Cathepsin B/L-, elastase-, tryptase-, trypsin- and dipeptidyl peptidase IV-like activities in gingival crevicular fluid. A comparison of levels before and after basic periodontal treatment of chronic periodontitis patients

Impact of Smoking on Neutrophil Enzyme Levels in Gingivitis: A Case-Control Study

Background: The determination of the impact of risk factors such as smoking in periodontal disease development is of importance to better characterize the disease. However, its impact on host response remains unclear. This study aimed to evaluate the effects of tobacco smoking on GCF levels of neutrophil enzymes (myeloperoxidase (MPO), beta-glucuronidase (BGD), neutrophil elastase (NE) and periodontal parameters in healthy young adults with dental plaque biofilm-induced gingivitis. Methods: The study population consisted of 60 systemically healthy young adults (39 smokers (Sm) and 21 non-smokers (n-Sm)) diagnosed with plaque-induced gingivitis. The periodontal examination consisted of a plaque index (PI); gingival index (GI); probing depth (PD); bleeding on probing (BoP), and clinical attachment level (CAL). GCF MPO, BGD, and NE levels were determined by means of an enzyme-linked immunosorbent assay (ELISA). Results: PI, GI, and BoP were significantly increased in the Sm group (p < 0.05). PD and CAL showed no significant difference between Sm and n-Sm groups (p > 0.05). In GCF, MPO, BGD, and NE levels were significantly increased in Sm group (p < 0.05). NE levels showed a significant correlation with GI and BoP (p < 0.05 for both). Moreover, a positive correlation between BGD and NE levels (p < 0.05) was measured. Conclusions: It may be concluded that, even in young patients, tobacco consumption affects the host’s immune response related to gingival inflammation. It is, therefore, mandatory to inform young patients about the risk related to tobacco consumption for their gingival health.

Predictive Periodontitis: The Most Promising Salivary Biomarkers for Early Diagnosis of Periodontitis

The primary cause of tooth loss in the industrialized world is periodontitis, a bacterial anaerobic infection whose pathogenesis is characterized by composite immune response. At present, the diagnose of periodontitis is made by a complete status check of the patient’s periodontal health; full-mouth plaque score, full-mouth bleeding score, probing depth, clinical attachment level, bleeding on probing, recessions, mobility, and migration are evaluated in order to provides a clear picture of the periodontal conditions of a single patient. Chair-side diagnostic tests based on whole saliva could be routinely used by periodontists for a very early diagnosis of periodontitis, monitoring, prognosis, and management of periodontal patients by biomarker detection, whose diagnostic validity is related to sensitivity and specificity. Recent paper reviews and meta-analyses have focused on five promising host derived biomarkers as candidate for early diagnosis of periodontitis: MMP-8 (Metalloproteinase-8), MIP-1α (Macrophage inflammatory protein-1 alpha), IL-1 β (Interleukin-1 beta), IL-6 (Interleukin-6), and HB (Hemoglobin), and their combinations. Chair-side Lab-on-a-chip (LOC) technology may soon become an important part of efforts to detect such biomarkers in saliva medium to improve worldwide periodontal health in developed nations as well as in underserved communities and poor countries. Their applications in preventive and predictive medicine is now fundamental, and is aimed at the early detection of risk factors or the presence or evolution of the disease, and in personalized medicine, which aims to identify tailor-made treatments for individual patients. The aim of the present paper is to be informative about host derived periodontal biomarkers and, in particular, we intend to report information about the most important immune response derived biomarkers and Hemoglobin as candidates to be routinely utilized in order to obtain a chair-side early diagnosis of periodontal disease.

The Role of Proteinase-Activated Receptors 1 and 2 in the Regulation of Periodontal Tissue Metabolism and Disease

Proteinase-activated receptors 1 (PAR1) and 2 (PAR2) are the most highly expressed members of the PAR family in the periodontium. These receptors regulate periodontal inflammatory and repair processes through their activation by endogenous and bacterial enzymes. PAR1 is expressed by the periodontal cells such as human gingival fibroblasts, gingival epithelial cells, periodontal ligament cells, osteoblasts, and monocytic cells and can be activated by thrombin, matrix metalloproteinase 1 (MMP-1), MMP-13, fibrin, and gingipains from Porphyromonas gingivalis. PAR2 is expressed by neutrophils, osteoblasts, oral epithelial cells, and human gingival fibroblasts, and its possible activators in the periodontium are gingipains, neutrophil proteinase 3, and mast cell tryptase. The mechanisms through which PARs can respond to periodontal enzymes and result in appropriate immune responses have until recently been poorly understood. This review discusses recent findings that are beginning to identify a cardinal role for PAR1 and PAR2 on periodontal tissue metabolism.

Periodontal care as a fundamental step for an active and healthy ageing

In the industrialized part of the world, an increasing number of people live the old age without too many restrictions due to illness or physiological impairment. This group is known as the young elderly. On the contrary, a consistent part of seniors develops a greater number of medical conditions and become more and more dependent, these are the old elderly. The first cause of tooth lost in industrialized word is periodontitis that generally strikes people older than 40 years and determines serious detriment of the stomatognatic organ. Smoking and stress are risk factors for periodontitis that are common and shared between young, adult, and older age. Diabetes mellitus, obesity, and osteoporosis are very frequent pathological situations in older age. They have been identified as cofactors in the progression of periodontitis. Many dental associations recognize the importance of continued research on oral fluids diagnostics and welcome the development of rapid point-of-care tests providing accurate measurements of clinically validated biomarkers. At present, well-studied molecules associated with host response factors and with derived tissue destruction mediators have been proposed as diagnostic biomarkers for periodontitis detected in the oral fluids.

Predictive, preventive, personalised and participatory periodontology: 'the 5Ps age' has already started

An impressive progress in dentistry has been recorded in the last decades. In order to reconsider guidelines in dentistry, it is required to introduce new concepts of personalised patient treatments: the wave of predictive, preventive and personalised medicine is rapidly incoming in dentistry. Worldwide dentists have to make a big cultural effort in changing the actual 'reactive' therapeutic point of view, belonging to the last century, into a futuristic 'predictive' one. The first cause of tooth loss in industrialised world is periodontitis, a Gram-negative anaerobic infection whose pathogenesis is genetically determined and characterised by complex immune reactions. Chairside diagnostic tests based on saliva, gingival crevicular fluid and cell sampling are going to be routinely used by periodontists for a new approach to the diagnosis, monitoring, prognosis and management of periodontal patients. The futuristic '5Ps' (predictive, preventive, personalised and participatory periodontology) focuses on early integrated diagnosis (genetic, microbiology, host-derived biomarker detection) and on the active role of the patient in which networked patients will shift from being mere passengers to responsible drivers of their health. In this paper, we intend to propose five diagnostic levels (high-tech diagnostic tools, genetic susceptibility, bacterial infection, host response factors and tissue breakdown-derived products) to be evaluated with the intention to obtain a clear picture of the vulnerability of a single individual to periodontitis in order to organise patient stratification in different categories of risk. Lab-on-a-chip (LOC) technology may soon become an important part of efforts to improve worldwide periodontal health in developed nations as well as in the underserved communities, resource-poor areas and poor countries. The use of LOC devices for periodontal inspection will allow patients to be screened for periodontal diseases in settings other than the periodontist practice, such as at general practitioners, general dentists or dental hygienists. Personalised therapy tailored with respect to the particular medical reality of the specific stratified patient will be the ultimate target to be realised by the 5Ps approach. A long distance has to be covered to reach the above targets, but the pathway has already been clearly outlined.

