ADULT HUMAN KERATINOCYTES MIGRATING OVER NONVIABLE DERMAL COLLAGEN PRODUCE COLLAGENOLYTIC ENZYMES THAT DEGRADE TYPE-I AND TYPE-IV COLLAGEN

Human adult keratinocytes migrating on a nonviable dermal substrate in cultures without fibroblasts induce thin-ning and degradation of the collagen substrate beneath the migrating epithelium. Further, unconcentrated conditioned medium from the cultures exhibit collagenolytic activity against both type I and type IV vollagen which is inhibited by EDTA but not by phenylmethylsulfonyl fluoride or N-ethylmaleimide. Since the migrating epithelium and dermal substrate do not contain fibroblasts, this study shows that migratory keratinocytes in contact with interstitial collagen are capable of producing collagenases against type I and type IV collagen. Moreover, migratory keratinocytes appear to be similar to highly metastatic cells in their ability to degrade basement membrane collagen.