Gingival crevicular fluid matrix metalloproteinase (MMP)-7, extracellular MMP inducer, and tissue inhibitor of MMP-1 levels in periodontal disease

Inflammation and tissue remodeling mediator expression during gingivitis: A comparison between experimental, naturally occurring gingivitis, and periodontal health

BACKGROUND

The aim of this study is to evaluate the immune regulation and tissue remodeling responses during experimental gingivitis (EG) and naturally occurring gingivitis (NG) to provide a comprehensive analysis of host responses. Gingival crevicular fluid (GCF) was obtained from 2 human studies conducted in university settings.

METHODS

The EG study enrolling 26 volunteers provided controls for the baseline (Day 0) from healthy disease-free participants, while Day 21 (the end of EG induction of the same group) was used to represent EG. Twenty-six NG participants age-matched with those of the EG group were recruited. GCF samples were analyzed for 39 mediators of inflammatory/immune responses and tissue remodeling using commercially available bead-based multiplex immunoassays. The differences in GI and mediator expression among groups were determined at a 95% confidence level (p ≤ 0.05) by a 2-way analysis of variance (ANOVA) with a post-hoc Tukey's test.

RESULTS

Our findings showed that EG had a greater gingival index than NG and was healthy (p < 0.01 of all comparisons). Furthermore, EG showed significantly higher levels of MPO (p < 0.001), CCL3 (p < 0.05), and IL-1B (p < 0.001) than NG. In contrast, NG had increased levels of MIF (p < 0.05), Fractalkine (p < 0.001), angiogenin (p < 0.05), C3a (p < 0.001), BMP-2 (p < 0.001), OPN (p < 0.05), RANKL (p < 0.001), and MMP-13 (p < 0.001) than EG.

CONCLUSIONS

Consistent with the findings from chronic (NG) versus acute (EG) inflammatory lesions, these data reveal that NG displays greater immune regulation, angiogenesis, and bone remodeling compared to EG.

Macrophages induce gingival destruction via Piezo1-mediated MMPs-degrading collagens in periodontitis

Macrophages are an integral part of the innate immune response in periodontal tissue and play a crucial role in the progression of periodontitis. Here we reported that macrophages also provoke periodontitis-induced gingival destruction through Piezol-mediated collagen degradation. We discovered that the PIEZO1 expression was markedly elevated in patients with periodontitis through transcriptomic profiling. Moreover, Piezo1 promoted macrophage polarization toward the M1 type in response to lipopolysaccharide (LPS) and induced production of proinflammatory cytokines, which in turn stimulated production of matrix metalloproteinases (MMPs) leading to collagen degradation. Our study suggests that Piezol might be a potential therapeutic target for treating periodontitis-induced gingival destruction.

Is TIMP-1 a biomarker for periodontal disease? A systematic review and meta-analysis

Objective

One of the most important families of proteases associated with periodontal disease is the family of the matrix metalloproteinases (MMPs). Their activity is regulated by tissue inhibitors of metalloproteinases (TIMPs), and an imbalance between MMP activity and regulation by TIMPs has been associated with the progression of periodontal disease. This strong interaction between TIMPs and MMPs might be an indication that TIMPs can be used as a biomarker to monitor periodontal disease progression in oral fluids. In particular, TIMP‐1 is a frequently studied biomarker for periodontal diseases. Therefore, the aim of this systematic review was to evaluate the scientific literature regarding TIMP‐1 concentrations in oral fluids of patients suffering from periodontitis or gingivitis in comparison to healthy individuals.

Material and Methods

PubMed/ MedLine and Web of Science databases were searched electronically. Studies that met the inclusion criteria were systematically evaluated and assessed for eligibility and risk of bias. Meta‐analysis was performed through the random effects model to assess the association between periodontitis/gingivitis and TIMP‐1 concentration in stimulated saliva, unstimulated saliva, and gingival crevicular fluid (GCF).

Results

The search strategy provided a total of 322 studies of which 10 studies met all inclusion criteria. Two studies investigated TIMP‐1 concentrations in GCF, three studies in unstimulated saliva, and five studies investigated TIMP‐1 concentrations in stimulated saliva. Three studies revealed that TIMP‐1 levels in oral fluids were significantly decreased in periodontal disease. Meta‐analysis revealed that there is no statistically significant difference between TIMP‐1 concentration in oral fluids of periodontitis/gingivitis patients in comparison to healthy individuals.

Conclusions

This systematic review with meta‐analysis shows that periodontal diseases are not associated with a statistically significant change in TIMP‐1 concentration in oral fluids.

Diagnostic potential and future directions of matrix metalloproteinases as biomarkers in gingival crevicular fluid of oral and systemic diseases

Gingival crevicular fluid (GCF) is a physiological fluid and an inflammatory serum exudate derived from the gingival plexus of blood vessels and mixed with host tissues and subgingival plaque flows. In addition to proteins, GCF contains a diverse population of cells, including desquamated epithelial cells, cytokines, electrolytes, and bacteria from adjacent plaques. Recently, matrix metalloproteinases(MMPs), which are endopeptidases that are active against extracellular macromolecules, in GCF have been revealed as potential utility biomarkers for the diagnosis and follow-up of oral and systemic diseases, thereby facilitating the early evaluation of malignancy risk and the monitoring of disease progression and treatment response. Tissue inhibitors of metalloproteinases (TIMPs) are specific inhibitors of matrixins that participate in the regulation of local activities of MMPs in tissues. This review provides an overview of the latest findings on the diagnostic and prognostic values of MMPs and TIMPs in GCF of oral and systemic diseases, including periodontal disease, pulpitis, peri-implantitis and cardiovascular disease as well as the extraction, detection and analytical methods for GCF.

Altered expression of SARS-CoV-2 entry and processing genes by Porphyromonas gingivalis-derived lipopolysaccharide, inflammatory cytokines and prostaglandin E2 in human gingival fibroblasts

Objective

The aim of this in vitro study was to investigate the expression of SARS-CoV-2 entry and processing genes in human gingival fibroblasts (HGnF) following treatment with Porphyromonas gingivalis-derived lipopolysaccharide (PgLPS) or inflammatory cytokines/mediators.

Design

We assessed the expression of SARS-CoV-2 entry and processing genes; angiotensin-converting enzyme 2 (ACE2), cellular serine proteases transmembrane serine protease 2 (TMPRSS2), Furin, and basigin (BSG) in HGnF by real-time PCR. To further asses the contribution of PgLPS and inflammatory cytokines/mediators to proliferation and SARS-CoV-2 entry and processing gene expression, HGnF were treated with PgLPS, IL1β, TNFα, and PGE₂.

