PROCESSING OF HCG IN NORMAL AND ABNORMAL PREGNANCIES

我们实验室的初步研究与 在高糖基化之间(额外的触角和岩藻糖残基 N-连接的寡糖)和hCG的划痕或裂解。其他 初步研究表明，结构的不稳定性和减少量 高糖化和含镍hCG分子的生物活性， 以及它们如何可能是循环中游离β-亚基的来源 和尿样中的Beta-core片段。大量的论文都有 已发表的报告显示hCG水平提高，免费比例提高 血清或尿样中的β-亚基和β-核心片段水平 唐氏综合征患者妊娠、子痫前期、滋养细胞 疾病，或妊娠剧吐。这是我们的假设，所有 这些水平的升高是由于hCG的高糖基化，通过 一条涉及高糖化hCG缺口的途径，无效 自分泌控制人绒毛膜促性腺激素的产生，并快速解离生成 切割游离的β-亚基，降解为β-核心区片段。五 提出了一系列实验来检验这一假说并研究 正常与异常观察的临床分支 怀孕。建议进行研究，以确认和比较 720对人绒毛膜促性腺激素、游离β-亚基和β-核心区片段 正常和异常妊娠的血清和尿液样本(目标1A)； 从正常妊娠早、中、晚三个月分离纯化hCG 尿样和滋养细胞疾病、先兆子痫、剧吐 妊娠和唐氏综合征孕妇尿样(各3份)和 比较划痕的范围和地点，以及类型、金额和 高糖基化N-连接低聚糖的位置(目标2)； 通过比较研究高糖基化与划痕的关系 正常和高糖基化的hCG作为划痕酶的底物(目的 3)；检测正常和异常的生物活性 妊娠hCG和通过胎盘反馈的能力和 控制hCG合成(目标4)；调查和比较 人绒毛膜促性腺激素在正常和异常妊娠中的稳定性 解离能否解释游离β-受体比例的升高 亚单位(目标5)；并使用平行的血清和尿液样本 专门研究新的免疫分析方法的临床应用 测量含镍或高糖基化的hCG分子(目标1B)。

Preliminary studies in our laboratory are consistent with a relationship between hyperglycosylation (additional antennae and fucose residues on N-linked oligosaccharides) and nicking or cleavage of hCG. Other preliminary studies indicate the structural instability and diminished biological activity of hyperglycosylated and of nicked hCG molecules, and how they may be the source of free Beta-subunit in the circulation and Beta-core fragment in urine samples. A large number of papers have been published showing raised hCG levels, and raised proportions of free Beta-subunit and Beta-core fragment levels in serum or urine samples from patients with Down syndrome pregnancies, preeclampsia, trophoblast disease, or hyperemesis gravidarum. It is our hypothesis, that all of these raised levels arise from the hyperglycosylation of hCG, through a pathway involving nicking of hyperglycosylated hCG, ineffective autocrine control of hCG production, and rapid dissociation to generate nicked free Beta-subunit, and degradation to Beta-core fragment. Five sets of experiments are proposed to test this hypothesis and investigate the clinical ramification of the observations in normal and abnormal pregnancies. Studies are proposed to confirm and compare the levels of hCG, free Beta-subunit and Beta-core fragment in 720 sets of parallel serum and urine samples from normal and abnormal pregnancies (Aim 1A); to purify hCG from normal first, second, and third trimester pregnancy urine samples and trophoblast disease, preeclampsia, hyperemesis gravidarum and Down syndrome pregnancy urine samples (3 each) and compare the extents and sites of nicking, and the type, amounts and locations of hyperglycosylated N-linked oligosaccharides (Aim 2); to investigate the hyperglycosylation-nicking relationship by comparing normal and hyperglycosylated hCG as substrates for nicking enzymes (Aim 3); to examine the biological activities of normal and abnormal pregnancy hCG and abilities to feedback through to the placenta and control hCG synthesis (Aim 4); to investigate the and compare the stabilities of hCG from normal and abnormal pregnancy, and determine whether dissociation could explain the raised proportion of free Beta- subunit (Aim 5); and to use the parallel serum and urine samples to investigate the clinical utility of new immunoassays specifically measuring nicked or hyperglycosylated hCG molecules (Aim 1B).