Host-derived diagnostic markers related to soft tissue destruction and bone degradation in periodontitis

BACKGROUND

A major challenge in clinical periodontics is to find a reliable molecular marker of periodontal tissue destruction with high sensitivity, specificity and utility.

OBJECTIVES

The aim of this systematic review is to evaluate available literature on 'the utility of molecular markers of soft and hard periodontal tissue destruction'.

MATERIALS AND METHODS

Based on the focused question, 'What is the utility of molecular markers of soft and hard periodontal tissue destruction', an electronic and manual search was conducted for human studies presenting clinical data for the potential of molecular markers of tissue destruction in biofluids; gingival crevicular fluid (GCF), saliva, and serum.

RESULTS

Papers fulfilling the inclusion criteria were selected. All relevant data from the selected papers were extracted and recorded in separate tables for molecules in GCF, saliva, and serum.

CONCLUSION

Within the defined limits of the Problem/Population, Intervention, Comparison, Outcome, the present analysis reveals that (a) no single or combination of markers exists that can disclose periodontal tissue destruction adequately; (b) while the most fruitful source of biomarkers for periodontal destruction appears to be in molecules tightly related to bone and soft tissue destruction, this remains to be objectively demonstrated. Currently, clinical measurements are still the most reliable.

What do 'omic technologies have to offer periodontal clinical practice in the future?

BACKGROUND AND OBJECTIVE

Periodontal diseases are the most common chronic inflammatory diseases of humans and a major cause of tooth loss. Inflammatory periodontitis is also a complex multifactorial disease involving many cell types, cell products and interactions. It is associated with a dysregulated inflammatory response, which fails to resolve, and which also fails to re-establish a beneficial periodontal microbiota. There is a rich history of biomarker research within the field of periodontology, but exemplary improvements in analytical platform technologies offer exciting opportunities for discovery. These include the 'omic technologies, such as genomics, transcriptomics, proteomics and metabolomics, which provide information on global scales that can match the complexity of the disease. This narrative review focuses on the recent advances made in in vivo human periodontal research by use of 'omic technologies.

MATERIAL AND METHODS

The Medline database was searched to identify articles currently available on 'omic technologies with regard to periodontal research.

RESULTS

One hundred and sixty-one articles focusing on biomarkers of and 'omic advances in periodontal research were analysed for their contributions to the understanding of periodontal diseases.

CONCLUSION

The data generated by the use of 'omic technologies have huge potential to inform paradigm shifts in our understanding of periodontal diseases, but data management, analysis and interpretation require a thoughtful and systematic bioinformatics approach, to ensure meaningful conclusions can be made.

Comparison of gingival crevicular fluid sampling methods in patients with severe chronic periodontitis

BACKGROUND

The analysis of samplings from periodontal pockets is important in the diagnosis and therapy of periodontitis. In this study, three different sampling techniques were compared to determine whether one method yielded samples suitable for the reproducible and simultaneous determination of bacterial load, cytokines, neutrophil elastase, and arginine-specific gingipains (Rgps). Rgps are an important virulence factor of Porphyromonas gingivalis, the exact concentration of which in gingival crevicular fluid (GCF) has not been quantified.

METHODS

GCF was sampled from four sites per patient (one sample per quadrant using two samples per method) in 36 patients with chronic periodontitis. One week later, the procedure was repeated with alternative methods. Variables determined were loads of Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans) and P. gingivalis, levels of interleukin-6 and -8, activity of neutrophil elastase, and level of Rgps.

RESULTS

The detected cytokine levels were higher using paper strips compared to paper points. Bacteria were found in similar loads from paper strips and paper points. Rgps were only detectable in high quantities by washing the periodontal pocket. The level of Rgps correlated with the load of P. gingivalis.

CONCLUSIONS

The use of paper strips was suitable for the simultaneous determination of microbial and immunologic parameters. Obtaining GCF by washing can be useful for special purposes. The gingipain concentration in periodontal pockets was directly determined to be ≤1.5 μM. This value indicated that most of the substrates of these proteases by in vitro assays identified until now can be easily degraded in P. gingivalis-infected sites.

Nafamostat mesilate, a potent tryptase inhibitor, modulates periodontitis in rats

Previous reports have demonstrated increased tryptase-like proteolytic activity in the crevicular fluid of patients with periodontal disease. In the present study, we have investigated the effect of tryptase inhibition with nafamostat mesilate (NM, 6-amino-2-naphtlyl p-guanidinobenzoate dimethansulfonate) on the development of experimental periodontitis in rats. Eighty (80) male Wistar rats were randomly separated into four groups: Control group, NM group (daily 0.1 mg/kg body weight of NM, i.p.), Ligature group (ligature placed at lower right first molars), and NM+Ligature group. The amount of alveolar bone loss (ABL) around the mesial root surface of the first mandibulary molar, as well as the myeloperoxidase (MPO) activity, and total proteolytic activity [N-benzoyl-L: -arginine-p-nitroanilide (BApNA) substrate] were determined at 7 and 14 days. NM led to significantly (p < 0.05) decreased ABL in animals subjected to ligature-induced periodontitis. Tryptase inhibition prevented the onset of significant ABL at 7 days of experiment (0.44 ± 0.16 and 0.60 ± 0.22, p > 0.05, NM+Ligature and Control, respectively) and significantly decreased the ABL at 14 days (0.97 ± 0.17 versus 1.82 ± 0.26, p < 0.001, NM+Ligature versus Ligature, respectively). In addition, NM significantly decreased MPO and total proteolytic activity at 14 days (p < 0.05). These data provided evidence that tryptase inhibition with NM attenuates gingival granulocyte infiltration and ABL in an experimental model of periodontitis in rats.

Oral fluid-based biomarkers of alveolar bone loss in periodontitis

Periodontal disease is a bacteria-induced chronic inflammatory disease affecting the soft and hard supporting structures encompassing the teeth. When left untreated, the ultimate outcome is alveolar bone loss and exfoliation of the involved teeth. Traditional periodontal diagnostic methods include assessment of clinical parameters and radiographs. Though efficient, these conventional techniques are inherently limited in that only a historical perspective, not current appraisal, of disease status can be determined. Advances in the use of oral fluids as possible biological samples for objective measures of current disease state, treatment monitoring, and prognostic indicators have boosted saliva and other oral-based fluids to the forefront of technology. Oral fluids contain locally and systemically derived mediators of periodontal disease, including microbial, host-response, and bone-specific resorptive markers. Although most biomarkers in oral fluids represent inflammatory mediators, several specific collagen degradation and bone turnover-related molecules have emerged as possible measures of periodontal disease activity. Pyridinoline cross-linked carboxyterminal telopeptide (ICTP), for example, has been highly correlated with clinical features of the disease and decreases in response to intervention therapies, and has been shown to possess predictive properties for possible future disease activity. One foreseeable benefit of an oral fluid-based periodontal diagnostic would be identification of highly susceptible individuals prior to overt disease. Timely detection and diagnosis of disease may significantly affect the clinical management of periodontal patients by offering earlier, less invasive, and more cost-effective treatment therapies.

