Collagenase and collagenase inhibitor activities in crevicular fluid of patients receiving treatment for localized juvenile periodontitis

Expression of matrix metalloproteinase-9 in gingival tissue biopsy in patients with slowly/ moderately and rapidly progressing periodontitis: An observational study

Background

Matrix metalloproteinases (MMPs) are a group of host-derived zinc-dependent enzymes which mediates the destruction of the extracellular matrix. In periodontitis, there is excess production of MMPs associated with periodontal tissue destruction. The aim of this study was to estimate the level MMP-9 in both active and latent form in gingival tissue (GT) samples collected from periodontitis patients with different rates of progression and compare it with healthy individuals.

Materials and Methods

Sixty patients were selected and divided into three groups, 20 each: Group A (slowly/moderately progressing periodontitis), Group B (rapidly progressing periodontitis), and Group C (clinical periodontal health). Plaque index, gingival index, periodontal probing depth (PPD), and clinical attachment level were recorded. GT samples were collected from all 60 patients and MMP-9 expressions were measured using gelatin zymography and western blotting.

Results

Levels of active MMP-9 (aMMP-9) and latent MMP-9 (lMMP-9) were significantly high in both Group A (GA) (aMMP-9: 2.05 arbitrary unit [AU]/lMMP-9: 2.54 AU) and Group B (GB) (aMMP-9: 1.32 AU/lMMP-9: 1.74 AU) when compared to that of Group C (GC) (aMMP-9: 0.93/lMMP-9: 1.08 AU). In GA, levels of aMMP-9 showed a significant correlation with PPD values. No other correlations were found.

Conclusion

The levels of aMMP-9 and lMMP-9 were increased in both the types of periodontitis when compared with periodontally healthy individuals. A significant correlation was found between PPD and activities of aMMP-9 in slowly/moderately progressing periodontitis patients. However, further studies are required to confirm these findings.

Gingival Crevicular Fluid: An Overview

Gingival crevicular fluid is an inflammatory exudate derived from the periodontal tissues. It is composed of serum and locally generated materials such as tissue breakdown products, inflammatory mediators, and antibodies directed against dental plaque bacteria. It plays a special part in maintaining the structure of junctional epithelium and the antimicrobial defense of periodontium. Some of the suspected periodontal pathogens such as Porphyromonas gingivalis and Treponema denticola produce broad-spectrum neutral proteinases as part of their virulence arsenal. These proteinases may be detected in plaque and gingival crevicular fluid samples of patients with periodontitis. The potential diagnostic importance of gingival fluid was recognized more than six decades ago. The fluid component of gingival crevicular fluid is derived primarily from microvascular (postcapillary venule) leakage. There are number of distinct advantages and challenges of using gingival crevicular fluid as a diagnostic test for periodontal disease.

Periodontal treatment reduces matrix metalloproteinase levels in localized aggressive periodontitis

BACKGROUND

Matrix metalloproteinases (MMPs) are a family of host-derived proteinases reported to mediate multiple functions associated with periodontal breakdown and inflammation. High MMP levels in African-American children with localized aggressive periodontitis (LAgP) have been reported previously by the present authors. However, little is known about MMP reductions in gingival crevicular fluid (GCF) after therapy. This study aims to evaluate MMP levels in the GCF after treatment of LAgP and to correlate these levels with clinical response.

METHODS

GCF samples were collected from 29 African-American individuals diagnosed with LAgP. GCF was collected from one diseased site (probing depth [PD] >4 mm, bleeding on probing [BOP], and clinical attachment level ≥ 2 mm) and one healthy site (PD ≤ 3 mm, no BOP) from each individual at baseline and 3 and 6 months after periodontal treatment, which consisted of full-mouth scaling and root planing (SRP) and systemic antibiotics. The volume of GCF was controlled using a calibrated gingival fluid meter, and levels of MMP-1, MMP-2, MMP-3, MMP-8, MMP-9, MMP-12, and MMP-13 were assessed using fluorometric kits.

RESULTS

MMP-1, MMP-8, MMP-9, MMP-12, and MMP-13 levels were reduced significantly up to 6 months, comparable to healthy sites at the same point. Significant correlations were noted between MMP-2, MMP-3, MMP-8, MMP-9, MMP-12, and MMP-13 levels and percentage of sites with PD >4 mm. MMP-3, MMP-12, and MMP-13 levels also correlated with mean PD of affected sites.

CONCLUSION

Treatment of LAgP with SRP and systemic antibiotics was effective in reducing local levels of specific MMPs in African-American individuals, which correlated positively with some clinical parameters.

Occlusal adjustment associated with periodontal therapy--a systematic review

OBJECTIVES

Occlusal adjustment as part of periodontal therapy has been controversial for years, mostly because the literature does not provide enough evidence regarding the influence of trauma from occlusion (TfO) on periodontitis. The need for occlusal adjustment in periodontal therapy is considered uncertain and requires investigation. The aim of this systematic review was to identify and analyse those studies that investigated the effects of occlusal adjustment, associated with periodontal therapy, on periodontal parameters.

DATA

A protocol was developed that included all aspects of a systematic review: search strategy, selection criteria, selection methods, data collection and data extraction.

SOURCES

A literature search was conducted using MEDLINE via PubMed, the Cochrane Central Register of Controlled Trials, and EMBASE.

STUDY SELECTION

Three reviewers screened the titles and abstracts of articles according to the established criteria. Every article that indicated a possible match, or could not be excluded based on the information given in the title or abstract, was considered and evaluated. On final selection, four articles were included.

CONCLUSIONS

Although the selected studies suggest an association between occlusal adjustment and an improvement in periodontal parameters, their methodological issues (explored in this review) suggest the need for new trials of a higher quality. There is insufficient evidence at present to presume that occlusal adjustment is necessary to reduce the progression of periodontal disease.

CLINICAL SIGNIFICANCE

Although it is still not possible to determine the role of occlusal adjustment in periodontal treatment, adverse effects have not been related to occlusal adjustment. This means that the decision made by clinicians whether or not to use occlusal adjustment in conjunction with periodontal therapy hinges upon clinical evaluation, patient comfort, and tooth function.

The expressions of inflammatory factors and tissue inhibitor of matrix metalloproteinase-2 in human chronic periodontitis with type 2 diabetes mellitus

PURPOSE

The purpose of this study was to observe and quantify the expression of interleukin-4 (IL-4), interferon-gamma (IFN-gamma), and tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) in the gingival tissue of patients with type 2 diabetes mellitus (DM) and healthy adults with chronic periodontitis.

METHODS

Twelve patients with type 2 DM and chronic periodontitis (Group 3), twelve patients with chronic periodontitis (Group 2), and twelve healthy individuals (Group 1) were included in the study. Clinical criteria of gingival (sulcus bleeding index value, probing depths) and radiographic evidences of bone resorption were divided into three groups. The concentrations of cytokines were determined by a western blot analysis and compared using one-way ANOVA followed by Tukey's test.

RESULTS

The expression levels of IFN-gamma and TIMP-2 showed an increasing tendency in Groups 2 and 3 when compared to Group 1. On the other hand, the expression of IL-4 was highest in Group 1.

CONCLUSIONS

The findings suggest that IFN-gamma and TIMP-2 may be involved in the periodontal inflammation associated with type 2 DM. IL-4 may be involved in the retrogression of the periodontal inflammation associated with type 2 DM.

The effect of epidermal growth factor on matrix metalloproteinases and tissue inhibitors of metalloproteinase gene expression in cultured human gingival fibroblasts

OBJECTIVE

Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) play a role in the breakdown of the extracellular matrix during normal physiological processes, and in pathological processes, including periodontitis. The aim of this study was to evaluate the effect of epidermal growth factor (EGF) on the expression of MMPs and TIMPs in cultured human gingival fibroblasts.

METHODS

Fibroblasts were stimulated with 10(-3), 10(-6) or 10(-12)M EGF for 24h; untreated fibroblasts served as controls. Alterations in the expression of MMP-1, 2, 3, 7, 11, TIMP-1 and 2 were evaluated using real-time PCR and Western blotting. beta-Actin expression was used as a reference to normalize gene expression.

