Identification of matrix metalloendoproteinase inhibitor (TIMP) in human parotid and submandibular saliva: partial purification and characterization

Active Matrix Metalloproteinase-8 (aMMP-8) Versus Total MMP-8 in Periodontal and Peri-Implant Disease Point-of-Care Diagnostics

Active matrix metalloproteinase-8 (aMMP-8) is a promising biomarker candidate for the modern periodontal and peri-implant disease diagnostics utilizing the chairside/point-of-care oral fluid technologies. These rapid biomarker analysis technologies utilize gingival crevicular fluid (GCF), peri-implant sulcular fluid (PISF), or mouth rinse as the oral fluid matrices that can be collected patient-friendly and non-invasively without causing bacteremia. aMMP-8, but not total or latent proMMP-8, has been shown to be a relevant biomarker to be implemented to the latest 2017 classification system of periodontitis and peri-implantitis. Thus, aMMP-8 point-of-care-testing (POCT)-but not total or latent proMMP-8-can be conveniently used as an adjunctive and preventive diagnostic tool to identify and screen the developing and ongoing periodontal and peri-implant breakdown and disease as well as predict its episodic progression. Similarly, aMMP-8 POCT provides an important tool to monitor the treatment effect of these diseases, but also other diseases such as head and neck cancer, where it can identify and predict the rapid tissue destructive oral side-effects during and after the radiotherapy. Additionally, recent studies support aMMP-8 POCT benefitting the identification of periodontitis and diabetes as the escalating risk diseases for COVID-19 infection. Overall, aMMP-8 POCT has launched a new clinical field in oral medicine and dentistry, i.e., oral clinical chemistry.

The Role of Matrix Metalloproteinases (MMPs) in Human Caries

The objective of this review is to summarize our understanding of the role of host matrix metalloproteinases (MMPs) in the caries process and to discuss new therapeutic avenues. MMPs hydrolyze components of the extracellular matrix and play a central role in many biological and pathological processes. MMPs have been suggested to play an important role in the destruction of dentin organic matrix following demineralization by bacterial acids and, therefore, in the control or progression of carious decay. Host-derived MMPs can originate both from saliva and from dentin. They may be activated by an acidic pH brought about by lactate release from cariogenic bacteria. Once activated, they are able to digest demineralized dentin matrix after pH neutralization by salivary buffers. Furthermore, the degradation of SIBLINGs (Small Integrin-binding Ligand N-linked Glycoproteins) by the caries process may potentially enhance the release of MMPs and their activation. This review also explores the different available MMP inhibitors, natural or synthetic, and suggests that MMP inhibition by several inhibitors, particularly by natural substances, could provide a potential therapeutic pathway to limit caries progression in dentin.

Evaluation of gelatinases, tissue inhibitor of matrix metalloproteinase-2, and myeloperoxidase protein in healthy and inflamed human dental pulp tissue

INTRODUCTION

The aim of this study was to compare the gelatinolytic activity of matrix metalloproteinase (MMP)-2 and MMP-9 and the expression of tissue inhibitor of matrix metalloproteinase (TIMP)-2 and myeloperoxidase protein (MPO) in clinically healthy human pulp and inflamed pulp tissue specimens.

METHODS

Twenty dental pulps clinically diagnosed as inflammatory tissues and 20 healthy pulp tissues from enclosed third molars were harvested and evaluated. The gelatinolytic activity for MMP-2 and MMP-9 was assessed by using the zymography technique, TIMP-2 gene expression was evaluated using the enzyme-linked immunosorbent assay, and MPO was determined using the MPO assay.

RESULTS

Data showed increased levels of MMP-9, active MMP-2, TIMP-2, and MPO in inflammatory pulp tissues compared with healthy tissues (P < .05). No statistical difference could be observed for pro-MMP-2 (P > .05).

CONCLUSIONS

Although all samples were associated with MMP-2 expression, the active form of this MMP was observed only in inflamed pulps. Inflamed pulps showed an up-regulation of MMP-9, TIMP-2, and MPO.

