The Aging Pituitary/Gonadal Axis

项目摘要/摘要 更年期过渡的开始缺乏合适的诊断标志，但伴随着 严重发病率包括生殖周期不规律、功能失调性子宫出血、泌尿生殖系统 改变、生育能力受损、骨量下降、血管舒缩症状和心理障碍。这个 该项目的长期目标是了解卵泡刺激素(FSH)的作用。 糖基化突变体hFSH21和hFSH24在衰老中的作用。年轻女性拥有更多的低糖 HFSH21高于完全糖基化的hFSH24，而老年女性拥有的hFSH21较少。因为两种糖型都是 在尿液中发现，它们都进入血液循环，影响性腺和非性腺靶点。在上一次 资助期间我们确定hFSH21在结合FSHR、激活FSHR方面比hFSH24更活跃 性腺靶细胞在体外，并在体内刺激卵巢。相比之下，hFSH24的活性要比 HFSH21在激活破骨细胞分化中的作用因此，我们的总体假设是，面对日益衰老的 卵巢，从hFSH21到hFSH24的额外切换进一步损害了生育能力，并可能有助于 骨质流失。每个项目都将通过以下具体目标来检验这一假设的各个方面：1. 确定部分糖基化hFSH导致FSHR显著升高的机制(S) 有约束力的。我们的工作假设是hFSH21和小分子结合改变了FSHR的构象， 使两种糖体都有更多的FSH结合部位，从而提高生物活性。一场激动人心的 元素是合作的超分辨率显微镜研究，将监测FSHR齐聚 直接去吧。2.明确传统性腺中FSH糖型激活的不同信号通路 靶细胞和骨骼中的靶细胞都是非传统的靶细胞。在这一目标下，项目2将比较FSH糖形式 激活小鼠或人类颗粒细胞或细胞系，以及破骨细胞前体。我们的工作 假设hFSH21在性腺靶细胞中比hFSH24更活跃，而在性腺靶细胞中则相反 非性腺靶细胞。因此，与年龄相关的糖型比率的变化具有重要的生理意义。 后果。3.利用遗传模型研究FSH糖体在卵巢衰老和增龄中的作用 相关的骨质流失。在这一目标下，FSH低糖基化糖形式将由项目3评估其 挽救FSHB基因缺失雌性小鼠免于不孕的能力及其对骨丢失的影响。我们的工作假说 与年龄相关的从FSH21到FSH24的转变对卵巢功能有有害影响，但促进 破骨细胞激活。这些项目将得到两个科学核心的支持。核心B将提供关键的 将FSH糖类制剂用于所有项目。核心C将协助分析质谱学数据，提供 下一代测序(NGS)和分析NGS数据。总而言之，这些项目将提供新的 卵泡刺激素糖体在生殖衰老中的作用可用于诊断发病的知识 更年期转变的证据，以及支持或驳斥FSH在骨丢失中有争议的作用的证据。

Project Summary/Abstract The beginning of the menopausal transition lacks suitable diagnostic markers, yet is attended by significant morbidity including irregular reproductive cycles, dysfunctional uterine bleeding, urogenital changes, impaired fertility, declining bone mass, vasomotor symptoms, and psychological impairment. The long-term objective of this project is to understand the role of follicle-stimulating hormone (FSH) glycosylation variants hFSH21 and hFSH24 in aging. Young women possess more hypo-glycosylated hFSH21 than fully-glycosylated hFSH24, while older women possess less hFSH21. As both glycoforms are found in urine, both enter the circulation where they affect gonadal and non-gonadal targets. In the previous funding period we determined that hFSH21 is much more active than hFSH24 in binding FSHR, activating gonadal target cells in vitro, and stimulating the ovary in vivo. In contrast, hFSH24 is much more active than hFSH21 in activating osteoclast differentiation. Thus, our overall hypothesis is, in the face of a senescing ovary, the additional switch from hFSH21 to hFSH24 further compromises fertility and may contribute to bone loss. Each project will test various aspects of this hypothesis via the following specific aims: 1. Determine the mechanism(s) by which partial glycosylation of hFSH leads to significantly increased FSHR binding. Our working hypothesis is that hFSH21 and small molecule binding alter FSHR conformation, making more FSH binding sites available to both glycoforms, thus increasing bioactivity. An exciting element is collaborative super-resolution microscopy studies that will monitor FSHR oligomerization directly. 2. Define the different signaling pathways activated by FSH glycoforms in traditional gonadal targets as well as in bone, a nontraditional target cell. Under this aim, Project 2 will compare FSH glycoform activation of murine or human granulosa cells or cell lines, and osteoclast precursors. Our working hypothesis is that hFSH21 is more active than hFSH24 in gonadal target cells, while the reverse is true for non-gonadal target cells. The age-related shift in glycoform ratio thus has important physiological consequences. 3. Use genetic models to study the role of FSH glycoforms in the aging ovary and age- related bone loss. Under this aim, FSH hypo-glycosylatedglycoforms will be evaluated by Project 3 for their ability to rescue Fshb null female mice from infertility and their effects on bone loss. Our working hypothesis is the age-related shift from FSH21 to FSH24 has deleterious effects on ovarian function, yet promotes osteoclast activation. These projects will be supported by two scientific cores. Core B will provide critical FSH glycoform preparations to all projects. Core C will assist in analyzing mass spectrometry data, provide next generation sequencing (NGS) and analyze NGS data. Together, the projects will provide new knowledge about the role of FSH glycoforms in reproductive aging that can be used to diagnose the onset of the menopausal transition, and evidence to support or refute the controversial role of FSH in bone loss.