Hippo Signaling Mediates the Development of Liver Fibrosis

Hippo 信号传导介导肝纤维化的发展

基本信息

批准号：
9033112
负责人：
DEAN YIMLAMAI
金额：
$ 15.26万
依托单位：
BOSTON CHILDREN'S HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-04-01 至 2020-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9033112
关键词：
Ablation Binding Candidate Disease Gene Cell Line Cell Proliferation Cell Separation Cell division Cell surface Cells ChIP-seq Characteristics Chemicals Chronic Cicatrix Cirrhosis Coculture Techniques Complement Cues Data Development Disease Epithelial Epithelial Cells Equilibrium Failure Fibrosis Fractionation Functional disorder Gatekeeping Gene Expression Gene Expression Profiling Genes Genetic Genetic Transcription Genomics Goals Growth Hepatic Hepatic Stellate Cell Hepatocyte High-Throughput RNA Sequencing Human Hypertrophy In Situ In Vitro Inflammatory Infiltrate Injury Liver Liver Fibrosis Liver Regeneration Liver parenchyma Lobe Mediating Mediator of activation protein Mesenchymal Metabolic Modeling Mus Natural regeneration Nuclear Organ Outcome Study Partial Hepatectomy Pathogenesis Pathway interactions Phenotype Phosphotransferases Population Process RNA RNA Interference Recovery Reverse Transcriptase Polymerase Chain Reaction Role Sampling Signal Pathway Signal Transduction Small Interfering RNA Staining method Stains Stem cells Supporting Cell Techniques Technology Therapeutic Trans-Activators Transcription Coactivator Validation cell type improved in vivo inhibitor/antagonist insight interest knock-down liver injury loss of function overexpression programs public health relevance response single cell sequencing transcriptome sequencing

项目摘要

DESCRIPTION (provided by applicant): The overarching goal of this proposal is to investigate the Hippo signaling pathway in the liver and how it contributes to the pathogenesis of hepatic fibrosis. The outcome of these studies will impact on our understanding of hepatic development and recovery after injury. The Hippo signaling pathway is an important regulator of liver size, cellular proliferation and cell fate. The Hippo pathway negatively regulates Yap. High levels of Yap in hepatocytes convert these cells into a hepatic progenitor cell (HPC)-like phenotype. Rapidly dividing HPCs are associated with the development of fibrosis, and it is known that Yap directly activates genes associated with this process. Cirrhotic liver samples often display nuclear Yap staining (a sign of Hippo inactivation) and hepatic stellate cell (HSC) activation is temporally associated with increasing Yap. These observations suggest that inactivating Hippo signaling in epithelial cells can activate a profibrotic gene program. This proposal will validate and dissect the mechanism of this observation. In AIM 1, several fibrogenic liver injury models will be examined to see if Hippo signaling is inactivated. This will be complemented with loss of function studies in the epithelial compartment to determine if abrogating Hippo signaling will minimize the development of fibrosis. In AIM 2, Yap-expressing hepatocytes will be examined by cellular fractionation and using single-cell sequencing techniques to determine if a priori, a particular hepatocyte "type" is most sensitive to Yap expression and if this cell-type likely orchestrates the development of liver fibrosis. AIM 3, focuses on determining which secreted factors from Yap-expressing hepatocytes likely activate HSCs. This will be performed using RNA interference and Cas9-Crispr technologies to knockdown expression of candidate molecules defined by microarray expression and ChIP-Seq data from Yap overexpressing hepatocytes. This screen will be performed in vitro followed by in vivo validation. Understanding if Hippo signaling is a common mechanism for the development of hepatic fibrosis, the characteristics of the epithelial cells that may orchestrate this process, and potential secreted factors to activate HSCs will be important information in developing therapeutics to treat liver fibrosis.

描述（由适用提供）：该提案的总体目标是研究肝脏中的河马信号通路及其对肝纤维化的发病机理的贡献。这些研究的结果将影响我们对受伤后肝发育和恢复的理解。河马信号通路是肝脏大小，细胞增殖和细胞命运的重要调节剂。河马途径对YAP进行负调节。肝细胞中高水平的YAP将这些细胞转化为肝祖细胞（HPC）样表型。快速分裂的HPC与纤维化的发展有关，众所周知，YAP直接激活与该过程相关的基因。肝硬化肝样品通常显示出核YAP染色（河马灭活的迹象），而肝星状细胞（HSC）激活暂时与YAP的增加有关。这些观察结果表明，上皮细胞中的河马信号传导可以激活纤维化基因程序。该建议将验证和剖析该观察的机制。在AIM 1中，将检查几种纤维化肝损伤模型，以查看河马信号是否被灭活。这将在上皮室中的功能研究损失来完成，以确定废除河马信号是否会最大程度地减少纤维化的发展。在AIM 2中，将通过细胞分馏和使用单细胞测序技术来检查表达YAP的肝细胞，以确定先验，特定的肝细胞“类型”是否对YAP表达最敏感，并且该细胞类型是否可能调节肝纤维化的发展。 AIM 3，专注于确定表达YAP的肝细胞中哪些分泌因素可能会激活HSC。这将使用RNA干扰和Cas9-Crispr技术进行，以敲低由微阵列表达和YAP过表达的肝细胞的芯片seq数据定义的候选分子。该屏幕将在体外进行，然后进行体内验证。了解河马信号传导是否是肝纤维化发展的常见机制，可能会策划这一过程的上皮细胞的特征以及激活HSC的潜在分泌因素将是开发治疗肝纤维化治疗的重要信息。