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)