Immunohistochemical localization of tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) in human carious dentine

We evaluated if immunolocalization of tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) in odontoblast dentinal tubuli changes in response to caries attack in human carious teeth. Ten permanent premolar teeth with moderate to advanced caries and two sound teeth were collected. The premolars were decalcified in ethylene-diamininetetracetic acid (EDTA) and processed for embedding in paraffin wax. Sections of 3-4mum thick were cut and processed for immunohistochemistry. A mouse monoclonal anti-TIMP-1 antibody was used for the localization of TIMP-1 using an immunperoxidase technique. TIMP-1 immunoreactivity was observed in dentine of both sound and carious teeth. In both cases, the density of immunolabelled dentinal tubuli was typically higher toward the pulp chamber. In all the carious teeth, most, but never all, dilated dentinal tubuli were strongly positively immunolabelled. In sound teeth, a weak immunoreaction, only slightly above the background, was observed in dentinal tubuli. These results provide evidence for increased TIMP-1 immunolabelling in dentinal tubuli of carious teeth, in contrast to sound teeth. Overall, these in vivo findings indicate a possible role for TIMP-1 in the pathology of adult human dental tissues following an injury such as a caries lesion.

Increase in the ratio of matrix metalloproteinase-9 to tissue inhibitor of metalloproteinase-1 in saliva from patients with primary Sjögren's syndrome

BACKGROUND

To investigate the ratio of matrix metalloproteinase (MMP) to tissue inhibitor of metalloproteinase (TIMP) in primary Sjögren's syndrome (PSS), patients and healthy subjects MMP-2, 9 and TIMP-1, 2 levels were measured in saliva.

METHODS

Stimulated whole-mixed saliva was collected from 32 patients and 26 healthy subjects. MMP-2, 9 and TIMP-1, 2 levels were measured using enzyme-linked immunosorbent assay (ELISA) and the sandwich enzyme immunoassay (sandwich EIA). Zymography and reverse zymography were used to identify MMPs and TIMPs.

RESULTS

MMP-9 (gelatinase-B) level in saliva was significantly increased in the patients. MMP-9 (ng/ml): patients 231.02 +/- 151.77 (mean +/- S.D.), healthy subjects 145.87 +/- 111.65 (p < 0.05). MMP-2 levels were not detected with this system kit in either healthy subjects or patients. The differences in TIMPs were only trends and not statistically significant (p > 0.05). Accordingly, MMP-9/TIMP-1 was greatly increased in the patients (2.60 +/- 1.18) than in the healthy subjects (1.28 +/- 1.11) (p < 0.01).

CONCLUSION

This study found that MMP-9/TIMP-1 and MMP-9 levels in the saliva were significantly higher in pSS patients than those in healthy subjects. Our results indicate that the increase in MMP-9/TIMP-1, rather than the increase in MMP-9, in pSS patients' saliva is strongly involved in destruction of glandular and salivary duct tissues.

The relationship between MMPs and pH in whole saliva of radiated head and neck cancer patients

BACKGROUND

Radiation therapy for head and neck tumour patients may lead to decreased salivary flow, oral mucosal lesions and increased caries experience. Salivary matrix metalloproteinases (MMPs) may participate in the pathogenesis of mucosal lesions and dentinal caries. The aims of this study were: (i) to assay the presence, molecular forms and proteolytic activity of MMP-8 (collagenase-2) and MMP-9 (gelatinase B) in the whole saliva of head and neck cancer patients having radiation therapy; (ii) to see whether salivary pH affects the activity of MMP-8 and MMP-9; and (iii) to find out the possible connection between MMP-8 and MMP-9 with the eruption of oral mucosal lesions during radiation therapy.

METHODS

The whole saliva samples of 39 head and neck cancer patients having radiation therapy were collected before, during and after radiation therapy, and saliva flow rate, pH, buffer capacity, Streptococcus mutans, Lactobacillus and Candida albicans were measured. Any oral mucosal lesions were examined during each visit. The levels of MMP-8 were measured by immunofluorometric assay (IFMA) and the presence of different MMP-8 forms was analysed using Western immunoblotting. The presence and molecular forms of MMP-9 were analyzed by gelatin zymography. MMP-9 capture activity assay was used to determine the APMA-activated MMP-9 activity (total) and the endogenously active MMP-9 (free activity).

