we be able to promote or inhibit the events associated with metalloproteinase action during the ovulatory process thereby facilitating and increasing fertility or acting in a contraceptive manner to decrease fertility.