Objective: To compare the expression of the genes encoding transforming growth factor-beta1 (TCF-beta1) and several extracellular matrix proteins between fascial and dermal fibroblasts from 3 patients with diffuse fasciitis with eosinophilia (DFE) of recent onset.
Methods: Fibroblasts were separately cultured from the fascia and dermis from each patient. Collagen production and mRNA levels for fibronectin, alpha1(I) procollagen, alpha1(III) procollagen. and the 3 chains of type VI collagen were compared between fascial and dermal fibroblasts from the same patient using biosynthetic studies with 14C-proline and Northern and dot blot hybridizations with specific cDNA. The expression of the gene encoding TGF-beta1 was also examined in these cultures by Northern hybridizations with human TGF-beta1 cDNA.
Results: Fascial fibroblasts displayed 1.75 to 4.6-fold greater collagen biosynthesis, 3.4 to 8.5-fold elevation of the steady state levels of fibronectin mRNA, up to 3.9-fold elevation of the steady state mRNA levels for alpha1(I), alpha1(III) and alpha3(VI) collagens, and a marked increase in TGF-beta1 mRNA levels compared to fibroblasts from the adjacent dermis from the same individuals.
Conclusion: The expression of genes encoding several extracellular matrix proteins is increased in fascial fibroblasts from patients with diffuse fasciitis compared to fibroblasts from the adjacent dermis of the same individuals. The elevation of TGF-beta1 mRNA in the fascial cells indicates that this growth factor may play an important role in the pathogenesis of fibrosis in DFE.