Anti-Neutrophil Cytoplasmic Autoantibodies: A Renewed Paradigm in Periodontal Disease Pathogenesis?

In the past, various models including the autoimmunity model have been proposed to explain the pathogenesis of periodontal diseases. The aim of this review is to introduce the pathogenic role of anti-neutrophil cytoplasmic autoantibodies (ANCAs) in various autoimmune diseases and compare these conditions with periodontal disease to elucidate common pathogenic mechanisms. Also, a novel model to explain the pathogenesis of periodontal disease based on the concept of ANCA-associated autoimmunity is proposed. This encompasses a wide array of biochemical mediators that range from direct and indirect initiators of ANCA production and eventual release of proinflammatory mediators and free radicals, all of which have been implicated in periodontal tissue destruction in the past. In addition, specific links between the typical ANCA-associated diseases and periodontal disease are discussed. Finally, a new paradigm in the periodontal disease-associated destruction is proposed that includes the currently accepted mechanism, namely, the genetic-microbial-host interactions.

Cysteine peptidases of mammals: their biological roles and potential effects in the oral cavity and other tissues in health and disease

Cysteine peptidases (CPs) are phylogenetically ubiquitous enzymes that can be classified into clans of evolutionarily independent proteins based on the structural organization of the active site. In mammals, two of the major clans represented in the genome are: the CA clan, whose members share a structure and evolutionary history with papain; and the CD clan, which includes the legumains and caspases. This review focuses on the properties of these enzymes, with an emphasis on their potential roles in the oral cavity. The human genome encodes at least (but possibly no more than) 11 distinct enzymes, called cathepsins, that are members of the papain family C1A. Ten of these are present in rodents, which also carry additional genes encoding other cathepsins and cathepsin-like proteins. Human cathepsins are best known from the ubiquitously expressed lysosomal cathepsins B, H, and L, and dipeptidyl peptidase I (DPP I), which until recently were considered to mediate primarily "housekeeping" functions in the cell. However, mutations in DPP I have now been shown to underlie Papillon-Lefevre syndrome and pre-pubertal periodontitis. Other cathepsins are involved in tissue-specific functions such as bone remodeling, but relatively little is known about the functions of several recently discovered enzymes. Collectively, CPs participate in multiple host systems that are active in health and in disease. They are involved in tissue remodeling and turnover of the extracellular matrix, immune system function, and modulation and alteration of cell function. Intracellularly, CPs function in diverse processes including normal protein turnover, antigen and proprotein processing, and apoptosis. Extracellularly, they can contribute directly to the degradation of foreign proteins and the extracellular matrix. However, CPs can also participate in proteolytic cascades that amplify the degradative capacity, potentially leading to pathological damage, and facilitating the penetration of tissues by cancer cells. We know relatively little regarding the role of human CPs in the oral cavity in health or disease. Most studies to date have focused on the potential use of the lysosomal enzymes as markers for periodontal disease activity. Human saliva contains high levels of cystatins, which are potent CP inhibitors. Although these proteins are presumed to serve a protective function, their in vivo targets are unknown, and it remains to be discovered whether they serve to control any human CP activity.

Interleukin-1beta, tumor necrosis factor-alpha levels and neutrophil elastase activity in peri-implant crevicular fluid

The aim of this study was to determine interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha) levels and neutrophil elastase (NE) activity in peri-implant crevicular fluid (PICF) of smoker and nonsmoker patients, and to investigate their relationships with clinical parameters. A total of 42 endosseous root-form dental implants of 14 patients were clinically examined by modified Plaque index (PI), modified Gingival index (GI) and probing depth (PD). Smoking habits of the patients were recorded. PICF of implants were collected by Periopaper strips and IL-1beta, TNF-alpha levels were determined by enzyme-linked immunosorbent assay (ELISA). NE was analyzed with a neutrophil specific chromogenic substrate, N-methoxysuccinyl-Ala-Ala-Pro-Val-p-nitroanilide. The cytokine and enzyme levels in PICF were expressed as total amount/activity and as concentrations. NE activity in PICF significantly correlated with GI and PD, and IL-1beta levels with GI and PICF volume (P < 0.05). The correlations were stronger when the PICF levels were expressed as total IL-1beta amount and as total NE activity. The implants with inflamed gingiva (GI > 1) had higher levels of IL-1beta and NE activity than implants with noninflamed or slightly inflamed gingiva (GI <or= 1) (P < 0.05). Total NE activity in implants with deep pockets (PD > 3 mm) was greater than the implants with shallow pockets (PD <or= 3 mm) (P < 0.05). The implants of smoker patients had significantly lower PICF NE activity and IL-1beta levels, and significantly higher TNF-alpha levels than the implants of nonsmokers (P < 0.05). The findings of the present study indicate that NE activity and IL-1beta levels in PICF may be used to measure implant health status of patients who do not smoke.

Specific fibronectin fragments as markers of periodontal disease status

BACKGROUND

The diagnosis of progressing periodontal disease typically relies on retrospective methods that detect changes in the amount of periodontal breakdown. Fibronectin (FN) fragments are found in vivo in association with periodontal disease, and specific FN fragments compromise periodontal ligament cell functions in vitro. The overall goal of this cross-sectional study was to determine whether specific FN fragments are present in gingival crevicular fluid (GCF) and can be used as markers for periodontal disease status. The eventual goal is to test these FN fragments in a longitudinal study as potential markers of disease activity.

METHODS

GCF was collected from 94 subjects with untreated periodontitis from clinically healthy, mild/moderate periodontitis, and severe periodontitis sites. Sites were defined on the basis of clinical criteria, including gingival bleeding index, probing depth, and clinical attachment level. Western immunoblotting was used to detect FN fragments in GCF using antibodies to specific FN domains, including the collagen/gelatin-, central cell-, and carboxyl terminal heparin-binding domains, plus the CS-1 site on the alternatively spliced V region and the EIIIA region. FN fragments identified by immunoblotting and analyzed by NIH image software were scored based on pixel intensity and an ordinal grade scale.

RESULTS

We identified several fragments highly associated with severe periodontitis sites, including 40-kDa, 120-kDa, and 68-kDa fragments.

CONCLUSIONS

This study demonstrates that specific FN fragments are markers for periodontal disease status and supports the role of FN fragments as potential components in the pathogenesis of periodontal disease.

