PROCESSING OF HCG IN NORMAL AND ABNORMAL PREGNANCIES

正常和异常妊娠中 HCG 的处理

• 批准号: 2859054
• 负责人: LAURENCE Anthony COLE
• 金额: $ 4.94万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-09-01 至 1998-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2859054
• 关键词: Downs syndrome; biomarker; blood chemistry; carbohydrate structure; choriocarcinoma; chorionic gonadotropin; clinical research; gel filtration chromatography; gestational age; glycoprotein structure; glycosylation; human pregnant subject; ion exchange chromatography; oligosaccharides; preeclampsia; pregnancy disorder; prenatal diagnosis; protein purification; protein sequence; tissue /cell culture; urinalysis

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).

我们实验室的初步研究表明 高糖基化（额外的触角和岩藻糖残基， N-连接的寡糖）和hCG的切口或切割。 其他 初步研究表明，结构不稳定， 高糖基化和切口hCG分子的生物活性， 以及它们如何成为循环中游离β亚基的来源 和β核心片段 大量论文已 已发表的研究显示，hCG水平升高， 血清或尿液样本中的β亚基和β核心片段水平 唐氏综合症孕妇，先兆子痫，滋养细胞 疾病，或妊娠剧吐。 我们的假设是， 这些升高的水平由hCG的高糖基化引起， 涉及高糖基化hCG切口的途径，无效 自分泌控制hCG的产生，并快速解离产生 切口游离β亚基，降解为β核心片段。五 提出了一组实验来检验这一假设，并调查 正常和异常情况下观察结果的临床分支 怀孕。 建议进行研究，以确认和比较 hCG、游离β亚基和β核心片段在720组平行 正常和异常妊娠的血清和尿液样本（目标1A）; 纯化正常妊娠早期、中期和晚期的hCG 尿样和滋养层疾病、先兆子痫、剧吐 妊娠和唐氏综合征妊娠尿液样本（各3份）， 比较切口的范围和部位，以及切口的类型、数量和 高糖基化N-连接寡糖的位置（目标2）; 通过比较来探讨高糖基化与切口的关系 正常和高糖基化hCG作为切口酶的底物（Aim 3）;检查正常和异常的生物活性 妊娠hCG和反馈到胎盘的能力， 控制hCG合成（目的4）;研究并比较 正常和异常妊娠hCG的稳定性，并确定 解离是否可以解释游离β- 亚单位（目标5）;并使用平行血清和尿液样本， 研究新的免疫测定法的临床效用， 测量有切口的或高糖基化的hCG分子（Aim 1B）。