RESULTS

Increased MMP-1, 3, 7 and 11 expressions were observed at all EGF concentrations (p<0.05). At the lowest EGF concentration, MMP-1, 3 and 7 presented the lowest expression and MMP-11 presented the greatest expression; at higher EGF concentrations, MMP-1, 3 and 7 presented greater up-regulation, and MMP-11 lower up-regulation (p<0.05). Protein expression was similarly regulated by EGF: increased up-regulation of MMP-1, 3 and 7 was observed with increasing EGF concentrations, except for MMP-11 that exhibited greater up-regulation at the lower EGF concentration. The gene expression of MMP-2, TIMP-1 and 2 was not affected by EGF (p<0.05).

CONCLUSIONS

We conclude that EGF regulates expression for MMP-1, 3, 7 and 11 in a dose-dependent manner, suggesting that EGF may play a role in periodontal destruction and wound repair.

The effect of topical doxycycline usage on gingival crevicular fluid MMP-8 levels of chronic and aggressive periodontitis patients: a pilot study

The aim of this study was to evaluate the efficacy of topical subgingival application of doxycycline hyclate (DH) gel adjunctive to non-surgical periodontal therapy on gingival crevicular fluid (GCF) matrix metalloproteinase (MMP)-8 levels in chronic and aggressive periodontitis patients. Forty teeth of 10 chronic periodontitis patients and 32 teeth of eight aggressive periodontitis patients were screened for 6 months. Scaling and root planing (SRP) was applied to the control sites and DH gel adjunctive to SRP was applied to the test sites of each patient simultaneously. GCF MMP-8 levels were analysed at baseline, 7 days; and at 1, 3 and 6 months by Sandwich Elisa Method. At 1, 3 and 6 months, probing depth (P < 0.0051) and plaque scores and bleeding on probing values (P = 0.000) significantly decreased in each group when compared with the baseline, but there was no statistically significant difference between the test and control sites. GCF MMP-8 levels reduced presenting statistically significant differences on 7 days, 1, 3 and 6 months in four of the groups (P < 0.05); however, intergroup differences were not statistically significant. Developing functional and immunological-based chair-side MMP tests might serve as useful adjunctive diagnostic tools when monitoring the effects of DH gel application.

Host response modulation in the management of periodontal diseases

OBJECTIVE

To review the biological mechanisms and clinical utility of therapeutic modulation of the host response in the management of periodontal diseases.

MATERIAL AND METHODS

A search of MEDLINE-PubMed was performed up to and including December 2004. The search was limited to in vitro, experimental animal and clinical studies published in English. The selection criteria included all levels of available evidence: systematic reviews, randomised-controlled clinical trials, controlled clinical trials, prospective and retrospective cohort studies and case reports of human and experimental animal studies.

RESULTS

Six targets for non-microbial chemotherapeutic intervention were identified. Clinical trials have demonstrated the ability of non-steroidal anti-inflammatory drugs to slow periodontal disease progression. However, recently reported serious adverse effects preclude the use of cyclooxygenase-2 inhibitors as an adjunct to periodontal therapy. Adjunctive use of subantimicrobial dose doxycycline to non-surgical periodontal therapy is beneficial in the management of chronic periodontitis over 12 months. Controversial data exist on the effects of bisphosphonate administration as an adjunct to periodontal therapy. Evidence on modulation of other host mediators including lipoxins, cytokines and nitric oxide synthase is limited to animal research.

CONCLUSION

After validation in long-term clinical trials, adjunctive host modulation therapy may prove advantageous in the management of periodontal diseases.

Membrane type (MT) 1-matrix metalloproteinase (MMP) and MMP-2 expression in ligature-induced periodontitis in the rat

BACKGROUND

Matrix metalloproteinases (MMPs) have been shown to be involved in the degradation of the extracellular matrix (ECM). In particular, MMP-2 and MMP-9 (gelatinase A and gelatinase B, respectively) have been identified as the predominant MMPs during periodontitis. Recent studies have indicated that a novel transmembrane MMP, mebrane-type 1 matrix metalloproteinase (MT1-MMP), can activate pro-MMP-2 in tumor metastasis. This study aims to elucidate the presence and localization of MT1-MMP and MMP-2 in periodontitis in a rat model.

METHODS

In 2 groups of 40-day-old male Sprague-Dawley rats, periodontitis was initiated by ligating floss around maxillary second molars. A group of control animals were left untreated. Maxillary dentoalveolar segments were isolated after 7 and 21 days postinduction and were prepared for gross and radiographic analysis of bone loss and for histological analysis. Samples were also prepared for gel zymography to detect the presence of MMP-2, and for Northern blot analysis and in situ hybridization with MT1-MMP probes.

RESULTS

MMP-2 expression increased at 21 days following ligature placement, in conjunction with MT1-MMP expression. MT1-MMP mRNA expression was observed in epithelial cells, fibroblasts, and in multinucleated cells in the periodontium.

CONCLUSION

Our data suggest that MT1-MMP may play a role in extracellular matrix degradation during periodontitis, in concert with MMP-2 and other proteinases.

Mediators of periodontal osseous destruction and remodeling: principles and implications for diagnosis and therapy

Osteoclastic bone resorption is a prominent feature of periodontal disease. Bone resorption via osteoclasts and bone formation via osteoblasts are coupled, and their dysregulation is associated with numerous diseases of the skeletal system. Recent developments in the area of mediators of osteoclastic differentiation have expanded our knowledge of the process of resorption and set the stage for new diagnostic and therapeutic modalities to treat situations of localized bone loss as in periodontal disease. This review describes the current state of knowledge of osteoclast differentiation and activity, mediators, and biochemical markers of bone resorption and their use and potential use in clinical periodontics. Finally, therapeutic strategies based on knowledge gained in the treatment of metabolic bone diseases and in periodontal clinical trials are discussed, and the potential for future strategies is proposed relative to their biologic basis. The intent is to update the field of periodontics on the current state of pathophysiology of the osteoclastic lesion and outline diagnostic and therapeutic strategies with a rational basis in the underlying biology.

The effect of subgingival controlled-release delivery of chlorhexidine chip on clinical parameters and matrix metalloproteinase-8 levels in gingival crevicular fluid

BACKGROUND

The present study evaluated the efficacy of controlled-release delivery of chlorhexidine gluconate (CHX) on clinical parameters and on gingival crevicular fluid (GCF) matrix metalloproteinase (MMP)-8 levels in chronic periodontitis patients.

METHODS

Twenty patients with chronic periodontitis were screened for 6 months. Two interproximal sites were selected from mesial surfaces of anterior teeth with probing depths of 6 to 8 mm that bled on probing in each patient. There were at least 2 teeth between the selected sites. CHX chip was inserted into a randomly selected site following scaling and root planing (SRP+CHX), while the other selected site received only SRP in each patient. Probing depth (PD), clinical attachment level (CAL), plaque index (PI), and papilla bleeding index (PBI) were recorded at baseline and at 1, 3, and 6 months. GCF MMP-8 levels were analyzed at baseline; 2 and 10 days; and at 1, 3, and 6 months by immunofluorometric assay (IFMA).

RESULTS

At baseline, there were no statistically significant differences in the mean PD, CAL, PBI, and PI scores between SRP+CHX and SRP alone groups. At 1, 3, and 6 months, all clinical parameters in each group significantly decreased (P <0.0167) when compared to baseline. The reduction of PD and improvement in CAL were higher in the SRP+CHX group compared to SRP alone at 3 and 6 months. However, the differences between the 2 groups were not statistically significant. PBI and PI scores were not significantly different between SRP+CHX and SRP alone groups at any visit. GCF MMP-8 levels were similar in both groups at baseline. Intragroup analysis showed significant decreases in the GCF MMP-8 level for the SRP+CHX group between baseline and 1, 3, and 6 months (P<0.01). Intergroup analysis demonstrated significantly lower mean levels of GCF MMP-8 at 1 month in the SRP+CHX group compared to the SRP alone group (P <0.05).

CONCLUSIONS

These data suggest that CHX chip application following SRP is beneficial in improving periodontal parameters and reducing GCF MMP-8 levels for 6 months' duration. The use of a chairside MMP-8 dipstick periodontitis test might be a useful adjunctive diagnostic tool when monitoring the course of CHX chip treatment.