PMN responses in chronic periodontal disease: evaluation by gingival crevicular fluid enzymes and elastase-alpha-1-proteinase inhibitor complex

OBJECTIVES

In the present trial, the hypothesis was examined that the local PMN responses in untreated and treated chronic periodontitis can be differentiated by gingival crevicular fluid lysosomal enzyme activities and elastase-alpha-1-proteinase inhibitor complex.

METHODS

In nine subjects (average age 49.2 +/- 7.1 years) with chronic periodontitis, clinical parameters and markers of the PMN-derived inflammatory tissue response in gingival crevicular fluid (GCF) were assessed before and 6 months after surgical periodontal therapy. Myeloperoxidase (MPO), beta-N-acetyl-hexosaminidase (beta-NAH) and cathepsin D (CD) were analyzed as indicators of the PMN-associated host tissue destruction, and elastase-alpha-1-proteinase inhibitor complex (alpha-1-EPI) as the major serum protein inactivating PMN elastase. The total activities of the lysosomal enzymes MPO and beta-NAH were evaluated spectrophotometrically, the CD levels by liquid scintillation counting with [14C] hemoglobin as substrate, and the total alpha-1-proteinase inhibitor complex using a sandwich-immunoassay.

RESULTS

The clinical parameters revealed a statistical significant decrease at the 6-month reexamination. PD levels dropped from 5.40 to 2.88 mm (change 2.52 +/- 1.04 mm), the CAL scores from 6.67 to 4.43 mm (change 2.24 +/- 0.77 mm). The 30 s GCF volumes dropped from 129.8 to 68.6, displaying a change of 61.1 +/- 18.6, p </= 0.05. The decrease in total MPO, beta-NAH and CD levels (medians: 1.7/0.6 micro U MPO, 0.035/0.020 micro U beta-NAH, 1.3/0.5 ng CD) following therapy was associated with a significant drop in total GCF amounts of alpha-1-EPI from 76.3 ng at baseline to 52.4 ng after 6 months.

CONCLUSION

The clinical healing in chronic periodontal disease is associated with a downregulation of the local PMN responses following periodontal therapy. The reorganization of periodontal tissues is characterized by a decrease of lysosomal enzyme activities and the alpha-1-proteinase inhibitor complex in gingival crevicular fluid.

Relationship of changes in interleukin-8 levels and granulocyte elastase activity in gingival crevicular fluid to subgingival periodontopathogens following non-surgical periodontal therapy in subjects with chronic periodontitis

OBJECTIVES

To determine the effect of scaling and root planing (SRP) on the interrelations of subgingival periodontopathogens and both interleukin-8 (IL-8) and granulocyte elastase activity in gingival crevicular fluid (GCF), and to assess their relations to the short-term treatment response in management of chronic periodontitis.

MATERIAL AND METHODS

GCF and subgingival plaque were collected from 16 subjects with untreated chronic periodontitis at baseline and 4 weeks after SRP. IL-8 levels were determined by ELISA. Granulocyte elastase activity was analyzed with a specific substrate, pGluProVal-pNA, and the maximal rate of elastase activity (MR-EA) was calculated. 5 DNA-probes were used to detect the presence of A. actinomycetemcomitans (A. a.), B. forsythus (B.f.), P. gingivalis (P.g.), P. intermedia (P.i.), and T. denticola (T.d.), with a sensitivity = 103 cells/paper point.

RESULTS

IL-8 and MR-EA levels in GCF decreased significantly after SRP (p < 0.001) with a corresponding reduction of total count of the species. Of the sites with probing depth (PD) >/= 5.0 mm and co-infection by B.f., P.g., P.i. & T.d. at baseline, the sites without persistent co-infection of these species after SRP exhibited a significant reduction of IL-8 levels (p < 0.02), MR-EA levels (p < 0.02) and PD (p < 0.01). No such change was found in the sites where such a co-infection persisted. Moreover, reduction of IL-8 levels in those pocket sites was accompanied by a concomitant reduction of MR-EA (p < 0.02) and PD (p < 0.01), while no significant change in MR-EA levels and PD was noted in those pocket sites that exhibited an increase of IL-8 levels after SRP. At baseline, the former group of sites showed significantly higher IL-8 levels than the latter group of sites (p < 0.02).

CONCLUSIONS

IL-8-related granulocyte elastase activity was related to the change in infection patterns of the target periodontopathogens following scaling and root planing. Varying initial IL-8 levels in GCF and a corresponding shifting change of granulocyte elastase activity in GCF may characterize the different short-term treatment responses.

Isolation and characterisation of dipeptidyl peptidase IV from Prevotella loescheii ATCC 15930

A proline-specific dipeptidyl aminopeptidase, dipeptidyl peptidase IV (EC 3.4.14.5), was purified from a cell sonicate soluble fraction of Prevotella loescheii ATCC 15930 by sequential column chromatography. The molecular mass of the native enzyme was estimated as 160 kDa by high-pressure liquid gel filtration column chromatography and unheated sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The subunit molecular mass was 80 kDa when the enzyme was heated to 100 degrees C in the presence of 2-mercaptoethanol before SDS-PAGE, suggesting that the native enzyme consists of two identical subunits and is folded in 2% SDS. The optimum pH, with glycyl-prolyl-4-methyl-coumaryl-7-amide as the substrate, was 8.0; the isoelectric point was 5.2. Purified enzyme showed a strong preference for dipeptide substrates containing proline and, less efficiently, alanine in the P1 position. The enzyme was markedly inhibited by Cd(2+), Zn(2+), Hg(2+), Co(2+), and serine proteinase inhibitor di-isopropylfluorophosphate.

Microassay for the detection of elastase activity in the gingival crevice

BACKGROUND, AIMS

A new microassay for the detection of elastase activity (EA) in gingival crevicular fluid (GCF) has been established. GCF was collected with Periopaper strips and quantified in a Periotron.

METHODS

Enzyme activity was measured in a microtiter plate reader, using a fluorometric assay. To ensure quality and precision of the assay, recovery rates were determined at different activities with a recovery of >90%. In a 2nd step, stability of the enzyme was investigated during storage at room temperature, +4 degrees C, -22 degrees C, -88 degrees C. GCF samples retained elastase activity of almost 100% after a storage of 3 days at -22 degrees C. In a group of 12 healthy volunteers, elastase activity was assayed throughout an 18 day experimental gingivitis protocol.

RESULTS

Median activity increased from 481 microU/microl at baseline to 1444 microU/microl at day 18, which was accompanied by the development of the signs of gingivitis. The increase of EA during the experimental phase of the study was highly significant (p<0.001) and correlated well with the increasing severity of gingivitis.

CONCLUSION

The data suggest that elastase activity in GCF is an excellent quantitative measure of gingival inflammation.

