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Expression of human collagenase‐3 (MMP‐13) by fetal skin fibroblasts is induced by transforming growth factor‐β via p38 mitogen‐activated protein kinase

Human collagenase‐3 (MMP‐13) is characterized by wide substrate specificity and limited tissue specific expression. We have previously noted that human collagenase‐3 (MMP‐13) is expressed by gingival fibroblasts in culture and during gingival wound repair characterized by minimal scarring. Here we show that human MMP‐13 is expressed by dermal fibroblasts during early wound repair in fetal skin grafted on SCID mice. The expression of MMP‐13 by fetal skin fibroblasts in monolayer culture was enhanced by transforming growth factor β1 (TGF‐βΙ) and TGF‐β3, whereas MMP‐13 expression was not detected in neonatal skin fibroblasts. Treatment of fetal skin fibroblasts with TGF‐β1 potently activated p38 mitogen‐activated protein kinase (MAPK). Induction of MMP‐13 expression by TGF‐β1 was blocked by p38 MAPK inhibitor SB203580, and by adenovirally delivered dominant negative form of p38α. These observations demonstrate a remarkable difference in the regulation of collagenolytic capacity between fetal and neonatal skin fibroblasts, which suggests a role for MMP‐13 in rapid turnover of collagenous matrix during repair of fetal cutaneous wounds, which heal without scar.