Results

The expression for ACE2 in HGnF was significantly elevated after PgLPS or IL1β, TNFα, PGE₂ treatment. The expression of TMPRSS2 was increased by PgLPS, IL1β, or PGE₂ while BSG was elevated by PgLPS and IL1β. The expression of BSG and FURIN decreased after TNFα treatment.

Conclusion

SARS-CoV-2 entry and processing genes are expressed in human gingival fibroblasts and their expressions are altered by PgLPS, IL1β, TNFα and PGE₂ treatment.

The Role of Matrix Metalloproteinases in Periodontal Disease

This review provides a detailed description of matrix metalloproteinases (MMPs), focusing on those that are known to have critical roles in bone and periodontal disease. Periodontal disease is an inflammatory process initiated by anaerobic bacteria, which promote the host immune response in the form of a complex network of molecular pathways involving proinflammatory mediators such as cytokines, growth factors, and MMPs. MMPs are a family of 23 endopeptidases, collectively capable of degrading virtually all extracellular matrix (ECM) components. This study critically discusses the available research concerning the involvement of the MMPs in periodontal disease development and progression and presents possible therapeutic strategies. MMPs participate in morphogenesis, physiological tissue turnover, and pathological tissue destruction. Alterations in the regulation of MMP activity are implicated in the manifestation of oral diseases, and MMPs comprise the most important pathway in tissue destruction associated with periodontal disease. MMPs can be considered a risk factor for periodontal disease, and measurements of MMP levels may be useful markers for early detection of periodontitis and as a tool to assess prognostic follow-ups. Detection and inhibition of MMPs could, therefore, be useful in periodontal disease prevention or be an essential part of periodontal disease therapy, which, considering the huge incidence of the disease, may greatly improve oral health globally.

CD147 self-regulates matrix metalloproteinase-2 release in gingival fibroblasts after coculturing with U937 monocytic cells

BACKGROUND

Cluster of differentiation 147 (CD147) is a multifunctional glycoprotein that functions as an inducer of matrix metalloproteinase (MMP) expression in fibroblasts. Synergistically enhanced MMP-2 expression was recently observed in the coculture of human gingival fibroblasts (HGFs) and U937 human monocytic cells; however, the responsible mechanisms have not yet been fully established. The aim of this study was to evaluate the release of soluble CD147 in HGFs after coculturing with U937 cells and its functional effect on the enhancement of MMP-2 expression in HGFs.

METHODS

Enzyme-linked immunosorbent assay was used to determine the amount of CD147 protein in media, whereas real-time polymerase chain reaction was performed to evaluate the mRNA levels of CD147 and MMP-2 in HGFs and U937 cells. The enzyme activities of MMP-2 released from cells were examined by zymography. Transwell coculturing and conditioned media treatments were selected to rule out the effect of direct contact of HGFs and U937 cells.

RESULTS

The protein and mRNA expression of CD147 in HGFs were enhanced after transwell coculturing with U937 cells and exposure to U937-conditioned medium. MMP-2 enzyme activities in HGFs were also significantly increased by the coculturing methods. Administration of exogenous CD147 enhanced MMP-2 expression in HGFs, whereas treatment with cyclosporine-A, which inhibited CD147 expression, reduced U937-enhanced MMP-2 expression in HGFs.

CONCLUSIONS

CD147 can interact with fibroblasts to stimulate the expression of MMPs associated with periodontal extracellular matrix degradation. This study has demonstrated that CD147 released from fibroblasts might play a role in monocyte-enhanced MMP-2 expression in HGFs.

Association of oral health with lung cancer risk in a low-income population of African Americans and European Americans in the Southeastern United States

OBJECTIVES

Previous studies have suggested that poor oral health might increase the risk of lung cancer among European- and Asian- descendants. The association has not been investigated among African Americans or socially disadvantaged populations. In this nested case-control study, we investigated whether oral health was associated with lung cancer risk among a low-income population of African Americans and European Americans in the Southeastern United States.

MATERIALS AND METHODS

A total of 403 incident lung cancer cases and 1612 matched controls from the Southern Community Cohort Study were included. Multivariate conditional logistic regression models were fitted to evaluate the risk of lung cancer linked to tooth loss, tooth decay, and history of periodontal disease.

RESULTS

Tooth loss was significantly associated with an increased risk of lung cancer: the odds ratio (OR) of more than 10 teeth lost was 1.64 (95% CI: 1.00, 2.69). Tooth decay was also significantly associated with increased lung cancer risk; those with ≥ 6 decaying teeth had an OR of 1.65 (1.18, 2.31). An increased lung cancer risk was significantly associated with a history of periodontal disease among African Americans (OR = 1.56, 95% CI: 1.05, 2.31) and heavy smokers (OR = 2.05, 95% CI: 1.38, 3.05).

CONCLUSION

Poor oral health is associated with increased lung cancer risk, and this association appears to vary by race and smoking behavior among a low-income population of African Americans and European Americans in the Southeastern United States.

Levels of Pro and Anti-inflammatory Citokynes and C-Reactive Protein in Patients with Chronic Periodontitis Submitted to Nonsurgical Periodontal Treatment

Aim

to compare the levels of IFN-γ, TGF-β and C-reactive protein (CRP) in healthy patients (HP) and chronic periodontitis patients (CP) before and seven days after the last session of Non-Surgical Periodontal Treatment (NSPT).

Materials and Methods

40 subjects were divided into two groups: healthy (n= 20), and with chronic periodontitis (n = 20). Serum and gingival crevicular fluid (GCF) were collected from each patient and quantified for IFN-γ, TGF-β and CRP using the enzyme-linked immunosorbent assay (ELISA).

Results

IFN-γ was found to be higher in the GCF of the CP group before NSPT in relation to the HP group (p<0.05), and it had significant higher levels after seven days of NSPT (p<0.05). The levels of TGF-β in the GCF of CP patients before NSPT were significantly higher when compared to HP (p<0.05), but they decreased after seven days of NSPT (p>0.05). Serum CRP levels did not show statistical difference between CP and HP before or after NSPT.

Conclusion

Therefore, our results demonstrated for the first time that NSPT causes early exacerbation of the immune response at the local level represented by increased levels of IFN-γ and decreased levels of TGF-β in the gingival crevicular fluid after seven days of treatment.