Gingival crevicular fluid matrix metalloproteinase-8 levels following adjunctive use of meloxicam and initial phase of periodontal therapy

BACKGROUND

The purpose of the present study was to assess the effects of adjunctive meloxicam on the matrix metalloproteinase-8 (MMP-8) levels of gingival crevicular fluid (GCF) in chronic periodontitis patients following the initial phase of periodontal therapy.

METHODS

Twelve chronic periodontitis patients received 7.5 mg meloxicam, and 10 patients received placebo tablets together with scaling and root planing in a 1 x 1 regimen for 10 days. Scaling and root planing were performed on day 3 of drug intake. The MMP-8 levels in GCF samples obtained before and on day 10 of drug intake were determined by using the immunofluorescence assay. Plaque index (PI), papilla bleeding index (PBI), and GCF MMP-8 levels were compared within each patient group, between the 2 patient groups, and also with a clinically healthy control group using non-parametric statistical analyses.

RESULTS

Both meloxicam and placebo groups showed statistically significant reductions in PBI, PI, and GCF MMP-8 levels on day 10 compared to baseline (P<0.01). The GCF MMP-8 level on day 10 in the meloxicam group was similar to the clinically healthy control group (P>0.05), while it was significantly higher in the placebo group (P<0.01). Positive correlations were found between MMP-8 total amounts and PBI scores at baseline and day 10 of drug intake in the patient groups.

CONCLUSIONS

Meloxicam showed a tendency to reduce GCF MMP-8 levels in vivo within the first 10 days when used as an adjunct in the initial phase of periodontal treatment that consists of scaling and root planing. Verification of this effect on collagenase-2 downregulation, as well as on the clinical periodontal parameters in long-term studies using larger test and control groups, is needed to provide further support for the adjunctive use of selective cyclooxygenase (COX)-2 inhibitors in the treatment of chronic periodontitis.

Is collagen breakdown during periodontitis linked to inflammatory cells and expression of matrix metalloproteinases and tissue inhibitors of metalloproteinases in human gingival tissue?

BACKGROUND

Evidence of the role of matrix metalloproteinases (MMPs) produced by resident and inflammatory cells in periodontal destruction is now well established. The purpose of this study was to quantify, in healthy and diseased upper gingival connective tissue, the area fraction (AA%) occupied by collagen fibers, the cell number belonging to inflammatory cell subsets, and the amounts of MMPs and TIMPs (tissue inhibitors of MMPs) in order to investigate the possible correlations, if any, between such molecules, collagen loss, and inflammatory cell subsets.

METHODS

Gingival tissue specimens from 6 healthy controls (C) and 6 patients with severe periodontitis (P) were divided into 2 groups. The first group of specimens was frozen and used for the staining of collagen fibers by sirius red F3Ba and for immunohistochemistry with antibodies against CD8, CD4, CD22, CD68, and TIA-1 molecules. The second group was used for organ culture, zymography, Western blotting, and dot blotting. Morphometric and automated image analysis was performed for the evaluation of the area fraction occupied by collagen fibers, the number of inflammatory cell subsets and for enzymatic activities developed by MMPs, and the amounts of TIMPs expressed during periodontal disease.

RESULTS

In group P, the area fraction of collagen fibers (33 +/- 10%) was significantly decreased (P < 0.0002) when compared to group C (60 +/- 7%), and was correlated with the number of all inflammatory cells and amounts of MMPs and TIMPs. In group P, there were significant increases of CD8+, CD22+, CD68+, and TIA-1+ cells, as well as increases in the amounts of MMP-1, MMP-2, MMP-3, MMP-9, and the active form of MMP-9. The active form of MMP-9 and the amount of TIMP-1 were positively correlated with the number of CD22+, CD68+, and TIA-1+ cells.

CONCLUSIONS

The present study showed an imbalance between MMPs and TIMPs associated with the pathologic breakdown of the extracellular matrix during periodontitis. The active form of MMP-9 could be a marker for the clinical severity of periodontal disease.

Longitudinal evaluation of GCF MMP-3 and TIMP-1 levels as prognostic factors for progression of periodontitis

BACKGROUND

To determine whether matrix metalloproteinase-3 (MMP-3) and tissue inhibitor of metalloproteinases-1 (TIMP-1) in gingival crevicular fluid (GCF) could serve as prognostic factors for the progression of periodontitis, we monitored GCF MMP-3 and TIMP-1 and periodontal status of selected sites in 40 medically healthy subjects over a 6-month period.

METHOD

Clinical measurements including gingival index (GI), plaque index, bleeding on probing, suppuration, probing depth (PD), attachment loss (AL), and GCF samples were taken from 2 healthy sites (including sites with gingival recession, GI=0 PD < or =3 mm; AL < or =2 mm) and 2 periodontitis sites (GI > or =1; PD > or =5 mm; AL > or =3 mm) of each patient at baseline, 3-month and 6-month visits by means of sterile paper strips. GCF levels of MMP-3 and TIMP-1 were determined by sandwich ELISA assays.

RESULTS

The mean amounts of MMP-3 and TIMP-1 in diseased sites were significantly higher than in healthy sites (p<0.0001). Significantly higher GCF levels of MMP-3 and TIMP-1 were found at progressing sites than in nonprogressing periodontitis sites (0.001<p<0.01). A progressing site was defined as a site which had > or =2 mm loss of attachment during 6- month study period. GCF levels of MMP-3 were highly correlated with clinical measurements taken at baseline, 3-month and 6-month visits (p<0.001). TIMP-1 levels were only moderately correlated with probing depth and attachment level (p<0.01). Step-wise multiple regression analysis was performed to construct models for the prediction of probing depth and attachment loss increases. The most parsimonious regression models which had the best R2 values included the following variables and accounted for the indicated % of variability. The regression model for the prediction of probing depth increase included MMP-3, smoking pack-years, TIMP-1 and accounted for 53% of the variability. The best model for the prediction of attachment loss increase included MMP-3, smoking pack-years, age, TIMP-1 and explained 59% of the variability.

CONCLUSION

These data indicate that sites with high GCF levels of MMP-3 and TIMP-1 are at significantly greater risk for progression of periodontitis.

Use of a fluorogenic septapeptide matrix metalloproteinase assay to assess responses to periodontal treatment

BACKGROUND

Quantification of gingival crevicular fluid matrix metalloproteinase activity may provide improved assessment of periodontal disease status and response to treatment. A fluorogenic matrix metalloproteinase substrate assay (FSA) has been developed using a methoxycoumarin-containing septapeptide analog of the alpha2(I) collagen cleavage site. This substrate exhibits increased fluorescence following cleavage by many matrix metalloproteinases, and the enzyme activity can be readily estimated with a fluorimeter. Here we compared this assay with classical methods of periodontal assessment including bleeding on probing, crevicular fluid flow, and probing depth to assess its utility as an indicator of changes in periodontal status and treatment response.

METHODS

Complete measurements of probing depth were obtained for Ramfjord teeth on subjects who had been previously treated for periodontitis. Subjects were subsequently divided into groups based on existing periodontal disease severity: gingivitis (n = 21), stable periodontitis (n = 41), and severe periodontitis (n = 50). Crevicular fluid volume, bleeding on probing, and FSA were measured at each Ramfjord tooth or substitute. After baseline measurements, subjects received subgingival scaling and prophylaxis; 3 months later, they were reassessed.

RESULTS

FSA measurements were positively associated with severity of disease at baseline. After treatment there were substantial reductions of FSA in gingivitis (approximately 51%; P <0.01) and severe periodontitis (approximately 45%; P <0.001), but not in stable periodontitis (13%; P >0.2). All groups showed a positive association between FSA measurements and higher bleeding scores at individual sites. FSA measurements were also positively associated with crevicular fluid flow at baseline, but after treatment there was a approximately 67% decrease (P <0.01) in the highest crevicular fluid flow class. There were significant reductions of FSA at follow-up for sites with probing depths between 0 to 3 mm (23%; P <0.05) and 4 to 6 mm (31%; P <0.05). However, the largest reduction was for sites with probing depth between 7 to 9 mm (49%; P <0.001).

