The Role of FAK-related-non-kinase (FRNK) in Lung Fibrosis

描述(申请人提供)：特发性肺纤维化(IFF)的特征是成纤维细胞/肌纤维母细胞病灶和细胞外基质(ECM)蛋白过度聚集，其中成纤维细胞向受损区域的迁移起关键作用。粘着斑激酶(FAK)介导整合素和生长因子启动的细胞迁移。在间充质细胞中过表达FAK的C端同源蛋白FAK相关的非激酶(Frnk)，可抑制由生长因子和整合素受体促进的FAK依赖的细胞迁移。然而，Frnk在肺成纤维细胞迁移中的作用以及它在体内包括肺纤维化在内的组织损伤/修复过程中的作用仍不清楚。我们假设FrnK通过抑制依赖于FAK的成纤维细胞迁移来调节体内的肺纤维化。为了验证这一假设，本文提出了三个具体目标。在特定的目标1中，我们将确定FrnK在抑制FAK介导的肺成纤维细胞迁移和迁移信号中的作用。使用来自肺纤维化患者和非纤维化对照的患者来源的原代人肺成纤维细胞，将在获得/丧失Frnk功能的方法中测试成纤维细胞的迁移。在特定的目标2中，我们将在体内确定Frnk在肺纤维化中的作用。对促纤维化药物博莱霉素的损伤/修复反应将在frnk基因敲除小鼠和同源野生型小鼠中进行评估。此外，还将确定从这些小鼠分离的原代肺成纤维细胞的细胞迁移和迁移信号。FRNK在骨髓源性细胞和纤维细胞的募集和由此产生的纤维化效应，以及在骨膜-间充质转化和肌成纤维细胞分化中的作用将被确定。在特定的目标3中，我们将确定在博莱霉素诱导的肺纤维化中FRANK的表达与纤维增生性病变的时空关系，并表征肺成纤维细胞中FRANK表达的体内介体。这些数据将支持或驳斥我们的假设，即FRANK在肺损伤和修复过程中调节成纤维细胞的迁移，从而影响体内的纤维化过程。这些研究将支持我的实验室的长期目标，即利用从这些研究中获得的知识，开发针对人类特发性肺纤维化的新的治疗方法。

DESCRIPTION (provided by applicant): Idiopathic pulmonary fibrosis (IFF) is characterized by fibroblast/myofibroblastic foci and excessive extracellular matrix (ECM) protein accumulation, in which fibroblast migration into the injured areas plays a critical role. Focal Adhesion Kinase (FAK) mediates integrin- and growth factor-initiated cell migration. Overexpression of FAK's C-terminal homologous protein, FAK-related-non-kinase (FRNK), inhibits FAKdependent cell migration promoted by growth factors and integrin receptors in mesenchymal cells. However, the role of FRNK in lung fibroblast migration and its role in tissue injury/repair processes in vivo including lung fibrosis remain undefined. We hypothesize that FRNK modulates lung fibrosis in vivo through inhibition of FAK-dependent fibroblast cell migration. To test this hypothesis, three specific aims are proposed. In Specific Aim 1, we will determine the role of FRNK in inhibiting FAK-mediated lung fibroblast cell migration and migration signaling. Fibroblast migration will be tested in gain/loss of FRNK function approaches using patient-derived primary human lung fibroblast cells from pulmonary fibrotic patients and non-fibrotic controls. In Specific Aim 2, we will determine the role of FRNK in lung fibrosis in vivo. The injury/repair response to the pro-fibrotic agent, Bleomycin, will be assessed in FRNK-knockout mice and congenic wild type mice. Furthermore, cell migration and migration signaling of primary lung fibroblasts isolated from these mice will be determined. The role of FRNK in the recruitment, and its resultant fibrotic effects, on bone-marrow derived cells and fibrocytes, and on epitheilal-mesenchymal transition, and on myofibroblast differentiation will be determined. In Specific Aim 3, we will determine the spatial-temporal relationship of FRNK expression with fibroproliferative lesions in Bleomycin-induced lung fibrosis, and characterize the in vivo mediators of FRNK expression in lung fibroblasts. These data will either support or refute our hypothesis that FRNK modulates fibroblast migration during lung injury and repair, and thereby affects the fibrotic processes in vivo. These studies will support the long-term goal of my laboratory to utilize knowledge gained from these studies to develop novel therapeutic approaches targeted to idiopathic pulmonary fibrosis in humans.