RESULTS

Salivary flow rate, buffer capacity and pH decreased, and the levels of Lactobacilli increased significantly, during the first half of the radiation therapy. The endogenously activated salivary MMP-9 correlated with low salivary pH (P = 0.013). No connection was found between the oral mucosal lesions and salivary MMP-8 or MMP-9.

CONCLUSIONS

In this study, salivary MMP-8 or MMP-9 did not correlate with the presence of radiation induced oral mucosal lesions, but the activation of MMP-9 may be dependent on pH.

Neutrophil tissue inhibitor of matrix metalloproteinases-1 occurs in novel vesicles that do not fuse with the phagosome

The human neutrophil granule location of precursors of matrix metalloproteinases (MMPs), MMP-8 and -9, has been established, but that of the tissue inhibitor of matrix metalloproteinases-1 (TIMP-1) has not. In this study, labeling for TIMP-1, pro-MMP-8, pro-MMP-9, and established granule marker proteins reveals that TIMP-1 is mainly located in distinct oval, electron translucent organelles, a little larger than azurophil granules. A lack of labeling for the fluid phase endocytic marker, bovine serum albumin-gold, the lysosome-associated membrane protein markers, and for glycosylphosphatidylinositol-linked proteins, which are enriched in secretory vesicles, indicates the non-endosomal, non-lysosomal, and non-secretory nature of this organelle. Density gradient cofractionation with the least dense, secretory population and some pleomorphism of the organelle suggest it is a "vesicle" rather than a "granule" population. Colocalization with pro-MMP-9 or pro-MMP-8, in minor subpopulations, suggests that TIMP-1 vesicle biogenesis occurs between metamyelocytic and terminal differentiation and before secretory vesicle synthesis. Pulse-chased IgG-coated latex beads and immunolabeling show that specific and azurophil granules fuse with the phagosome whereas TIMP-1 and pro-MMP-9-containing organelles do not. This suggests that these play no role in phagosomal destruction of IgG-opsonized bacteria. Separate localization and colocalization of these proteins may, however, facilitate fine regulation of extracellular proteolysis.

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.

Postnatal changes of gene expression for tissue inhibitors of metalloproteinase-1 and -2 and cystatins S and C, in rat submandibular gland demonstrated by quantitative reverse transcription-polymerase chain reaction

The rat submandibular gland is not fully developed at birth and definitive differentiation takes place postnatally. The steady-state mRNA expression for the four proteinase inhibitor molecules, tissue inhibitors of metalloproteinase (TIMP)-1 and -2, and cystatins S and C, and for a housekeeping gene, glyceraldehyde-3-phosphate dehydrogenase (G3PDH), in rat submandibular glands was measured by quantitative competitive reverse transcription-polymerase chain reaction (RT-PCR) at different stages of postnatal development. The gene-expression patterns of TIMP-1 and -2 relative to G3PDH were similar to each other. The TIMP-2 and cystatin C genes were more highly expressed than those of TIMP-1 and cystatin S at all stages. Moreover, the gene expressions of TIMP-1 and -2, and of cystatins S and C, were predominant between 1 and 7, and 7 and 12 weeks of age, respectively, and coincided developmentally with the regression of terminal tubule cells and the differentiation of granular convoluted tubule cells, respectively. Quantitative competitive RT-PCR allowed accurate measurement of small changes in the steady-state concentrations of these proteinase-inhibitor mRNA molecules.