CONCLUSIONS

These results indicate that monitoring patients by measurement of matrix metalloproteinase levels in gingival crevicular fluid with the quenched fluorescent substrate assay provides estimates of inflammatory status, periodontal destruction, and response to treatment, especially in more severe periodontitis lesions.

Analysis of human gingival tissue and gingival crevicular fluid beta-glucuronidase activity in specific periodontal diseases

BACKGROUND

Beta-glucuronidase (betaG) is one of the enzymes involved in the destruction of non-collagenous components of the extracellular matrix. It is also considered an indicator or predictor of periodontal disease activity. The present study was conducted to determine the presence and the levels of betaG activity in gingival tissue and gingival crevicular fluid (GCF) in periodontal disease and health status. The validity of 2 expressions of data, total betaG activity versus betaG concentration, and the correlations between clinical periodontal status and betaG profile was also evaluated.

METHODS

betaG activities in gingival tissues and GCF samples from 57 individuals, divided into 3 equal groups of adult periodontitis (AP), early-onset periodontitis (EOP), and periodontally healthy subjects were spectrophotometrically examined.

RESULTS

Both patient groups had higher betaG levels in both gingiva and GCF than controls. Significant differences were observed among all groups when total GCF betaG activities were examined (P <0.05). However, the difference between AP and controls was not significant when concentration values were compared (P >0.05). The highest GCF betaG activity, with both expressions, was detected in EOP group. No absolute correlations between clinical parameters and betaG activity were observed, except for random correlations in the patient groups with mean total betaG activities. Also GCF/gingiva betaG levels and the 2 expressions did not show absolute correlations.

CONCLUSIONS

The findings of the present study confirm the relationship between betaG activity and periodontal diseases. The differences in data concerning GCF total betaG activity and betaG concentration may suggest that they are not matching measures. Data presentation seems to be an important factor in GCF/enzyme profile studies.

The association of calprotectin level in gingival crevicular fluid with gingival index and the activities of collagenase and aspartate aminotransferase in adult periodontitis patients

BACKGROUND

Calprotectin, a major cytosol protein of leukocytes, exists in plasma and other body fluids of healthy human subjects. Since the calprotectin concentration rises markedly in some inflammatory diseases including rheumatoid arthritis, this protein has been thought to be a marker of inflammatory disease. Recently, we identified calprotectin in human dental calculus and gingival crevicular fluid (GCF), and found that the calprotectin concentration in GCF from patients with periodontitis was significantly higher than that in GCF from healthy subjects. In the present study, the association of GCF calprotectin level with GCF volume, gingival index (GI), and levels of biochemical markers including collagenase and aspartate aminotransferase (AST) in GCF was investigated to clarify the relationship between GCF calprotectin level and periodontal inflammation.

METHODS

Ninety GCF samples collected from periodontal pockets with a probing depth of more than 4 mm in 54 patients with adult periodontitis were used for these assays. The GCF volume was measured, and GI in each site was recorded. The calprotectin content in GCF samples was determined by ELISA using a specific antibody. The activity of collagenase or AST was measured by a respective assay kit.

RESULTS

The total amount of calprotectin and GCF volume showed a highly significant correlation (r = 0.64, P <0.0001), whereas the calprotectin concentration had no correlation with the GCF volume (r = 0.01, P= 0.924). The mean calprotectin concentration in GCF increased with the degree of GI, and the concentration in individual samples was significantly correlated with the GI score (r = 0.56, P<0.0001). Significant positive correlations were observed in GCF calprotectin versus collagenase (r = 0.57, P <0.0001) and GCF calprotectin versus AST levels (r = 0.40, P <0.005).

CONCLUSIONS

From the present results and our previous findings, it is shown that the GCF calprotectin level significantly correlates not only with clinical indicators but also with current biochemical marker levels and that calprotectin may be a useful marker for periodontal inflammation.

Assessment of a novel screening test for neutrophil collagenase activity in the diagnosis of periodontal diseases

BACKGROUND

Increased levels of active neutrophil collagenase (MMP-8) in the gingival crevicular fluid (GCF) are associated with progressive periodontitis. The measurement of this enzyme in GCF could facilitate diagnosis. However, assays with sufficient sensitivity to detect collagenase in whole-mouth GCF currently use radiolabeled substrates and require several days to complete. To provide more rapid analyses of collagenase activity that are better adapted to clinical studies, we developed and validated a novel assay (soluble biotinylated-collagen assay: SBA) based on chemiluminescent detection of biotinylated collagen digestion products.

METHODS

The concordance of the novel SBA assay with a radioactive collagen substrate assay was assessed by parallel analyses of enzyme from 35 neutrophil preparations and from 41 samples of GCF from periodontitis patients, followed by Pearson correlation analysis. To test whether the assay appropriately measured MMP-8 activity, enzyme activity was assessed after incubation with specific collagenase blockers. We examined the diagnostic utility of the SBA in cross-sectional and longitudinal analyses of 125 patients with adult periodontitis, 5 patients with early-onset periodontitis, 1 edentulous patient, and in 32 control patients without periodontitis.

RESULTS

The assay detected <56 pg collagen degraded/hour/microl sample, which is comparable to the most sensitive radioactive assay. The total assay time was 22 hours and reproducibility on replicate measurements was high (r = 0.96). In direct comparisons of MMP-8 activity in GCF with enzyme from peripheral blood neutrophils using the SBA and radioactive assays, there was a high correlation (r = 0.97). As expected, EDTA and TIMP-1 and -2, known inhibitors of MMP-8, completely blocked enzyme activity with this assay. Cross-sectional and longitudinal analyses of GCF showed that MMP-8 activity was >18-fold higher in severe periodontitis than in stable periodontitis and decreased to <25% of pretreatment levels following therapy. Based on measurements of collagenase activity in different disease groups, we estimated a value of 80 nano units as a threshold for severe periodontitis.

CONCLUSIONS

These results indicate that active MMP-8 is detected in GCF by a novel assay that is specific, simple, rapid, and reproducible and which may facilitate diagnostic discrimination between stable and progressive lesions.

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.

Tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) distribution in normal and pathological human bone

Degradation of skeletal connective tissue is regulated, at least in part, by the balance between matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinase (TIMPs), their natural inhibitors. The balance between MMPs and TIMPs may therefore be a determinant of normal bone turnover, and imbalance could thus lead to reduced organization of bone structure. To test this hypothesis, the cellular expression of MMPs and TIMP-1 was investigated by immunohistochemistry in human neonatal rib and osteophytic and heterotopic bone; these differ in their structure, with heterotopic bone showing the least and normal rib the most organized development. In all samples, high levels of MMPs were expressed. Collagenase and stromelysin-2 were detected in chondrocytes, osteoblasts, and osteoclasts, whereas gelatinase-B was confined to osteoclasts and mononuclear cells. Matrix-associated stromelysin-1 was present in fibrous tissue and osteoid. In contrast, the expression of TIMP-1 varied markedly between the three types of bone. In heterotopic bone only occasional low level TIMP-1 expression was detected in chondrocytes and osteoblasts. Osteophytic bone showed varying levels of TIMP-1, which was matrix-bound in fibrous tissue and cell-associated in osteoblasts, chondrocytes, and occasional mononuclear cells. In both types of bone, expression of TIMP-1 by osteoclasts was absent despite large numbers of these cells. Neonatal rib bone showed consistent expression of TIMP-1, particularly in chondrocytes, osteoblasts, and lining cells. In contrast to pathological bone, many osteoclasts were TIMP-1 positive. These results suggest that, in heterotopic and osteophytic bone, the low levels of TIMP-1, and in particular its absence in osteoclasts, may partly explain the more poorly organized bone formation in these pathological bone samples. Furthermore, TIMP-1 may play a role in the regulation of bone modeling and remodeling in normal developing human bone.

Tissue inhibitors of metalloproteinases level and collagenase activity in gingival crevicular fluid: the relevance to periodontal diseases

OBJECTIVES

To provide an overall assessment of levels of tissue inhibitors of metalloproteinases (TIMPs), collagenase activities, and of immuno-reactivities for matrix metalloproteinases (MMP)-1 and -8 in gingival crevicular fluid (GCF) obtained from healthy subjects, and gingivitis and periodontitis patients, and to analyse the relationships between periodontal tissue destruction and the GCF components in periodontal diseases by principal component analysis.

