Secretion and binding of transforming growth factor beta by scleroderma and normal dermal fibroblasts.

The production and binding of transforming growth factor beta (TGF beta) were compared in dermal fibroblast lines derived from scleroderma patients and normal control donors. The mean +/- SEM 24-hour level of secretion of TGF beta by fibroblast lines derived from the involved skin of scleroderma patients was 30.8 +/- 5.5 pmoles/10(6) cells, and it was 29.7 +/- 5.8 pmoles/10(6) cells for fibroblast lines derived from the normal skin of the healthy donors. Thus, we found that the fibroblasts themselves produced TGF beta. TGF beta production was equivalent in fibroblast lines derived from clinically involved and uninvolved skin of scleroderma patients. The mean +/- SEM number of TGF beta receptors per cell on scleroderma fibroblasts was 9,736 +/- 1,375, with a mean +/- SEM Kd of 25.2 +/- 3.9 pM. This value was similar in control fibroblasts, at 12,431 +/- 2,425 TGF beta receptors per cell, with a mean +/- SEM Kd of 27.1 +/- 5.2 pM.