TGF-beta, matrix, and myofibroblasts in hepatic fibrosis

肝纤维化中的 TGF-β、基质和肌成纤维细胞

• 批准号: 7811750
• 负责人: REBECCA G WELLS
• 金额: $ 23.9万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-30 至 2011-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7811750
• 关键词: Area; Cells; Chronic; Cirrhosis; Collagen; Collagen Fibril; DNA Sequence Rearrangement; Data; Deposition; Development; Environment; Enzymes; Extracellular Matrix; Family; Fibroblasts; Fibrosis; Figs - dietary; Funding; Goals; Grant; Hepatic Stellate Cell; Heterogeneity; Injury; Integrin-mediated Cell Adhesion Pathway; Integrins; Literature; Liver; Liver Fibrosis; Mechanics; Mediating; Mediator of activation protein; Methods; Modeling; Movement; Mus; Myofibroblast; Parents; Pattern; Population; Property; Protein-Lysine 6-Oxidase; ROCK1 gene; Rattus; Recovery; Research; Reticulin; Role; Staging; Staining method; Stains; Stream; Techniques; Testing; Tissues; Traction; Transforming Growth Factor beta; United States National Institutes of Health; Work; base; crosslink; end stage disease; in vivo; parent grant; public health relevance; research study; response; second harmonic

DESCRIPTION (provided by applicant): This application is in response to NOT-OD-09-058 - Notice entitled NIH Announces the Availability of Recovery Act Funds for Competitive Revision Applications. The goal of this competitive revision application for R01-DK058123 is to add an additional specific aim - directly related to the three existing aims and derived from data already generated - to investigate mechanical factors in bridging fibrosis. The goal of the parent grant is to develop a model of fibrosis that incorporates soluble, cellular, and mechanical factors. The original proposal concentrated on early fibrosis, in particular on early mechanical changes in the liver that resulted in a favorable environment for myofibroblastic differentiation. The three original specific aims were: 1) To determine the role of integrins in hepatic stellate cell (HSC) mechanosensing during myofibroblastic differentiation; 2) To develop a mechanical model of fibrosis that incorporated both HSC and portal fibroblast (PF) differentiation, with an emphasis on characterizing regional mechanical differences; and 3) To identify mediators of matrix stiffness in fibrosis, with a particular focus on the lysyl oxidase (LOX) family of collagen cross-linking enzymes. Our original model extended to the point where HSC and PF differentiated into fibrogenic myofibroblasts. We propose here to extend the model to encompass the architectural changes that occur in bridging fibrosis. We suggest that bridging fibrosis results mechanistically from the regional mechanics of the liver combined with the contractile properties of HSC and PF in a stiff environment. We propose the following hypothesis: that mechanical heterogeneity in early fibrosis combined with myofibroblast contractility can explain the development of bridging fibrosis. The new specific aim is to determine the contribution of mechanical factors (myofibroblast contractility and regional increases in liver stiffness) to the development of bridging fibrosis. The research plan includes 1) a detailed morphological analysis of fibrotic rat liver tissue for evidence of collagen fibril translocation and alignment; 2) an analysis of collagen fibril orientation using second harmonics and a comparison, using microindentation techniques, of the stiffness in portal and intervening regions in early fibrosis; and 3) use of ROCK1 mice in an in vivo fibrosis model to determine whether cell-mediated integrin adhesion and traction is required for bridging fibrosis to occur. If the hypothesis underlying this proposal is proven correct, it would have major implications for understanding and, potentially, treating fibrosis. PUBLIC HEALTH RELEVANCE: Late stage liver fibrosis and the end-stage of the disease, cirrhosis, are devastating complications of chronic liver injury. The mechanisms whereby fibrosis progresses, eventually becoming cirrhosis, are not well understood. This application proposes a new model to explain components of fibrosis progression, that, if supported by the experiments proposed here, would have significant implications for the understanding and treatment of fibrosis.

描述（由申请人提供）：本申请是对NOT-OD-09-058 -通知的回应，标题为NIH宣布恢复法案资金可用于竞争性修订申请。R 01-DK 058123的竞争性修订申请的目的是增加一个额外的特定目的-与现有的三个目的直接相关，并来源于已生成的数据-以研究桥接纤维化的机械因素。该基金的目标是开发一种结合可溶性、细胞和机械因素的纤维化模型。最初的建议集中在早期纤维化，特别是在肝脏的早期机械变化，导致一个有利的环境，肌纤维母细胞分化。三个最初的具体目标是：1）确定整合素在成肌纤维细胞分化期间肝星状细胞（HSC）机械感受中的作用; 2）开发一种纤维化的机械模型，其包括HSC和门静脉成纤维细胞（PF）分化，重点在于表征区域机械差异;和3）鉴定纤维化中基质硬度的介质，特别关注胶原交联酶的赖氨酰氧化酶（LOX）家族。我们最初的模型扩展到HSC和PF分化为纤维化肌成纤维细胞的点。我们建议在这里扩展模型，以包括发生在桥接纤维化的结构变化。我们认为，桥接纤维化的结果机械地从区域力学的肝脏相结合的收缩性能的HSC和PF在一个僵硬的环境。我们提出以下假设：早期纤维化的力学异质性结合肌成纤维细胞收缩性可以解释桥接纤维化的发展。新的具体目标是确定机械因素（肌成纤维细胞收缩性和肝脏硬度的区域增加）对桥接纤维化发展的贡献。研究计划包括：1）对纤维化大鼠肝组织进行详细的形态学分析，以寻找胶原纤维移位和排列的证据; 2）使用二次谐波分析胶原纤维的方向，并使用显微压痕技术比较早期纤维化中门静脉和介入区域的硬度;和3）在体内纤维化模型中使用ROCK 1小鼠以确定桥接纤维化的发生是否需要细胞介导的整联蛋白粘附和牵引。如果这一假设被证明是正确的，它将对理解和治疗纤维化产生重大影响。 公共卫生相关性：晚期肝纤维化和疾病的终末期肝硬化是慢性肝损伤的毁灭性并发症。纤维化进展，最终成为肝硬化的机制还不清楚。本申请提出了一种新的模型来解释纤维化进展的组成部分，如果得到本文提出的实验的支持，将对纤维化的理解和治疗产生重大影响。