MATERIALS AND METHODS

GCF was sampled with sterile paper strips from 10 gingivitis and 11 periodontitis patients. Ten volunteers served as clinically healthy controls. TIMP-1 and -2 protein amounts in GCF were measured by ELISA, and active and APMA-activatable collagenase activities were determined by functional assays using image-analysis after SDS-PAGE.

RESULTS

GCF TIMP-1 level and both active and latent collagenase activities were significantly higher in the diseased groups than in the healthy group. TIMP-2 was detectable in only 29% of all subjects (mean: 2.06 ng). Western blot analysis showed that MMP-8 was the major interstitial collagenase in the GCF of the diseased groups. Principal component analysis using clinical parameters and the GCF components has indicated components one to three account for 87% of total variation when evaluating the relevance of their measurements to periodontal diseases.

CONCLUSIONS

We conducted the functional and immunological characterization of MMPs and TIMPs in the GCF of periodontally diseased patients. Principal component analysis indicated components one to three explaining 87% of total variation, and further suggested that higher collagenase activity (especially in active collagenase) would be an important marker in evaluating the pathogenesis of periodontitis. Consequently, these observations may have significant therapeutic and diagnostic implications.

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.

Cytokines modulate routes of collagen breakdown. Review with special emphasis on mechanisms of collagen degradation in the periodontium and the burst hypothesis of periodontal disease progression

In this paper, we review recent work on collagen degradation, 2 main routes of breakdown are described and their relevance during healthy and inflammatory conditions of the periodontium is discussed. Special attention is paid to the possible role of cytokines, in particular interleukin 1 (IL-1) and transforming growth factor beta (TGF-beta), on the modulation of collagen phagocytosis and metalloproteinase production. IL-1 has been shown to have a dual function in collagen digestion. It inhibits the intracellular phagocytic pathway, but at the same time, it strongly promotes extracellular digestion by inducing the release of collagenolytic enzymes like collagenase. TGF-beta has an opposite effect on both pathways and antagonizes IL-1. Collagenase is released in an inactive form, and a considerable fraction of the proenzyme may become incorporated in the extracellular matrix. This reservoir of latent enzyme can be activated (for instance by plasmin), leading to a sudden and extensive breakdown of the collagenous fibre meshwork. It is suggested that this phenomenon may also take place during progressive periodontitis and could explain an episodic nature of collagenolysis, clinically resulting in bursts of attachment loss (burst hypothesis).

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.

Effect of Porphyromonas gingivalis on epithelial cell MMP-9 type IV collagenase production

Porphyromonas gingivalis is reportedly capable of stimulating the expression of host cell matrix metalloproteinases (MMP), contributing to tissue destruction. However, the impact of this bacterium on specific molecules remains to be determined. In this study, we evaluate the effect of P. gingivalis on regulation of MMP-9 expression in human gingival epithelial cells (HGEC). Various inocula of P. gingivalis were added to cultures of HGEC. The effects of live bacteria, heat-killed bacteria, and outer membrane extract were analyzed. MMP-9 secretion by HGEC was evaluated by enzyme-linked immunosorbent assay. For inocula smaller than one bacterium per cell, the quantity of MMP-9 secreted by HGEC was increased in comparison to control conditions. For inocula from 2.5 to 250 bacteria per cell, an inhibition of MMP-9 secretion in a dose-response fashion was observed, with a maximum reduction (ranging from 80 to 95% in five experiments) at 50 bacteria per cell. Gelatin zymograms confirmed the decrease in MMP-9 secretion. A band of 83 kDa, corresponding to activated enzyme, was present for inocula of 0.5 to 50 bacteria. Inhibition took place without any alteration of epithelial cell viability. Heat-killed bacteria and outer membrane extract also provoked proenzyme activation but did not inhibit MMP-9 secretion. These results demonstrate a direct effect of P. gingivalis on HGEC, suggesting a specific action on the collagen renewal process at the interface between the epithelium and connective tissue.

Matrix metalloproteinases-1 and -8 and TIMP-1 mRNA levels in normal and diseased human gingivae

Interstitial collagenases, including matrix metalloproteinase-1 (MMP-1) and -8 (MMP-8), serve as initiators of extracellular matrix destruction in periodontal disease. Collagenase activities are mainly regulated by tissue inhibitors of metalloproteinases (TIMPs). We tested the effects of inflammation on MMP-1 and MMP-8 gene expression in periodontal disease. To determine the relative abundance of these mRNAs in gingiva, we used a reverse transcription-polymerase chain reaction (RT-PCR) assay. Gingival biopsies were divided into 2 groups; a control group and an inflamed group with severe gingivitis or periodontitis. The MMP-1 mRNA levels were significantly elevated in inflamed gingiva, while the levels of the MMP-8 transcript were not different in the 2 groups and barely detectable by RT-PCR assay. The expression of the TIMP-1 gene was not altered, and remained higher than any of these other genes in both control and diseased gingivae. These results suggest that MMP-1 rather than MMP-8 may play an important role in the initiation of collagen degradation in periodontal disease. However, the possibility remains that MMP-8 plays an important role in periodontal tissue destruction, since the mRNA abundance and not the enzyme activity was assessed.

The effect of subgingival antimicrobial therapy on the levels of stromelysin and tissue inhibitor of metalloproteinases in gingival crevicular fluid

Recent investigations imply that a key mechanism in the pathogenesis of periodontal disease may be the ability of oral microorganisms to induce production and/or activation of matrix metalloproteinases (MMPs) in the host tissues. It has been suggested that the pharmacologic inhibition of MMP activity could play an important role in achieving a desirable outcome in periodontal therapy. The efficacy of locally delivered antibiotics on the level of gingival crevicular fluid (GCF) stromelysin (SL) and tissue inhibitor of metalloproteinases (TIMP) on sites with a history of a poor response to mechanical treatment was studied. Fifty-two patients with 4 periodontal pockets > or = 5 mm and bleeding on probing were randomized into four groups of 13 patients. One group received scaling and root planing alone and the other three groups received scaling and root planing plus a locally delivered antimicrobial system. These included 25% tetracycline fiber, 2% minocycline gel, and 25% metronidazole gel. The GCF samples taken at baseline and 6 weeks after treatments were analyzed using an enzyme linked immunosorbent assay (ELISA). GCF SL levels significantly decreased after adjunctive tetracycline fiber (paired t-test, P = 0.020) and minocycline gel (paired t-test, P = 0.023) treatments whereas it remained almost unchanged in the other two groups. While the GCF TIMP level did not change significantly in the scaling and root planing alone group, it significantly increased for all three adjunctive antimicrobial treatments (for tetracycline fiber P < 0.001, minocycline gel P = 0.005, metronidazole gel P < 0.001). The use of adjunctive locally delivered antimicrobial systems, particularly the tetracycline family, may offer an advantage in changing the metalloproteinase profile of the GCF to one more compatible with periodontal health.

Interleukin-1 alpha produced in human gingival fibroblasts induces several activities related to the progression of periodontitis by direct contact

Previous observations suggest that interleukin-1 (IL-1) may play an important role in the progression of periodontitis. In the present study, we investigated whether a cell-associated IL-1 alpha (CAIL-1 alpha) produced in human gingival fibroblasts (HGF) induces biological activities related to the progression of periodontitis. HGF were treated with recombinant human IL-1 beta (rhIL-1 beta) for 12 h. After that, the cell layers of HGF were washed 3 times with fresh medium and were then fixed with 1% paraformaldehyde. The fixed cell layers of HGF were used for assays for bone resorbing activity, prostaglandin E2 (PGE2) production and collagenase activity. Fixed cell layers of HGF treated with rhIL-1 beta enhanced not only calcium release from BALB/c mouse calvaria but also PGE2 production and collagenase activity in HGF and human periodontal ligament fibroblasts (HPLF) cultured on the fixed cell layers. These activities were neutralized by treatment with monoclonal mouse anti-human IL-1 alpha antibody, but monoclonal mouse anti-human IL-1 beta antibody showed no effects on these activities. The induction of these activities by fixed cell layers of HGF required direct contact between the fixed cell layers and the calvaria, HGF, or HPLF. These results suggest that CAIL-1 alpha produced in HGF treated with rhIL-1 beta induces bone resorbing activity, PGE2 production and collagenase activity in the target cells by direct contact; CAIL-1 alpha may play an important role in the progression of periodontitis.

