Proliferation and collagen synthesis by human dermal fibroblasts cultured from different body sites

Distal areas in systemic sclerosis (scleroderma), such as the dorsal skin of the hand are more frequently involved and more indurated than proximal areas. On the contrary, the observation often made after surgical excision or trauma is that distal body areas heal more slowly than proximal areas. A possible explanation may be that dermal fibroblasts from distal body parts are more capable, when stimulated, to synthesize greater or lesser amounts of collagen and proliferate at different rates than dermal fibroblasts from more proximal skin. In this study, cultures of dermal fibroblasts from three different body sites (arm, forearm, and hand) of healthy volunteers were investigated for their proliferative activity and collagen synthesis after stimulation in 3% or 10% fetal bovine serum. No significant differences were observed in cell proliferation or in the relative or absolute collagen synthesis by fibroblasts cultured from the hand, forearm or upper arm. We conclude that other in vivo factors are responsible for the observed differences in fibrosis and healing at different body sites. Moreover, if clonal expansion of different fibroblast phenotypes occurs in these physiologic or disease states, it must be of a magnitude that overcomes the fundamental proliferative and biosynthetic baseline.