Roles for Pkd1l1 in bile duct development

Pkd1l1 在胆管发育中的作用

基本信息

批准号：
10751883
负责人：
dominick Hellen
金额：
$ 4.77万
依托单位：
EMORY UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-09-01 至 2026-08-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10751883
关键词：
1 year old Abnormal Cell Address Adult Age Agonist Alleles Antibodies Basic Science Bile Acids Biliary Biliary Atresia Biliary cirrhosis Biology Cell Communication Cell Separation Cell physiology Cells Cellular Structures Child Cholestasis Cilia Confocal Microscopy Data Defect Detection Development Disease Distal Duct (organ) structure Dysmorphology Embryonic Development Epithelium Etiology Evaluation Extrahepatic Bile Ducts Fibrosis Functional disorder Genes Genetic Genetic Transcription Genetic study Goals Handedness Hepatology Histologic Human Immunoprecipitation Impairment In Situ In Vitro Individual Infant Intrahepatic bile duct Knock-out Knowledge Ligation Liquid substance Liver Liver diseases Medical Membrane Membrane Proteins Modeling Molecular Molecular Analysis Mus Mutation Neonatal Obstruction Organ PKD2 protein Participant Pathogenesis Pathology Phenotype Polycystic Kidney Diseases Proliferating Proteomics Publishing RNA Regulation Reporter Reporting Research Research Personnel Role Sensory Signal Transduction Solid Structural Protein Syndrome Techniques Testing Therapeutic Training Translational Research Transmission Electron Microscopy Transplantation Work bile duct biliary tract cholangiocyte exome sequencing experimental study in vivo insight intrahepatic liver transplantation malformation mouse model neonate novel postnatal pre-clinical prenatal response skills stem therapeutic target three-dimensional modeling transcriptome sequencing

项目摘要

PROJECT SUMMARY Biliary atresia (BA) is the main indication to transplant any solid organ in infants less than 1 year of age and has eluded major discoveries of etiology and pathophysiology for decades. BA is a neonatal liver disease that is best characterized by fibroinflammatory obstruction of both intra- and extrahepatic bile ducts. Through exome sequencing of a subset of BA individuals with heterotaxic (laterality) features (those with the BA Splenic Malformation syndrome), several participants were identified with biallelic damaging mutations in the ciliary gene PKD1L1 (Polycystic kidney disease 1 like 1). To explore mechanistic consequences of impaired PKD1L1 signaling in humans, we developed an intrahepatic cholangiocyte-restricted Pkd1l1Fl/Fl;Afp-Cre (LKO) mouse. Recently published data indicates that the absence of Pkd1l1 in the developing mouse liver leads to early biliary dysmorphology and enhanced peribiliary fibroinflammation at adult ages, moreso in the setting of distal obstruction after bile duct ligation (BDL). These histologic features strongly mimic those seen in human BA livers, offering a novel opportunity to discover specific cellular and molecular insights into BA’s rapid and profound pathogenesis. There are two paradigms that must be uncovered to provide a more thorough understanding of Pkd1l1, and thus the molecular pathogenesis of BA. First, the consequences of absent Pkd1l1 in the developing biliary tree that leads to adulthood biliary fibroinflammation are unknown. Second, the mechanism of Pkd1l1 signaling within cholangiocytes, which when absent contributes to biliary pathology, remains to be elucidated. The overarching hypothesis in this proposal is that Pkd1l1 is required for proper biliary development and signaling. This hypothesis will be tested through the following two aims. Aim 1 explores the delineation and characterization of early bile duct dysmorphology in developing prenatal and early postnatal livers. This aim will utilize the recently developed Pkd1l1Null/Fl (NullFl) and Pkd1l1Null/Fl;Afp-cre (NullLKO) mouse lines. Aim 2 is an in vitro set of experiments with isolated cholangiocyte studies to define Pkd1l1-interactors and signaling consequences, specifically in response to various bile acids, in isolated Pkd1l1Fl/Fl and LKO cholangiocytes. Taken together, we anticipate that these two aims will discover new cellular and molecular mechanisms of biliary tract development and signaling. In addition, information stemming from these Pkd1l1-based mouse models will help provide supportive pre-clinical evidence to address the current paucity of effective medical therapeutics in BA.

项目概要胆道闭锁（BA）是 1 岁以下婴儿移植任何实体器官的主要指征， BA 是一种新生儿肝脏疾病，几十年来一直未能得到病因学和病理生理学的重大发现。其特征是通过外显子组导致肝内和肝外胆管的纤维炎症阻塞。对具有异位性（偏侧性）特征的 BA 个体子集（具有 BA 脾脏的个体）进行测序畸形综合征），几名参与者被鉴定出睫状基因具有双等位基因破坏性突变 PKD1L1（多囊肾病 1 类似 1）探讨 PKD1L1 受损的机制后果。为了研究人类信号传导，我们开发了一种肝内胆管细胞限制性 Pkd1l1Fl/Fl;Afp-Cre (LKO) 小鼠。最近发表的数据表明，发育中的小鼠肝脏中 Pkd1l1 的缺失会导致早期胆汁性病变成年时形态异常和增强的胆周纤维炎症，尤其是在远端的情况下胆管结扎 (BDL) 后的阻塞，这些组织学特征与人类 BA 肝脏中所见的特征非常相似。提供了一个新的机会来发现 BA 快速而深刻的特定细胞和分子见解为了更彻底地理解发病机制，必须揭示两种范式。 Pkd1l1，以及 BA 的分子发病机制首先，发育中缺乏 Pkd1l1 的后果。导致成年胆管纤维炎症的胆管树尚不清楚。其次，Pkd1l1 的机制尚不清楚。胆管细胞内的信号传导，当其缺失时会导致胆道病理学，仍有待阐明。该提案的总体假设是 Pkd1l1 是胆道正常发育所必需的该假设将通过以下两个目标进行检验：目标 1 探讨了描述。产前和产后早期肝脏发育中的早期胆管畸形的特征和特征。将利用最近开发的 Pkd1l1Null/Fl (NullFl) 和 Pkd1l1Null/Fl;Afp-cre (NullLKO) 小鼠系 Aim 2。一组离体胆管细胞研究的体外实验，用于定义 Pkd1l1 相互作用物和信号传导在分离的 Pkd1l1Fl/Fl 和 LKO 胆管细胞中，特别是对各种胆汁酸的反应。总而言之，我们预计这两个目标将发现胆道的新细胞和分子机制此外，来自这些基于 Pkd1l1 的小鼠模型的信息将帮助提供支持性临床前证据，以解决目前缺乏有效医疗疗法的问题学士