Demonstration of tissue collagenase activity in vivo and its relationship to inflammation severity in human gingiva.

Abstract

To directly demonstrate both the presence and in vivo activity of tissue collagenase (EC 3.4.24.7) during gingival inflammation, tissue extracts from 54 specimens of variously inflamed human gingiva were analyzed individually for: a) collagenase‐specific collagen degradation products, and b) collagen‐bound collagenase. The TCA collagen degradation product, identified using SDS‐PAGE, was shown in 13/19 (68.4%) of insoluble tissue‐residue fractions extracted from moderate‐to‐severely inflamed gingiva, but in only 2/21 (9.6%) slight‐to‐mildly inflamed gingival specimens, suggesting differences in the in vivo collagenase activity between the two groups. Using in vitro collagenase assays, gingival collagenase (as bound to insoluble collagen) was demonstrated in 92.8% of the moderate‐to‐severely inflamed gingival specimens and in 50% of the slight‐to‐mildly inflamed gingival specimens. A relationship was established between the active and latent forms of the enzyme and the degree of inflammation. Active enzyme was present in 78% of the moderate‐to‐severely inflamed specimens and in 14% of the slight‐to‐mildly inflamed gingiva. In contrast, latent collagenase was predominant in the slight‐to‐mildly inflamed group (86% of coliagenase‐positive samples) compared with 46% of coliagenase‐positive moderate‐to‐severely inflamed gingival samples. The collagen‐bound gingival collagenase was inhibited by metal ion chelators, sulphydryl reagents and 10% FBS, but not by serine nor thiol‐proteinase inhibitors and is therefore a neutral metalloproteinase.