Effects of platelet derived growth factor (PDGF) on fibronectin (FN) production by human skin and scar fibroblasts.

The fibroblast-type cell found in hypertrophic scars and keloids demonstrates an elevated fibronectin (FN) production, compared to the same type of cell in normal dermis. We wished to determine if the effects of platelet derived growth factor (PDGF) on FN production in these cell types would be equivalent or different. Cell lines were established from the dermis (reticularis) of hypertrophic scars, keloids, uninvolved normal skin adjacent to the lesions, including an assumed normal skin adjacent to a keloid (AS), and normal skin from a different uninjured patient (DS). Each parent tissue from which the cell lines originated was diagnosed histologically. Each hypertrophic scar, keloid and normal adjacent skin, with one exception, showed typical histologic findings confirming the clinical diagnosis. DS was also normal. AS, although assumed to be normal, in fact, demonstrated portions of nodules from the adjacent keloid. All cell lines were grown under standard conditions with subconfluent cells metabolically labeled for radioimmunoassays measuring FN at passage 3 (8 to 9 weeks in culture) in the absence and presence of PDGF. Significant differences in production of FN/cell and FN/PR/cell between two hypertrophic scars and their matched normal skins and for one keloid and its matched normal skin were observed. However, no significant difference was observed between the other keloid and AS, nor between the other hypertrophic scar and DS. PDGF significantly stimulated FN production in 2 of 4 NS cell lines, and in the AS cell line. By FN/cell values, 2 of 5 cell lines from the lesions were inhibited and one was increased. In terms of FN/PR/cell, 1 of 5 cell lines from the lesions was stimulated and the others showed no differences. The mixed results may be attributable to the likelihood that the cell lines represent mixed populations. This study demonstrates the importance of: 1) histological characterization of all parent tissues from which cell lines are derived, and 2) matching cell lines from lesions with cell lines from uninvolved normal dermis, in the same individual.