The tripeptide-copper complex glycyl-L-histidyl-L-lysineCu2+ (GHK-Cu) was first described as a growth factor for differentiated cells. Recent in vitro data showed that it possesses several properties of a potential activator of wound repair. We investigated the effects of GHK-Cu in vivo, using the wound chamber model described previously (Schilling, J. A., W. Joel, and M. T. Shurley, 1959 Stainless steel wire mesh cylinders were implanted subcutaneously on the back of rats. The animals were divided into groups that received sequential injections into the wound chamber of either saline (control group) or various concentrations of GHK-Cu. At the end of the experiments, rats were killed, wound chambers were collected, and their content was analyzed for dry weight, total proteins, collagen, DNA, elastin, glycosaminoglycans, and specific mRNAs for collagens and TGFfI. In the GHK-Cu-injected wound chambers, a concentration-dependent increase of dry weight, DNA, total protein, collagen, and glycosaminoglycan contents was found. The stimulation of collagen synthesis was twice that of noncollagen proteins. Type I and type III collagen mRNAs were increased but not TGFft mRNAs. An increase ofthe relative amount ofdermatan sulfate was also found. A control tripeptide, L-glutamyl-L-histidyl-Lproline, had no significant effect. These results demonstrate that GHK-Cu is able to increase extracellular matrix accumulation in wounds in vivo. (J. Clin. Invest. 1993.92:2368-2376

We report a case of fibroblastic rheumatism (FR). Only eight other cases of this recently described entity have been reported previously. FR is characterized by polyarthralgia and joint stiffness without joint destruction, associated with cutaneous nodules and sclerodactyly. Histology shows an increase in the number of fibroblasts and marked dermal fibrosis. Rheumatological and skin manifestations may improve with corticosteroid therapy. In our patient, immunohistochemical studies of involved and uninvolved skin showed an increase in fibronectin and tenascin deposition. In the dermis, the hyperplastic cells had phenotypic features of muscle, suggesting myofibroblastic differentiation. Ultrastructural study showed an increase in active fibroblastic cells with features of myofibroblasts. A hyperproliferative capacity was observed in fibroblasts cultured from involved skin. Biochemical studies of the production of collagen and non-collagen proteins were performed on these cultured cells, and showed a reduction in collagen and non-collagen protein synthesis by FR fibroblasts. Thus, FR appears to differ from other fibrotic skin diseases such as scleroderma, in that dermal fibrosis may be due predominantly to fibroblast proliferation with myofibroblastic differentiation without any increase in collagen synthesis.

Two techniques for fibroblast culture in three-dimensional fibrin matrices (fibrin lattices) were used to study the behavior and metabolism of cells in this physiological support. When the fibrin lattices were prepared in silicone-coated glass petri dishes, fibroblasts induced retraction of lattices to an extent dependent on both cell density and serum concentration, the cells stopped dividing, and their protein and collagen syntheses proceeded at a lower rate, like that in collagen lattices. When fibrin lattices were prepared in plastic petri dishes, the matrix attached to the walls, there was no retraction, and the protein synthesis was very active even as regards collagen. The optimal concentration of ascorbic acid in nonretracting fibrin lattices was lower (10 micrograms/ml) than in monolayers (50 micrograms/ml). The comparison of collagen and fibrin lattices showed that the collagenic nature of the lattice was not compulsory for supporting the phenomenon of retraction and that fibroblasts, when exposed to a stress in a fibrin matrix prevented from retracting, secreted far more collagen.