Increase of CD26/dipeptidyl peptidase IV expression on human gingival fibroblasts upon stimulation with cytokines and bacterial components

CD26/dipeptidyl peptidase IV (DPPIV) is a cell surface ectoenzyme which participates in immune and inflammatory reactions. We found that CD26 was only partially expressed on human fibroblasts from periodontal tissues, whereas fibroblasts from lung and skin expressed CD26 constitutively as revealed by flow cytometry. We examined the possible upregulation of CD26 expression on human gingival fibroblasts in response to various stimulants. Interleukin-1alpha (IL-1alpha); tumor necrosis factor alpha; gamma interferon; lipopolysaccharide from Porphyromonas gingivalis, Prevotella intermedia, and Escherichia coli; and Prevotella glycoprotein augmented CD26 expression on gingival fibroblasts. Among the stimulants, IL-1alpha exhibited the most potent activity. Enzymatic activity of CD26 induced by IL-1alpha on fibroblasts was determined colorimetrically in terms of Gly-Pro hydrolysis of a synthetic chromogenic substrate, Gly-Pro p-nitroanilide. Among various inhibitors tested, diprotin A and phenylmethylsulfonyl fluoride inhibited the enzymatic activity, suggesting that the enzyme induced by IL-1alpha was DPPIV. The upregulation of CD26 mRNA expression upon stimulation with IL-1alpha was also revealed by a quantitative reverse transcription-PCR assay. In the kinetic experiment, 48 h and several days were required for maximum CD26 mRNA accumulation and CD26 molecule expression on the cell surface, respectively. The addition of cycloheximide at 2 h before IL-1alpha stimulation almost completely inhibited the accumulation of CD26 mRNA. These results suggested that induction of CD26 on human gingival fibroblasts is regulated at the transcriptional level and is also dependent on a de novo-synthesized protein factor(s).

Cysteine protease inhibitory activity and levels of salivary cystatins in whole saliva of periodontally diseased patients

The 3 human salivary cystatins S, SA and SN are multifunctional proteins that possess a cysteine protease inhibitory property, but their ability to act as such is very different (SN > SA >> S). One form, S, also appears to possess antibacterial properties towards the bacterium Porphyromonas gingivalis, often associated with periodontal diseases. In this study we measured the total cystatin inhibitory activity and the levels of each salivary cystatin in the whole saliva of 8 periodontally diseased patients and 2 groups of control subjects (n = 6 and n = 10). The total cystatin inhibitory activity and the total salivary cystatin concentration in the periodontally diseased patients were found to be lower than the controls (p < or = 0.005). The concentration of S was depleted to levels that would not allow it to be an effective antibacterial agent, and the concentration of SA, although depleted in some cases, was still present at sufficient levels to allow it to act as an effective physiological inhibitor of cathepsin L. The concentration of cystatin SN was also depleted in the periodontally diseased patients, but was still present in sufficient quantities to act as an effective physiological cysteine protease inhibitor of cathepsins H and L. In comparison, the concentration of all 3 salivary cystatins in the control subjects were sufficient to enable these proteins to be both effective physiological cysteine protease inhibitors and antibacterial agents.

Purification of large quantities of human salivary cystatins S, SA and SN: their interactions with the model cysteine protease papain in a non-inhibitory mode

OBJECTIVES

Our aim was to purify large quantities of human salivary cystatins S, SA and SN in order to determine whether these salivary cystatins have a stable interaction with cysteine proteases at a second binding site, other than the protease active site. This property may affect their availability to act as cysteine protease inhibitors within the oral environment.

METHODS

Salivary cystatins S, SA and SN were purified from human submandibular sublingual saliva to homo- geneity by column chromatography. Formation of stable complexes between the model cysteine protease papain in the absence of reductant was assessed by SDS-PAGE and probing Western blots with antibody to human salivary cystatin SN. Proteolytic activity of the complex was determined in the gel after electrophoresis.

RESULTS AND CONCLUSIONS

Only cystatin SN (14.3 kD) was found to form a stable complex with papain (22 kD) that could be separated by SDS-PAGE producing a Coomassie stained band at (37 kD). After western transfer this same band (37 kD) cross-reacted with antibody to SN. In the presence of E64, an active site inhibitor of cysteine proteases, the same complex was formed, suggesting that SN is able to bind to papain at a site other than the active site. Activity staining of the gel confirmed that this complex (-E64) retained proteolytic activity. Such complex formation between cystatin SN and cysteine proteases in a non-inhibitory mode may reduce its availability to act as an effective cysteine protease inhibitor in the oral environment.

Purification and characterization of a novel cysteine proteinase (periodontain) from Porphyromonas gingivalis. Evidence for a role in the inactivation of human alpha1-proteinase inhibitor

Periodontal disease is characterized by inflammation of the periodontium manifested by recruitment of neutrophils, which can degranulate, releasing powerful proteinases responsible for destruction of connective tissues, and eventual loss of tooth attachment. Although the presence of host proteinase inhibitors (serpins) should minimize tissue damage by endogenous proteinases, this is not seen clinically, and it has been speculated that proteolytic inactivation of serpins may contribute to progression of the disease. A major pathogen associated with periodontal disease is the Gram-negative anaerobe Porphyromonas gingivalis, and in this report, we describe a novel proteinase that has been isolated from culture supernatants of this organism that is capable of inactivating the human serpin, alpha1-proteinase inhibitor, the primary endogenous regulator of human neutrophil elastase. This new enzyme, referred to as periodontain, belongs to the cysteine proteinase family based on inhibition studies and exists as a 75-kDa heterodimer. Furthermore, periodontain shares significant homology to streptopain, a proteinase from Streptococcus pyogenes, and prtT, a putative proteinase from P. gingivalis. Clearly, the presence of this enzyme, which rapidly inactivates alpha1-proteinase inhibitor, could result in elevated levels of human neutrophil elastase clinically detected in periodontal disease and should be considered as a potential virulence factor for P. gingivalis.

A novel mechanism for bradykinin production at inflammatory sites. Diverse effects of a mixture of neutrophil elastase and mast cell tryptase versus tissue and plasma kallikreins on native and oxidized kininogens

Coprocessing of kininogens by a mixture of human mast cell tryptase and neutrophil elastase was explored as a potential substitute for the kallikrein-dependent pathway for kinin generation during inflammation. Tryptase easily excised bradykinin from the synthetic heptadecapeptide, ISLMKRPPGFSPFRSSR, but was unable to produce significant amounts of kinin by proteolysis of kininogens. However, a mixture of tryptase and elastase released bradykinin from each protein with a yield comparable to that of human plasma kallikrein. Significantly, neither plasma nor tissue kallikrein was able to effectively process N-chlorosuccinimide-oxidized high molecular weight kininogen, an effect attributed to the oxidation of a methionine residue upstream from the N terminus of the kinin domain. In support of these results the model heptadecapetide, ISL(MO)KRPPGFSPFRSSR, was also resistant to hydrolysis by either kallikrein. In contrast, the release of bradykinin from oxidized peptide or protein substrates by the tryptase/elastase mixture was not altered. Because kininogen modification may occur at inflammatory sites, as a result of the oxidative burst of recruited neutrophils and macrophages, these results suggest an alternative pathway for kinin production and the necessity for the novel utilization of two specific proteinases known to be released from these cells during inflammatory episodes.

