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）：此申请响应于NOT-OD-09-058-通知标题为NIH，宣布了竞争性修订申请的恢复法案资金的可用性。 R01 -DK058123的此竞争性修订应用程序的目的是添加一个其他特定目标 - 与现有的三个目标直接相关，并从已经生成的数据中衍生出来 - 研究桥接纤维化的机械因素。父授予的目标是开发一种纤维化模型，该模型结合了可溶性，细胞和机械因素。最初的建议集中在早期纤维化上，尤其是肝脏的早期机械变化，从而带来了肌纤维细胞分化的有利环境。三个最初的特定目的是：1）确定整联蛋白在肌纤维细胞分化过程中的肝星状细胞（HSC）机械传感器中的作用； 2）开发一种纤维化的机械模型，该模型同时融合了HSC和门户成纤维细胞（PF）分化，并着重于表征区域机械差异； 3）鉴定纤维化中基质刚度的介体，特别关注胶原蛋白交联酶的赖氨酸氧化酶（LOX）家族。我们的原始模型扩展到HSC和PF分化为纤维纤维纤维细胞的点。我们在这里提议扩展模型，以涵盖桥接纤维化中发生的结构变化。我们建议从肝脏的区域力学和HSC和PF在僵硬的环境中的收缩特性结合起来，从机理上进行桥接纤维化。我们提出以下假设：早期纤维化中的机械异质性与肌成纤维细胞收缩力相结合可以解释桥接纤维化的发展。新的具体目的是确定机械因素（肌纤维细胞收缩性和肝脏刚度的区域增加）对桥接纤维化的发展的贡献。研究计划包括1）纤维化大鼠肝组织的详细形态分析，以证明胶原纤维易位和比对的证据； 2）使用第二谐波分析胶原蛋白原纤维方向，并使用显微标记技术比较早期纤维化中的门户和中间区域的刚度； 3）在体内纤维化模型中使用岩石1小鼠来确定是否需要桥接纤维化发生细胞介导的整联蛋白粘附和牵引力。如果证明该提议的基础假设是正确的，则将对理解和治疗纤维化具有重大影响。 公共卫生相关性：晚期肝纤维化和疾病的终阶段，肝硬化是慢性肝损伤的毁灭性并发症。纤维化发展最终成为肝硬化的机制尚不清楚。该应用提出了一个新的模型来解释纤维化进展的组成部分，如果这里提出的实验支持，该模型将对理解和治疗纤维化具有重要意义。