AGE-REALTED CHANGES IN GONADOTROPIN GLYCOSYLATION AND FUNCTION

我们的长期目标是确定促性腺激素的功能。促性腺激素需要N-聚糖 即使高亲和力结合仅涉及蛋白质-蛋白质， 交互.促性腺激素用于治疗不孕症，但随着患者年龄的增长， 年龄尿和重组hFSH制剂缺乏新的、高活性的糖型，即二糖基化hFSH， 其仅具有亚基N-聚糖并且在年轻女性的垂体中占主导地位。的 二糖基化和四糖基化hFSH的相对丰度似乎是生理学调节的。 本提案将定义这些变化，并研究可能的机制，以解释活动的差异， 2具体目标1.表征hFSH糖型丰度的周期性和年龄相关变化。 首先，我们将测量年轻健康的骑自行车女性的尿FSH糖型丰度。我们的工作 假设卵巢反馈会改变FSH糖型丰度。第二，我们将评估 在围月经期的糖型丰度，因为糖型丰度的转变的时间是 未知一种假设是FSH糖型丰度在妊娠期间逐渐变化， 因此，这导致了生育率的下降。另一种假设是， 糖型丰度在绝经过渡期突然变化。最后，我们将检查糖型 在绝经后妇女中的丰度，并与接受雌激素替代疗法的个体进行比较 那些没有得到任何东西的人。我们的工作假设是雌激素选择性抑制hFSHf 1糖基化。2. 确定a和/？调节FSH受体结合的亚基糖基化模式， FSH刺激的类固醇生成。我们将比较受体结合和类固醇的活动，二， 和四糖基化hFSH。我们的假设是，双糖基化hFSH的作用速度比 四糖基化hFSH。将比较FSHR结合和类固醇生成活性的关系。我们 工作假设是二糖基化hFSH将表现出比其预测更大的生物活性， 更高的受体结合活性。 这个项目是围绕糖型容易识别的蛋白质印迹和奠定了基础 为将来的研究，通过促进方法的发展，快速表征FSH糖基化。一 围绝经期标志物和更有效的治疗不孕症的制剂具有潜在的实用价值 这个项目的成果。

Our long-term goal is to determine how gonadotropins function. Gonadotropins require N-glycans to fully activate their cognate receptors even though high affinity binding involves only protein-protein interactions. Gonadotropins are used to treat infertility, but become progressively less effective as patients age. Urinary and recombinant hFSH preparations lack a novel, highly active glycoform, di-glycosylated hFSH, that possesses only a subunit N-glycans and which predominates in pituitaries of young women. The relative abundance of di-glycosylated and tetra-glycosylated hFSH appear to be physiologically regulated. This proposal will define these changes and study possible mechanisms to explain differences in activity via 2 specific aims. 1. Characterize cyclic- and age-related changes in hFSH glycoform abundance. First, we will measure urinary FSH glycoform abundance in young healthy cycling women. Our working hypothesis is that ovarian feedback will alter FSH glycoform abundance. Second, we will evaluate glycoform abundance during the perimenopausal period, as the timing of the shift in glycoform abundance is unknown. One hypothesis is that FSH glycoform abundance changes gradually during the perimenopausal period, thereby contributing to declining fertility. An alternative hypothesis is that glycoform abundance changes abruptly at the menopausal transition. Finally, we will examine glycoform abundance in post-menopausal women and compare individuals receiving estrogen replacement therapy with those receiving none. Our working hypothesis is estrogen selectively inhibits hFSHfi glycosylation. 2. Identify a and /? subunit glycosylation patterns modulating FSH receptor-binding and FSH-stimulated steroidogenesis. We will compare receptor-binding and steroidogenic activities of di- and tetra-glycosylated hFSH. Our hypothesis is that di-glycosylated hFSH on rate is faster than tetra-glycosylated hFSH. The relationship of FSHR binding and steroidogenic activity will be compared. Our working hypothesis is that di-glycosylated hFSH will exhibit greater biological activity than predicted by its significatly higher receptor-binding activity. This project is centered around glycoforms readily identified by western blotting and lays the ground for future studies by contributing to the development of methods to rapidly characterize FSH glycosylation. A perimenopausal marker and more effective preparations for treating infertility are potential practical outcomes of this project.