Analysis of gingival crevicular fluid intracytoplasmic enzyme activity in patients with adult periodontitis and rapidly progressive periodontitis. A longitudinal study model with periodontal treatment

In the present study, the activity of 3 functionally related enzymes, creatine kinase (CK), lactate dehydrogenase (LDH), and aspartate aminotransferase (AST) levels in the rest and flow gingival crevicular fluid (rGCF, fGCF) from patients with rapidly progressive periodontitis (RPP) and adult periodontitis (AP) were determined before and after periodontal treatment, including maintenance. When rGCF and fGCF mean enzyme levels were compared, rGCF was found to contain approximately twice as much enzyme levels than fGCF throughout the study. The findings of the present study revealed that both the rGCF and fGCF samples also contained higher CK, LDH, and AST levels than serum samples. Baseline clinical parameters and GCF enzyme levels presented a significant decline throughout the non-surgical and surgical treatment phases in both patient groups, with surgical treatment being more effective. Despite clinical stability, in the AP group levels of LDH and AST showed a tendency to increase in the third month, while enzyme levels still continued to decrease in the RPP group, who received additional antibiotics during the surgical phase. These findings suggest that GCF intracytoplasmic enzyme profile is related with periodontal status and successful periodontal treatment, in addition to clinical improvement, has a significant effect on this profile. Analysis of biochemical events, more specifically intracytoplasmic enzyme levels in GCF, are likely to offer a sensitive measure of periodontal pathology which may help in overcoming the existing limitations of clinical parameters. For this purpose, analysis of rGCF intracytoplasmic enzymes seems to be more beneficial.

A possible association of alpha1-antitrypsin deficiency with the periodontal condition in adults

Alpha1-antitrypsin (alpha1AT) is a serum inhibitor of several neutrophil-derived proteolytic enzymes, the serine proteinases. In certain individuals, a deficiency of this enzyme inhibitor is present, whereby only 10 to 20% of the normal concentration is present in the circulation. The purpose of this study was to evaluate the influence of this alpha1AT deficiency on the periodontal condition in a case control study. 10 patients aged 20-50 years with a mean age of 32 and showing a deficiency of alpha1AT were randomly selected from a national data bank, which contains persons known to be affected with the alpha1AT deficiency state. Control subjects were matched for age, gender and socio-economic status. Full periodontal charting on all subjects was performed on 6 sites per tooth, including probing attachment level, probing depth, bleeding on probing and a plaque score. Analysis of the data revealed no differences with regard to attachment loss between the two groups. The deficiency group showed 9.3% pockets > or =5 mm and the matched control group 5.9%. When these results were covariated with plaque scores, the deficiency group appeared to have a higher number of sites with probing depths > or =5 mm.

Association of crevicular fluid elastase-like activity with histologically-confirmed attachment loss in ligature-induced periodontitis in beagle dogs

Experimental periodontitis was induced using ligatures in 6 beagle dogs over 57 days. Levels of elastase like activity in healthy sites, gingivitis sites, and in sites ligated for different time points were analyzed with respect to levels of histologically confirmed attachment loss. Attachment loss increased with increasing periods of ligation and reached a maximum of 0.15 mm at 57 days. Maximum loss of histological attachment was found to coincide with the period of maximum enzyme activity; during the first 7 days of ligature. Spearman correlation analysis of enzyme activity with attachment loss yielded a significant correlation (0.73, p=0.0396). The healthy and gingivitis sites were found to have minimal levels of enzyme activity throughout. Thus, this prospective study in beagle dogs found a relationship between histologically confirmed attachment loss and increased levels of elastase like activity indicating the probable usefulness of this parameter, either alone or in conjunction with other markers, for disclosing active periodontitis.

Protease activity in gingival crevicular fluid: presence of free protease

Our aim was to study protease activity in GCF from inflamed sites with or without tissue destruction. 19 patients with both periodontitis and gingivitis sites and 12 patients having gingivitis alone participated in the study. GCF samples were collected by an intracrevicular washing method. The protease activity was measured as degradation of FITC-conjugated casein. To obtain a semiquantitative estimate of the harvested GCF volume, we measured the transferrin concentration in the wash-fluid. The protease activity was significantly higher in the deep pockets in periodontitis patients than in shallow pockets in the same patients. This difference was still higher when the ratio of protease activity to the amount of transferrin in the sample was plotted. Although protease activity was lower in samples from gingivitis patients than in the deep pockets in periodontitis patients, the difference was not significant. About 90% of the activity could be inhibited by the addition of an excess amount of alpha-1-antitrypsin (A1AT). This study shows that protease activity is higher in inflamed sites with tissue destruction than in inflamed sites without. Most of this activity could be inhibited by A1AT, which suggests that the activity is due to an imbalance between protease and antiprotease rather than to proteases insensitive to A1AT.

Cathepsin B, alpha2-macroglobulin and cystatin levels in gingival crevicular fluid from chronic periodontitis patients

Gingival crevicular fluid (GCF) was collected from 16 molar and premolar sites in each of 20 chronic periodontitis patients before and after periodontal therapy using filter paper strips. These were eluted individually into buffer for determination of cathepsin B and its endogenous inhibitors, alpha2-macroglobulin and cystatin. Cathepsin B activity was assayed with a fluorogenic peptide substrate, alpha2-macroglobulin by enzyme-linked immunosorbent assay and cystatin activity by inhibition of papain. Total amounts of enzyme and inhibitor per GCF sample decreased after treatment and correlated positively with pocket depth and gingival, bleeding and plaque indices. These comparisons were nearly always statistically significant for pooled site data and sometimes so for mean patient values. The amounts of alpha2-macroglobulin and cystatin were greater than those of cathepsin B and, surprisingly, enzyme and inhibitor levels correlated positively with each other. Experiments with purified reagents, however, demonstrated that the cathepsin B: alpha2-macroglobulin complex was still active against the low molecular weight substrate and that cystatin levels in GCF are probably insufficient to inhibit the enzyme substantially These factors may explain why GCF cathepsin B activity reflects the clinical status of periodontal lesions and has been identified in another study as a promising indicator of disease progression.

Investigations into the cellular contribution to host tissue proteases and inhibitors in gingival crevicular fluid

Gingival crevicular fluid (GCF) was collected from chronic periodontitis patients using plastic micropipettes and coverslip smears stained with antibodies for leukocyte markers and Toluidine Blue for mast cells. The smears consisted of 70-80% granulocytes, 10-20% monocytes/macrophages, 5% mast cells and 5% T lymphocytes; no B lymphocytes were found. Proteases and inhibitors in GCF cells were investigated by enzyme cytochemistry using 2-methoxy-4-naphthylamine-linked peptide substrates and simultaneous coupling to Fast Blue B and immunocytochemistry using biotinylated secondary antibodies and an alkaline phosphatase/new fuchsin detecting system. Elastase was detected in granulocytes, cathepsin B in macrophages, dipeptidyl peptidases II and IV in a small proportion of macrophages, dipeptidyl peptidase IV in a few T lymphocytes, tryptase in mast cells and alpha-1-proteinase inhibitor and alpha-2-macroglobulin in some macrophages. GCF was also collected on filter paper strips and eluted into buffer for biochemical enzyme assays. Lysis of cells by addition of detergent to the elution buffer increased activities to 140-240% of control values. Removal of cells by centrifugation reduced measured activities to 1-30% of original figures; this effect was less if samples were pre-treated with detergent. Proteases from inflammatory cells therefore appear to make up most of the measured enzyme activity in GCF, and this association may explain recent correlations with periodontal disease progression.

