RENAL CRYSTAL GROWTH INHIBITOR PROTEINS

肾晶体生长抑制蛋白

• 批准号: 6177135
• 负责人: JACK G KLEINMAN
• 金额: $ 12.45万
• 依托单位: MEDICAL COLLEGE OF WISCONSIN
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-07-01 至 2003-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6177135
• 关键词: calcium; chemical structure; clinical research; crystallization; enzyme linked immunosorbent assay; gene expression; human subject; hydroxyapatites; kidney pharmacology; laboratory rat; nephrolithiasis; osteopontin; oxalates; pathologic process; posttranslational modifications; sodium; tissue /cell culture

Kidney stones are a common clinical problem responsible for significant morbidity and economic costs in excess of 2 billion dollars/year. Despite progress in treatment, the recurrence rate of stones remains high. Interrupting early steps in the formation of kidney stones have the greatest likelihood of successfully preventing recurrence. These early steps include nucleation of stone crystals in tubular fluid and their growth and aggregation within the nephron to a size that can interact with some intrarenal structure. It is the hypothesis of this grant that these processes are primarily determined by specific interactions between stone constituent crystals and macromolecules present in tubular fluid and urine. The overall goal of this project is to advance our understanding of the role of one of these interactions by studying those of the principal urinary inhibitory macromolecule osteopontin/uropontin (OPN) and other macromolecular inhibitors of crystal formation in general in the development of kidney stones. The specific aims are: (1) Determining structural motifs of OPN responsible for effects on nucleation, growth, aggregation of calcium oxalate and hydroxyapatite (crystal formation), specifically, (a) the contributions of the N-terminal and C-terminal halves of the molecule, (b) the roles of putative Ca-binding sites, and (c) the effects of post-translational modifications; (2) Characterizing OPN from normals and Ca stone-formers with respect to its effects on crystal formation, including, (a) isolation and biochemical characterization of OPN from urine of normals and stone-formers, and (b) determining whether OPN from Ca-stone formers inhibits stone crystal formation to the same degree as OPN from normal individuals; (3) Investigating the physical chemistry of the interaction of OPN and other macromolecules and stone crystals, by determining (a) the quantitative relationship between macromolecules and growing crystal nuclei, (b) the relationship between their structure and crystal formation, and (c) the effects of the reactions conditions on the interaction between them and growing crystal nuclei, and by examining (d) the interactions between immobilized macromolecules and crystal formation; (4) Examining the effects of regulating OPN production on an experimental model of CaOx stone disease. Specifically, (a) determining whether pharmacolgic upregulation of OPN production ameliorates crystal deposition in animals given Na oxalate either acutely or chronically, (b) developing an in vivo system for transient renal expression of OPN, and (c) determining whether upregulation of OPN expression protects and down-regulation aggrevates crystal deposition in animals given Na oxalate either acutely or chronically.

肾结石是一种常见的临床问题，导致严重的肾结石 每年造成的发病率和经济损失超过 20 亿美元。 尽管治疗取得进展，结石的复发率仍然存在 高的。 阻断肾结石形成的早期步骤 成功预防复发的最大可能性。 这些 早期步骤包括管状流体中石晶体的成核和 它们在肾单位内生长和聚集到可以 与某些肾内结构相互作用。 就是这个假设 承认这些过程主要是由特定的 石材成分晶体与大分子之间的相互作用 存在于肾小管液和尿液中。 本项目的总体目标 是为了增进我们对这些相互作用之一的作用的理解 通过研究主要的泌尿抑制大分子 骨桥蛋白/尿桥蛋白（OPN）和其他大分子抑制剂 晶体的形成通常发生在肾结石的发展过程中。 这 具体目标是： (1) 确定 OPN 负责的结构基序 对草酸钙的成核、生长、聚集的影响 羟基磷灰石（晶体形成），具体来说，(a) 的贡献 分子的 N 端和 C 端部分，(b) 的作用 假定的 Ca 结合位点，以及 (c) 翻译后的影响 修改； (2) 区分正常 OPN 和钙结石形成者的特征 关于其对晶体形成的影响，包括，(a) 正常人尿液中 OPN 的分离及生化特性 和结石形成者，以及 (b) 确定 OPN 是否来自钙结石形成者 抑制结石晶体形成的程度与正常情况下的 OPN 相同 个人； (3) 研究相互作用的物理化学 OPN 和其他大分子和石晶体，通过确定 (a) 大分子与生长晶体之间的数量关系 原子核，(b) 其结构与晶体之间的关系 形成，以及（c）反应条件对 它们与生长的晶核之间的相互作用，并通过检查 (d) 固定化大分子与晶体之间的相互作用 形成； (4) 检验调节 OPN 生产对 氧化钙结石病实验模型。 具体来说，（a）确定 OPN 产生的药理上调是否会改善晶体 急性或长期给予草酸钠的动物体内沉积， (b) 开发 OPN 瞬时肾表达的体内系统， (c) 确定 OPN 表达的上调是否可以保护和 下调会加剧给予Na的动物体内的晶体沉积 草酸盐急性或慢性。