BILIARY SECRETORY PATHWAYS IN CYSTIC FIBROSIS

囊性纤维化中的胆道分泌途径

• 批准号: 6489605
• 负责人: WON KYOO CHO
• 金额: $ 9.05万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-05-01 至 2003-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6489605
• 关键词: adenosine triphosphate; bicarbonates; bile ducts; biological signal transduction; bombesin; chloride channels; cystic fibrosis; disease /disorder model; ion transport; laboratory mouse; micropuncture; microspectrophotometry; neuropeptides; secretion; tissue /cell culture; ursodeoxycholate; vasoactive intestinal peptide; video microscopy; voltage /patch clamp

Cystic fibrosis (CF) is the most common lethal inherited diseases in white population. As CF patients live longer, liver disease has become the second leading cause of death. The development of CF disease is believed to result from the secretory defects in the bile ducts leading to the obstructions of bile ductules by tenacious bile secretions, thereby secreting in focal periportal biliary fibrosis/cirrhosis. This explanation in addition to the recent finding that CFTR is only expressed on bile duct cells, but not on hepatocytes, suggest that studying biliary secretion is crucial to understanding the pathophysiology and developing therapeutic strategies for CF liver. A novel polarized isolated bile duct unit (IBDU) prepared from rat liver has demonstrated to be an ideal tool to study bile ductular secretion but the lack of CF rat model limited its use in CF studies. By applying these isolation methods, recently, IBDUs have been isolated from normal and CF mice. Therefore, the aims of this research are to further characterize bile duct cells (BDC) and IBDU from normal and CF knockout mice, to characterize ion transporters in BDC, and to study the actions and mechanisms of various secretagogues including neuroendocrine peptides in biliary secretion in order to find ways to activate alternative, cAMP-independent biliary secretory pathways in CF mice. Preliminary experiments to isolate IBDU from normal mouse yielded intact polarized functional IBDU that responds to secretin, vasoactive intestinal peptide, and DBcAMP-IBMX. Similar IBDUs were also isolated from CF mice but need further characterization. Quantitative videomicroscopy will be used to screen potential secretagogues to stimulate biliary secretion in normal and CF mice and to characterize their underlying ion transporters by using ion substitutions and inhibitor studies. These ion transporters will be further studied by BCECF dual ratio methods for measuring pH, micropuncture, and patch clamping techniques. Signal transduction systems involved in their action will be studied by monitoring changes in the concentrations of secondary messengers. Understanding transport systems and their underlying mechanisms of biliary secretion in normal and CF mice will help to formulate therapeutic approaches to overcome the CFTR defect. This project, in turn, will provide the candidate with an excellent opportunity to broaden and develop research and cognitive skills to become independent researcher, as well as help to successfully compete for future research grants.

囊性纤维化（CF）是白人人口中最常见的致命遗传疾病。随着CF患者的寿命更长，肝病已成为死亡的第二大原因。 CF疾病的发展被认为是由于胆管中的分泌缺陷导致的，导致顽强的胆汁分泌物妨碍胆管障碍物，从而在局灶性周围胆汁纤维纤维化/cir虫中分泌。除了最近发现CFTR仅在胆管细胞上表达而不是在肝细胞上表达的发现外，这种解释表明，研究胆道分泌对于理解病理生理学和开发CF肝脏的治疗策略至关重要。从大鼠肝脏制备的一种新型的极化胆管单元（IBDU）已证明是研究胆管分泌的理想工具，但缺乏CF大鼠模型限制了其在CF研究中的使用。通过应用这些隔离方法，最近已经从正常小鼠和CF小鼠中分离出IBDU。因此，这项研究的目的是从正常和CF敲除小鼠中进一步表征胆管细胞（BDC）和IBDU，以表征BDC中的离子转运蛋白，并研究各种促分泌物的作用和机制，包括神经内分泌肽在胆汁分泌中的神经内分泌肽，以便在CAMP-GRIADERATIONS CAMPIRETINDERTICATE BILIARE BILIRETICE BILILEDICEFICATINE PATICTORETARETARECTINDERACTION cARTICENTICS FARTICATION cAMP-INTEPTICTORDE BILIRETICATICEFIRETICARETICATINE。将IBDU与正常小鼠分离的初步实验产生了完整的极化功能性IBDU，该功能性IBDU对Sectionin，血管活性肠道肽和DBCAMP-IBMX做出了反应。也从CF小鼠中分离出类似的IBDU，但需要进一步表征。定量视频显微镜将用于筛选潜在的促分泌物，以刺激正常小鼠和CF小鼠的胆道分泌，并通过使用离子取代和抑制剂研究来表征其基础离子转运蛋白。这些离子转运蛋白将通过BCECF双比方法进一步研究，以测量pH，微插入和贴片夹具技术。通过监视次级信使浓度的变化，将研究参与其动作的信号转导系统。了解正常和CF小鼠中胆道分泌的运输系统及其基本机制将有助于制定治疗方法以克服CFTR缺陷。反过来，该项目将为候选人提供一个很好的机会，以扩大和发展研究和认知能力，成为独立研究人员，并帮助成功争夺未来的研究赠款。