Collagenases and tissue inhibitors of metalloproteinases: a functional balance in tissue degradation

BACKGROUND

Members of the family of matrix metalloproteinases (MMPs; also called collagenases or matrixins) are key enzymes in matrix degradation. They function at neutral pH and can digest synergistically all the matrix macromolecules. Biochemical and clonal studies indicate that there are three major groups: the specific collagenases cleave interstitial collagens; the gelatinases degrade types IV, V, VII and XI collagens and act synergistically with collagenases by degrading denatured collagens (gelatins); and the stromelysins have broader specificity and can degrade basement membrane collagens as well as proteoglycans and matrix glycoproteins. Others not in these groups are matrilysin, metalloelastase and a recently cloned membrane-bound metalloproteinase. MMPs are Zn(2+)- and Ca(2+)-requiring endopeptidases and are secreted in a latent proform: activation involves the loss of a propeptide. Naturally occurring inhibitors, TIMPs (Tissue Inhibitors of MetalloProteinases), are important controlling factors in the actions of MMPs, and tissue destruction in disease processes often correlates with an imbalance of MMPs over TIMPs. The major inhibitor is TIMP-1 (or TIMP), a 30-kDa glycoprotein that is synthesised by most cells. A second unglycosylated inhibitor, TIMP-2, which is less abundant, has the interesting property of binding to the proform of gelatinase A and is involved in controlling its activation.

BIOLOGICAL AND PSYCHOLOGICAL IMPLICATIONS

The expression of MMPs and TIMPs by cells is regulated by many cytokines (particularly interleukin-1, IL-1), growth factors and hormones, some of which are specific to cell type and others that are ubiquitous (eg transforming growth factor beta, TGF-beta). Many of these factors are products of monocytes/macrophages and their production in inflammatory situations is therefore part of the chain of events leading to tissue degradation. From many recent studies it seems that tissue destruction, both physiological and pathological, is correlated with an imbalance of inhibitors over proteinases. We proposed that one way in which pathogenic organisms might mediate tissue degradation in periodontal diseases is through the ability of cell wall antigens to stimulate cytokine production by circulating mononuclear cells. These would then induce MMP synthesis by resident gingival cells (or by the mononuclear cells themselves), thereby initiating degradative events. We have identified MMPs in human gingival biopsy specimens by using specific polyclonal antibodies and indirect immunofluorescence. Their distributions are extremely variable, both in the connective tissue and the epithelium, but the results indicate that host cell production of MMPs may contribute to tissue degradation in periodontal disease. TIMP could also be found in some situations and could be a limiting factor.

Expression of mRNA for matrix metalloproteinases and tissue inhibitors of metalloproteinases in periodontitis-affected human gingival tissue

It is known that the host responds to an increased concentration of collagenase [or matrix metalloproteinase (MMP)-1] by preferentially expressing mRNA for the tissue inhibitor of metalloproteinase-1 (TIMP-1) in order to overcome tissue destruction due to periodontitis. To further elucidate the relation between MMPs and TIMPs in periodontitis-affected tissues, the expression of mRNA for MMP-1, -3 and -8, and TIMP-1 and -2, in 10 gingival samples from patients and five from healthy individuals was assessed by reverse transcription-polymerase chain reaction. The diseased group showed significantly higher levels of MMP-1, -3, -8 and TIMP-1 mRNA relative to beta-actin than the control group (mean +/- SE: diseased vs healthy (%): 0.26 +/- 0.05 vs 0.018 +/- 0.0040 for MMP-1; 0.09 +/- 0.16 vs 0.063 +/- 0.016 for MMP-3; 0.068 +/- 0.017 vs 0.006 +/- 0.0010 for MMP-8; 12.66 +/- 2.90 vs 2.71 +/- 0.54 for TIMP-1; p < 0.01). TIMP-2 did not significantly differ between the two groups (1.79 +/- 0.33 vs 1.42 +/- 0.53; p > 0.05). The preferential increase in the level of MMP-3 mRNA relative to that of MMP-1 and -8 in inflamed gingiva would be relevant to tissue destruction because MMP-3 is a broad-spectrum MMP and a pivotal activator of latent MMP-1 and -8. Therefore, the overall increase in MMP-1, -3 and -8 mRNA in periodontitis-affected gingiva might account for a concerted action of MMPs during connective tissue destruction in periodontitis.

Effects of treatment on gingival crevicular collagenase, stromelysin and tissue inhibitor of metalloproteinases and their ability to predict response to treatment

Fibroblast collagenase (FIB-CL) and stromelysin (SL) are members of a family of enzymes which are capable of degrading most of the extracellular matrix macromolecules. Extracellular control of these enzymes is performed by tissue inhibitor of metalloproteinases (TIMP). During healing, inflammation and normal tissue turnover, levels of MMPs and TIMP will change. The effect of treatment on the levels of FIB-CL, SL and TIMP as well as their ability, at baseline, to predict the outcome of therapy was investigated. 21 patients each provided 8 gingival crevicular fluid (GCF) samples from sites with probing depths > or = 4 mm. Clinical recordings and GCF sampling were performed at 3 time points. Assays for SL, FIB-CL and TIMP were performed by a sandwich ELISA. Attachment level changes were detected by the "tolerance method". The ability of the GCF constituents to predict the response to treatment was assessed by comparing pre-treatment levels between sites which did or did not show attachment gain after therapy. Although no GCF constituents could reliably predict the response to treatment, SL reduced significantly (p = 0.029) after the hygiene phase of therapy. In addition, both SL and TIMP levels showed a highly significant reduction at follow-up visit (p = 0.003 and p = 0.005 respectively). Thus, SL and TIMP levels are reduced by treatment, but these GCF proteins do not appear to have an ability to predict treatment outcome from baseline.

Oral fluid elastase as an indicator of periodontal health

The study was designed to find out whether oral elastase activity could be used as a simple biochemical indicator of periodontal health. Both stimulated whole saliva and water rinse samples were collected from subjects with different degrees of adult periodontitis, gingivitis or healthy periodontium. In both sample types, elastase was mostly bound to insoluble fraction and preferred valine containing synthetic substrate, similar to neutrophil elastase. The elastase measurement required very little manipulation or time and its reproducibility was found to be good. The elastase levels were found to be negligible in edentulous subjects and usually very low in subjects with healthy periodontium. In about 85% of periodontitis cases having at least 1 deep periodontal pocket ( > or = 6 mm), clearly elevated elastases levels were detected in both the saliva and r rinse samples. In advanced periodontitis cases, the colour reaction took place in 0.5 to 2 h. In localized periodontitis cases, 2- to 18-h incubations were required for positive reaction. There was a good correlation between the elastase activity and the number of deep periodontal pockets and the average community periodontal index of the subjects. Elastase activity was not a good indicator of gingivitis. About 45% of gingivitis cases were positive with the elastase test, and the enzyme values were not significantly increased in experimental gingivitis. In a longitudinal study on advanced periodontitis cases, elastase levels dropped dramatically as a result of clinically successful therapy, close to the values of healthy subjects. The oral elastase test could serve as a valuable adjunct in periodontal screening and assessment of treatment efficacy.

