ECM REMODELING IN EXCESSIVE FIBROPLASIA

阐明过度瘢痕形成的细胞和分子基础 在伤口修复过程中。 本申请将集中于蜂窝通信系统。 正常瘢痕和瘢痕疙瘩成纤维细胞之间的分子差异 特别强调PAI/uPA系统调节的改变 瘢痕疙瘩成纤维细胞中。从本研究中获得的信息可能导致 预防和治疗过度瘢痕的方法进展 在伤口修复过程中形成。 调查人员将接近长 通过阐明过度瘢痕的病理机制， 使用体外纤维增生模型作为环境， 干扰由正常瘢痕和纤维化引导的基质重塑 成纤维细胞 研究人员已经证明了瘢痕疙瘩 成纤维细胞表现出纤维蛋白基质重塑的变化， 纤溶酶原激活物抑制剂-1（PAI-1）和基础水平升高 和转化生长因子-β（TGF-β）刺激水平的 胶原 这些变化可能在TGF-β受体水平介导， 由于瘢痕疙瘩中TGF-β I型受体分布的差异 鉴定成纤维细胞。 研究人员假设a）， 瘢痕疙瘩成纤维细胞中PAI-1表达增加直接导致 瘢痕疙瘩中的纤维蛋白降解缺陷和持续性纤维增生，以及 B）增加对TGF-B的反应性，由改变的 受体的表达，诱导瘢痕疙瘩中PAI-1表达升高 细胞 研究人员将用四个具体的假设来检验这些假设。 目的：具体目的1：表征基质重塑表型 正常瘢痕和瘢痕疙瘩成纤维细胞。具体目标二。 以测试 uPA/PAI-1与 通过操纵uPA/PAI表型的纤维蛋白降解的急性变化 使用逆转录病毒在正常瘢痕和瘢痕疙瘩成纤维细胞中的表达 将PAI-1/反义PAI-1转导到这些细胞中。 具体目标 三. 以确定是否存在直接因果关系 特异性改变的uPA/PAI-1表型与 随着时间的推移而发展的重塑ECM。 具体目标四。表征 瘢痕疙瘩成纤维细胞的TGF-β受体，并确定是否配体 结合或受体信号传导负责增加 该模型中瘢痕疙瘩成纤维细胞合成PAI-1和胶原。

To elucidate the cellular and molecular basis of excess scar formation during wound repair. The present application will focus on the cellular and molecular differences between normal scar and keloid fibroblasts with a special emphasis on the altered regulation of the PAI/uPA system in keloid fibroblasts. Information obtained from this study may lead to development of methods for prevention and treatment of excess scar formation during wound repair. The investigators will approach the long term goal by elucidating the pathologic mechanisms of excess scar formation using an in vitro fibroplasia model as an environment for perturbing matrix remodeling directed by normal scar and fibrotic fibroblasts. The investigators have demonstrated that keloid fibroblasts exhibit changes in fibrin matrix remodeling by expressing elevated levels of plasminogen activator inhibitor-1 (PAI-1) and basal and transforming growth factor-beta (TGF-b) stimulated-levels of collagen. These changes may be mediated at the TGF-b receptor level, since a difference in the TGF-b type I receptor profile in keloid fibroblasts was identified. The investigators hypothesize a) that increased expression of PAI-1 in keloid fibroblasts leads directly to defective fibrin degradation and persistent fibroplasia in keloids, and b) that increased responsiveness to TGF-b, mediated by an altered profile of receptors, induces this elevated PAI-1 expression in keloid cells. The investigators will test these hypotheses with four specific aims: Specific Aim 1: To characterize a matrix remodeling phenotype for normal scar and keloid fibroblasts. Specific Aim II. To test for the presence of a cause and effect relationship between uPA/PAI-1 and acute changes in fibrin degradation by manipulating uPA/PAI phenotypic expression in normal scar and keloid fibroblasts using retroviral transduction of PAI-1/antisense PAI-1 into these cells. Specific Aim III. To determine if a direct cause and effect relationship exists between a specifically altered uPA/PAI-1 phenotype and the nature of the remodeled ECM that develops over time. Specific Aim IV. To characterize TGF-b receptors from keloid fibroblasts and determine whether ligand binding or receptor signaling are responsible for the increased synthesis of PAI-1 and collagen by keloid fibroblasts in this model.