The activation and function of host matrix metalloproteinases in dentin matrix breakdown in caries lesions

Matrix metalloproteinases (MMPs) are a family of enzymes which, in concert, are capable of degrading collagen. We investigated whether human MMPs could participate in the degradation of dentin organic matrix after demineralization. We performed Western blot analyses using MMP-specific antibodies to identify MMPs in human dental caries lesions. Enzymography and functional activity assays, with 125I-labeled gelatin as substrate or quantitating the degradation of type I collagen, were used to determine the activity of purified and salivary gelatinolytic (MMP-2 and MMP-9) and collagenolytic (MMP-8) enzymes with and without acid-activation in pHs relevant to caries. Respective analyses were done with caries-related bacteria. We performed electron microscope analyses to assess the degradative activity of sterilized salivary host MMPs on demineralized human dentin. Human MMP-2, MMP-8, and MMP-9 were identified in demineralized dentinal lesions. The latent purified forms of these enzymes were activated at low pH (4.5), followed by neutralization, mimicking the conditions during caries progression. Incubation of human saliva at low pH followed by neutralization resulted in a four-fold increase in the gelatinolytic activity. No gelatinolytic or collagenolytic activity was observed in bacterial samples. The activated enzymes in saliva degraded demineralized dentin organic matrix in vitro. These results demonstrate the pH-dependent activation mechanism of MMPs, which may have a distinct role in different physiological and pathological conditions. They further demonstrate that host MMPs, activated by bacterial acids, have a crucial role in the destruction of dentin by caries.

Matrix metalloproteinases and their inhibitors in gingival crevicular fluid and saliva of periodontitis patients

Matrix metalloproteinases (MMPs) and serine proteinases seem to be related to tissue destruction in periodontitis. The presence of MMPs in gingival crevicular fluid (GCF) and saliva, however, has not been studied comprehensively with the enzyme-linked immunosorbent assay (ELISA)-technique. We therefore examined the levels of MMP-1, -3, -8 and -9, and their endogenous inhibitor, tissue inhibitor of matrix metalloproteinases (TIMP-1), in GCF and saliva of patients with adult periodontitis (AP) and localized juvenile periodontitis (LJP). Elevated levels of MMP-1 were detected in LJP GCF compared to AP and control GCF. Elevated levels of TIMP-1 were also detected in LJP GCF in comparison to AP and control GCF. Higher MMP-8 levels were detected in AP GCF compared to LJP and control GCF. The relative low levels of MMP-3 were present in all studied GCF samples. Elevated levels of MMP-8 were further detected in saliva of AP compared to LJP and the controls. Both MMP-1 and TIMP-1 were detected in all studied saliva samples, but not significant differences were detected between the studied groups. Our ELISA-results confirm that (i) PMN MMP-8 and MMP-9 are the main collagenase and gelatinase in AP GCF, whereas GCF collagenase in LJP seems to be of the MMP-1-type; (ii) only low levels of TIMP-1, endogenous MMP-inhibitor, are present in AP GCF, which emphasises the importance of doxycycline as a possible adjunctive drug in the treatment of AP patients; (iii) tests based on specific antibodies against PMN MMPs, especially MMP-8, might serve as a reliable method of measuring and monitoring enzyme levels in GCF from different periodontitis patients.

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.

Effects of tetracyclines on neutrophil, gingival, and salivary collagenases. A functional and western-blot assessment with special reference to their cellular sources in periodontal diseases

The characterization and regulation of matrix metalloproteinases (MMPs) have been studied to determine their role(s) in periodontal tissue destruction. Progress in elucidating the roles of MMPs in periodontal tissue destruction has led to a new concept involving the chemotherapeutic inhibition on MMPs, a therapeutic strategy which less than a decade ago was considered "a difficult and perhaps impossible task." Tetracyclines/doxycycline (DOXY) and their chemically modified nonantimicrobial derivatives (CMTs) are known to inhibit the matrix metalloproteinases, especially preferring human neutrophil collagenase (MMP-8), and prevent the oxidative activation of procollagenases. We characterized by Western blotting the molecular forms and cellular sources of gingival tissue, dental plaque, gingival crevicular fluid (GCF), and salivary MMPs associated with periodontitis. Also the molecular forms of tissue inhibitors of matrix metalloproteinases (TIMP-1 and TIMP-2) in periodontitis were studied by Western blot. Neutrophil (PMN)-derived MMPs were found to predominate in periodontitis, and phospholipase C present in increased amounts in periodontitis sites was found to be a potential inducer of PMN degranulation. We further studied the effects of DOXY on molecular forms of different latent and active MMPs purified from different cellular sources (PMNs, fibroblasts, keratinocytes) and present in vivo in oral exudates (gingival extracts, GCF, and saliva). DOXY inhibition of activated (oxidatively or proteolytically) MMPs were not associated with MMP fragmentation. Michaelis-Menten plots of initial rates of degradation of soluble type I collagen revealed an apparent Km value of 0.3-0.6 microM for MMP-8, and 75 microM DOXY inhibited MMP-8 in a manner which did not result in changes in apparent Km value but did prevent the initial degradation reaching Vmax providing evidence for noncompetitive inhibition. Treatment of patients with long-term DOXY medication results in decreased MMP-8 activities/levels in gingival tissue, crevicular fluid, and saliva, but not fragmentation of MMP-8 in vivo. These data further support and extend the key role of PMN-MMPs in periodontitis, and the activities of these PMN MMPs can be inhibited directly by therapeutic levels of DOXY.

