AGE-REALTED CHANGES IN GONADOTROPIN GLYCOSYLATION AND FUNCTION

我们的长期目标是确定促性腺激素如何发挥作用。促性腺激素需要N-糖链来 完全激活它们的同源受体，即使高亲和力结合只涉及蛋白质-蛋白质 互动。促性腺激素被用来治疗不孕症，但随着患者的增加，效果越来越差。 年龄。尿液和重组hFSH制剂缺乏一种新的、高活性的糖形式，即二糖基化的hFSH， 它只有一个亚基N-糖链，主要存在于年轻女性的脑下垂体中。这个 二糖基化和四糖基化hFSH的相对丰度似乎受到生理调节。 这项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糖体丰度的周期性和增龄性变化。 首先，我们将测量年轻健康骑自行车女性的尿促卵泡刺激素糖体丰度。我们的工作 假说是卵巢反馈会改变FSH糖体丰度。第二，我们将评估 围绝经期的糖类丰度，因为糖类丰度转变的时间是 未知。一种假说是FSH糖体丰度在 围绝经期，从而导致生育率下降。另一种假设是 糖类丰度在绝经过渡期突然变化。最后，我们将检查糖型 绝经后妇女的丰度，并比较接受雌激素替代治疗的个体 而那些没有收到任何东西的人。我们的工作假设是雌激素选择性地抑制hFSHFI糖基化。2. 确定a和/？亚基糖基化模式调节FSH受体结合和 促性腺激素刺激类固醇激素的生成。我们将比较两个化合物的受体结合活性和类固醇生成活性。 四糖基化hFSH。我们的假设是二糖化hFSH的开启速度比 四糖基化hFSH。将比较FSHR结合和类固醇生成活性的关系。我们的 工作假说是，二糖基化的hFSH将表现出比其预测的更大的生物活性 显著提高了受体结合活性。 该项目以蛋白质印迹法容易识别的糖类为中心，并奠定了基础。 用于未来的研究，有助于开发快速表征FSH糖基化的方法。一个 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.