Injury, progression, and fibrosis of the extrahepatic bile duct

肝外胆管的损伤、进展和纤维化

• 批准号: 10410456
• 负责人: REBECCA G WELLS
• 金额: $ 36.56万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-01 至 2023-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10410456
• 关键词: Address; Adult; Affect; Aftercare; Age; Anatomy; Apical; Architecture; Autoimmune Responses; Basement membrane; Bicarbonates; Bile Acids; Bile Duct Diseases; Biliary; Biliary Atresia; Bilirubin; Birth; Cells; Child; Childhood; Cirrhosis; Collagen; Communication; Data; Deposition; Development; Devices; Disease; Duct (organ) structure; Etiology; Event; Extrahepatic; Extrahepatic Bile Ducts; Fibroblasts; Fibrosis; Functional disorder; Glycocalyx; Human; Icterus; Inflammatory Response; Injury; Intercellular Junctions; Knowledge; Lead; Life; Liquid substance; Liver; Liver Cirrhosis; Liver diseases; Microfluidic Microchips; Microfluidics; Modeling; Mothers; Mus; Neonatal; Newborn Infant; Patients; Permeability; Population; Predisposition; Pregnant Women; Rest; Role; Scheme; Specificity; Submucosa; Surface; System; Therapeutic; Toxic effect; Toxin; Transplantation; Work; base; bile duct; biliary tract; cholangiocyte; epithelial injury; epithelial repair; experimental study; fetal; human disease; insight; liver transplantation; monolayer; mouse model; neonatal mice; neonate; novel; novel therapeutics; palliative; prenatal; repaired; response; response to injury; tool

PROJECT SUMMARY Biliary atresia (BA) is a fibro-obliterative disease of the bile ducts, especially the extrahepatic ducts (EHBDs), that afflicts neonates around the world. BA is the most common indication for liver transplant in the pediatric population, with 50% of patients requiring transplant by age 2 and most of the rest before adulthood. The etiology and early course of the disease are unknown; however, important recent data suggest that BA results from a prenatal environmental insult (sparing the mother) that is followed by progression of the original injury after birth. This proposal seeks to answer three key questions in BA: 1) Why is toxicity specific to neonates? 2) What determines repair versus progression of cholangiocyte injury? and 3) How and why does fibrosis occur in the EHBD? Our underlying hypothesis is that the answers to these questions are found in the unique features of the neonatal biliary system: that BA results from an injury that occurs in the context of a developmentally immature bile duct with anatomic features that make it susceptible to injury and promote progression of damage and a fibrotic response.Our preliminary work identified key features of the neonatal bile ducts that potentially increase their susceptibility to injury. These include lack of a protective apical glycocalyx on cholangiocytes and immature cholangiocyte cell-cell junctions. We also showed that the submucosa of the neonatal EHBD contains a large population of fibrogenic cells that are “primed' to respond to insults and that the anatomical structure of the neonatal submucosa may propagate injury.We developed two unique tools to study the role of duct immaturity in susceptibility and response to injury. First, we developed a mouse model of prenatal EHBD damage. We identified and synthesized a previously unknown isoflavonoid biliary toxin, biliatresone, that causes EHBD injury in fetal and neonatal mice after treatment of pregnant mothers. Damage is worsened by humanizing the bile acid profile. This model will enable us to use genetically-modified and specially-treated mice to investigate the importance of neonatal duct susceptibility factors in injury. Second, we developed a microfluidic bile duct-on-a-chip device that allows us to culture neonatal, adult, and genetically- modified cholangiocytes in a confluent, impermeable monolayer, to apply various treatments selectively to the apical or basal surface, and to determine their impact on key cholangiocyte functions, including the permeability barrier.Our three specific aims use these and other tools we have developed to study: 1) neonatal susceptibility to injury, including the role of the glycocalyx; 2) the determinants of injury progression, including the role of bile acids; and 3) the identity of the fibrogenic cells of the EHBD and the role of submucosal architecture in the spread of injury. This work has the potential to both significantly shift our understanding of BA and lead to new therapeutic options.

项目概要 胆道闭锁（BA）是一种胆管纤维闭塞性疾病，尤其是肝外管（EHBD）， BA 是儿科肝移植最常见的适应症。 人口中，50% 的患者在 2 岁时需要移植，其余大部分在成年之前需要移植。 该病的病因和早期病程尚不清楚；然而，最近的重要数据表明 BA 结果 来自产前环境伤害（不伤害母亲），随后原伤进一步恶化 出生后 该提案旨在回答 BA 中的三个关键问题：1) 为什么毒性只针对新生儿？2) 什么是毒性？ 决定胆管细胞损伤的修复与进展？以及 3) 纤维化是如何以及为何发生的？ EHBD？我们的基本假设是这些问题的答案可以在以下特征中找到： 新生儿胆道系统：BA 是由于发育过程中发生的损伤造成的 未成熟胆管的解剖学特征使其容易受伤并促进胆管的进展 损伤和纤维化反应。我们的初步工作确定了新生儿胆管的关键特征 可能会增加它们对损伤的敏感性，其中包括缺乏保护性顶端糖萼。 我们还表明，胆管细胞和未成熟胆管细胞的细胞间连接。 新生儿 EHBD 含有大量纤维化细胞，这些细胞已“准备好”对损伤做出反应，并且 新生儿粘膜下层的解剖结构可能会传播损伤。我们开发了两种独特的工具来 研究导管不成熟在损伤敏感性和反应中的作用首先，我们开发了小鼠模型。 我们鉴定并合成了一种以前未知的异黄酮胆汁毒素， biliatresone，在怀孕母亲治疗后引起胎儿和新生小鼠的 EHBD 损伤。 通过将胆汁酸谱人性化，该模型将使我们能够使用转基因和胆汁酸。 其次，我们对经过特殊处理的小鼠进行了研究，以研究新生导管易感因素在损伤中的重要性。 开发了一种微流体胆管芯片设备，使我们能够培养新生儿、成人和遗传- 在汇合的、不可渗透的单层中修饰胆管细胞，选择性地对胆管细胞应用各种治疗 顶端或基底表面，并确定它们对关键胆管细胞功能的影响，包括 渗透性屏障。我们的三个具体目标使用这些和我们开发的其他工具来研究：1）新生儿 对损伤的易感性，包括糖萼的作用；2) 损伤进展的决定因素，包括 胆汁酸的作用；3) EHBD 纤维化细胞的特性和粘膜下层的作用 这项工作有可能显着改变我们对伤害传播的理解。 BA 并带来新的治疗选择。