Collagenase activity and tissue inhibitor of metalloproteinases-1 (TIMP-1) content in human whole saliva from clinically healthy and periodontally diseased subjects

Total TIMP-1 concentration in whole saliva of periodontally diseased subjects, 137 +/- 67 ng/ml (mean +/- SD), was clearly lower (p < 0.001) than that of clinically healthy subjects, 273 +/- 145, and that of edentulous subjects, 332 +/- 121. On the contrary, both active [1.58 +/- 0.35 units/ml (mean +/- SD)] and total (2.08 +/- 0.25) collagenase activities in TIMP-1-free whole saliva of diseased subjects were significantly higher than the activities (0.14 +/- 0.14 and 0.50 +/- 0.27, respectively) in TIMP-1-free whole saliva of healthy subjects. Most of the total collagenase in whole saliva of healthy subjects consisted of procollagenase, while mainly active collagenase was present in whole saliva from patients with periodontal diseases. Significant reciprocal changes of TIMP-1 and collagenase levels, that is, increase in TIMP-1 concentration and decrease in collagenase activity, were observed after the initial therapy of periodontitis patients.

Matrix metalloproteinases (MMP-2 and MMP-9) of the oral cavity: cellular origin and relationship to periodontal status

Proteolytic enzymes released by the host cells are associated with the tissue destruction in periodontal diseases. Matrix metalloproteinases (MMPs) have the primary role in this process, since, in concert, they can degrade most of the extracellular matrix components. In the present study, we investigated MMP-2 and MMP-9 in oral fluids of healthy subjects and periodontitis patients and the contributions of different oral cells to the enzyme production. The enzymograms revealed that the main gelatinase in oral rinses, crevicular fluid, and whole saliva migrated at 92 kDa. Activity was also detected at 200 kDa and 130 kDa and minor activity at 86 kDa, 72 kDa, and 40 kDa. Traces of gelatinolytic activity were also detected in pure parotid secretions. The 92-kDa enzyme was identified to MMP-9 and the 200-kDa gelatinase to MMP-2, by means of specific anti-72-kDa antiserum. Gingival keratinocytes produced mainly MMP-9, while gingival and granulation tissue fibroblasts expressed MMP-2. Glandular tissue contained mainly MMP-9, and mRNA for MMP-9 was also found in acinar epithelial cells. Periodontitis patients had significantly higher levels of MMP-9 than healthy subjects. Also, MMP-2 was elevated in periodontitis patients. Periodontal treatment reduced the amount of gelatinases dramatically. This study shows that gelatinases are produced by various cells in the oral cavity. The amount of gelatinases is elevated during periodontal disease, while conventional periodontal treatment efficiently reduces the levels these enzymes. We suggest that MMP-2 and MMP-9 could participate in tissue destruction in periodontitis.

