Molecular mechanisms of Bile Duct Proliferation in Mice with Glycosylation Defect

糖基化缺陷小鼠胆管增殖的分子机制

• 批准号: 8334622
• 负责人: MATTHEW Joseph RYAN
• 金额: $ 8.38万
• 依托单位: CHILDREN'S HOSP OF PHILADELPHIA
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-22 至 2013-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8334622
• 关键词: Adult; Affect; Affinity; Age; Alagille Syndrome; Area; Biliary; Blood Vessels; Cell Proliferation; Cells; Cessation of life; Child; Childhood; Cholestasis; Data; Defect; Development; Disease; Ductal; Ear; Evolution; Eye; Family; Gene Expression; Genes; Genetic; Goals; Growth; Growth and Development function; Hepatic; Hepatic Duct; Hepatocyte; In Vitro; Individual; Intrahepatic bile duct; Investigation; Knowledge; Lead; Life; Ligands; Liver; Liver diseases; Mentors; Molecular; Morbidity - disease rate; Morphogenesis; Mus; Mutant Strains Mice; Mutation; Pathway interactions; Phenotype; Play; Point Mutation; Population; Process; RNA; Regulation; Research Personnel; Role; Running; Sampling; Scientist; Signal Pathway; Signal Transduction; System; Time; Tissues; bile duct; biliary tract; bone; cholangiocyte; clinical phenotype; critical period; glycosylation; glycosyltransferase; human MFNG protein; insight; laser capture microdissection; mouse model; mutant; notch protein; novel; postnatal; receptor; research study

DESCRIPTION (provided by applicant): Cholestatic liver disease remains a significant cause of morbidity and death in the pediatric population, yet little is known about the molecular processes that regulate intrahepatic bile duct growth and remodeling. Alagille syndrome (ALGS) is an autosomal dominant multi-system disorder caused by mutations in either the JAG1 or NOTCH2 genes and characterized by a paucity of bile ducts in the liver with resultant cholestasis. Despite the knowledge of the genes responsible for ALGS, there exists a wide phenotypic variability even within families with the same point mutations raising the possibility that modifier genes may play a role. Radical Fringe (Rfng) is a glycosyltransferase that modifies the Notch receptor and alters its affinity for its ligands. We have identified a phenotype of bile duct proliferation with an onset between two and three weeks of age in mice heterozygous for Jag1 and Rfng. The aims proposed in this application seek to examine the changes in gene expression prior to this critical period of bile duct growth and remodeling. We will identify other potential targets of Rfng glycosylation and gene pathways involved in bile duct regulation. State-of-the-art laser capture microdissection will be employed to isolate RNA specifically from portal tracts. Collected samples will be run on the Affymetrix GeneChiph Mouse Gene 1.0 ST Array to evaluate for gene expression changes. In addition, the relationship between Notch2 and Rfng during bile duct remodeling will be examined using a novel mouse model haploinsufficient for Notch2 and Rfng. The goals of this application are to advance the investigation of the Jag1+/-Rfng+/- mutant mice and explore Notch pathway modifiers. Understanding the effect of glycosylation on the Notch receptor, subsequent downstream signaling and the involvement of alternate signaling pathways is vital for further insight into the hepatic phenotype in ALGS and potentially other biliary diseases. Ideally, the information gained from these experiments will lead to further insights into bile duct development, reveal new avenues for additional investigation and eventually lead to possible directed liver therapies for children and adults. )

描述（由申请人提供）：胆固性肝病仍然是儿科人群发病和死亡的重要原因，但对于调节肝内胆管内生长和重塑的分子过程知之甚少。 Alagille综合征（ALGS）是由JAG1或Notch2基因突变引起的常染色体显性多系统疾病，其特征是肝脏在肝脏中缺乏导致的胆汁淤积。尽管了解了负责ALG的基因，但即使在具有相同点突变的家庭中，也存在广泛的表型变异性，从而增加了修饰基因可能发挥作用的可能性。自由基条纹（RFNG）是一种糖基转移酶，可修饰Notch受体并改变其对配体的亲和力。我们已经确定了一种胆管增殖的表型，在JAG1和RFNG的杂合子中，杂合子的发作在两到三周之间。本应用中提出的目的旨在检查在这个关键的胆管生长和重塑的关键时期之前基因表达的变化。我们将确定其他 RFNG糖基化和涉及胆管调节的基因途径的潜在靶标。将使用最新的激光捕获显微解剖来专门隔离门户区域。收集的样品将在Affymetrix Genechiph小鼠基因1.0 ST阵列上运行，以评估基因表达变化。此外，将使用新颖的小鼠模型单倍助是Notch2和RFNG检查Notch2和RFNG之间的Notch2和RFNG之间的关系。该应用的目标是提高对JAG1 +/- RFNG +/-突变小鼠的研究，并探索Notch途径修饰符。了解糖基化对缺口受体的影响，随后的下游信号传导和替代信号传导途径的参与对于进一步深入了解ALG中的肝表型和潜在的其他胆汁疾病至关重要。理想情况下，从这些实验中获得的信息将导致对胆管发展的进一步见解，揭示了新的途径进行其他研究，并最终导致可能针对儿童和成人的定向肝疗法。 ）