The Role of Matrix Rigidity and Hepatocyte Mechanotransduction in Fibrotic Liver Disease

基质刚性和肝细胞机械转导在纤维化肝病中的作用

• 批准号: 10200030
• 负责人: TAMMY T CHANG
• 金额: $ 35.66万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-15 至 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10200030
• 关键词: 3-Dimensional; Address; Atomic Force Microscopy; Back; Biochemical; Bioinformatics; Biological; Biomedical Engineering; Cause of Death; Cells; Characteristics; Chronic; Cirrhosis; Clinical; Complex; Cues; Data; Data Set; Development; Disease; Down-Regulation; Etiology; Experimental Models; Extracellular Matrix; Failure; Fibrosis; Functional disorder; Gene Expression Profiling; Genes; Genetically Engineered Mouse; HNF4A gene; Hepatic; Hepatic Insufficiency; Hepatocyte; Human; Knowledge; Lasers; Lead; Liver; Liver Cirrhosis; Liver Failure; Liver Fibrosis; Liver diseases; Location; Mechanics; Microdissection; Modality; Molecular; Morbidity - disease rate; Organ Donor; Organoids; Pathologic; Pathway interactions; Patients; Pattern; Process; Property; Protein Kinase; Proteins; Replacement Therapy; Research; Role; Sampling; Side; Signal Pathway; Signal Transduction; Signaling Protein; Source; Stimulus; Technology; Testing; Therapeutic; Tissue Engineering; Tissue Model; Tissue Sample; Tissues; Translating; United States; Up-Regulation; Validation; bioprinting; chronic liver disease; clinical application; clinical translation; clinically relevant; clinically significant; design; drug testing; genetic signature; human disease; human model; human tissue; implantation; induced pluripotent stem cell; innovation; liver function; liver transplantation; mechanical properties; mechanotransduction; mortality; multidisciplinary; novel strategies; novel therapeutics; predictive modeling; prognostic model; replacement tissue; response; rho; scaffold; targeted treatment; therapeutic target

PROJECT SUMMARY Liver fibrosis, and ultimately cirrhosis, is the final common pathway of chronic liver diseases induced by any etiology. Liver failure due to cirrhosis is the 12th leading cause of death by disease in the United States and there is no effective current treatment other than liver transplantation. One hallmark of liver cirrhosis is that the liver extracellular matrix becomes stiffer, but how the stiffened microenvironment causes hepatocyte dysfunction is not completely understood. Our proposed research addresses this gap in knowledge and is designed to deliver data that will lead to tangible advances in the treatment of liver cirrhosis, which may include development of 1) novel therapies that maintain adequate liver function in patients with progressive fibrotic liver disease, 2) clinical prognostic models that predict which patients with resolving fibrosis may regain sufficient hepatic function, and 3) highly functional tissue-engineered liver constructs for tissue replacement therapy in patients with end-stage liver insufficiency. Our preliminary studies show that hepatocytes are exquisitely responsive to the mechanical cues of extracellular matrix tuned to the stiffness of fibrotic livers, and that the induced downstream signaling pathways (i.e. mechanotransduction) directly inhibit hepatocyte function. Using a multi-disciplinary cross-modality approach, we propose to further delineate the mechanism of how a stiffened microenvironment induces hepatocyte dysfunction and its clinical applicability. These scientific objectives will be achieved first, by determining the key molecular players that translate mechanical cues into intracellular signals that inhibit hepatocyte function using genetically engineered mouse models with tissue-specific and temporally-induced expression of key mechanotransduction molecules. Subsequently, we propose to verify the clinical relevance of these molecular mechanisms by characterizing matrix rigidity at the microscale level in normal and cirrhotic human livers as determined by atomic force microscopy, in conjunction with single-cell gene expression analysis. Finally, we propose to test whether the relationship between microenvironment rigidity and hepatocyte function may be recapitulated in complex tissue-engineered liver constructs that are produced by three-dimensional bioprinting ex vivo and tuned to the stiffness of normal or fibrotic human liver. The proposed research is conceptually innovative because, instead of attempting to therapeutically target the process of fibrosis, we aim to understand the hepatocyte response to fibrosis, thereby prompting new approaches to treat and prognosticate chronic liver disease that focus on modulating the hepatocyte response to the fibrotic stimulus. It is, in the end, liver functional failure that causes death from liver disease, and not necessarily the process of fibrosis in itself. Results from this proposed study will authoritatively define the role of matrix rigidity in modulating hepatocyte function and illuminate several paths toward clinical translation.

项目摘要 肝纤维化，最终肝硬化，是由任何原因引起的慢性肝病的最终共同途径。 病因学在美国，肝硬化导致的肝衰竭是疾病死亡的第12大原因， 除了肝移植外，目前没有有效的治疗方法。肝硬化的一个标志是 肝细胞外基质变得更硬，但硬化的微环境如何导致肝细胞 功能障碍尚未完全了解。我们提出的研究解决了这一知识差距， 旨在提供将导致肝硬化治疗取得切实进展的数据，其中可能包括 开发1）在进行性肝纤维化患者中维持足够肝功能的新疗法 2）临床预后模型，其预测哪些具有消退纤维化的患者可以重新获得足够的 肝功能，和3）用于组织替代疗法的高功能性组织工程化肝脏构建体， 终末期肝功能不全患者。我们的初步研究表明，肝细胞 响应于细胞外基质的机械提示，调节纤维化肝脏的硬度， 诱导的下游信号传导途径（即机械转导）直接抑制肝细胞功能。使用 一个多学科的跨模态的方法，我们建议进一步描绘的机制，如何僵硬 微环境诱导肝细胞功能障碍及其临床应用。这些科学目标将 首先，通过确定将机械信号转化为细胞内信号的关键分子， 使用具有组织特异性的基因工程小鼠模型抑制肝细胞功能， 暂时诱导关键机械转导分子的表达。随后，我们提议核查 这些分子机制的临床相关性，通过表征基质硬度在微观水平， 通过原子力显微镜测定的正常人和肝硬化人的肝脏，结合单细胞 基因表达分析。最后，我们建议测试微环境之间的关系是否 刚性和肝细胞功能可以在复杂的组织工程化肝脏结构中重现， 通过离体三维生物打印产生，并调整到正常或纤维化人类肝脏的硬度。 拟议的研究在概念上是创新的，因为，而不是试图治疗目标， 纤维化的过程中，我们的目标是了解肝细胞对纤维化的反应，从而促进新的 治疗和预防慢性肝病的方法，重点是调节肝细胞反应 纤维化刺激。最终，肝功能衰竭导致肝病死亡，而不是 纤维化的过程。从这项拟议的研究结果将authority定义的作用 基质刚性在调节肝细胞功能中的作用，并阐明了临床转化的几条途径。