Collagenase activities in healthy and inflamed gingiva of dogs

Dissolution of type I collagen fibrils by gingival fibroblasts isolated from patients of various periodontitis categories

The classification of periodontitis in various disease categories, including juvenile periodontitis, rapidly progressive adult periodontitis and slowly progressive adult periodontitis is based mainly on differences in disease progression and age group susceptibility. Because dissolution of collagen fibers is an integral part of periodontal attachment loss, we investigated whether the clinical differences among these periodontitis/control groups are reflected in the collagen-degrading activity of gingival fibroblasts isolated from affected tissues. All fibroblast strains isolated from the 4 groups (n = 48) displayed cell-associated collagenolytic activity when seeded in contact with a reconstituted film of type I collagen fibrils. Cells from the control group (n = 14) dissolved the collagen fibril film twice as fast as those from each of the 3 disease groups (juvenile periodontitis (n = 13), rapidly progressive adult periodontitis (n = 7), and slowly progressive adult periodontitis (n = 14)). Both interleukin-1 beta and phorbolester accelerated the rate of dissolution 2-4-fold, but even after cytokine or phorbolester stimulation control cells were still considerably more effective in dissolving the collagen fibrils than cells from the disease groups. The observation made in this study, that dissolution of collagen fibrils by gingival fibroblasts from periodontally diseased individuals is significantly slower than by cells from healthy control subjects, challenges disease paradigms based on a direct relationship between collagenolytic potential and disease activity.

Factors affecting IL-1-mediated collagen metabolism by fibroblasts and the pathogenesis of periodontal disease: a review of the literature

Fibroblasts have been studied extensively for their contribution to connective tissue destruction in diseases where the metabolism of extracellular matrix components plays an essential part in their pathogenesis. A considerable dissolution, especially of collagen fibrils, is a well-known characteristic of the periodontal ligament and the gingival connective tissue in microbial-induced periodontal disease. Fibroblasts, responsible for the assembly of the extracellular matrix, are capable of responding directly to oral microbial challenges or indirectly, following activation of the host immune response, and can alter the composition of connective tissue in several ways: synthesis of inflammatory mediators, their receptors and antagonists; fibroblast proliferation; collagen synthesis; phagocytosis of collagen fibrils; and synthesis of proteolytic enzymes, including matrix metalloproteinases and their corresponding inhibitors. The contributions of these cellular fibroblastic properties to the pathogenesis of periodontal disease are reviewed in the context of the cytokine, interleukin-1, as the inflammatory regulator.

Expression of TIMP-1, TIMP-2 and collagenase mRNA in periodontitis-affected human gingival tissue

Collagenolysis in periodontitis is thought to be modulated by the expression of three genes, collagenase, tissue inhibitors of metalloproteinases-1 and -2 (TIMP-1 and -2). We assessed the possible difference in TIMP-1, TIMP-2 and collagenase mRNA levels between gingival samples from patients with periodontitis and those from healthy subjects by reverse transcription-polymerase chain reaction (RT-PCR). This technique allows detection of transcripts from a very small sample quantity. The experiments showed that levels of TIMP-1 and collagenase transcripts relative to beta-actin are significantly higher in the diseased group than in healthy controls (8.11 +/- 0.83 versus 1.38 +/- 0.28% for TIMP-1 and 0.50 +/- 0.10 versus 0.0075 +/- 0.0024% for collagenase, respectively). The difference in TIMP-2 between the two groups (2.91 +/- 0.46 versus 1.84 +/- 0.87%) did not differ. Therefore, the host would have responded to the increase in collagenase level by preferentially producing TIMP-1 against tissue destruction. The differential gene expression of TIMP-1 and TIMP-2 in our study may account for a distinct genetic regulation of TIMP-1 and -2 in vivo.

Separation and partial characterization of three forms of collagenase inhibitor from bovine gingiva

Three forms of collagenase inhibitor were isolated; one bound to Con A-Sepharose and the other two did not. The Con A-bound (Mr 38,000) and the two unbound (Mr 50,000 and 22,000) inhibitors contained about 20, 15 and 65% of the total inhibitory activity, respectively. The bound and one of the unbound (Mr 22,000) inhibitors were fairly specific for mammalian collagenase; the other unbound inhibitor was rather non-specific and also inhibited trypsin and thermolysin, but not bacterial collagenase. All the inhibitors were heat stable (90 degrees C, 30 min) and unaffected by 4-aminophenylmercuric acetate, but were inactivated by reduction and alkylation.

Correlation of collagenolytic enzymes and inhibitors in gingival crevicular fluid with clinical and microscopic changes in experimental periodontitis in the dog

The quadrants of the jaw in 2 beagle dogs had various forms of periodontal disease induced by ligatures placed around second, third and fourth premolars in one quadrant and, 2.5 months later, around the same teeth in a second quadrant; gingivitis was allowed to develop in a third quadrant after 4 months; the fourth quadrant served as a healthy control. Crevicular fluid flow, plaque index, gingival index, attachment levels and recession were determined at intervals and collagenolytic activity measured in the fluid. The dogs were killed after 5 months and sections of each site prepared for histomorphometry. Clinically-inflamed and degenerating sites had significantly higher collagenolytic activities (p less than 0.001), lower collagenase inhibitor activities and greater fluid flow than control sites which showed abundant inhibitor activity and minimal active enzyme. Periodontitis sites had higher active enzyme, compared to latent enzyme activities, whereas latent collagenase was predominant in control and gingivitis sites. The collagenolytic activities in periodontitis sites fluctuated with time, suggesting a cyclical pattern. Active enzyme activities correlated strongly with gingival crevicular fluid flow and attachment loss. Periodontitis sites had much more inflammatory-cell infiltration than control and gingivitis sites (p less than 0.001). Thus periodontal disease may be monitored by examination of crevicular fluid collagenolytic enzymes, inhibitors and fluid flow, and these criteria may prove more meaningful than current clinical criteria.

Reduced collagen biosynthesis in oral mucosa of beige (Chediak-Higashi) mice

Oral mucosa of beige (Chediak-Higashi) mice had decreased levels of collagen synthesis and prolyl hydroxylase activity compared with normal animals. No significant difference was observed in non-collagen protein synthesis between the two groups. These results suggest that decreased collagen biosynthesis in oral tissues may be partially involved in the increased incidence of periodontal disease in the Chediak-Higashi syndrome.