In situ localization and characterization of active proteases in chronically inflamed and healthy human gingival tissues.
BACKGROUND
Studies have indicated an important role for host-derived proteases in the pathogenesis of periodontal disease. The objectives of this study were: 1) to develop an assay measuring protease activity in situ and 2) to localize and characterize the enzymatic activity in intact inflamed and healthy gingiva.


METHODS
Gingival specimens were prepared and over-laid with a quenched fluorescent substrate. Protease activity was visualized by fluorescence microscopy and correlated with histologic features.


RESULTS
In inflamed tissues, enzymatic activity was detected mainly in the connective tissue (predominantly matrix metalloproteases) and, to some extent, in the epithelium (predominantly serine proteases). In contrast, clinically healthy tissues failed to exhibit significant amounts of protease activity. Quantitative and qualitative characteristics of protease activity in intact tissues were found to be pH dependent.


CONCLUSIONS
The method described here enabled assessment of active proteases in intact tissues where cell-cell and cell-matrix interactions had been maintained. Our results indicate that there are substantial differences in the distribution of specific proteases between clinically healthy and inflamed periodontal tissues.
Sarment
D P
DP
Department of Periodontics, School of Dental Medicine, University of Pennsylvania, Philadelphia, USA. sarment@umich.edu
Korostoff
J
J
D'Angelo
M
M
Polson
A M
AM
Feldman
R S
RS
Billings
P C
PC
D000328:Adult; D004591:Electrophoresis, Polyacrylamide Gel; D010450:Endopeptidases / Q000032:analysis* / Q000378:metabolism; D005881:Gingiva / Q000201:enzymology*; D005891:Gingivitis / Q000201:enzymology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D020782:Matrix Metalloproteinases / Q000032:analysis / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008875:Middle Aged; D012697:Serine Endopeptidases / Q000032:analysis / Q000378:metabolism; D018709:Statistics, Nonparametric; D014018:Tissue Distribution
D010450:Endopeptidases; D012697:Serine Endopeptidases; D020782:Matrix Metalloproteinases