GENE TRANSFER OF FIBRINOLYTIC AGENTS IN LUNG FIBROSIS

导致肺纤维化的一系列致病过程 表示多条并行的冗余路径。一种治疗方法 针对多个路径共同的单个步骤的干预将 是目前令人沮丧的治疗选择的一个受欢迎的补充 治疗肺纤维性疾病。在许多炎症性肺部疾病期间， 纤维蛋白在肺泡腔内积聚，部分原因是 肺泡腔正常纤溶活性的损害。 纤维蛋白的持续存在具有重要的病理意义，因为它可以 作为一种支架，成纤维细胞在其上侵入形成胶原疤痕。 使用转基因小鼠，我们最近发现纤维化量 气管内注射博莱霉素酶活性对其影响较大。 纤溶系统。纤溶功能受抑的转基因小鼠 小鼠纤溶酶原激活物过表达的活性 抑制物-1(PAI-1)转基因导致纤维化增加，而 灭活的PAI-1基因相对受到保护。这些结果加在一起 结合其他人的观察，鼓励我们探索 促进肺泡腔纤溶酶原激活的策略 一种在肺部炎症过程中限制纤维化的方法。尽管一个 可以使用的方法有很多，我们选择使用基因 转移技术作为增强纤维溶解作用的手段。我们的经验 通过这种模式，我们得出结论，肺定向基因 使用重组腺病毒载体的转移可以提供这种手段 为了验证我们的假设：血管内纤溶活性的增强 使用基因转移技术的肺泡腔将减少肺组织 伴随炎症性肺损伤的纤维化。 我们提出三个具体目标： 1)尿激酶型纤溶酶原激活物(UPA)和纤溶酶原激活物(PAI)的转移基因 1耐药uPA体外对人和小鼠细胞的作用 对细胞介导的纤溶酶原激活和纤维蛋白基质的影响 退化。 2)将uPA和PAI-1耐药的uPA基因转移到小鼠肺内 并测定对纤溶酶原激活物活性和纤维蛋白的影响 肺泡腔内的降解。 3)将uPA和PAI-1耐药的uPA基因转移到小鼠肺内 并测定其对炎症所致肺纤维化的影响。 除了评估一种新的治疗纤维化肺的策略 疾病，我们的研究将提供关于 纤溶与肝纤维化的关系及体内基因研究 转移到远端空域。另一个好处是提供 将基因转移技术应用于该SCOR的其他项目(见项目 5)。

The spectrum of pathogenic processes that leads to pulmonary fibrosis represents a number of parallel, redundant pathways. A therapeutic intervention that targets a single step common to multiple pathways would be a welcome addition to the currently dismal state of treatment options for fibrotic lung diseases. During many inflammatory lung diseases, fibrin accumulates within the alveolar compartment, due in part to impairment of the normally fibrinolytic activity of the alveolar space. The persistence of fibrin has pathologic importance because it can serve as a scaffold on which fibroblasts invade to form collagenous scars. Using transgenic mice, we have recently found that the amount of fibrosis induced by intratracheal bleomycin is strongly influenced by the activity of the fibrinolytic system. Transgenic mice with suppressed fibrinolytic activity from over-expression of a murine plasminogen activator inhibitor-1 (PAI-1) transgene develop increased fibrosis, while mice with inactivated PAI-1 genes are relatively protected. These results, combined with the observations of others, have encouraged us to explore the strategy of increasing plasminogen activation in the alveolar space as a means to limit fibrosis during pulmonary inflammation. Although a number of approaches could be employed, we have elected to use gene transfer technology as the means to augment fibrolysis. Our experience with this modality leads us to conclude that pulmonary directed gene transfer using recombinant adenovirus-based vectors can supply the means to test our Hypothesis: Enhancement of fibrinolytic activity within the alveolar space using gene transfer technology will reduce the pulmonary fibrosis that accompanies inflammatory lung injury. We propose three Specific Aims: 1) Transfer genes for urokinase-type plasminogen activator (uPA) and PAI- 1-resistant uPA to human and murine cells in vitro and determine the effects on cell-mediated plasminogen activation and fibrin matrix degradation. 2) Transfer genes for uPA and PAI-1-resistant uPA to the lungs of mice and determine the effects on plasminogen activator activity and fibrin degradation within the alveolar space. 3) Transfer genes for uPA and PAI-1-resistant uPA to the lungs of mice and determine the effects on pulmonary fibrosis induced by inflammation. In addition to evaluating a novel therapeutic strategy for fibrotic lung diseases, our studies will provide valuable information on the relationship between fibrinolysis and fibrogenesis, and on in vivo gene transfer to the distal airspaces. A further benefit will be the provision of gene transfer technology to other Projects of this SCOR (see Project 5).