Angiogenesis for tumor vascular normalization of Endostar on hepatoma 22 tumor-bearing mice is involved in the immune response

Tumor vascular normalization involved in immune response is beneficial to the chemotherapy of tumors. Recombinant human endostatin (Endostar), an angiogenesis inhibitor, has been demonstrated to be effective in hepatocellular cancer (HCC). However, its vascular normalization in HCC and the role of the immune response in angiogenesis were unclear. In the present study, effects of Endostar on tumor vascular normalization were evaluated in hepatoma 22 (H22) tumor-bearing mice. Endostar was able to inhibit the proliferation and infiltration of tumor cells and improve α-fetoprotein, tumor necrosis factor-α and cyclic adenosine 5′-phosphate levels in the serum of H22-bearing mice, as well as the protein expression levels of the immune factors interferon-γ and cluster of differentiation (CD)86 in liver tissue. Endostar also exhibited more marked downregulation of the levels of vascular endothelial growth factor, CD31, matrix metalloproteinase (MMP)-2, MMP-9 and interleukin-17 during day 3–9 treatment, resulting in short-term normalization of tumor blood vessels. The period of vascular normalization was 3–9 days. The results of the present study demonstrated that Endostar was able to induce the period of vascular normalization, contributing to a more efficacious means of HCC treatment combined with other chemotherapy, and this effect was associated with the immune response. It may be concluded that Endostar inhibited immunity-associated angiogenesis behaviors of vascular endothelial cells in response to HCC. The results of the present study provided more reasonable possibility for the combination therapy of Endostar for the treatment of HCC.

Mucin 4 and matrix metalloproteinase 7 as novel salivary biomarkers for periodontitis

AIM

Periodontitis is a chronic inflammatory disease, characterized by irreversible destruction of tooth-supporting tissue including alveolar bone. We recently reported mucin 4 (MUC4) and matrix metalloproteinase 7 (MMP7) as highly associated with periodontitis in gingival tissue biopsies. The aim of this study was to further investigate the levels of MUC4 and MMP7 in saliva and gingival crevicular fluid (GCF) samples of patients with periodontitis.

MATERIALS AND METHODS

Saliva and GCF samples were collected from periodontitis patients and healthy controls. The levels of MUC4, MMP7, and total protein concentrations were analysed using ELISA or Bradford assay.

RESULTS

MUC4 levels were significantly lower in saliva and GCF from periodontitis patients relative to healthy controls. MMP7 levels were significantly higher in saliva and GCF from periodontitis patients. Multivariate analysis revealed that MUC4 was significantly associated with periodontitis after adjusting for age and smoking habits and, moreover, that the combination of MUC4 and MMP7 accurately discriminated periodontitis from healthy controls.

CONCLUSIONS

MUC4 and MMP7 may be utilized as possible novel biomarkers for periodontitis.

The impact of smoking on levels of chronic periodontitis-associated biomarkers

OBJECTIVE

To investigate the effect of smoking on the expression levels of matrix metalloproteinase (MMP)-1, MMP-9, tissue inhibitor of metalloproteinase-1 (TIMP-1), and the concentrations of TNF-α and IL-10 in patients with chronic periodontitis (ChP).

METHODS

This is an ex-vivo study. Our study consisted of 78 cases, all of which were diagnosed with ChP and were selected according to the inclusion and exclusion criteria. Among these 78 cases, 38 patients were classified into the smoking group (S-ChP group), and 40 patients in the non-smoking group (NS-ChP group). The clinical periodontal parameters of all patients were recorded, including the plaque index (PLI), probing depth (PD), loss of attachment (LA) and sulcus bleeding index (SBI). Serum was collected from forearm blood to establish a Porphyromonas gingivalis (Pg) internalizing KB cell model. Enzyme-linked immunosorbent assay (ELISA) was used to determine the concentrations of MMP-1, MMP-9 and TIMP-1 in the KB cell lysis solution as well as IL-10 and TNF-α in the gingival crevicular fluid (GCF).

RESULTS

Fewer Pg internalizing KB cell colonies were observed in the NS-ChP group than in the S-ChP group (P<0.01). When 400μL serum was added, there were remarkable differences in the concentrations of MMP-1 and TIMP-1 secreted from the KB cells between the S-ChP and NS-ChP groups (MMP-1: t=-21.71, P<0.01; TIMP-1: t=64.35, P<0.001). Additionally, when 800μL serum was added, there were significant differences in the concentrations of MMP-1, MMP-9 and TIMP-1 in the KB cells between the S-ChP and NS-ChP groups (MMP-1: t=-81.89, P<0.001; MMP-9: t=-15.67, P<0.001; TIMP-1: t=109.4, P<0.001). The TNF-α levels were higher, but the IL-10 levels were lower in the GCF from the ChP patients in the S-ChP group than those in the NS-ChP group (both P<0.001).

CONCLUSION

The serum of S-ChP patients can enhance the concentrations of MMP-1 and MMP-9, but reduce TIMP-1 secreted from Pg internalizing KB cells. However, the concentration of TNF-α was increased and IL-10 was decreased. Abnormal concentrations of ChP-associated biomarkers may be conducive to the development and progression of ChP.

Evaluation of gingival crevicular fluid cyclophilin a and extracellular matrix metalloproteinase inducer levels in different periodontal diseases

OBJECTIVE

Cyclophilin A (CypA) is able to regulate inflammatory responses and matrix metalloproteinase production via its interaction with extracellular matrix metalloproteinase inducer (EMMPRIN). EMMPRIN is the cell surface receptor of CypA. The aim of the present study was to evaluate the gingival crevicular fluid (GCF) CypA and EMMPRIN levels in patients with chronic periodontitis (CP), generalized aggressive periodontitis (G-AgP) and periodontally healthy controls.

METHODS

Twenty CP patients, 19 G-AgP patients and 20 healthy control subjects were included in the present study. All study participants were non-smokers. Full mouth clinical periodontal parameters including probing depth, clinical attachment level, plaque index, and papilla bleeding index were recorded. GCF CypA and EMMPRIN levels were analyzed by enzyme-linked immunosorbent assay. Data were analyzed statistically with parametric and non-parametric tests.

RESULTS

GCF CypA total amount was higher in the G-AgP group compared to healthy controls (p<0.05), whereas CypA total amounts were similar in CP and healthy controls (p>0.05). No significant difference in GCF CypA total amount between CP and G-AgP was observed (p>0.05). Also, there was no significant difference in GCF EMMPRIN total amounts among the study groups (p>0.05).

CONCLUSION

Higher levels of GCF CypA in patients with G-AgP might demonstrate that CypA is associated with the inflammatory infiltrate and alveolar bone destruction of G-AgP. However, GCF CypA level does not seem to be affected by CP. Similar GCF EMMPRIN levels in diseased and healthy groups might suggest that EMMPRIN has role in the turn over of connective tissues in physiological conditions as well as pathological state.

