Comparison of growth factor expression in fetal and adult fibroblasts: a preliminary report.

BACKGROUND Fetal wounds can heal without any histological evidence of scarring. Fetal wounds lack the inflammatory infiltrate characteristic of adult wounds, and the fetal environment is not necessary for scarless healing to occur. Recent evidence suggests that fibroblasts are the main effector of scarless healing in fetal tissue. What has not been shown is what profile of growth factors the fibroblast uses to influence wound repair. OBJECTIVE To determine the expression of growth factors (transforming growth factors beta1, beta2, and beta3; acidic and basic fibroblast growth factors; keratinocyte growth factor; and platelet-derived growth factor AA, BB, and AB) of fetal and adult fibroblasts in vitro. DESIGN Adult and fetal fibroblasts were grown in culture, and messenger RNA was extracted by standard techniques. Northern hybridization was used to identify messenger RNA transcripts for the aforementioned growth factors. Densitometry was used to compare growth factor messenger RNA expression with that of a ubiquitously expressed control, glyceraldehyde phosphate dehydrogenase. RESULTS The data suggest that fetal and adult fibroblasts express acidic and basic fibroblast growth factor and transforming growth factor beta1. Adult fibroblasts show twice the relative expression of these growth factors compared with fetal fibroblasts. CONCLUSIONS The adult fibroblasts demonstrate a relative excess production of cytokines compared with fetal fibroblasts. This is thought to contribute to suboptimal wound healing in adult wounds compared with the scarless healing of fetal wounds.