Characterization of interstitial collagenases in jaw cyst wall

Neutral salt extracts of 14 specimens of jaw cysts were prepared. Histopathological analysis showed that the specimens consisted of 6 radicular cysts, 6 dentigerous cysts, 1 residual cyst, and 1 odontogenic keratocyst. One periapical granuloma, 1 dental follicle and a sample of clinically healthy oral mucosa were similarly processed and used as controls. Measurement of collagenase activity by monitoring the formation of specific degradation products of type I and II collagen in solution by SDS-PAGE demonstrated that all the cyst extracts contained collagenase, some of which was endogenously activated. Cyst wall collagenase preferably degraded type I over type II collagen, which suggests that the degradation was due to MMP-1 (matrix metalloproteinase-1) rather than the MMP-8 type. This was further supported by the doxycycline-inhibition profile of cyst collagenase, which was similar to that of MMP-1. Part of the cyst wall collagenase was in latent proenzyme form and probably derived, at least in part, from the newly synthesized intracellular collagenase pool. Latent cyst collagenase was efficiently activated with phenylmercuric chloride and to a lesser extent by gold (I) thioglucose and NaOCl. Western-blotting, using specific antibodies against collagenase from human polymorphonuclear neutrophilic leukocytes (MMP-8) and from fibroblasts (MMP-1), revealed a typical 55/45 kDa doublet; also MMP-8 in the latent 80 kDa form and fragmented to 65 kDa active species were found. These results suggest the presence of MMP-1 and, to a lesser extent, MMP-8 type collagenase in the cyst wall.(ABSTRACT TRUNCATED AT 250 WORDS)