Comparison of growth factor expression in fetal and adult fibroblasts - A preliminary report

Background: Fetal wounds can heal without any histological evidence of scar ring. 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 o f growth factors the fibroblast uses to influence wound repair. Objective: To determine the expression of growth factors (transforming grow th factors beta 1, beta 2, and beta 3; acidic and basic fibroblast growth f actors; keratinocyte growth factor; and platelet-derived growth factor AA, BE, and AB) of fetal and adult fibroblasts in vitro. Design: Adult and fetal fibroblasts were grown in culture, and messenger RN A was extracted by standard techniques. Northern hybridization was used to identify messenger RNA transcripts for the aforementioned growth factors. D ensitometry was used to compare growth factor messenger RNA expression with that of a ubiquitously expressed control, glyceraldehyde phosphate dehydro genase. Results: The data suggest that fetal and adult fibroblasts express acidic a nd basic fibroblast growth factor and transforming growth factor pi. Adult fibroblasts show twice the relative expression of these growth factors comp ared with fetal fibroblasts. Conclusions: The adult fibroblasts demonstrate a relative excess production of cytokines compared with fetal fibroblasts. This is thought to contribut e to suboptimal wound healing in adult wounds compared with the scarless he aling of fetal wounds.