The Role of Dysfunctional CCK-1R in Cholelithogenesis

功能失调的 CCK-1R 在胆石形成中的作用

• 批准号: 7369647
• 负责人: DAVID Q WANG
• 金额: $ 36.13万
• 依托单位: BETH ISRAEL DEACONESS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-01-15 至 2011-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7369647
• 关键词: AKR/J Mouse; Accounting; Address; Biliary calculi; Biochemical; Cholecystokinin; Cholecystokinin Receptor; Cholelithiasis; Cholesterol; Complex; Congenic Mice; Crystallization; Data; Defect; Diagnosis; Diet; Environmental Risk Factor; G-Protein-Coupled Receptors; Gallbladder; Gallbladder Emptying; Genes; Genetic; Genetic Determinism; Genetic Techniques; Genotype; Human; Individual; Knockout Mice; Knowledge; Laboratories; Lead; Localized; Mediating; Molecular Genetics; Mouse Strains; Mus; Mutate; Mutation; Patients; Phenotype; Play; Predisposition; Prevention; Prevention strategy; Quantitative Trait Loci; Rate; Receptor Gene; Research; Resistance; Role; Sincalide; Structure; Subfamily lentivirinae; Susceptibility Gene; base; disorder prevention; gene therapy; interest; motility disorder; mouse genome; novel strategies; prevent; receptor; response

DESCRIPTION (provided by applicant): The long-term objectives of this laboratory are to identify, localize, and estimate the lithogenic effects of pathophysiologically relevant gallstone (LITH) genes; understand at a fundamental level the genetic mechanisms of cholesterol gallstones; and explore the genotypes and phenotypes of LITH genes in mice and eventually in humans. Studies on both humans and mice have clearly demonstrated that a complex genetic basis determines the individual predisposition to develop cholesterol gallstones in response to environmental factors. A powerful genetic technique, quantitative trait locus (QTL) analysis can identify primary, usually rate- limiting genetic defects and discriminate them from secondary downstream pathophysiologic effects caused by mutations of the primary genes. We performed a QTL analysis in intercross progeny of gallstone-susceptible 129S3/SvlmJ mice and resistant AKR/J mice, and determined the subset of gallstone susceptibility genes possessed in the susceptible strain. Our molecular and genetic data from these mouse studies support the notion that dysfunctional cholecystokinin-1 receptor (CCK-1R) in the gallbladder plays a critical role in the formation of cholesterol gallstones in 129S3/SvlmJ mice challenged to a lithogenic diet. Furthermore, abnormalities in gallbladder emptying function in response to exogenously administered CCK-8 have been observed in patients with cholesterol gallstones, suggesting that altered structure and function of the gallbladder CCK-1R gene could be involved in the formation of cholesterol gallstones in humans. However, the identification of the lithogenic mechanisms of the mutated CCK-1R gene still remains a challenging task. This application will be focused on identifying the lithogenic effects of dysfunctional CCK-1R by systematically studying its pathophysiological functions in some "manufactured" mouse strains such as CCK-1R congenic mice and CCK-1R knockout mice. Also, we will investigate pathophysiological effects of gallbladder stasis on cholesterol crystallization and gallstone formation, as well as gene therapy of gallbladder dysmotility in these mice. In this application, the applicant proposes to (i) elucidate whether the mutated CCK-1R results in gallbladder stasis due to a defect in receptor-G protein coupling; (ii) determine the alterations induced by gallbladder hypomotility that account for rapid cholesterol crystallization and gallstone formation in mice with the mutated CCK-1R; and (iii) explore whether lentivirus-mediated transfer of the mouse CCK-1R gene prevents cholesterol gallstone formation in mice with gallbladder hypomotility. Due to the close homology between human and mouse genomes, the identification of lithogenic effects of dysfunctional CCK-1R in mice may elucidate previously unknown but pathophysiologically relevant genetic determinants of cholesterol cholelithiasis in humans.

描述（由申请人提供）：该实验室的长期目标是识别、定位和估计病理生理相关胆结石（LITH）基因的成石效应；从根本上了解胆固醇胆结石的遗传机制；并探索小鼠以及最终人类的 LITH 基因的基因型和表型。对人类和小鼠的研究清楚地表明，复杂的遗传基础决定了个体因环境因素而形成胆固醇胆结石的倾向。数量性状位点 (QTL) 分析是一种强大的遗传技术，可以识别主要的、通常是限速的遗传缺陷，并将其与主要基因突变引起的次要下游病理生理效应区分开来。我们对胆结石敏感的 129S3/SvlmJ 小鼠和抗性 AKR/J 小鼠的杂交后代进行了 QTL 分析，并确定了敏感品系中拥有的胆结石易感基因的子集。我们从这些小鼠研究中获得的分子和遗传数据支持这样的观点：在接受石质饮食的 129S3/SvlmJ 小鼠中，胆囊中功能失调的胆囊收缩素-1 受体 (CCK-1R) 在胆固醇胆结石的形成中发挥着关键作用。此外，在胆囊胆固醇结石患者中观察到外源性给予 CCK-8 后胆囊排空功能异常，这表明胆囊 CCK-1R 基因结构和功能的改变可能与人类胆固醇胆结石的形成有关。然而，突变CCK-1R基因的成石机制的鉴定仍然是一项具有挑战性的任务。该应用将重点通过系统地研究功能失调的 CCK-1R 在一些“人造”小鼠品系（例如 CCK-1R 同源小鼠和 CCK-1R 敲除小鼠）中的病理生理功能，来确定功能失调的 CCK-1R 的成石效应。此外，我们还将研究胆囊瘀滞对胆固醇结晶和胆结石形成的病理生理学影响，以及这些小鼠胆囊运动障碍的基因治疗。在本申请中，申请人提出：(i)阐明突变的CCK-1R是否由于受体-G蛋白偶联缺陷而导致胆囊瘀滞； (ii) 确定 CCK-1R 突变小鼠中胆囊运动不足引起的变化，这些变化导致胆固醇快速结晶和胆结石形成； (iii) 探讨慢病毒介导的小鼠 CCK-1R 基因转移是否可以预防胆囊动力不足的小鼠中胆固醇胆结石的形成。由于人类和小鼠基因组之间的密切同源性，鉴定小鼠中功能失调的 CCK-1R 的成石效应可能会阐明人类胆固醇胆石症的先前未知但病理生理学相关的遗传决定因素。