2003 Volume 45 Issue 1 Pages 22-32
In periodontal disease, the periodontium is gradually destroyed, along with a decrease in the extracellular matrix. Proteinases are thought to be involved in this destructive process. The objective of this study was to identify the proteinases in human periodontal ligaments with parodontopathy to better characterize destructive processes in the periodontium.
Inflammed periodontal ligament was obtained from extracted human teeth with periodontal disease. Human intact periodontal ligament was used as a control. The enzymatic fraction was prepared from each sample in the sample loading buffer for SDS-PAGE, and the proteolytic activities were examined using zymograms and Western blotting (Zymo-Western analysis).
An increase in MMP-9 and neutrophil elastase activities was observed in the inflammed periodontal ligament, compared to that in the control ligament. When non-collagenous proteins prepared from porcine intact periodontal ligament (PLNCP) were used as the substrate for the zymogram, only neutrophil elastase activity was detected. On surveying the physiological substrate of the neutrophil elastase in the PLNCP, an acidic protein with a molecular mass of approximately 110 kDa and that stained blue with Stains-all staining was found to be the main product of degradation.
SEM observations of PLNCP after neutrophil elastase digestion were similar to those of human inflammed periodontal ligament, with exposed collagen fibrils visible the surface. The PLNCP structure before digestion was similar to that of human intact periodontal ligament. The collagen fibers in the intact periodontal ligament were covered by a complex of non-collagenous proteins.
During the destructive processes leading to inflammed periodontal ligament, neutrophil elastase appears to be involved in the initiation of the degradation, of the non-collagenous protein-complex that covers the collagen fibers. J Jpn Soc Periodontol, 45: 22-32, 2003.