A meta-analysis of MMP-9 promoter -1562 C/T polymorphism on susceptibility of chronic periodontitis

Background

Although many studies have focused on the association of the MMP-9 promoter −1562 C/T polymorphism with the susceptibility and/or severity of chronic periodontitis (CP), results have been inconsistent. Therefore, a meta-analysis of all eligible studies was performed to derive a more precise estimation of the association between this polymorphism and CP risk.

Methods

All relevant studies were identified through a database search in PubMed, Medline, and Web of Science. All the full-text studies with appropriate analytical design, published in English, which evaluated the association of MMP-9 promoter −1562C/T polymorphism with CP risk using validated genotyping methods, and with non-duplicated data were selected for this study. A fixed-effect model was used to calculate pooled ORs in the absence of heterogeneity across included trials (P > 0.1 and I² < 50 %), otherwise the random-effect model was applied.

Results

In an overall meta-analysis, pooled ORs revealed that T variant in the MMP-9 promoter −1562 C/T polymorphism was associated with a significantly decreased risk for CP under all comparison models. In subgroup analyses by ethnicity, pooled ORs showed that a significant association of the MMP-9 promoter −1562 C/T polymorphism with CP risk was only detected in Caucasians and Asians but not in mixed population. In the subgroup analysis by severity of CP, pooled ORs indicated that T allele of the MMP-9 promoter −1562 C/T polymorphism was associated with decreased susceptibility to severe CP while there was no significant association between this polymorphism and moderate CP.

Conclusions

Our meta-analysis showed that T allele in the MMP-9 promoter −1562 C/T polymorphism might be a protective factor for CP, especially in Caucasians and Asians. Moreover, there was a significant association of the MMP-9 promoter −1562 C/T polymorphism with decreased susceptibility to severe CP, while the allelic and/or genotype distributions of this polymorphism were not associated with moderate CP.

Electronic supplementary material

The online version of this article (doi:10.1186/s40064-016-2135-3) contains supplementary material, which is available to authorized users.

Neutrophil proteolytic activation cascades: a possible mechanistic link between chronic periodontitis and coronary heart disease

Cardiovascular diseases are chronic inflammatory diseases that affect a large segment of society. Coronary heart disease (CHD), the most common cardiovascular disease, progresses over several years and affects millions of people worldwide. Chronic infections may contribute to the systemic inflammation and enhance the risk for CHD. Periodontitis is one of the most common chronic infections that affects up to 50% of the adult population. Under inflammatory conditions the activation of endogenous degradation pathways mediated by immune responses leads to the release of destructive cellular molecules from both resident and immigrant cells. Matrix metalloproteinases (MMPs) and their regulators can activate each other and play an important role in immune response via degrading extracellular matrix components and modulating cytokines and chemokines. The action of MMPs is required for immigrant cell recruitment at the site of inflammation. Stimulated neutrophils represent the major pathogen-fighting immune cells that upregulate expression of several proteinases and oxidative enzymes, which can degrade extracellular matrix components (e.g. MMP-8, MMP-9 and neutrophil elastase). The activity of MMPs is regulated by endogenous inhibitors and/or candidate MMPs (e.g. MMP-7). The balance between MMPs and their inhibitors is thought to mirror the proteolytic burden. Thus, neutrophil-derived biomarkers, including myeloperoxidase, may activate proteolytic destructive cascades that are involved in subsequent immune-pathological events associated with both periodontitis and CHD. Here, we review the existing studies on the contribution of MMPs and their regulators to the infection-related pathology. Also, we discuss the possible proteolytic involvement and role of neutrophil-derived enzymes as an etiological link between chronic periodontitis and CHD.

Is there a relationship between periodontal disease and oral cancer? A systematic review of currently available evidence

Oral cancer (OC) is known to have a multi-factorial etiology; tobacco, alcohol and betel quid being the major risk factors. Tooth loss and periodontal disease (PD) have been implicated to increase the risk of developing various cancers. The aim of this systematic review was to assess any possible association between PD and OC. Indexed databases were searched using different combinations of the following key words: "oral cancer", "periodontal disease", "tooth loss", "squamous cell carcinoma", "missing teeth" "alveolar bone loss", "clinical attachment loss" and "periodontitis". PRISMA criteria were followed to accrue data and databases were searched from 1984 up to and including June 2015. In total, 12 case-control studies were selected from the published literature.

RESULTS

Nine studies reported a 2-5 fold increase in the risk of OC among patients with PD as compared to those without PD. Three studies reported no association between PD and OC. In one study, an increased risk of tongue cancer was associated with each millimeter of alveolar bone loss and in two studies clinical attachment loss of more than 1.5mm was associated with an increased risk of OC. In studies reporting significant findings these associations persisted after adjusting for major risk factors. PD is associated with a small but significant increase in risk for OC. In several reported studies this association was attenuated following adjustment for tobacco and alcohol use.

Inflammation Biomarkers of Advanced Disease in Nongingival Tissues of Chronic Periodontitis Patients

Chronic periodontitis is a multifactorial inflammatory disease that affects supporting structures of the teeth. Although the gingival response is largely described, little is known about the immune changes in the alveolar bone and neighboring tissues that could indicate periodontal disease (PD) activity. Then, in this study we identified the ongoing inflammatory changes and novel biomarkers for periodontitis in the tissues directly affected by the destructive disease in PD patients. Samples were collected by osteotomy in 17 control subjects during extraction of third molars and 18 patients with advanced PD, in which alveoloplasty was necessary after extraction of teeth with previous extensive periodontal damage. Patients presented mononuclear cells infiltration in the connective tissue next to the bone and higher fibrosis area, along with increased accumulation of IL-17⁺ and TRAP⁺ cells. The levels of TNF-α and MMP-2 mRNA were also elevated compared to controls and a positive and significant correlation was observed between TNF-α and MMP-2 mRNA expression, considering all samples evaluated. In conclusion, nongingival tissues neighboring large periodontal pockets present inflammatory markers that could predict ongoing bone resorption and disease spreading. Therefore, we suggested that the detailed evaluation of these regions could be of great importance to the assessment of disease progression.

Impact of metronidazole and amoxicillin combination on matrix metalloproteinases-1 and tissue inhibitors of matrix metalloproteinases balance in generalized aggressive periodontitis

OBJECTIVE

Generalized aggressive periodontitis (GAgP) is a complex periodontal disease affecting the entire dentition with a rapid destruction of the periodontium and resulting in loss of teeth. We hypothesized that better clinical healing of adjunctive use of amoxicillin plus metronidazole combination may be related to the effect of this combination therapy to restore imbalance between matrix metalloproteinases (MMP) and their tissue inhibitors (TIMP) which is associated with connective tissue and alveolar bone destruction in patients with GAgP.

