The Role Of CCL20 In Ovulation: A Novel Mediator Of Ovarian Leukocyte Recruitment

描述（由申请人提供）：排卵前黄体生成素激增引发一系列事件，最终导致卵巢卵泡壁破裂，卵子释放，这一过程被称为排卵。排卵涉及一个炎症过程，其特征是大量白细胞涌入卵巢。白细胞的流入对生育至关重要，因为在实验模型中去除白细胞会阻碍卵母细胞的释放。然而，白细胞向卵巢募集的潜在因素尚不清楚。本提案将研究一个新发现的候选，趋化因子配体20 （CCL20）。我们的初步数据表明，CCL20 mRNA在人类卵泡颗粒细胞和卵泡膜细胞的排卵期早期和晚期被大量诱导。然而，除了我们的初步数据外，对CCL20及其受体CCR6在卵巢中的时间表达模式、调节或功能一无所知。目前的建议建立在这些具有挑战性的发现之上，并将测试LH激增刺激CCL20增加的总体假设，并且这种趋化因子的增加导致白细胞的募集，从而影响排卵所需的事件。这一假设将通过一个独特的模型来解决，该模型将在hCG诱导排卵之前和之后的三个指定时间收集人类排卵期卵泡的颗粒和卵泡，以诱导排卵（早、晚和排卵后）。这些人类样本将与大鼠卵巢中CCL20和CCR6的变化进行比较和对比，并使用具有良好特征的啮齿动物排卵模型。这将通过以下三个目标来实现。目的1将确定CCL20和CCR6系统在人和大鼠卵巢中的表达变化。本研究还将确定黄体生成素诱导的主要排卵途径如何调节CCL20和CCR6的表达。目的2将利用具有良好特征的迁移和侵袭模型，探讨CCL20在白细胞募集到卵巢中的作用。由于CCL20在调节细胞分化方面的潜在作用，Aim 3将研究CCL20对卵巢细胞功能的作用，特别是颗粒细胞存活、分化和产生甾体激素的能力。此外，将使用微阵列技术评估CCL20对卵巢细胞的影响。本研究的主要优势在于利用人类排卵前卵泡作为基础，了解细胞表达、调节和CCL20对人类排卵相关事件的影响，并通过跨物种的综合比较方法阐明该趋化因子在排卵过程中的作用。目前对CCL20及其在卵巢中的受体一无所知。因此，提出的研究非常及时地阐明了该趋化因子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基本方面。

DESCRIPTION (provided by applicant): The preovulatory LH surge sets in motion a chain of events that culminate in breakdown of the ovarian follicle wall and release of the egg in a process known as ovulation. Ovulation involves an inflammatory process that is characterized by a massive influx of white blood cells, known as leukocytes, to the ovary. This influx of leukocytes is critical for fertility as removal of leukocytes in experimental models blocks oocyte release. However, the factor(s) underlying the recruitment of leukocytes to the ovary are unknown. The present proposal will examine a newly identified candidate, chemokine ligand 20 (CCL20). Our preliminary data shows that mRNA for CCL20 is massively induced in the human during the early and late preovulatory stage in the granulosa and theca cells from the ovarian follicle. Yet other than our preliminary data, nothing is known as to temporal patterns of expression, the regulation, or function of CCL20 and its receptor CCR6 in the ovary. The present proposal builds on these provocative findings and will test the overall hypothesis that the LH surge stimulates an increase in CCL20 and the increase in this chemokine results in recruitment of leukocytes that impact events necessary for ovulation. This hypothesis will be addressed using a unique model where the granulosa and theca from human periovulatory follicles will be collected prior to and at three designated times after hCG to induce ovulation (early, late and postovulatory). These human samples will be compared and contrasted to changes in CCL20 and CCR6 in the rat ovary using a well characterized rodent model for ovulation. This will be accomplished by the following three Aims. Aim 1 will determine the changes in the expression of the CCL20 and CCR6 system in both the human and rat ovary. This Aim will also determine how CCL20 and CCR6 expression is regulated via the major ovulatory pathways induced by LH. Aim 2 will explore the role of CCL20 in leukocyte recruitment into the ovary using well-characterized migration and invasion models. Due to the potential role of CCL20 to regulate cellular differentiation, Aim 3 will investigate the role of CCL20 on ovarian cell function, specifically the ability of granulosa cells to survive, differentiate, and make sterid hormones. Additionally, the impact of CCL20 on ovarian cells will be assessed using microarray technology. The major strengths of the current proposal lie in the use of well characterized human preovulatory follicles as a foundation to understand the cellular expression, regulation, and the impact of CCL20 on the events associated with ovulation in the human and, our integrated comparative approach across species to elucidate the role that this chemokine plays in the ovulatory process. Nothing is known about CCL20 and its receptor in the ovary. As such, the proposed studies are extremely timely to elucidate the role that this chemokine system plays in the coordinated processes of follicular rupture and oocyte release which are fundamental 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 protein, chemokine ligand 20 (CCL20), that we believe serves to attract white blood cells into the ovary to help 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 the ovulatory process thereby facilitating and increasing fertility or acting in a contraceptive manner to decrease fertility.