Exploring the Role of the Prokineticin System in Human Reproduction

描述（由申请人提供）： 下丘脑内独特的神经网络启动并维持人类的生殖功能。它通过协调来自该神经网络的单个神经内分泌十肽促性腺激素释放激素（GnRH）的合成和脉冲式分泌来完成这一任务。在过去的二十年里，通过研究GnRH缺乏症的人类，发现了几个控制GnRH个体发育的基因和途径。几种G蛋白偶联受体（GPCR）及其同源配体与人类生殖的神经内分泌控制有关。然而，关于这些新基因和途径的知识仍处于早期阶段，需要进一步研究。我的研究项目的总体目标是探索th prokineticin系统在控制人类生殖发育和功能的神经网络中的作用。前动力蛋白信号系统，前动力蛋白2（PROK 2）和PROK 2受体（PROKR 2），最近已经成为小鼠和人类生殖神经内分泌控制的关键调节因子。PROK 2和PROKR 2在中枢神经系统中高度表达，并在嗅球神经发生和随后的GnRH神经元迁移中发挥重要作用。前动力蛋白2也作为一个关键的昼夜输出分子从视交叉上核和调节摄食行为的动物。虽然人类和小鼠的研究已经证实并牢固确立了prokineticin途径在哺乳动物生殖中的关键作用，但这种生物学的几个特征仍然令人困惑，这表明人类中这种途径的系统生物学更复杂。本提案的目的是阐明GnRH缺乏症的遗传结构，并研究PROKR 2突变影响受体功能的分子机制。我的第一个目的是确定PROKR 2杂合突变在孤立性低促性腺激素性性腺功能减退症（IHH）中的作用，检验以下假设：GnRH缺乏症患者PROKR 2杂合突变不足以单独引起低促性腺激素性性腺功能减退症表型，但可以导致与第二次遗传“命中”相关的表型。我的第二个目的是阐明保守氨基酸突变干扰PROKR 2功能的机制，以识别这些氨基酸和该受体结构域的功能，并鉴定与细胞内运输（伴侣）相关的蛋白质， GPCR的降解途径。总之，这些研究将推进我们对GnRH缺乏症的病因学和前动力素系统在这一过程中的作用的理解，并将提供对PROKR 2的结构-活性关系的见解，对GPCR生物学具有潜在的影响。这项工作将扩大我的研究培训，包括分子方法来理解导致疾病的机制和翻译方法，将我的发现与生殖发育和功能障碍患者的表型联系起来。 公共卫生相关性： 该项目的目的是了解编码G蛋白偶联受体的PROKR 2突变导致生殖发育障碍的机制。我们将确定与这种疾病相关的新基因，并确定PROKR 2的结构-功能关系。成功完成拟议的研究将促进我们对GnRH缺乏症遗传学的理解，并可能导致开发新的诊断和治疗策略来治疗这些人类疾病。

DESCRIPTION (provided by applicant): A unique neural network within the hypothalamus initiates and maintains reproductive function in humans. It accomplishes this task by coordinating the synthesis and pulsatile secretion of a single neuroendocrine decapeptide, gonadotropin-releasing hormone (GnRH), from this neural network. In the last two decades, several genes and pathways that govern GnRH ontogeny have been discovered by studying humans with GnRH deficiency. Several G protein-coupled receptors (GPCRs) and their cognate ligands have been implicated in the neuroendocrine control of human reproduction. However, the knowledge about many of these new genes and pathways are still in the early stages and require further investigation. The overall goal of my research project is to explore the role of th prokineticin system in the neural network that controls human reproductive development and function. The prokineticin signaling system, prokineticin 2 (PROK2) and PROK2 receptor (PROKR2), has recently emerged as a critical regulator of the neuroendocrine control of reproduction in both mice and humans. PROK2 and PROKR2 are highly expressed in the central nervous system and play an important role in olfactory bulb neurogenesis and subsequently in GnRH neuronal migration. Prokineticin 2 also acts as a key circadian output molecule from the suprachiasmatic nucleus and regulates ingestive behavior in animals. Although both human and mouse studies have confirmed and firmly established a key role of the prokineticin pathway in mammalian reproduction, several features of this biology remain puzzling, suggesting a more complex systems biology of this pathway in humans. The objective of this proposal is to clarify the genetic architecture of GnRH deficiency and to investigate the molecular mechanisms through which PROKR2 mutations affect receptor function. My first aim is to define the role of the PROKR2 heterozygous mutations in isolated hypogonadotropic hypogonadism (IHH), testing the hypothesis that heterozygous mutations in PROKR2 in patients with GnRH deficiency are not sufficient to cause the hypogonadotropic hypogonadism phenotype in isolation, but can contribute to the phenotype in association with a second genetic "hit". My second aim is to elucidate mechanisms by which mutations in conserved amino acids interfere with PROKR2 function to recognize the functions of these amino acids and domains of this receptor and also to identify proteins connected to intracellular trafficking (chaperones) and degradation pathways of GPCRs. Together, these studies will advance our understanding of the etiology of GnRH deficiency and the role of prokineticin system in this process, and will provide insights into the structure-activity relationships of the PROKR2, with potential implications for GPCR biology in general. This work will expand my research training to encompass both a molecular approach to understanding the mechanisms that cause disease and a translational approach in relating my findings to the phenotypes of patients with disorders of reproductive development and function. PUBLIC HEALTH RELEVANCE: The aim of this project is to understand the mechanisms by which mutations in PROKR2, which encodes a G protein-coupled receptor, contribute to disorders of reproductive development. We will identify new genes linked with this disorder and determine structure-function relationships of PROKR2. The successful completion of the proposed studies will advance our understanding of the genetics of GnRH deficiency and may lead to the development of new diagnostic and therapeutic strategies to treat these human disorders.