Salivary collagenase, elastase- and trypsin-like proteases as biochemical markers of periodontal tissue destruction in adult and localized juvenile periodontitis

The profile of salivary proteases and their cellular origin, with special reference to polymorphonuclear leukocytes and bacteria, was studied in localized juvenile periodontitis and compared with adult periodontitis and healthy controls. General proteolytic activity in saliva as well as collagenase, elastase-like and trypsin-like activity was measured. In addition, the sensitivity of salivary collagenase of patients with localized juvenile periodontitis to doxycycline inhibition was studied. The saliva of localized juvenile periodontitis patients contained low amounts of collagenase compared with adult periodontitis saliva, and almost all salivary collagenase was found to exist in endogenously active form, as was found to be the case also in adult periodontitis patients and healthy controls. The salivary collagenase of localized juvenile periodontitis patients was relatively insensitive to 100 mumol/l doxycycline but was completely inhibited by 600 mumol/l doxycycline, reflecting rather matrix metalloproteinase-1 (fibroblast-type) than matrix metalloproteinase-8 (polymorphonuclear leukocyte) enzyme. The saliva of localized juvenile periodontitis patients also contained low amounts of elastase-like activity compared with the saliva of untreated adult periodontitis patients. Scaling and root planing caused a significant decrease in elastase-like activity in the saliva of adult periodontitis patients. General proteolytic and trypsin-like activities were also low in the saliva of localized juvenile periodontitis patients. Furthermore, the reducing agent beta-mercaptoethanol did not activate or inhibit the salivary trypsin-like activity of localized juvenile periodontitis or adult periodontitis patients, although the reductant readily activated partially purified Porphyromonas gingivalis trypsin-like protease in a characteristic manner.(ABSTRACT TRUNCATED AT 250 WORDS)

The release of tissue inhibitor of metalloproteinases by calvarial bone explants and its immunolocalization

Tissue inhibitors of metalloproteinases (TIMPs) play an important role in the regulation of the activity of matrix metalloproteinases (MMPs) such as collagenase, stromelysin and gelatinase. Although it has been shown that upon culturing bone tissue releases relatively large amounts of TIMP, little is known as to the source of the inhibitor. In an attempt to investigate this in more detail calvarial bone explants from young rabbits were cultured in serum-free medium. The explants were cultured with or without adhering periosteum. In some experiments solitary periosteal fragments were maintained in the absence of bone. Media were analyzed for the presence of TIMP by immunoblotting and ELISA as well as for their capacity to inhibit the activity of collagenase. In addition, TIMP was immunolocalized in cryosections of the explants. The data demonstrated that bone-conditioned medium contained significantly more (2-10 times) collagenase inhibitor than periosteum-conditioned medium. Removal of the (convex and/or concave) periosteum from the calvariae did not significantly affect the amount of inhibitor released. Immunoblots and ELISA showed the presence of TIMP in the media, being more in bone- than in periosteum-conditioned medium. In immunolabeled cryosections TIMP appeared to be present in osteoblast-like cells lining both the outer bone surface as well as the endosteal spaces. Label was also found in a number of osteocyte lacunae. The periosteum was almost negative. It is suggested that TIMP contributes to the regulation of MMP-activity involved in the remodeling and turnover of bone.

Matrix metalloproteinases: a review

Matrix metalloproteinases (MMPs) are a family of nine or more highly homologous Zn(++)-endopeptidases that collectively cleave most if not all of the constituents of the extracellular matrix. The present review discusses in detail the primary structures and the overlapping yet distinct substrate specificities of MMPs as well as the mode of activation of the unique MMP precursors. The regulation of MMP activity at the transcriptional level and at the extracellular level (precursor activation, inhibition of activated, mature enzymes) is also discussed. A final segment of the review details the current knowledge of the involvement of MMP in specific developmental or pathological conditions, including human periodontal diseases.

Dissociation of collagenase-tissue inhibitor of metalloproteinases-1 (TIMP-1) complex--its application for the independent measurements of TIMP-1 and collagenase activity in crude culture media and body fluids

Collagenase-tissue inhibitor of metalloproteinases-1 (TIMP-1) complex was prepared from activated collagenase and TIMP-1 purified from culture media of human skin fibroblasts. After having been confirmed to be a complex by zinc chelate chromatography, the complex was demonstrated to dissociate by passage through an anti-TIMP-1 monoclonal antibody-affinity column. On the basis of above evidence, a simple strategy was set up for the independent measurements of TIMP-1 concentration, and both active and total collagenase activities in crude culture media and body fluids.

