[Response of keloid fibroblasts to the effect of tumor necrosis factor-alpha(TNF-alpha)].

OBJECTIVE

To investigate the biologic behavior of keloid fibroblasts and the pathogenesis of keloid.

METHODS

Human dermal fibroblasts cultured from normal skin and keloid were treated with tumor necrosis factor-alpha(TNF-alpha) for 48 hours at 10(3) U/ml and 10(4) U/ml. Collagen production by fibroblasts was assessed by 3H-proline in corporation into pepsin-resistant, precipitated extracellular collagenous protein.

RESULTS

TNF-alpha caused a concentration-dependent reduction in collagen production in normal dermal fibroblasts. Treatment with TNF-alpha at 10(3) U/ml significantly reduced the collagen synthesis in keloid fibroblasts (P < 0.01). However, the collagen synthesis in keloid fibroblasts did not further decreased after exposure to TNF-alpha at 10(4) U/ml.

CONCLUSIONS

Keloid fibroblasts may remain less sensitive to the inhibitory effects of TNF-alpha on collagen synthesis to a certain extent.