Degradation of type I collagen by rat mucosal keratinocytes. Evidence for secretion of a specific epithelial collagenase.

摘要: Abstract Feeder-cell-independent serially propagating keratinocytes from rat oral mucosa (tongue) dissolved reconstituted type I [3H]collagen fibrils, although rather slowly. Analysis of the conditioned medium such cultures revealed secretion a Mr = 65,000 collagenase which remained almost entirely latent in absence exogenous protease activity. Addition trypsin (0.1-1.0 microgram/ml) or plasmin (1.0-4.0 micrograms/ml) resulted substantial acceleration collagenolytic process stimulated and, at higher concentrations, conversion enzyme to catalytic form. The keratinocyte was indistinguishable interstitial, fibroblast-type collagenases by several criteria including: cleavage native collagen solution characteristic collagenase-sensitive locus 22 degrees C and dissolution fibrils 35 C; activation organomercurials inhibition Zn2+ Ca2+ chelators; cross-reaction with antibody procollagenase. Expression activity effectively regulated cell density. (on per basis) maximal 10-20% confluence more than 95% "contact-inhibited" subconfluent early confluent densities (2-4 X 10(5)/cm2). Our findings show that mucosal possess potent enzymatic apparatus for degradation interstitial includes classical vertebrate collagenase.