MATERIALS AND METHODS

Twenty-eight subjects diagnosed with GAgP were recruited. Patients were randomly assigned to test or control groups. MMP-1/TIMP-1 ratio was compared between groups receiving scaling and root planning (SRP) alone (control) or in combination with amoxicillin plus metronidazole (test). Clinical periodontal variables were measured. Gingival crevicular fluid samples were obtained and analyzed for MMP-1 and TIMP-1. Measurements were taken at baseline and repeated at 3 and 6 months after therapy.

RESULTS

Total MMP-1 levels were significantly decreased in both groups (P < 0.05) at 3 and 6 months. MMP-1 concentration levels showed a similar pattern to MMP-1 total levels decreasing significantly at 3 months (P < 0.05). TIMP-1 concentration levels increased in the test group throughout the study period, while the difference did not reach statistical significance (P > 0.05). TIMP-1/MMP-1 balance was restored in test group at 6 months significantly better than the control group (P < 0.05).

CONCLUSION

The results of this study suggest that metronidazole and amoxicillin combination as an adjunct to SRP results in better clinical healing through restoring TIMP-1/MMP-1 balance.

Functional role of EMMPRIN in the formation and mineralisation of dental matrix in mouse molars

Our previous research has shown that the extracellular matrix metalloproteinase inducer (EMMPRIN) is expressed during and may function in the early development of tooth germs. In the present study, we observed the specific expression of EMMPRIN in ameloblasts and odontoblasts during the middle and late stages of tooth germ development using immunohistochemistry. Furthermore, to extend our understanding of the function of EMMPRIN in odontogenesis, we used an anti-EMMPRIN function-blocking antibody to remove EMMPRIN activity in tooth germ culture in vitro. Both the formation and mineralisation of dental hard tissues were suppressed in the tooth germ culture after the abrogation of EMMPRIN. Meanwhile, significant reductions in VEGF, MMP-9, ALPL, ameloblastin, amelogenin and enamelin expression were observed in antibody-treated tooth germ explants compared to control and normal serum-treated explants. The current results illustrate that EMMPRIN may play a critical role in the processing and maturation of the dental matrix.

Estimation of tissue inhibitor of matrix metalloproteinase-1 levels in gingival crevicular fluid in periodontal health, disease and after treatment

Background:

Initial research has shown a negative correlation between the severity of periodontal disease and tissue inhibitor of matrix metalloproteinases (TIMPs) concentrations in gingival crevicular fluid (GCF). However, there are no enough reports to correlate the TIMP-1 concentrations in GCF in periodontal health, disease and after treatment. Hence, the present study aim is to estimate the levels of TIMP-1 in GCF in periodontal health, disease and to evaluate the effect of periodontal therapy on TIMP-1 concentrations in GCF.

Materials and Methods:

Periodontal examination and collection of GCF by extracrevicular method was performed in 25 subjects selected randomly and categorized into three groups. Group I (Healthy, n = 10), Group II (chronic periodontitis (CP), n = 15) and Group III (After treatment group, n = 15). Scaling and root planning was performed and GCF was collected after 8 weeks of treatment. TIMP-1 levels were estimated in GCF samples by using enzyme linked immunosorbent assay.

Results:

TIMPs-1 was detected in all samples. Highest mean TIMP-1 concentrations in GCF were obtained for Group I, whereas the lowest concentrations were seen in Group II. This suggests that TIMP-1 levels in GCF decreases proportionally with the progression of periodontal disease and increases after treatment.

Conclusion:

There is a substantial decrease in the concentrations of TIMP-1 in CP patients than in healthy and after treatment individuals. Since TIMP-1 levels in GCF are negatively correlated with periodontal disease, TIMP-1 may be considered as a biomarker in periodontal disease progression. However, controlled, longitudinal studies are needed to confirm this possibility.

The effect of adjunctive chlorhexidine mouthrinse on GCF MMP-8 and TIMP-1 levels in gingivitis: a randomized placebo-controlled study

Background

The aim of the present study was to evaluate the effect of adjunctive chlorhexidine (CHX) mouthrinse on gingival crevicular fluid (GCF) MMP-8 and TIMP-1 levels in plaque-associated gingivitis.

Methods

A total of 50 gingivitis patients were included in the present study. In addition to daily plaque control, CHX group rinsed with CHX, while placebo group rinsed with placebo mouthrinse for 4 weeks. GCF samples were collected, and clinical parameters including plaque index, papillary bleeding index, calculus index and pocket depth were recorded at baseline and 4 weeks. GCF MMP-8 and TIMP-1 levels were determined by immunofluorometric assay (IFMA) and enzyme-linked immunosorbent assay (ELISA), respectively.

Results

In both groups, GCF MMP-8 levels of anterior and posterior sites at four weeks were not different from baseline (p > 0.05). There were no significant differences in GCF MMP-8 levels between the study groups at four weeks (p > 0.05). GCF TIMP-1 levels of anterior and posterior sites at four weeks were higher compared to baseline in both groups (p < 0.05). There was no significant difference in GCF TIMP level between the study groups at four weeks (p > 0.05).

Conclusions

CHX usage had no significant effects on the GCF MMP-8 and TIMP-1 levels in plaque-associate gingivitis. However, daily plaque control resulted in the increase of GCF TIMP-1 levels regardless of CHX usage.

Prioritization of candidate genes for periodontitis using multiple computational tools

BACKGROUND

Both genetic and environmental factors contribute to the development of periodontitis. Genetic studies identified a variety of candidate genes for periodontitis. The aim of the present study is to identify the most promising candidate genes for periodontitis using an integrative gene ranking method.

METHODS

Seed genes that were confirmed to be associated with periodontitis were identified using text mining. Three types of candidate genes were then extracted from different resources (expression profiles, genome-wide association studies). Combining the seed genes, four freely available bioinformatics tools (ToppGene, DIR, Endeavour, and GPEC) were integrated for prioritization of candidate genes. Candidate genes that identified with at least three programs and ranked in the top 20 by each program were considered the most promising.

