MUCIN AND NON-MUCIN PROTEINS IN GALLSTONE PATHOGENESIS

这个项目的总体目标是了解胆汁的作用。 粘蛋白在胆固醇结石发病机制中的作用。内科或外科 对有症状的胆结石的治疗是导致 在美国住院和消费超过80亿美元 每年的医疗保健成本。已显示出胆囊粘蛋白 在胆结石的发病机制中起中心作用。粘蛋白高分泌 在实验动物和人类中都发生在结石形成之前。 粘蛋白还促进胆固醇结晶成核，这是一个关键的早期步骤 在石层中，和粘蛋白凝胶衬里。胆汁提供 胆固醇晶体成熟的理想生长环境 石头。人类胆囊表达五种不同粘蛋白的基因和 其中两个，MUC5B和MUC3已被确定为主要的人类 胆囊黏蛋白。对它的结构特征一无所知 这些蛋白质与胆汁脂类相互作用，导致 成岩状态。 在这个项目中，将使用一种新的重组方法来识别 MUC5B和MUC3结合胆汁脂类的结构域。这个 这项建议的具体目的是：(L)描述主要的人类 通过测定胆囊黏蛋白MUC5B和MUC3的核苷酸和 糖基化较差的氨基和氨基的推导氨基酸序列 羧基末端区域，(2)决定了 这些粘蛋白和(3)确定MUC5B和MUC3的功能结构域。 在具体目标1和2中获得的信息将用于设计 包含单个粘蛋白结构域的构建体。重组粘蛋白 多肽将在细菌中表达，并在脂结合中进行检测， 胆固醇结晶成核法和囊泡融合法。结果是 这些研究将提供关于两国之间关系的新信息 人体主要胆囊黏蛋白的结构及其功能 在正常和病理性胆囊炎中。此信息对于以下项目是必需的 合理设计防治高血压病的治疗方法 胆石症。

The overall goal of this project is to understand the role of gallbladder mucin in the pathogenesis of cholesterol gallstones. Medical or surgical treatment for symptomatic gallstones is a frequent cause for hospitalization in the United States and consumes more than 8 billion dollars in health care costs per year. Gallbladder mucin has been shown to have a central role in gallstone pathogenesis. Mucin hypersecretion occurs prior to stone formation in both experimental animals and man. Mucin also promotes cholesterol crystal nucleation, a critical early step in stone formation, and the mucin gel lining. The gallbladder provides an ideal environment for growth of cholesterol crystals into mature stones. Human gallbladder expresses genes for five different mucins and two of these, MUC5B and MUC3 have been identified as the major human gallbladder mucins. Nothing is known about the structural features of these proteins which interact with biliary lipids and lead to the lithogenic state. In this project, a novel recombinant approach will be used to identify the structural domains of MUC5B and MUC3 which bind biliary lipids. The specific aims of this proposal are to: (l) characterize the major human gallbladder mucins MUC5B and MUC3 by determining the nucleotide and deduced amino acid sequences of the poorly glycosylated amino- and carboxyl-terminal regions, (2) determine the genomic organization of these mucins and (3) to identify functional domains in MUC5B and MUC3. Information obtained in specific aims 1 and 2 will be used to design constructs containing individual mucin domains. Recombinant mucin polypeptides will be expressed in bacteria and examined in lipid binding, cholesterol crystal nucleation and vesicle fusion assays. The results of these studies will provide new information about the relationship between the structure of the major human gallbladder mucins and their function in normal and pathologic gallbladder. This information is necessary for the rational design of therapies for the prevention and treatment of gallstone disease.