Porphyromonas gingivalis proteinases as virulence factors in the development of periodontitis

Porphyromonas gingivalis contains exceedingly high concentrations of cysteine proteinases with trypsin-like activity which have been implicated as virulence factors in adult-onset periodontitis. These enzymes, referred to as gingipains, cleave protein and peptide substrates after arginine (gingipain R) and lysine residues (gingipain K), and it has been found that neither is easily inhibited by host proteinase inhibitors. Examination of the properties of each proteinase clearly indicates a role(s) for both in the dysregulation of a number of normally tightly controlled pathways. The effects of such uncontrolled proteolysis are the development of edema (kallikrein/kinin pathway activation by gingipain R), neutrophil infiltration (complement pathway activation by gingipain R), and bleeding (degradation of fibrinogen by gingipain K). Since three of the major hallmarks of periodontitis involve increased crevicular flow, neutrophil accumulation at infected sites and bleeding on probing, it seems likely that both P. gingivalis-derived proteinases are important virulence factors in the development of periodontal disease.

Histochemical and immunocytochemical localization of dipeptidyl peptidases II and IV in human gingiva

Dipeptidyl peptidase (DPP) II and IV activities were demonstrated in unfixed cryostat sections of gingival tissue from chronic periodontitis patients using histochemistry with 2-methoxy-4-naphthylamine (MNA) substrates. In the case of DPP IV, enzyme localization was confirmed by immunocytochemistry with mouse monoclonal antihuman DPP IV (CD26) antibody. Inflammatory cells containing enzyme were identified in adjacent sections with mouse monoclonal antibodies directed against leukocyte differentiation antigens. Lys-Ala-MNA and Ala-Pro-MNA staining in acid buffer for DPP II was only found in a few fibroblasts in superficial tissue. Staining with Gly-Pro-MNA and Ala-Pro-MNA in alkaline buffer for DPP IV was localized in some CD4 and CD8 positive T lymphocytes, CD68 positive macrophages, and fibroblasts and these cells also reacted with the enzyme antibody. DPP IV-containing macrophages and T lymphocytes were seen in the epithelium. In deeper granulomatous tissue Gram positive and negative bacteria stained with the histochemical substrates, but not the DPP IV antibody. Fibroblast DPP II and IV might participate in cellular interactions with collagen, while T lymphocyte DPP IV may be involved in cell signalling.

The relationship between gingival crevicular fluid cathepsin B activity and periodontal attachment loss in chronic periodontitis patients: a 2-year longitudinal study

This study aims to determine whether gingival crevicular fluid (GCF) cathepsin B levels, total activity (TA) and concentration (EC) predict progressive attachment loss (AL). Seventy-five previously untreated patients with moderate periodontitis were recruited. GCF was collected from 16 molar and premolar mesiobuccal sites and probing attachment level (PAL) and probing depth (PPD) were measured with an electronic probe. Gingival, gingival bleeding and plaque indices were then scored. Prior to baseline patients were given basic periodontal treatment after which the above procedures were repeated. Carefully localized radiographs were taken of the test teeth and repeated annually. Patients were seen 3-monthly for 2 yr and the procedures were repeated. One hundred and twenty-one AL sites, 90 rapid AL (RAL) and 31 gradual AL (GAL), in 49 patients were detected. Cathepsin B levels (TA & EC) at RAL sites were significantly higher (p < 0.0001) than paired control sites at the attachment loss time (ALT) and prediction time (PT). Mean levels (TA & EC) over the study period at GAL sites were significantly higher (p < 0.0001) than paired control sites. Using a critical value (CV) of 7.5 microU/30 s (TA) and 30 microU/microL (EC) showed a sensitivity of 100% and specificity of 99.83% (TA) and 100% and 99.75%(EC) at both ALT & PT. Mean cathepsin B levels (TA & EC) were significantly higher (p < 0.0001) at RAL and GAL sites than non-attachment loss (NAL) sites in AL patients in intrapatient comparisons and mean patient levels were significantly higher (p < 0.0001) in AL patients than NAL patients in interpatient comparisons. These results indicate that GCF cathepsin B may serve as a predictor of attachment loss.

A 2-year longitudinal study of elastase in human gingival crevicular fluid and periodontal attachment loss

The purpose of this study is to determine whether gingival crevicular fluid (GCF) elastase total activity (TA) and concentration (EC) correlate with and predict progressive attachment loss (AL). 75 previously untreated patients with moderate periodontitis were recruited. GCF was collected from 16 molar and premolar mesiobuccal sites and probing attachment loss (PAL), probing depth (PPD), gingival index (GI), gingival bleeding index (GBI) and plaque index (Pl.I) were measured. PAL and PPD were measured with an electronic, constant pressure probe. Patients were given basic periodontal treatment prior to baseline when the above procedures were repeated. In addition, carefully localised radiographs were taken of the test teeth and repeated annually. Patients were seen at 3 months intervals to 2 years and the procedures were repeated. 119 AL sites were detected and 89 of these were rapid AL sites (RAL) and 30 were gradual AL sites (GAL). Elastase levels (TA & EC) at RAL sites were significantly higher (p < or = 0.0001) than paired control sites in the same patient at both the attachment loss time (ALT) and the prediction time (PT). The mean levels (TA & EC) over the study period at GAL sites were significantly higher (p < or = 0.0001) than paired control sites in the same patient. Using a critical value (CV) of 125 micronsU/30 s (TA) and 400 micronsU/micronsL (EC) in 2 x 2 contingency tables showed a sensitivity of 100% and specificity of 99.95% (TA) and a sensitivity of 100% and specificity of 99.91% (EC) at the PT with very similar values at the ALT. Patient level comparisons showed that the mean elastase levels (TA & EC) were significantly higher (p < or = 0.0001) at RAL and GAL sites than non-attachment loss (NAL) sites in AL patients and that the mean levels were significantly higher (p < or = 0.0001) in AL patients than NAL patients. All these results indicate that these CVs for GCF elastase activity may serve as a predictors of future attachment loss.

Correlation between gingival crevicular fluid dipeptidyl peptidase II and IV activity and periodontal attachment loss. A 2-year longitudinal study in chronic periodontitis patients

OBJECTIVE

The aim of this study is to determine whether gingival crevicular fluid (GCF) dipeptidyl peptidase (DPP) II or IV levels, total activity (TA) and concentration (EC), predict progressive attachment loss (AL).