RESULTS

Prioritization analysis resulted in 21 promising genes involved or potentially involved in periodontitis. Among them, IL18 (interleukin 18), CD44 (CD44 molecule), CXCL1 (chemokine [CXC motif] ligand 1), IL6ST (interleukin 6 signal transducer), MMP3 (matrix metallopeptidase 3), MMP7, CCR1 (chemokine [C-C motif] receptor 1), MMP13, and TLR9 (Toll-like receptor 9) had been associated with periodontitis. However, the roles of other genes, such as CSF3 (colony stimulating factor 3 receptor), CD40, TNFSF14 (tumor necrosis factor receptor superfamily, member 14), IFNB1 (interferon-β1), TIRAP (toll-interleukin 1 receptor domain containing adaptor protein), IL2RA (interleukin 2 receptor α), ETS1 (v-ets avian erythroblastosis virus E26 oncogene homolog 1), GADD45B (growth arrest and DNA-damage-inducible 45 β), BIRC3 (baculoviral IAP repeat containing 3), VAV1 (vav 1 guanine nucleotide exchange factor), COL5A1 (collagen, type V, α1), and C3 (complement component 3), have not been investigated thoroughly in the process of periodontitis. These genes are mainly involved in bacterial infection, immune response, and inflammatory reaction, suggesting that further characterizing their roles in periodontitis will be important.

CONCLUSIONS

A combination of computational tools will be useful in mining candidate genes for periodontitis. These theoretical results provide new clues for experimental biologists to plan targeted experiments.

Periodontal disease immunology: 'double indemnity' in protecting the host

During the last two to three decades our understanding of the immunobiology of periodontal disease has increased exponentially, both with respect to the microbial agents triggering the disease process and the molecular mechanisms of the host engagement maintaining homeostasis or leading to collateral tissue damage. These foundational scientific findings have laid the groundwork for translating cell phenotype, receptor engagement, intracellular signaling pathways and effector functions into a 'picture' of the periodontium as the host responds to the 'danger signals' of the microbial ecology to maintain homeostasis or succumb to a disease process. These findings implicate the chronicity of the local response in attempting to manage the microbial challenge, creating a 'Double Indemnity' in some patients that does not 'insure' health for the periodontium. As importantly, in reflecting the title of this volume of Periodontology 2000, this review attempts to inform the community of how the science of periodontal immunology gestated, how continual probing of the biology of the disease has led to an evolution in our knowledge base and how more recent studies in the postgenomic era are revolutionizing our understanding of disease initiation, progression and resolution. Thus, there has been substantial progress in our understanding of the molecular mechanisms of host-bacteria interactions that result in the clinical presentation and outcomes of destructive periodontitis. The science has embarked from observations of variations in responses related to disease expression with a focus for utilization of the responses in diagnosis and therapeutic outcomes, to current investigations using cutting-edge fundamental biological processes to attempt to model the initiation and progression of soft- and hard-tissue destruction of the periodontium. As importantly, the next era in the immunobiology of periodontal disease will need to engage more sophisticated experimental designs for clinical studies to enable robust translation of basic biologic processes that are in action early in the transition from health to disease, those which stimulate microenvironmental changes that select for a more pathogenic microbial ecology and those that represent a rebalancing of the complex host responses and a resolution of inflammatory tissue destruction.

Porphyromonas gingivalis-mediated shedding of extracellular matrix metalloproteinase inducer (EMMPRIN) by oral epithelial cells: a potential role in inflammatory periodontal disease

Extracellular matrix metalloproteinase inducer (EMMPRIN) or CD147 is a transmembrane glycoprotein expressed by various cell types, including oral epithelial cells. Recent studies have brought evidence that EMMPRIN plays a role in periodontitis. In the present study, we investigated the effect of Porphyromonas gingivalis, a major pathogen in chronic periodontitis, on the shedding of membrane-anchored EMMPRIN and on the expression of the EMMPRIN gene by oral epithelial cells. A potential contribution of shed EMMPRIN to the inflammatory process of periodontitis was analyzed by evaluating the effect of recombinant EMMPRIN on cytokine and matrix metalloproteinase (MMP) secretion by human gingival fibroblasts. ELISA and immunofluorescence analyses revealed that P. gingivalis mediated the shedding of epithelial cell-surface EMMPRIN in a dose- and time-dependent manner. Cysteine proteinase (gingipain)-deficient P. gingivalis mutants were used to demonstrate that both Arg- and Lys-gingipain activities are involved in EMMPRIN shedding. Real-time PCR showed that P. gingivalis had no significant effect on the expression of the EMMPRIN gene in epithelial cells. Recombinant EMMPRIN induced the secretion of IL-6 and MMP-3 by gingival fibroblasts, a phenomenon that appears to involve mitogen activated protein kinases. The present study brought to light a new mechanism by which P. gingivalis can promote the inflammatory response during periodontitis.

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.

GCF and serum myeloperoxidase and matrix metalloproteinase-13 levels in renal transplant patients

AIM

The rationale of this study was to address whether local or systemic changes reflect proteolytic (matrix metalloproteinase-13) or oxidative (myeloperoxidase) stress in renal transplant patients receiving cyclosporine-A (CsA) and having gingival overgrowth (GO), in patients receiving CsA therapy and having no GO and patients receiving tacrolimus therapy.

MATERIAL AND METHODS

Gingival crevicular fluid (GCF) samples were collected from sites with (GO+) and without GO (GO-) in CsA patients having GO; GO- sites in CsA patients having no GO; sites from tacrolimus, gingivitis and healthy subjects. GCF and serum myeloperoxidase (MPO) and matrix metalloproteinase-13 (MMP-13) levels were determined by ELISA.

RESULTS

GO+ sites in CsA patients having GO had elevated GCF MPO levels than those of CsA patients having no GO, tacrolimus and healthy subjects (p<0.005), but comparable to those of gingivitis. GCF MPO levels were higher in GO+ compared to GO- sites in CsA patients having GO (p<0.05). Patient groups had similar, but higher GCF MMP-13 levels than healthy group.

CONCLUSIONS

These results show that CsA and tacrolimus therapy have not a significant effect on GCF MPO and MMP-13 levels, and gingival inflammation seems to be the main reason for their elevations.

The temporal expression and localization of extracellular matrix metalloproteinase inducer (EMMPRIN) during the development of periodontitis in an animal model

BACKGROUND AND OBJECTIVE

We previously demonstrated extracellular matrix metalloproteinase inducer (EMMPRIN) was associated with the matrix metalloproteinases production of human periodontitis. The aim of this study was to investigate the temporal expression and localization of EMMPRIN during ligature-induced periodontitis in rats.

MATERIAL AND METHODS

Periodontitis was induced in rats by placing a thread around the cervix of the first mandibular molar. Animals were killed 3, 7, 11, 15 or 21 d after ligation. Mandibles were processed for paraffin sections and stained with hematoxylin and eosin or picrosirius red. The distance from the amelocemental junction to the alveolar crest (ACJ-AC) and the area fraction (Area%) of collagen fibers were measured. EMMPRIN was examined by immunohistochemistry and quantified by positive cell counting. Correlation analyses were then performed.