Growth factor effects on the expression of collagenase and TIMP-1 in periodontal ligament cells

The fibroblast is a prominent cellular component of the periodontal ligament. It is believed to play an important role in collagen metabolism in health and disease. The turnover of collagen in the periodontal ligament is believed to be controlled by the balance between collagen synthesis and degradation. The family of matrix metalloproteinases and their inhibitors is one of the mechanisms which regulates this balance. The factors that regulate the synthesis of collagenase and its inhibitor, TIMP-1, by the periodontal ligament cell are poorly understood. The present study was undertaken to assess the effect of interleukin-1 beta (IL-1 beta), platelet-derived growth factor (PDGF), and transforming growth factor-beta 1 (TGF-beta) on the expression of collagenase (MMP-1) and TIMP-1 mRNA in periodontal derived fibroblasts using reverse transcription polymerase chain reaction (RT-PCR). Early passage periodontal ligament derived fibroblasts were treated with IL-1 beta (10 and 100 pg/ml), two isoforms of PDGF, -AA and -BB (4 and 20 ng/ml) and TGF-beta (1 and 10 ng/ml). Treatment with growth factors from 2 to 24 hours revealed that the largest effects on MMP-1 mRNA occurred after 24 hours. IL-1 beta induced a 5 to 9 fold increase in MMP-1 mRNA. The two isoforms of PDGF had less of an effect (3 to 5 fold) on MMP-1 mRNA whereas TGF-beta induced a 25 to 50% decrease in the expression of this message. None of the growth factors had an effect on TIMP-1 mRNA expression.(ABSTRACT TRUNCATED AT 250 WORDS)

Gingival crevicular stromelysin, collagenase and tissue inhibitor of metalloproteinases levels in healthy and diseased sites

The ability of stromelysin (SL), fibroblast-type collagenase (FIB-CL) and tissue inhibitor of metalloproteinases (TIMP), to differentiate between healthy, gingivitis and periodontitis sites was investigated. SL and FIB-CL are members of a family of enzymes which are capable of degrading most of the extracellular matrix macromolecules. Extracellular control of these enzymes is performed by TIMP. 40 patients each provided 3 GCF samples from healthy, gingivitis and periodontitis sites. GCF samples were collected by means of sterile paper strips. GCF samples were eluted into 500 microliters of assay buffer and assays for SL, FIB-CL and TIMP were performed by a sandwich ELISA. The mean amounts of SL and TIMP in diseased sites (gingivitis and periodontitis) were significantly higher than the mean amount of these GCF components in healthy sites (MANOVA p values were: 0.006 for SL and 0.001 for TIMP). GCF SL and TIMP differentiated healthy from diseased sites. Both SL and TIMP showed moderate correlation with clinical indices. FIB-CL was detectable in only 20.8% of all sites and did not correlate with disease status.

Influence of gingival crevicular washing on the expression of polymorphonuclear leukocyte membrane receptors before and after periodontal therapy

Extensive data demonstrate that polymorphonuclear leukocytes (PMN) are the predominant cell type involved in periodontal disease and that gingival crevicular fluid constituents are influenced by the inflamed gingiva. The aim of the present study was to evaluate the ability of gingival crevicular washing (GCW) (a dilution of gingival crevicular fluid) from periodontal sites in different clinical conditions of modulating the PMN membrane receptors involved in motility, adhesion and phagocytosis before and after periodontal treatment. 10 patients affected by adult periodontitis (AP) were selected. From each patient, 2 test sites (TS) were chosen on the basis of a probing depth > 5 mm and attachment loss, and 2 control sites (CS) with probing depth < 3 mm without. Modifications of membrane receptor density of PMN from healthy donors incubated with GCW harvested from TS and CS was evaluated using fluorescent probes and flow cytometry. Compared to CS-GCW, TS-GCW before therapy increased the expression of the beta 2 integrin CD11b and the chemotactic receptor for the oligopeptide N-formyl methionyl leucyl phenylalanine (FMLP-R) while it reduced the expression of L-selectin. GCW collected from the same TS after the successful completion of periodontal treatment did not influence PMN receptors, indicating that the clinical improvement paralleled the disappearance of the PMN modulating capability contained in TS-GCW before therapy. In conclusion, the present data illustrate the relevant modifications occurring at PMN membrane in chronic adult periodontitis exerted by GCW obtained by a simple fluid collection technique. Thus, monitoring gingival crevicular fluid PMN activating capability may help disclose the presence of chronic periodontitis and may be useful in assessing successful treatment.

Stimulation of enzyme and cytokine production by methyl mercaptan in human gingival fibroblast and monocyte cell cultures

The volatile sulphur compound methyl mercaptan (CH3SH) is a by-product of protein metabolism and a principal component of oral malodour. This investigation examines the effect of CH3SH on the enzymatic activities of cathepsins B and G and elastase, and on the production by human gingival fibroblasts of two key factors, prostaglandin E (PGE) and cAMP, of the PGE2-cAMP-dependent pathway, which may contribute to the increased production of collagenase and tissue destruction in human periodontal disease. The results demonstrate that CH3SH alone, or in combination with interleukin-1 (IL-1) or lipopolysaccharide, can significantly enhance the secretion of PGE2, cAMP and procollagenase by human gingival fibroblasts. CH3SH also stimulated mononuclear cells to produce IL-1, which can increase cAMP production, and act in synergism with the direct effect of CH3SH on cAMP. CH3SH also significantly enhanced the activity of cathepsin B, moderately suppressed that of cathepsin G, but did not significantly affect elastase. These results provide evidence that CH3SH could be a contributing factor in the enzymatic and immunological cascade of events leading to tissue degradation in periodontal diseases.

Immunoglobulin isotypes in gingival crevicular fluid: possible protective role of IgA

In order to simultaneously assess the local humoral immune and polymorphonuclear leukocyte (PMN) responses in periodontal disease, IgG, IgM, and IgA, as well as the PMN lysosomal enzyme beta-glucuronidase (beta G), were examined in gingival crevicular fluid (GCF) from patients with varying degrees of periodontal pathology. Evaluations were made before and after conservative therapy (scaling and root planing). Thirty patients with varying degrees of periodontal pathology, ranging from mild inflammatory gingivitis to moderate periodontitis, were studied. GCF was collected from the mesial surfaces of all teeth. The presence of the 3 immunoglobulin isotypes was determined by enzyme linked immunosorbent assays (ELISA), while total beta G activity in GCF was determined by a fluorometric assay. Clinical parameters were obtained from 6 sites per tooth. Our data indicate that prior to treatment, total beta G activity is strongly related to the severity of periodontal disease as measured by mean probing attachment level (AL; r = 0.89; P < .005), mean probing depth (PD; 4 = 0.89; P < .0005) and percentage of sites exhibiting bleeding on probing (% BOP; r = 0.49; P < .005). Following treatment, no statistically significant relationship of disease severity and beta G is found. The concentrations of IgG and IgM in GCF do not follow a specific pattern when related to disease severity. In contrast, prior to treatment the concentration of IgA is negatively correlated to mean AL (r = -0.54; P < .005), mean PD (r = -0.59; P < .005), and % BOP (r = -0.47, P < .005).(ABSTRACT TRUNCATED AT 250 WORDS)

Evidence of a direct relationship between neutrophil collagenase activity and periodontal tissue destruction in vivo: role of active enzyme in human periodontitis

To assess the temporal relationship between periodontal tissue destruction and the activity of collagenase, exudate from inflamed periodontal tissues was collected and latent and active collagenase activities were measured by a functional assay in a longitudinal cohort study. Comparisons were made between human subjects with either: 1) inflammation with a previous history of progressive loss of connective tissue and bone support (n = 14); 2) inflammation and previous history of bone loss but now clinically stable (n = 27); or 3) inflammation and no loss of bone support (n = 17). Experiments using specific enzyme inhibitors, blocking antibodies and SDS-PAGE fluorograph to identify the pattern of collagen substrate degradation demonstrated that the collagenase activity was derived from neutrophils and not from bacteria or other host cells. Active collagenase activity pooled from 6 sites per subject was respectively 5 and 6-fold higher in the group with progressive loss of connective tissue compared to the groups with either inflamed tissues alone or with inflammation and previous bone loss. In contrast, latent collagenase was increased up to 2 fold higher in the group with inflammation but no bone loss compared to the group with progressive lesions. Moreover, the ratio of active to total collagenase activity was 50% higher in the group with progressive lesions. Although in all subjects successive measurements of site-specific active collagenase 1 month apart demonstrated wide variation (r < 0.50), only in sites with progressive periodontal destruction was there significant increase of active collagenase with time (1.28 x 10(-4) collagenase units per day). There were also sharp elevations in active enzyme level at the time of detection of loss of connective tissue attachment in specific sites of 8 subjects. At the time of detection of connective tissue attachment loss, there was an overall 40% increase of pooled active collagenase activity in all subjects with progressive loss of connective tissue compared to pre-breakdown sampling times. These data provide strong in vivo evidence for a direct role of active neutrophil collagenase in the pathological destruction of periodontal connective tissue.

