Targeting matrix stiffness in lung and liver fibrosis

项目摘要 基质硬化是肺和肝纤维化的一个定义特征。虽然传统上被视为端点，但矩阵 现在认识到硬化在纤维化开始的早期发展，并显著促进疾病的发生。 通过机械活化源自肺成纤维细胞（LF）或肝成纤维细胞的肌成纤维细胞的进展 星状细胞（HSC）。我们小组和其他人最近的研究已经确定了转录效应子雅普 和TAZ作为LF和HSC机械激活的关键介质，表明一个共同的分子 在这两个器官中的肌成纤维细胞活化的基础机制。在这里，我们建议大幅扩大 我们关注的是雅普和TAZ不仅是对基质硬度的反应，而且是启动， 放大和维持由LF和HSC驱动的基质硬化，从而突出其作为靶点的潜力 用于针对基质硬化本身的治疗。在我们的第一个目标中，我们将阐明雅普 和TAZ在LF和HSC介导的肺和肝硬化的起始、维持和传播中起作用， 使用异种移植研究细胞介导的完整器官硬化和模型ECM的细胞重塑 为了阐明雅普和TAZ通过细胞外基质收缩对基质硬化的具体贡献， 合成、交联和分解。认识到雅普和塔兹在许多领域发挥着突出作用， 细胞类型和背景，在我们的第二个目标中，我们试图确定LF/HSC特异性促凋亡的机制， 雅普和TAZ的纤维化活化可以被选择性地消除。我们专注于一个机械的方法，以目标G 通过Gs/cAMP途径的蛋白偶联受体信号传导作为抑制雅普的细胞特异性机制 和TAZ，并且即使在面对促纤维化的刚性基质条件下也消融LF和HSC活化。侵入性 原子力显微镜（AFM）和非侵入性磁共振弹性成像（MRE）方法将被 用于测试靶向这些途径在预防或逆转预处理中基质硬化的功效。 肺和肝纤维化的临床模型。这些研究将阐明新的分子机制 在体外和体内将细胞活化与基质硬化联系起来，并确定消融LF的新方法， HSC以细胞特异性方式活化，是迈向靶向基质硬度的新疗法的重要第一步 和纤维化。验证MRE作为评价基质治疗靶向和临床进展的指标 硬化将使我们能够将这种方法应用于肺纤维化疾病患者的临床 和肝脏。

PROJECT SUMMARY Matrix stiffening is a defining feature of lung and liver fibrosis. While traditionally viewed as an endpoint, matrix stiffening is now recognized to develop early during fibrosis initiation, and to contribute prominently to disease progression through mechano-activation of myofibroblasts derived from lung fibroblasts (LFs) or hepatic stellate cell (HSCs). Recent studies by our group and others have identified the transcriptional effectors YAP and TAZ as key mediators of LF and HSC mechano-activation, demonstrating that a common molecular mechanism underlies myofibroblast activation in these two organs. Here we propose to dramatically expand our focus on YAP and TAZ not just as responders to matrix stiffness, but as central effectors that initiate, amplify, and maintain the matrix stiffening driven by LFs and HSCs, and thus highlight their potential as targets for therapy directed at matrix stiffening itself. In our first aim we will elucidate the mechanistic roles that YAP and TAZ play in initiation, maintenance and propagation of LF- and HSC-mediated lung and liver stiffening, using xenografting to study cell-mediated stiffening of the intact organ, and cellular remodeling of a model ECM to elucidate specific contributions of YAP and TAZ to matrix stiffening via extracellular matrix contraction, synthesis, crosslinking and breakdown. Recognizing that YAP and TAZ play prominent roles in a multitude of cell types and contexts, in our second aim we seek to identify mechanisms by which LF/HSC-specific pro- fibrotic activation of YAP and TAZ can be selectively ablated. We focus on a mechanistic approach to target G protein coupled receptor signaling through a Gs/cAMP pathway as a cell-specific mechanism to inactivate YAP and TAZ and ablate LF and HSC activation even in the face of pro-fibrotic stiff matrix conditions. Invasive atomic force microscopy (AFM) and non-invasive magnetic resonance elastography (MRE) approaches will be employed to test the efficacy of targeting these pathways in preventing or reversing matrix stiffening in pre- clinical models of lung and liver fibrosis. The proposed studies will elucidate novel molecular mechanisms linking cellular activation to matrix stiffening in vitro and in vivo, and identify new approaches to ablate LF and HSC activation in a cell-specific manner, important first steps toward new therapies targeting matrix stiffness and fibrosis. Validation of MRE as a metric to evaluate therapeutic targeting and clinical progression of matrix stiffening will position us to translate this approach to the clinic for patients with fibrotic diseases of the lung and liver.