IDENTIFICATION OF TISSUE INHIBITOR OF METALLOPROTEINASES-1 (TIMP-1) IN HUMAN TEETH AND ITS DISTRIBUTION IN CEMENTUM AND DENTIN

An inhibitory activity toward matrix metalloproteinases such as interstitial collagenase,72-kDa gelatinase/type IV collagenase, and stromelysin-1 was detected in an EDTA extract of pulverized roots of human teeth, and identified as TIMP-1 by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and immunoblotting. Distribution of TIMP-1 in human cementum and dentine was investigated by a sandwich enzyme immunoassay in combination with an abrasive microsampling technique. TIMP-1 could not be detected in cementum from some teeth but in others decreased from a fairly low value at the surface towards the cementodentinal junction. TIMP-1 concentrations in the dentine increased consistently from the cementodentinal junction toward the predentine. The average TIMP-1 concentration in the dentine (54.1 +/- 18.5 pg/mg +/- SE) was significantly (P < 0.05) higher than that (9.6 +/- 6.0 pg/mg +/- SE) in the cementum.