Evaluation of transforming growth factor β and type I procollagen gene expression in fibrotic skin diseases by in situ hybridization

Abstract

Full thickness biopsies of affected skin and fascia from one patient with diffuse fasciitis and eosinophilia (DF), two patients with generalized morphea (GM), and five patients with progressive systemic sclerosis (PSS) of recent onset were examined for the expression of transforming growth factor β1 (TGFβ1) and type I procollagen genes by in situ hybridization with human sequence-specific cDNA. An increased number of fibroblasts showing clearly detectable expression of proaI(I)collagen gene was found in all fibrotic lesions when compared with unaffected skin from the patient with DF and skin from two normal individuals examined in parallel. Expression of the TGFβ1 gene was noted in a fibroblast subpopulation of the affected tissues from the patients with DF and GM. In contrast, the TGFβ1 gene was not expressed at a detectable level in affected skin from the five patients with PSS. The results suggest that TGFβ1 may play a role in the development of skin fibrosis in cases of DF and GM. However, from these studies, we cannot implicate TGFβ1 in the pathogenesis of skin fibrosis in PSS. © 1990.