siRNA Inhibition of Keloid Fibrosis in Fibrin Matrix Skin Equivalent Mouse Models

描述（由申请人提供）：瘢痕疙瘩是一种旺盛的肿瘤样皮肤瘢痕，在10 - 20%的深色皮肤人种中，非洲人、西班牙人和亚洲人后裔。目前没有有效的治疗方法来预防或控制瘢痕疙瘩病变的生长和扩展，这对受影响个体的心理社会和整体健康状态是严重的。该提案的目标是通过创建瘢痕疙瘩纤维化的基因靶向和纤维蛋白基质皮肤等效小鼠模型，并评估RNA干扰治疗方法，来弥合瘢痕疙瘩研究中的根本障碍。该计划是基于Tuan博士的长期研究努力以及Tuan博士和Benya博士（多个/Co-PI）的合作努力在瘢痕疙瘩发病机制方面的最新进展。目前不存在适用于常规测试或准确反映人类病变的瘢痕疙瘩纤维化动物模型。此外，为了开发基于知识的治疗方法及其在瘢痕疙瘩的临床应用，候选基因必须在动物模型中进行体内验证，并在此类模型中显示出对靶向治疗的反应。在本申请中提出了三个具体目标来解决这些障碍。特定目标的完成将提供基于临时伤口基质的三维纤维蛋白凝胶模拟物的稳健的、基因靶向的、瘢痕疙瘩衍生的皮肤等效动物模型。此外，我们的靶基因派-1被瘢痕疙瘩成纤维细胞过表达，并已被鉴定为体外正常和瘢痕疙瘩成纤维细胞中胶原积累的原因（发表于Am J Pathol.，2008年11月），将在体内被验证为瘢痕疙瘩纤维化的重要介质，同时证明RNA干扰治疗方法的功效。最后，在模型中模拟瘢痕疙瘩纤维化的正常人成纤维细胞系的遗传操作将在疗效评价中提供瘢痕疙瘩成纤维细胞的替代品，并避免瘢痕疙瘩组织的有限供应用于常规测试。我们还期望这些结果和工具将提高瘢痕疙瘩发病机制的发现研究率，此外，为其他研究人员提供一个易于修改的平台，以验证瘢痕疙瘩纤维化中感兴趣的靶基因并测试其他新的治疗方法。

DESCRIPTION (provided by applicant): Keloids are exuberant, tumor-like skin scars that occur unpredictably after injury to the skin in 10 to 20 % of dark skin races, i.e., people of African, Hispanic, and Asian descents. Currently there is no effective treatment to prevent or control the growth and expansion of keloid lesions, which are grievous to the psycho-social and overall health state of the affected individual. The goal of the proposal is to bridge the fundamental obstacles in keloid research by creating gene-targeted and fibrin matrix skin equivalent mouse models of keloid fibrosis, and assessing a RNA interference therapeutic approach. The plan is based on the long-term research effort of Dr. Tuan and the recent progress in keloid pathogenesis from the collaborative effort of Drs. Tuan and Benya (Multiple/Co-PIs). No animal models of keloid fibrosis currently exist that are applicable to routine testing or accurately reflect the human lesion. Moreover, for the development of knowledge-based therapies and their clinical application for keloids, candidate genes must be validated in vivo in animal models and shown to be responsive to targeted therapeutic treatments in such models. Three specific aims are proposed in this application to address the obstacles. Completion of the specific aims will provide a robust, gene-targeted, keloid-derived, skin equivalent animal model based on a three-dimensional fibrin gel mimic of provisional wound matrix. In addition, our target gene PAI-1, which is overexpressed by keloid fibroblasts and has been identified as causative in collagen accumulation in normal and keloid fibroblasts in vitro (published in Am J Pathol., Nov 2008), will have been validated in vivo as an important mediator of keloid fibrosis, while simultaneously demonstrating efficacy of an RNA interference therapeutic approach. Finally, the genetic manipulation of a normal human fibroblast cell line to mimic keloid fibrosis in the model will provide a substitute for keloid fibroblasts in efficacy evaluation and circumvent the limited supply of keloid tissues for routine testing. We also expect that these results and tools will enhance the rate of discovery research in keloid pathogenesis, furthermore, provide a platform, easily modified, for other investigators to validate target genes of interest in keloid fibrosis and test additional novel therapeutic approaches.