RESULTS

Histologically, alveolar bone was gradually destroyed from day 3 to 11 and then stabilized. Collagen fibers were slightly dissociated on day 3 and extensively broken on day 7. They were reconstructed from day 11 to 21. EMMPRIN was localized predominantly in infiltrating cells and adjacent fibroblasts in interdental gingiva. The number of EMMPRIN-positive cells increased on day 3, peaked on day 7 and then gradually subsided from day 11 to 21. Statistically, there was a moderate positive correlation regarding the ACJ-AC distance (r = 0.552, p < 0.01) and a strong negative correlation with the Area% of collagen fibers (r = -0.808, p < 0.01). In gingival epithelium, the immunoreactivity was extremely strong in basal layer cells and sulcular epithelial cells in health. It was greatly enhanced in the inflamed conditions on days 3 and 7. In the interradicular bone, EMMPRIN was localized in the osteoclasts on days 3 and 7, as well as in the osteoblasts from day 11 onwards.

CONCLUSION

The expression and localization of EMMPRIN are temporally varied during the development of periodontitis. In addition, the inflammation-dependent expression of EMMPRIN might be involved in alveolar bone resorption and collagen breakdown.

Grape seed extract suppresses lipopolysaccharide-induced matrix metalloproteinase (MMP) secretion by macrophages and inhibits human MMP-1 and -9 activities

BACKGROUND

Matrix metalloproteinases (MMPs) produced by resident and inflammatory cells in response to Gram-negative periodontopathogens play a major role in the tissue destruction observed during periodontitis, a disease that affects tooth-supporting structures. In this study, we investigated the effect of grape seed extract (GSE) on MMP secretion by human monocyte-derived macrophages stimulated with Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans) lipopolysaccharide (LPS) and on the activity of human recombinant MMP-1 and -9.

METHODS

Macrophages were treated with various concentrations of GSE prior to being stimulated with A. actinomycetemcomitans LPS. The secretion of MMPs and activation of nuclear factor-kappa B (NF-kappaB) p65 and activator protein-1 (AP-1) were assessed by enzyme-linked immunosorbent assay (ELISA). The effect of GSE on the catalytic activity of human recombinant MMP-1 and -9 was tested using fluorogenic assays.

RESULTS

GSE inhibited the secretion of MMP-1, -3, -7, -8, -9, and -13 by LPS-stimulated macrophages in a concentration-dependent manner. The suppression of MMP secretion was associated with inhibition of NF-kappaB p65 and AP-1 activation. Also, GSE dose-dependently inhibited the activity of MMP-1 and -9.

CONCLUSION

The present study suggests that GSE may be potentially used in the development of novel host-modulating strategies for the treatment of MMP-mediated disorders such as periodontitis.

Cranberry proanthocyanidins inhibit MMP production and activity

Matrix metalloproteinases (MMPs) produced by resident and inflammatory cells in response to periodontopathogens play a major role in periodontal tissue destruction. Our aim was to investigate the effects of A-type cranberry proanthocyanidins (AC-PACs) on: (i) the production of various MMPs by human monocyte-derived macrophages stimulated with Aggregatibacter actinomycetemcomitans lipopolysaccharide (LPS), and (ii) the catalytic activity of recombinant MMP-1 and MMP-9. The effects of AC-PACs on the expression of 5 protein kinases and the activity of nuclear factor-kappa B (NF-kappaB) p65 in macrophages stimulated with LPS were also monitored. Our results indicated that AC-PACs inhibited the production of MMPs in a concentration-dependent manner. Furthermore, the catalytic activity of MMP-1 and MMP-9 was also inhibited. The inhibition of MMP production was associated with reduced phosphorylation of key intracellular kinases and the inhibition of NF-kappaB p65 activity. AC-PACs thus show potential for the development of novel host-modulating strategies to inhibit MMP-mediated tissue destruction during periodontitis.

Effects of cytomegalovirus infection on the mRNA expression of collagens and matrix metalloproteinases in gingival fibroblasts

BACKGROUND AND OBJECTIVE

The purpose of this in vitro investigation was to study the effects of human cytomegalovirus infection on the mRNA expression for collagens I and III and for matrix metalloproteinases 1 and 2 in gingival fibroblasts.

MATERIAL AND METHODS

Gingival fibroblasts were experimentally infected with the Towne strain of human cytomegalovirus and the kinetics of expression of mRNA for collagens I and III and for matrix metalloproteinases 1 and 2 was studied at different time-points. Total RNA was isolated at the indicated time, and the reverse transcription-polymerase chain reaction was used to analyze the level of mRNA expression. In addition, gingival specimens were obtained from 14 periodontitis and from three non-periodontitis subjects and mRNA analysis for collagens and metalloproteinases was carried out. Nested polymerase chain reaction was used to determine the presence or absence of human cytomegalovirus in subgingival samples from each subject.

RESULTS

The infection of gingival fibroblasts with human cytomegalovirus during a 0-72-h period resulted in progressive reduction in the expression of mRNA for collagens I and III (p < 0.05). A higher concentration of human cytomegalovirus resulted in varying degrees of mRNA reduction, suggesting a virally mediated effect. Biopsies from human cytomegalovirus-positive individuals with periodontitis had a higher expression of mRNA for collagens I and III than biopsies from human cytomegalovirus-negative individuals. An up-regulation in the mRNA expression of matrix metalloproteinases 1 and 2 over time was observed (p < 0.05). Analysis of mRNA expression in gingival biopsies demonstrated higher expression of matrix metalloproteinase-1 in human cytomegalovirus-positive periodontitis specimens compared with human cytomegalovirus-negative periodontitis specimens.

CONCLUSION

Altered expression of mRNA for collagens and metalloproteinases in human cytomegalovirus-infected gingival fibroblasts should be considered as possible modifying mechanisms in periodontitis-infected sites.

A review of the relationship between tooth loss, periodontal disease, and cancer

Recent studies have investigated the association between periodontal disease, tooth loss, and several systemic diseases including cancer, cardiovascular disease, and preterm birth. Periodontal disease, a chronic inflammatory condition, is highly prevalent in adult populations around the world, and may be preventable. Estimates of prevalence vary between races and geographic regions, with a marked increase in the occurrence of periodontal disease with advancing age. Worldwide estimates for the prevalence of severe periodontal disease generally range from 10 to 15%. The relationship between oral health and cancer has been examined for a number of specific cancer sites. Several studies have reported associations between periodontal disease or tooth loss and risk of oral, upper gastrointestinal, lung, and pancreatic cancer in different populations. In a number of studies, these associations persisted after adjustment for major risk factors, including cigarette smoking and socioeconomic status. This review provides a summary of these findings, discusses possible biological mechanisms involved, and raises methodological issues related to studying these relationships.