Collagenase activity in recurrent periodontitis: relationship to disease progression and doxycycline therapy

Previous reports have suggested that active progression of periodontitis may be correlated with increased collagenolytic activity, and that improved clinical conditions after tetracycline treatment may be explained by inhibition of host collagenase. Eighty-two patients with a recent history of periodontal abscesses and/or loss of gingival attachment level (GAL) despite active periodontal therapy were enrolled in a double-blind, randomized, placebo-controlled trial. Clinical measurements, sampling of gingival crevicular fluid (GCF) and subgingival scaling were performed every 2 months. If any site exhibited greater than 2 mm loss of GAL or a periodontal abscess, patients were administered either 100 mg doxycycline per day for 3 weeks or placebo. During 12 months of monitoring, 55 patients exhibited recurrent active disease and were then randomly assigned to either the doxycycline (n = 30) or placebo (n = 25) groups. Analysis of active collagenase and latent collagenase in GCF samples were determined by functional assays and quantitated after SDS-PAGE and fluorography. Collagenase activities were assayed at sites exhibiting active destruction (study site), at sites with pocket depth comparable to the study site but without active destruction, and at healthy sites. Clinical measurements of GAL and collagenase activity were made at intervals between 1 wk and 7 months after completion of the drug regime. Within 7 months, 15 out of 19 patients on placebo exhibited recurrent disease compared to 13 out of 29 patients on doxycycline. Collagenase activity exhibited large variations among patients and was analyzed as presence or absence of active collagenase with a logistic model.(ABSTRACT TRUNCATED AT 250 WORDS)

Identification of polymorphonuclear leukocyte collagenase and gelatinase activities in mouthrinse samples: correlation with periodontal disease activity in adult and juvenile periodontitis

In previous studies, elevations in the levels of active and latent collagenase in gingival crevicular fluid (GCF) have been correlated positively with periodontal disease activity. To provide a simple diagnostic approach for testing collagenolytic activity, the feasibility of using a 3.0 ml water mouthrinse to collect GCF simultaneously from all sites in the mouth was assessed. Patients with adult periodontitis (AP, n = 23) and local juvenile periodontitis (LJP, n = 7) were sampled before periodontal therapy and some (12 AP, 4 LJP) were also assessed longitudinally after scaling and root planing, administration of antibiotics, and following periodontal surgery. Healthy patients (n = 19) were used as controls. The levels of active collagenase, procollagenase, and collagenase inhibitor activity were determined by functional assays and quantitated after SDS-PAGE and fluorography. Gelatinase and progelatinase were assayed by enzymography on gelatin-substrate gels. Active collagenase levels were found to be significantly higher (14- to 20-fold) in AP and LJP patients compared to controls, whereas matrix metalloproteinase activity was not detected in mouthrinses from edentulous patients. Collagenase inhibitor levels were generally low in all groups of subjects tested. Following clinical treatment the levels of active collagenase and gelatinase were reduced; the reduction was significant for active collagenase after tetracycline treatment and scaling in LJP patients. Of the clinical indices recorded (gingival index, plaque index, and pocket depth) there were no significant correlations with enzyme activity but similar trends were observed between the changes in active collagenase and gingival index. In patients with untreated periodontal disease, collagenase occurred predominantly in the active form. N-ethylmaleimide (NEM) and p-aminophenylmercuric acetate (AMPA) were equally effective as activators of the latent collagenase, indicating that the collagenase was derived from PMNs, which were also the source of gelatinase. The results of these studies indicate that measurement of active collagenase and gelatinase in mouthrinse samples is potentially useful in the diagnosis and assessment of periodontal disease activity.

