[Effect of the management of class I obesity with metformin on metalloproteinase activity in patients with chronic periodontitis]. / Efecto del manejo de la obesidad clase I con metformina sobre actividad de metaloproteinasas en pacientes con periodontitis crónica.

INTRODUCTION: Introduction: in Mexico the main problem in public health is obesity and other diseases that are associated whit this condition, including oral health. Objective: to evaluate the effect of metformin treatment in patients with class I obese on the activity of metalloproteinases present in periodontium with chronic periodontitis. Methods: a clinical study was conducted in 68 patients with class I obesity and periodontal disease. They were divided into 4 groups. 2 of them, in addition to the periodontal treatment, were administered metformin 850 mg per day for six weeks; 2 samples were taken per patient of periodontal tissue before and after each treatment, body mass index, plaque index and inflammation were measured. Acrylamide gel zymography was used to measure the activity of metalloproteinases in the sample of tissue collected. The data obtained were analyzed by descriptive statistics, student t for related samples and one-way ANOVA was performed considering p < 0.01 as statistically significant. Results: in the group of patients who were administered metformin at the end of the treatment, there was a decrease in the body mass index, the degree of inflammation and lower metalloproteinase activity, compared with the control group (65% vs 25%; < 0.01). Conclusions: treatment with metformin in patients with obesity class I and periodontal disease decreases BMI, improves the symptoms of chronic periodontitis and decreases the activity of metalloproteinases 1, 3, 8, V present in periodontium of these patients.

INTRODUCCIÓN: Introducción: el principal problema de salud pública en México es la obesidad y sus enfermedades asociadas, incluyendo las bucales. Objetivo: evaluar el efecto del tratamiento con metformina en pacientes obesos de clase I sobre la actividad de las metaloproteinasas presentes en el periodonto con periodontitis crónica. Métodos: se realizó un estudio clínico con 68 pacientes mujeres con obesidad de clase I y enfermedad periodontal. Se dividieron en 4 grupos; a 2 de ellos, además del tratamiento periodontal, se les administro metformina de 850 mg al día durante seis semanas. Se tomaron 2 muestras por paciente de tejido periodontal antes y después de cada tratamiento y se midió el índice de masa corporal (IMC), el índice de placa dentobacteriana y de inflamación. Mediante zimografía en gel de acrilamida se midió la actividad de las metaloproteinasas en la muestra de tejido recolectada. Los datos obtenidos fueron analizados mediante estadística descriptiva t de student para muestras relacionadas y se realizó ANOVA de una vía considerando p < 0,01 como estadísticamente significativa. Resultados: en el grupo de pacientes a las que se les administro metformina al final del tratamiento se observó una disminución del índice de masa corporal, del grado de inflamación y menor actividad de metaloproteinasas respecto al grupo control (65% frente a 25%; p < 0,01). Conclusiones: el tratamiento con metformina en pacientes con obesidad de clase I y enfermedad periodontal disminuye el IMC, mejora los síntomas de la periodontitis crónica y disminuye la actividad de las metaloproteinasas 1, 3, 8 y V presentes en el periodonto de estos pacientes.

The effects of smoking on the expression of gelatinases in chronic periodontitis: a cross-sectional study.

Smokers have a risk of developing periodontal disease. Matrix metalloproteinases (MMP) play a significant role in periodontal tissue destruction. In this study possible relationship between smoking and gingival tissue expression of gelatinases in chronic periodontitis patients relative to periodontally healthy subjects was investigated. Forty chronic periodontitis patients (20 smokers and 20 non-smokers) and forty periodontally healthy subjects (20 smokers and 20 non-smokers) were enrolled. The clinical periodontal measurements recorded, and gingival tissues harvested after that. After histologic evaluation, matrix metalloproteinases -2 and -9 expressions were analyzed immunohistochemically. In nonsmokers, higher expression of metalloproteinases -2 and -9 detected in chronic periodontitis group compared to the periodontally healthy group. In the smoker chronic periodontitis group, the expression of metalloproteinases-2 was lower than nonsmoker chronic periodontitis group. Statistically significant differences detected between smoker and nonsmoker periodontally healthy groups in metalloproteinases-2 expression. For metalloproteinases-9 expression, smoker chronic periodontitis group has lower values than nonsmoker chronic periodontitis group. In periodontally healthy group smokers showed higher metalloproteinases -9 expressions than non- smokers. Present findings support the role of gelatinases in chronic periodontitis pathogenesis. Based on the current results we conclude that smoking alters the expression of gelatinases in gingival tissues.

SOD2 is upregulated in periodontitis to reduce further inflammation progression.

