[Changes in TGF-beta 1 and type I, III procollagen gene expression in keloid and hypertrophic scar].

OBJECTIVE: The expression of mRNA for TGF-beta 1, type I, III procollagen in keloid and hypertrophic scar was investigated in order to elucidate the pathogenesis of and the difference between keloid and hypertrophic scar. METHOD: Dot-blot hybridization analysis was used to examine the type I, III procollagen and the expression levels of steady-state mRNA. In situ hybridization allowed direct assessment of the distribution of TGF-beta 1 mRNA in the tissue. RESULTS: 1. Our study indicated that the expression level of mRNA for TGF-beta 1 significantly increased in keloid and hypertrophic scar compared with normal scar and normal skin. 2. In keloid tissues, type I precollagen mRNA expression was selectively increased. However, in hypertrophic scar, type I and III collagen mRNAs expressions were simultaneously increased. CONCLUSION: TGF-beta 1 plays an important role in the pathogenesis of keloid and hypertrophic scarring. It implicates that distinct molecular mechanisms are operative in the development of keloid and hypertrophic scarring.