Matrix Regulation of Cell Function During Wound Healing

描述（由申请人提供）： 致病性瘢痕形成和纤维化代表了重要的临床问题，对患者具有潜在的严重后果，包括正常组织再生和邻近组织功能的损害。我们的长期目标是确定控制成纤维细胞分化为肌成纤维细胞的关键调节机制，从而开发控制瘢痕和纤维化的新策略。虽然TGF-β是这一机制的关键组成部分，但目前的证据表明，机械应力和含EIIIA的纤维连接蛋白（FN）都很重要。EIIIA（或ED-A）节段是FN内一系列弹簧样节段之一，被假设为抑制机械信号。该提案的具体目的是通过在愈合伤口中从细胞FN中消除EIIIA来靶向肌成纤维细胞分化，并鉴定控制肌成纤维细胞分化的EIIIA依赖性细胞内靶标。使用EIIIA空和野生型小鼠，我们将研究成纤维细胞分化和肌成纤维细胞的功能，利用组织学，免疫组织化学，定量蛋白质分析和张力测定的过程。我们还将在体外测试机械力和侧翼FN序列对EIIIA-整联蛋白相互作用的影响。用从无效或野生型小鼠分离的成纤维细胞以及建立的人系进行的实验将确定含EIIIA的FN、相关整合素和信号传导蛋白如何调节成肌纤维细胞分化。从这项工作中获得的发现将填补理解肌成纤维细胞调节的重要空白，并提出调节纤维化的新治疗策略。

DESCRIPTION (provided by applicant): Pathogenic scarring and fibrosis represent important clinical problems with potentially serious consequences for patients, including impairment of normal tissue regeneration and neighboring tissue function. Our long term goal is to identify the critical regulatory mechanisms that govern fibroblast differentiation into myofibroblasts and thereby develop new strategies to control scarring and fibrosis. Although TGF-beta is a critical component of this mechanism, current evidence suggests that both mechanical stresses and EIIIAcontaining fibronectins (FNs) are important. The EIIIA (or ED-A) segment is one of a series of spring-like segments within FN hypothesized to transduce mechanical signals. The specific aims of this proposal are to target myofibroblast differentiation by eliminating EIIIA from cellular FN in healing wounds and to identify EIIIA-dependent intracellular targets that control myofibroblast differentiation. Using EIIIA null and wild type mice, we will examine the process of fibroblast differentiation and myofibroblast function utilizing histology, immunohistochemistry, quantitative protein analyses and tensiometry. We will also test the impact of mechanical force and flanking FN sequences on EIIIA- integrin interactions, in vitro. Experiments performed with fibroblasts isolated from null or wild type mice, as well as established human lines, will determine how the EIIIA-containing FNs, relevant integrins and signaling proteins regulate myofibroblast differentiation. Findings obtained from this work will fill impotant gaps in understanding myofibroblast regulation and suggest new therapeutic strategies to modulate fibrosis.