OBJECTIVES: Periodontitis is a highly prevalent chronic inflammatory disease that results in destruction of tooth-supporting structures followed by tooth-loss. Until now, periodontitis has been regarded to be initiated by bacterial infection followed by aberrant host response. Although increasing evidence suggests a strong association between oxidative stress and periodontitis, precise molecular mechanism has been left unanswered. In this study, we investigated roles of SOD2, the main antioxidant enzyme maintaining reactive oxygen species (ROS) homeostasis, under inflammatory conditions. METHODS: We computationally analyzed SOD2 expression in periodontitis. To confirm this data, immunoblot assay was performed with samples from periodontitis patients. The cellular mechanism of change in SOD2 expression was identified through immunoblot assay and immunofluorescence. To evaluate the molecular function of SOD2, we generated SOD2-deficient cells by utilizing the CRISPR/Cas9 system. RESULTS: We first determined that SOD2 expression was significantly increased in periodontitis. We also confirmed that SOD2 expression was upregulated through the NF-κB pathway when the inflammatory signal was stronger and extended. Gene manipulation against SOD2 through the CRISPR/Cas9 system showed that the absence of SOD2 increased production of NLRP3 inflammasome components. CONCLUSIONS: Our study demonstrates that intracellular SOD2 has a protective role by suppressing NLRP inflammasome-caspase-1-IL-1ß axis under inflammatory conditions.

Increased serum PCSK9, a potential biomarker to screen for periodontitis, and decreased total bilirubin associated with probing depth in a Japanese community survey.

BACKGROUND AND OBJECTIVES: Previous reports suggest that several serum biomarkers play roles in the pathogenesis, inflammatory response, and oxidative stress in periodontitis caused by bacterial infections, linking chronic periodontitis to atherosclerotic vascular disease (ASVD). The aim of this preliminary study was to investigate, in a Japanese cross-sectional community survey, potential serum biomarkers of periodontitis that are associated with ASVD and chronic periodontitis. MATERIAL AND METHODS: The study cohort included a total of 108 male subjects who underwent annual health examinations. Serum biomarkers (high-sensitivity C-reactive protein [hs-CRP], proprotein convertase subtilisin/kexin type 9 [PCSK9], interleukin-6, tumor necrosis factor-α, soluble CD14, myeloperoxidase, matrix metalloproteinase-3, adiponectin, total bilirubin [TBIL], and serum lipids) were analyzed to determine their association (if any) with periodontal parameters. Aortic stiffness was evaluated using the brachial-ankle aortic pulse wave velocity (PWV) index and the cardio-ankle vascular index (CAVI). RESULTS: The concentrations of PCSK9 and hs-CRP were increased (P = .001 and .042, respectively), and the concentration of TBIL was decreased (P = .046), in subjects with periodontal disease (determined as a probing depth of ≥4 mm in at least one site) compared with periodontally healthy subjects. The ratio of low-density lipoprotein cholesterol (LDL-C) to high-density lipoprotein cholesterol and the concentrations of triglycerides, remnant-like particles-cholesterol, and oxidized LDL were elevated in subjects with periodontal disease compared with periodontally healthy subjects (P = .038, .007, .002, and .049, respectively). Multivariate regression analyses indicated that the number of sites with a pocket depth of ≥4 mm was associated with the concentration of PCSK9 and inversely associated with the concentration of TBIL independently (standardized ß = .243, P = .040; standardized ß = -.443, P = .0002; respectively). Analysis of receiver operating characteristic curves of PCSK9 indicated moderate accuracy for predicting the presence of disease sites (probing depth ≥ 4 mm) (area under the curve = 0.740). No significance in the values of PWV and CAVI was observed between subjects with periodontal disease and periodontally healthy subjects. CONCLUSION: In Japanese male subjects, the concentrations of serum PCSK9 and TBIL were correlated with periodontal parameters. Moreover, PCSK9 could be a candidate biomarker for diagnosing chronic periodontitis, and may also have potential to evaluate the risk for periodontitis to cause ASVD. Longitudinal studies of larger populations are necessary to confirm the exact association of periodontitis with increased serum PCSK9 and decreased TBIL.