SUBJECTS AND METHODS

Seventy five patients with moderate periodontitis were recruited. GCF was first collected from 16 molar and premolar mesiobuccal sites and then probing attachment level (PAL) and probing pocket depth (PPD) were measured with an electronic probe. Finally, gingival index, gingival bleeding and plaque indices were scored. Patients were given basic periodontal treatment prior to baseline after which the above procedures were repeated. Patients were seen 3 monthly for 2 years and the procedures were repeated. Carefully localised radiographs were taken of the test teeth annually.

RESULTS

One hundred and twenty AL sites, 88 rapid AL (RAL) and 32 gradual AL (GrAL), in 48 patients were detected. DPP II and IV levels (TA and EC) at RAL sites were significantly higher (P < or = 0.0001) than paired control sites at the attachment loss time (ALT) and prediction time (PT). Mean levels over the study period of both proteases (TA and EC) at GrAL sites were significantly higher (P < or = 0.0001) than other paired control sites. The GCF levels of DPP IV were always slightly higher than those of DPP II. Critical values (CV) of 5 microU per 30 s (TA) and 25 microU microL(-1) (EC) for both proteases showed high sensitivity and specificity values for TA and EC and these were the same at both ALT and PT. The positive predictive values were slightly higher for DPP II. Mean site DPP II and IV levels (TA and EC) in intra-patient comparisons were significantly higher (P < or = 0.0001) at RAL and GrAL sites than non-attachment loss (NAL) sites in AL patients and mean patient levels were significantly higher (P < or = 0.0001) in AL patients than NAL patients in inter-patient comparisons.

CONCLUSIONS

These results indicate that both GCF DPP II and IV may be predictors of periodontal attachment loss.

Localization of active and inactive elastase, alpha-1-proteinase inhibitor, and alpha-2-macroglobulin in human gingiva

Biochemically, there is usually much less elastase activity in gingival tissue than in crevicular fluid. The tissue distributions of active and inactive elastase and the endogenous inhibitors alpha-1-proteinase inhibitor (alpha 1PI) and alpha-2-macroglobulin (alpha 2M) were therefore compared. Inflamed tissue was obtained from chronic periodontitis patients, and cryostat sections were incubated with the histochemical elastase substrate MeOSuc-Ala-Ala-Pro-Val-MNA. Adjacent sections were examined immunocytochemically with antibodies to neutrophil elastase, alpha 1PI, alpha 2M, and leukocyte differentiation antigens. Antigenic elastase was widely distributed in CD15-positive granulocytes in both the epithelium and lamina propria as well as in granulomatous tissue from infrabony defects. However, there was very limited histochemical staining of these cells, and biochemical activity against the equivalent substrate MeOSuc-Ala-Ala-Pro-Val-AFC could be extracted only from sections with such staining. The pH optimum and effector response of the activity in the extracts were, nevertheless, consistent with those of leukocyte elastase. The large difference between the total elastase content of the tissue, as determined immunocytochemically, and the limited amount of active enzyme, as demonstrated histochemically, indicated that the majority was in an inactive form. The involvement of tissue inhibitors was suggested by the fact that extracts from sections with no histochemical staining reduced biochemical elastase activity in crevicular fluid. alpha 2M was found in many fibroblasts and also some CD68-positive macrophages, which additionally contained alpha 1PI.(ABSTRACT TRUNCATED AT 250 WORDS)

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?

Annual review of selected dental literature: report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

The annual review of selected dental literature this year cites 384 published papers and reports. This year's review contains more editorial comment than reviews of years passed. New data on the biological responses to materials is emphasized in several sections. Observations on new compounds able to prevent plaque formation are presented. Clinically relevant advances in knowledge concerning the etching of different tooth structures are reported along with the effect of etching procedures on the dental pulp. Evaluation of periodontal diseases in all age groups is a topic. Limitations of current diagnostic techniques in periodontal disease, temporomandibular disorders, and implant therapy are included. There are new views on the use of dental amalgam. The future use of dental mercury is predicted. Interest in new ceramic systems is indicated as the demand for esthetics continues. Clinical information is emphasized over scientific information throughout this year's review.

Correlation of gingival crevicular fluid proteases with clinical and radiological measurements of periodontal attachment loss

Probing attachment loss and radiographical measurements of bone loss were made on 20 untreated chronic periodontitis patients. At a second visit, gingival crevicular fluid was collected on filter paper strips from the deepest accessible interdental probing site of each tooth. Gingival crevicular fluid volumes were determined and the samples eluted into buffer. Protease activities in the resulting eluates were assayed with peptidyl derivatives of 7-amino-4-trifluoromethyl coumarin (AFC). Cathepsin B/L-like activity was determined with Bz-Val-Lys-Lys-Arg-AFC, elastase-like activity with MeOSuc-Ala-Ala-Pro-Val-AFC, tryptase-like activity with Z-Ala-Ala-Lys-AFC, trypsin-like activity with Z-Gly-Gly-Arg-AFC and dipeptidyl peptidase IV-like activity with Ala-Pro-AFC. Total enzyme activities and enzyme concentrations correlated positively with probing attachment loss and bone loss in linear regression analysis. This was true at both a patient level, using mean patient values, and a site level, using either individual patient or pooled patient data. All of these correlations were highly statistically significant for site comparisons. In inter- and intra-patient comparisons the proportion of significant correlations was greater for total enzyme activity than concentration. Clinical and radiological measurements of attachment loss showed generally similar levels of correlation. Total enzyme activities had good specificity and sensitivity as indicators of attachment loss in this cross-sectional study. The results support further investigation of the diagnostic potential of gingival crevicular fluid proteases in evaluation of the periodontal condition.

Dipeptidyl peptidase II- and IV-like activities in gingival tissue and crevicular fluid from human periodontitis lesions

Gingival tissue and gingival crevicular fluid were collected from patients with chronic periodontitis. Gel filtration chromatography of crude tissue extracts yielded separate fractions active against Lys-Ala-7-amino-4-trifluoromethyl-coumarylamide (AFC) at acid pH and Gly-Pro-AFC at alkaline pH. The molecular weights, pH optima and inhibitor responses of these activities were consistent with those of dipeptidyl peptidases (DPP) II and IV, respectively. When tested with the same substrates, crevicular fluid was also found to contain DPP II- and IV-like activities with very similar pH profiles and inhibitor responses to those in tissue. The close resemblance suggested that the crevicular fluid enzymes were derived mainly from inflamed gingival tissues. Slight differences in the DPP II-like activities might be explained by the additional presence in crevicular fluid of enzymes from subgingival bacteria. With use of appropriate buffers, a third substrate, Ala-Pro-AFC, gave selective detection of both DPP II- and IV-like activities in tissue and crevicular fluid. Assays with Ala-Pro-AFC had the advantage of greater sensitivity, especially with DPP II-like activity. Raised levels of this enzyme have previously been found in the gingiva of periodontitis patients and thus DPP II-like activity in crevicular fluid might prove of value in monitoring disease activity.