Collagenolytic enzymes in gingival crevicular fluid as diagnostic indicators of periodontitis

Periodontal diseases are associated with the production of several families of enzymes that are detectable in gingival crevicular fluid and that are released by stromal, epithelial or inflammatory cells. Measurement of collagen degrading enzymes in crevicular fluid could contribute to insights into pathogenesis of periodontal diseases and also provide a rational basis for the development of novel diagnostic tests. However, similar to the development of other diagnostic tests, the appropriate validation of collagenolytic enzymes as diagnostic indicators is dependent on clearcut demonstrations of the identity of the enzyme in the assay, and the reproducibility, diagnostic accuracy, and clinical utility of the test. If collagenolytic enzymes are to be of clinical usefulness, they should be easily measured over a broad range of disease severities and in varied clinical settings. Ideally, the diagnostic test should assay for an essential component of proposed pathogenic mechanisms. Neutrophil collagenase and gelatinase are promising enzymes for diagnostic tests because of (1) their apparently central role in periodontal attachment loss and disease progression; (2) demonstrations of positive associations between enzyme levels and attachment loss and inflammation; and (3) availability of sensitive and specific assays to quantify these enzymes. However, much less data exist on reproducibility, diagnostic accuracy, and clinical use in longitudinal studies. In the future, more emphasis must be placed on the importance of appropriate study design for establishing the efficacy of collagenolytic enzymes as diagnostic tests.

Effect of proteolytic enzymes on the lysis and growth of oral bacteria

Previous studies have shown increased levels of proteolytic enzymes in affected periodontal sites. The aim of the present investigation was to evaluate the effect of proteolytic environments on the lysis and growth of selected oral bacteria associated with either healthy or diseased periodontal sites. The effect of trypsin, chymotrypsin and proteinase K on cell lysis was determined following incubation with bacteria, whereas the effect of the same proteolytic enzymes on bacterial growth was tested using a disc-plate technique. Overall, gram-positive bacteria appeared to be more resistant to lysis than gram-negative bacteria. The most susceptible bacteria were Actinomyces spp., Eubacterium saburreum, Prevotella intermedia, Capnocytophaga ochracea, Fusobacterium nucleatum, Prevotella loescheii, Treponema denticola and Actinobacillus actinomycetemcomitans. The disc-plate procedure indicated that the growth of Actinomyces spp., E. saburreum, C. ochracea, P. intermedia, P. loescheii, Porphyromonas gingivalis and T. denticola were the most affected, more particularly by chymotrypsin and proteinase K. Interestingly, the growth of F. nucleatum was rather stimulated by proteolytic enzymes. The observations reported in this investigation indicate that specific and general proteolytic activities have the ability to lyse some oral bacterial species and to interfere with their growth. It is suggested that such effects could represent new mechanisms by which the bacterial ecology of subgingival sites may be affected.

Host enzymes in gingival crevicular fluid as diagnostic indicators of periodontitis

Host responses to periodontal infections include the production of several families of enzymes that are released by stromal, epithelial or inflammatory cells. Study of these enzymes in gingival crevicular fluid may lead to insights into pathogenesis and may provide a rational basis for the development of novel diagnostic tests. However, analogous to other diagnostic interventions in dentistry and medicine, validation of host enzymes as diagnostic indicators is dependent on clear-cut demonstrations of the identity of the enzyme, reproducibility, diagnostic accuracy and clinical utility. The enzyme of interest should be readily measured over a broad range of disease severity and in varied clinical settings. Ideally, the enzyme should also be an essential component of proposed pathogenic mechanisms. In this context, the connective tissue matrix degrading enzymes elastase, collagenase and gelatinase are promising because of their apparently central role in periodontal attachment loss and disease progression. Sensitive and specific assays are also available to quantify these enzymes. Other work on enzymes associated with cell death (aspartate aminotransferase, lactate dehydrogenase) and several neutrophil lysosomal enzymes (beta glucuronidase, arylsulphatase, cathepsins) has demonstrated positive associations between enzyme levels and attachment loss and inflammation. While numerous cross-sectional studies have indicated that the levels of hydrolytic enzymes in gingival crevicular fluid parallel the severity of periodontal lesions, there are much less data on reproducibility, diagnostic accuracy and clinical utility in longitudinal studies. As appropriate study design is an essential prerequisite for establishing the efficacy of host enzymes as diagnostic tests, future clinical investigations should include: (1) individuals who would most likely benefit by early diagnosis, i.e., rapidly progressive and recurrent periodontitis cases; (2) longitudinal, cohort study designs to show that attachment loss is temporally linked with large increases in enzyme activity; (3) the use of a battery of tests to overcome intrinsic problems of low predictive values when prevalence of active disease is low. In the final analysis, the utility of host enzymes as diagnostic indicators will need to be examined in randomized controlled trials in which the question is asked: are patients better off as a result of testing?

Connective tissue degradation in health and periodontal disease and the roles of matrix metalloproteinases and their natural inhibitors

Connective tissue remodeling is essential for normal growth and development, and many diseases have long been associated with the breakdown of the collagenous matrix of bone, cartilage, and related tissues. Recent work has established that members of the family of matrix metalloproteinases (MMPs) are key enzymes in matrix degradation. They function at neutral pH and can digest synergistically all the matrix macromolecules. Biochemical and cloning studies indicate that there are three major groups, collagenases, gelatinases, and stromelysins. Naturally occurring inhibitors, TIMPs (Tissue Inhibitors of MetalloProteinases), are important controlling factors in the actions of MMPs, and tissue destruction in disease processes often correlates with an imbalance of MMPs over TIMPs. The major inhibitor is TIMP-1 (or TIMP), a 30-kDa glycoprotein that is synthesized by most cells. The expression of MMPs and TIMPs by cells is regulated by many cytokines (particularly interleukin-1, IL-1), growth factors, and hormones, some of which are specific to cell type and others that are ubiquitous (e.g., transforming growth factor beta, TGF-beta). One way in which pathogenic organisms might mediate tissue degradation in periodontal diseases is through the ability of cell wall antigens to stimulate cytokine production by circulating mononuclear cells. These would then induce MMP synthesis by resident gingival cells, thereby initiating degradative events. Direct in vivo evidence for the source of collagenase and other MMPs in periodontal tissues is limited. By using specific polyclonal antibodies and indirect immunofluorescence, we could demonstrate the presence of collagenase, stromelysin-1, gelatinase A, and TIMP in human gingival biopsy specimens.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of cytokines and inflammatory mediators in tissue destruction

Colonization or emergence of microbial pathogens may result in tissue destruction by activation of one or more of five distinct host degradative pathways (matrix metalloproteinase pathway, plasminogen-dependent pathway, phagocytic pathway, PMN-serine proteinase pathway and osteoclastic bone resorption) or by direct cleavage of extracellular matrix constituents by microbial proteinases. Activation of endogenous destructive pathways may be mediated by immune responses resulting in expression of degradative cellular phenotypes among both immigrant and resident cell populations. In addition, expression of degradative phenotypes may be triggered by direct influences on host cells of microbial products (LPS, enzymes, toxins). A body of evidence suggests that each of these mechanisms involves local production of proinflammatory cytokines and growth factors. The matrix metalloproteinase pathway is centrally involved in dissolution of all unmineralized connective tissues and perhaps in resorption of bone as well. The matrix metalloproteinase family consists of nine or more genetically distinct Zn++ endopeptidases which collectively cleave all of the constituents of the extracellular matrix. Recent studies have uncovered many essential elements of a complex, but still incomplete, regulatory network that governs tissue destruction. Proinflammatory cytokines and growth factors induce signalling pathways several of which are dependent on protein kinase C and result in transient expression of the transcription factors c-jun and c-fos. Initiation of transcription of most matrix metalloproteinase genes requires binding of the transcription factor AP-1 (c-jun/c-fos) to a specific promoter sequence but attainment of maximal transcription rates is dependent on interaction with other promoter elements as well. Several matrix metalloproteinases have been detected in crevicular fluids and tissues of inflamed human gingiva as have the proinflammatory cytokines (IL-1 and TNF-alpha) which regulate their transcription. Although the mere presence of enzymes and cytokines does not necessarily impart function per se, these observations suggest that some level of spatial or temporal linkage exists between metalloproteinase/cytokine expression and gingival inflammation.