ENHANCED EXPRESSION OF MESSENGER-RNA FOR TRANSFORMING GROWTH-FACTOR-BETA, TYPE-I AND TYPE-III PROCOLLAGEN IN HUMAN POSTBURN HYPERTROPHIC SCAR TISSUES

To explore the possible role of locally synthesized transforming growt h factor beta-1 (TGF-beta1) and procollagen gene expression in postbur n hypertrophic scars, we have compared mRNA levels for type I and type III procollagen and TGF-beta1 in human hypertrophic scar tissue with normal dermis obtained from the same patients as a control. Northern b lot analysis of total RNA extracted from hypertrophic scar tissue and normal skin demonstrated two transcripts for the pro-alpha 1(I) chain (5.8 kb and 4.8 kb) and for the pro-alpha 1(III) chain (5.4 kb and 4.8 kb) and one transcript (4.9 kb) for TGF-beta1. Quantitative analysis of dot blot autoradiograms of mRNA from three samples of hypertrophic scar tissue and normal skin showed average increases of 102% (p < 0.05 ) for pro-alpha 1(I), 91% (p < 0.06) for pro-alpha 1(III), and 61% (p < 0.05) for TGF-beta1. Three additional hypertrophic scar samples were quantitatively analyzed on Northern blots and showed increases of 246 %, 102%, and 250% of the specific messages for pro-alpha 1(I), pro-alp ha 1(III), and TGF-beta1 relative to a normal skin control. Two transc ripts (4.9 kb and 2.5 kb) for TGF-beta1 were identified in cultured fi broblasts. In contrast to the results from tissue, the level of these transcripts in fibroblasts cultured from hypertrophic scar tissue and normal skin were not significantly different, suggesting that the synt hesis of this growth factor is stimulated in tissue by a presently unk nown mechanism. These findings further suggest that locally synthesize d TGF-beta1 may play a role in the regulation of type I and type III p rocollagen gene expression in postburn hypertrophic scars.