The effect of adjunctive subantimicrobial dose doxycycline therapy on GCF EMMPRIN levels in chronic periodontitis

BACKGROUND

The aim of the present randomized, double-masked, placebo-controlled, parallel-arm study was to examine the effectiveness of a 3-month regimen of subantimicrobial dose doxycycline (SDD) in combination with scaling and root planing compared to scaling and root planing alone on levels of gingival crevicular fluid (GCF) extracellular matrix metalloproteinase inducer (EMMPRIN) in patients with chronic periodontitis.

METHODS

GCF samples were collected, and clinical parameters, including probing depth (PD), clinical attachment level, gingival index (GI), and plaque index, were recorded. Thirty chronic periodontitis subjects were randomized to receive SDD or placebo. The SDD group received SDD (20 mg, twice a day) for 3 months plus scaling and root planing, whereas the placebo group took placebo capsules twice a day for 3 months and received scaling and root planing. The subjects were reevaluated at 3 and 6 months. At each visit, all clinical parameters were measured and GCF was sampled. GCF EMMPRIN levels were determined by Western immunoblotting assay. Intragroup comparisons were tested by the Friedman test followed by the Wilcoxon signed-rank test to analyze the significance of changes over time. The Mann-Whitney test was used to determine differences between the SDD and placebo groups.

RESULTS

Significant improvements were observed in all clinical parameters in the SDD group over the 6-month study period (P <0.025). The SDD group showed a significantly greater reduction in mean PD scores at 6 months and in mean GI scores at 3 and 6 months than the placebo group (P <0.05). From baseline to 6 months, the GCF EMMPRIN levels were reduced significantly in the SDD group (P <0.025). The GCF EMMPRIN level in the SDD group was significantly lower than that of the placebo group at 3 and 6 months (P <0.05).

CONCLUSIONS

SDD therapy in combination with scaling and root planing reduced GCF EMMPRIN levels and improved clinical periodontal parameters in subjects with chronic periodontitis. The ability of SDD to downregulate, in vivo, the GCF levels of EMMPRIN, a unique upregulator of matrix metalloproteinase expression, is one of its beneficial host-modulatory properties. These results expand the usefulness of SDD therapy as an adjunct to scaling and root planing in the long-term management of periodontal disease.

Gingival crevicular fluid and serum matrix metalloproteinase-8 and tissue inhibitor of matrix metalloproteinase-1 levels in renal transplant patients undergoing different immunosuppressive therapy

AIM

We investigated gingival crevicular fluid (GCF) and serum matrix metalloproteinase-8 (MMP-8) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) levels from renal transplant patients receiving cyclosporine-A (CsA) and having gingival overgrowth (GO), from patients receiving CsA therapy and having no GO and patients receiving tacrolimus therapy.

MATERIAL AND METHODS

GCF samples were collected from sites with GO (GO+) and without GO (GO-) in CsA patients having GO; and GO- sites in CsA patients having no GO; sites from tacrolimus, gingivitis and healthy subjects. GCF and serum MMP-8 and TIMP-1 levels were determined by a time-resolved immunofluorometric assay (IFMA) and enzyme-linked immunosorbent assay.

RESULTS

GO+ sites in CsA patients having GO had elevated GCF MMP-8 levels compared with those of CsA patients having no GO, tacrolimus and healthy subjects (p<0.005), but these levels were similar to those of gingivitis. The GCF MMP-8 level was higher in GO+ compared with GO- sites in CsA patients having GO (p<0.05). GCF TIMP-1 levels were similar between groups. Tacrolimus patients had lower GCF MMP-8 levels than gingivitis (p<0.005), but levels similar to the healthy group.

CONCLUSION

These results show that CsA and tacrolimus therapy has no significant effect on GCF MMP-8 levels, and gingival inflammation seems to be the main reason for their elevations.

Altered gene expression levels of matrix metalloproteinases and their inhibitors in periodontitis-affected gingival tissue

BACKGROUND

The balance between the degradation and synthesis of extracellular matrix determines periodontal attachment levels and alveolar bone matrix concentration in periodontal diseases. Matrix metalloproteinases (MMPs) are known to degrade periodontal ligamental attachment and bone matrix proteins. The purpose of this study was to examine the effect of different expression levels of MMPs and their inhibitors, the tissue inhibitors of matrix metalloproteinases (TIMPs), in periodontitis.

METHODS

Sixteen inflamed gingival tissue samples from subjects with generalized chronic periodontitis and 14 control tissue samples from systemically and periodontally healthy subjects were evaluated. The total RNA was extracted, and the transcript levels for MMP-1, -3, -9, and -13 and TIMP-1, -2, -3, and -4 relative to beta-actin were determined by quantitative real-time reverse transcription-polymerase chain reaction.

RESULTS

Gene transcript levels for MMP-1 and TIMP-4 were significantly higher in periodontitis-affected gingival tissues (P <0.05). MMP-3, -9, and -13 and TIMP-1 mRNAs also were elevated in periodontitis; however, the difference was not statistically significant. TIMP-2 and -3 mRNA levels were similar in healthy and diseased gingivae. The ratios of MMP-1/TIMP-2 (P <0.01), MMP-3/TIMP-2 (P <0.05), MMP-9/TIMP-2 (P <0.05), and MMP-1/TIMP-3 (P <0.01) from periodontitis lesions were significantly higher than those in the control tissues.

CONCLUSIONS

Upregulated MMP expression and an increased MMP/TIMP ratio indicate that a potential imbalance between degradation and synthesis of extracellular matrix persists in periodontitis-affected gingival tissues. This process may be responsible for increased tissue breakdown in periodontitis.

A potential role of EMMPRIN by regulating ECM degradation in periodontitis

Periodontitis are characterized by the destruction of the extracellular matrix (ECM) of periodontal tissues. Matrix metalloproteinases (MMPs) play an important role in the degradation of ECM. But until now, it is not clear about the regulation of MMPs expression level in periodontitis. EMMPRIN is a 58 kDa, highly glycosylated, transmembrane molecule belonging to the immunoglobin superfamily, which interacts with fibroblasts to stimulate the expression of MMPs. It is logical to postulate that EMMPRIN may play a critical role in the regulation of MMPs participating the destruction of periodontal ECM in periodontitis. The hypothesis will provide the brand-new direction that we may prevent and treat the periodontitis by regulating the expression of EMMPRIN in host aspect.