The long term goal of the research is to elucidate the cellular and molecular basis of excess scar formation during wound repair. Keloids are tumor-like skin scars that affect 10 to 20% of people of African decent, Asians, and Hispanics without appropriate treatments. During the past funding period, we used 14 freshly isolated and low passages (<3) strains of normal and keloid fibroblasts from human patients and provided new evidence that (PAI-1) overexpression and elevated collagen accumulation are intrinsic features of keloid fibroblasts. We also provided new and different evidence of a causal relationship between PAI-1 expression and collagen accumulation: adenoviral overexpression and siRNA and shRNAmir suppression demonstrate that PAI-1 produces elevated collagen accumulation in normal and keloid fibroblasts, respectively. Finally, by testing protease-inhibitory and vitronectin-binding mutants of PAI-1 for their capacity to induce collagen accumulation, we found that the latter was equipotent with wild-type PAI-1 and the former was only ~50% effective. Thus, PAI-1 utilizes protease inhibition as well as another of its functions to control collagen accumulation (Tuan et al., 2008, Am J Pathol). The goals of the renewal application are 1) to advance a therapeutic strategy that targets plasminogen activator inhibitor-1 (PAI-1) to control keloid collagen accumulation and prevent or treat keloid formation;2) to further define and expand the mechanisms utilized by PAI-1 to regulate collagen accumulation in keloid fibroblasts.
The long term goal of the research is to elucidate the cellular and molecular basis of excess scar formation during wound repair. The goals of the renewal application are to advance two potential therapeutic strategies in targeting plasminogen activator inhibitor- 1 to control keloid collagen accumulation based on our laboratory findings using freshly isolated/early passages of human patient cells, and to further the mechanism underlying PAI-1-dependent and -independent regulation of keloid collagen accumulation.
