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.

项目摘要 胆道闭锁（BA）是胆管的纤维菌血性疾病，尤其是外膜外管（EHBD）， 这困扰着世界各地的新生儿。 BA是小儿肝移植的最常见指示 人口，有50％的患者需要在成年之前按2岁时移植，其余大部分则需要移植。 病因和早期病程未知；但是，最新数据表明BA结果 从产前环境损伤（对母亲的保留），随后是原始伤害的进展 出生后。 该提议试图在BA中回答三个关键问题：1）为什么对新生儿有特定的毒性？ 2）什么 确定胆管细胞损伤的修复与进展？ 3）如何以及为什么在 ehbd？我们的基本假设是，这些问题的答案是在独特的特征中找到的 新生儿胆道系统：BA是由于在发展上发生的伤害而造成的 未成熟的胆管具有解剖特征，使其容易受到伤害并促进进展 损害和纤维化反应。我们的初步工作确定了新生儿胆管的关键特征 潜在地增加了他们对伤害的敏感性。这些包括缺乏受保护的顶端糖蛋白 胆管细胞和未成熟的胆管细胞细胞 - 细胞连接。我们还表明了 新生儿EHBD包含大量的纤维基因细胞，这些细胞“启动”以应对损伤，并且 新生儿粘膜的解剖结构可能会传播伤害。我们开发了两个独特的工具 研究管道不成熟在易感性和对损伤反应中的作用。首先，我们开发了一个鼠标模型 产前EHBD损害。我们确定并合成了先前未知的异黄素胆汁毒素， 胆汁酮，在孕妇治疗后导致胎儿和新生小鼠的EHBD损伤。损害 通过人性化胆汁酸的特征来恶化。该模型将使我们能够使用一般修改和 专门治疗的小鼠研究了新生儿管道易感性因素在损伤中的重要性。第二，我们 开发了一种微流体胆管在芯片上的装置，使我们能够培养新生儿，成人和遗传学 在汇合的，不可渗透的单层中修改的胆管细胞，选择性地将各种治疗方法应用于 根尖或基础表面，并确定它们对关键胆管细胞功能的影响，包括 渗透性障碍。我们的三个具体目的使用这些和其他我们开发的工具来研究：1）新生儿 损伤的敏感性，包括糖脂的作用； 2）伤害进展的决定者，包括 胆汁酸的作用； 3）EHBD的纤维基细胞的身份和粘膜下粘膜的作用 受伤传播中的建筑。这项工作有可能显着改变我们对 BA并导致新的治疗选择。