Targeting matrix stiffness in lung and liver fibrosis

项目总结 间质硬化是肺和肝纤维化的一个明显特征。虽然传统上被视为终端，但矩阵 硬化症现在被认为是在纤维化开始的早期发展起来的，并且对疾病有显著的贡献。 肺成纤维细胞(LFS)或肝脏来源的肌成纤维细胞机械激活的进展 星状细胞(HSC)。我们团队和其他人最近的研究已经确定了转录效应因子YAP 和TAZ作为LF和HSC机械活化的关键介质，证明了一个共同的分子 在这两个器官中，肌成纤维细胞激活的机制是基础。在这里，我们建议戏剧性地扩展 我们对YAP和TAZ的关注不仅仅是作为对基质僵硬的反应，而且作为启动的中心效应器， 放大并维持由LFS和HSC驱动的基质硬化，从而突出它们作为靶标的潜力 用于针对基质自身硬化的治疗。在我们的第一个目标中，我们将阐明YAP 和TAZ在LF和HSC介导的肺和肝脏硬化的启动、维持和传播中发挥作用， 应用异种移植研究细胞介导的完整器官僵硬和模型ECM的细胞重塑 为了阐明YAP和TAZ通过细胞外基质收缩在基质硬化中的具体作用， 合成、交联和击穿。认识到YAP和TAZ在众多 细胞类型和上下文，在我们的第二个目标中，我们试图确定LF/HSC特异性PRO-1的机制。 纤维化激活的YAP和TAZ可以选择性地消融。我们专注于一种机械性的方法来实现目标G 通过Gs/cAMP途径的蛋白偶联受体信号失活YAP的细胞特异性机制 和TAZ并消融LF和HSC的激活，即使面对促纤维化僵硬的基质条件。侵入性 原子力显微镜(AFM)和无创磁共振弹性成像(MRE)方法将是 用来测试靶向这些通路在预防或逆转预激反应中基质僵硬的效果 肺、肝纤维化的临床模型。拟议的研究将阐明新的分子机制。 在体外和体内将细胞激活与基质硬化联系起来，并确定消融LF和 以细胞特异性方式激活HSC，迈向针对基质僵硬的新疗法的重要第一步 和纤维化症。MRE作为评价基质治疗靶向性和临床进展的指标的有效性 僵硬将使我们能够将这种方法应用于肺纤维化患者的临床 还有肝脏。

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.