Fetal fibroblast contraction of collagen matrices in vitro : the effects of epidermal growth factor and transforming growth factor-β

Wound contraction is an important component of healing but, in the extreme, may lead to excessive scar formation and pathological wound contracture. Fetal rabbit wounds heal without contraction or scarring, whereas excisional fetal sheep wounds have been shown to contract, but no scarring or pathological wound contracture is noted. We used an in vitro model, the fibroblast-populated collagen lattice, to study the ability of fetal fibroblasts to coordinate contraction of a collagen matrix and the modulating effects of epidermal growth factor and transforming growth factor-beta 1 on this contraction. With increasing gestational age, fibroblasts increased the degree of collagen lattice contraction. Epidermal growth factor inhibited contraction by fetal fibroblasts, whereas transforming growth factor-beta 1 stimulated it. These findings suggest that while intrinsic differences between fetal and adult fibroblasts exist, polypeptide growth factors may operate at the site of tissue repair to alter cell phenotype. Further work is underway to delineate the role of soluble protein factors responsible for the absence of scarring and contracture seen in the fetal wound.