Salivary collagenase. Origin, characteristics and relationship to periodontal health

Saliva collected from subjects with healthy and with diseased periodontium was assayed for collagenase activity by incubation at 25 degrees C with soluble type I, II or III collagen. The degradation products were analyzed by separation in SDS-polyacrylamide gel electrophoresis followed either by protein staining or by exposure of the dried gel to X-ray film in the case of radioactively labeled type I collagen. Collagenase of vertebrate type was detected in the whole saliva of all subjects but not in parotid, sublingual or submandibular fluids. Most of the collagenase was in the soluble fraction of saliva that also contained factors which both activated and inhibited the enzyme. The salivary collagenase resembled the collagenase of human PMNs and gingival sulcular fluid in its molecular size of 70,000 daltons, in its activation by gold thioglucose and in its tendency to degrade types I and II collagens over type III collagen. Before periodontal treatment, the saliva of periodontitis patients had significantly higher collagenase than after treatment. In periodontitis, collagenase existed mainly in the active form, while in the healthy mouths most of the enzyme was latent but could be activated by sulfhydryl reagents or proteolytically with trypsin, and chymotrypsin but not by human plasma kallikrein or plasmin. In some of the samples from untreated periodontitis patients bacterial collagenase may have been present in small quantities. Most of the collagenase in the saliva from all subjects appeared to originate from PMNs entering the oral cavity through the gingival sulcus.

Microbiota and crevicular fluid collagenase activity in the osseointegrated dental implant sulcus: a comparison of sites in edentulous and partially edentulous patients

The soft tissues adjacent to osseointegrated dental implants (OII) were investigated using clinical, biochemical and microbiological methods. Tooth and implant crevices were compared in 15 partially edentulous patients, examining 28 peri-implant and 19 periodontal sites, and in 6 edentulous patients, examining 13 implant sites. Sites were classified by standard periodontal indices; the crevicular fluid flow determined; crevicular fluid was collected for collagenase assays; and the subgingival bacterial flora was examined and cultured. Differences in clinical parameters were noted in that implants had significantly less keratinized gingiva and deeper probing depths. Crevicular fluid was present in the OII sulcus but the crevicular fluid flow did not differ from that observed from tooth sites either in the partially edentulous or edentulous patients. Tissue collagenase activity and collagenase inhibitor were detected in the implant crevicular fluid and, as in periodontal sites, a strong inverse relationship was found between the levels of active collagenase and collagenase inhibitor. Microbiology included darkfield microscopy, anaerobic culturing for total colony forming unit counts and identification of black pigmented Bacteroides (BPB). Few differences were observed between implants and teeth in partially edentulous patients, indicating that crevices around teeth may act as reservoirs of bacteria which can colonize implant sites. A higher percentage of BPBs and wet spreaders (Capnocytophaga) was noted at partially edentulous implant sites when compared with edentulous implant sites, perhaps reflecting the lower numbers of periodontal pathogens present in edentulous mouths. Overall, the characteristics of implant sulci appear to be similar to periodontal sulci with respect to crevicular fluid flow and microflora.

Measurements of probing velocity with an automated periodontal probe and the relationship with experimental periodontitis in the Cynomolgus monkey (Macaca fascicularis)

The Toronto Automated Periodontal Probe allows simultaneous measurements of gingival attachment level and probing velocity. The efficacy of probing velocity in measuring the integrity of the dento-gingival junction was studied and compared with loss of gingival attachment level, gingival inflammation, tooth mobility and gingival crevicular fluid collagenolytic activity. The gingiva around the maxillary and mandibular incisor teeth of 2 monkeys were first brought to clinical health by daily prophylaxis. Baseline measurements were made and inflammation was then induced around the maxillary incisors by withdrawing plaque control and by placing silk ligatures subgingivally. The mandibular incisors served as controls. After 10 weeks, the ligatures were removed and the teeth scaled and polished daily for 1 week. The plaque index and gingival index reached maximum values within 1 week; crevicular fluid flow was significantly increased at 1 and 3 weeks but mobility did not change significantly. There was progressive loss of the gingival attachment level, which peaked at 10 weeks on experimental teeth; there was no significant loss on control teeth. Probing velocity around experimental teeth exhibited large and significant increases above controls between 1 and 3 weeks, coinciding with the largest weekly losses of the gingival attachment level. Thus probing velocity may be a useful clinical method for the ancillary measurement of early loss of the gingival attachment level. It can also detect biophysical changes in the dento-gingival junction of progressive inflammatory lesions.