The effects of smoking on the expression of gelatinases in chronic periodontitis: a cross-sectional study

Abstract Smokers have a risk of developing periodontal disease. Matrix metalloproteinases (MMP) play a significant role in periodontal tissue destruction. In this study possible relationship between smoking and gingival tissue expression of gelatinases in chronic periodontitis patients relative to periodontally healthy subjects was investigated. Forty chronic periodontitis patients (20 smokers and 20 non-smokers) and forty periodontally healthy subjects (20 smokers and 20 non-smokers) were enrolled. The clinical periodontal measurements recorded, and gingival tissues harvested after that. After histologic evaluation, matrix metalloproteinases -2 and -9 expressions were analyzed immunohistochemically. In nonsmokers, higher expression of metalloproteinases -2 and -9 detected in chronic periodontitis group compared to the periodontally healthy group. In the smoker chronic periodontitis group, the expression of metalloproteinases-2 was lower than nonsmoker chronic periodontitis group. Statistically significant differences detected between smoker and nonsmoker periodontally healthy groups in metalloproteinases-2 expression. For metalloproteinases-9 expression, smoker chronic periodontitis group has lower values than nonsmoker chronic periodontitis group. In periodontally healthy group smokers showed higher metalloproteinases -9 expressions than non- smokers. Present findings support the role of gelatinases in chronic periodontitis pathogenesis. Based on the current results we conclude that smoking alters the expression of gelatinases in gingival tissues.

Comparative evaluation of inhibitory effect of curcumin and doxycycline on matrix metalloproteinase-9 activity in chronic periodontitis.

BACKGROUND AND OBJECTIVES: The pathogenesis of inflammatory periodontal diseases essentially involves degradation of extracellular matrix molecules, and collagen breakdown and matrix metalloproteinases (MMPs) are proteinases primarily involved in this process. It is known that doxycycline downregulates MMP activity. Curcumin has anti-inflammatory effect and also downregulates MMP activity. Thus, a study was conducted to evaluate the anti-inflammatory effect of curcumin by its inhibition of MMP-9 activity and compare the same with doxcycline, which has known anticollagenase activity. SUBJECTS AND METHODS: Gingival tissue samples were obtained from thirty patients diagnosed with chronic periodontitis. The tissue extracts were treated with Curcumin and doxycycline and inhibition of MMP-9 analyzed by gelatinzymography. Gels obtained were stained with Coomassie Brilliant Blue, and enzymatic activities detected as bands of gelatinlysis against blue background. Relative MMP-9 levels were measured by scanning the clear zones and analyzing the percentage inhibition. RESULTS: Results showed that MMP-9 activity was significantly decreased by both the drugs. Curcumin showed 61.01% reduction in the MMP-9 activity at 1500 µg/ml concentration and doxycycline showed 59.58% reduction in the MMP-9 activity at 300 µg/ml concentration. CONCLUSION: The current study showed that curcumin has inhibitory effect on polymorphonuclear leukocyte-type MMP-9 involved in matrix degradation in periodontitis. Since Curcumin has a potent anti-inflammatory effect, it may have therapeutic potential as a host modulation agent in periodontal diseases.

[Correlation of matrix metalloproteinase-9 polymorphisms with chronic periodontitis in Uygur adults].

Objective: To investigate the association between matrix metalloproteinase-9 (MMP-9) polymorphisms and chronic periodontitis in Uygur adults. Methods: A total of 196 patients with chronic periodontitis and 97 healthy controls were selected from 2 500 Uygur people. Buccal swab samples were taken, the genomic DNA was extracted and the genotype distribution and allele frequency of MMP-9 were determined by PCR-restriction fragment length polymorphism (PCR-RFLP). The distribution of genotypes, allele frequencies and risk factors were analyzed by chi-square test and multiple logistic regression. Results: Significant difference was found between healthy controls and the mild periodontitis and moderate to severe periodontitis in the MMP-9 1562C/T CC genotype expression (χ(2)=9.901, P=0.002; χ(2)=13.397, P< 0.001), and detectable rate of MMP-9 1562C/T CC genotype in the three groups was 31.3%(30/96), 53.5% (53/99), 27.8%(27/97), respectively. The detectable rate of CT genotype expression in the three groups were 65.6% (63/96), 45.5% (45/99), 69.1% (67/97) respectively and there was significant difference between healthy controls and mild periodontitis and between the mild periodontitis and moderate to severe periodontitis (χ(2)=8.025, P=0.005; χ(2)=11.159, P<0.001). There was also significant difference in allele frequency between healthy controls and mild periodontitis and between mild periodontitis and moderate to severe periodontitis (χ(2)=6.270, P=0.012; χ(2)=8.184, P=0.004). Logistic analysis showed that age under 35 years old was the protective factor of chronic periodontitis (OR=0.061, 95% CI=0.035-0.108, P<0.001) while the male and CT genotype were the risk factors of chronic periodontitis (OR=2.392, 95%CI=1.496-3.819, P<0.001; OR=1.280, 95%CI=0.794-2.067, P=0.031). Conclusions: The susceptibility to chronic periodontitis in Uygur adults in Moyu county of Xinjiang is related to the age and gender and polymorphism of MMP-9. The age over 35 years old, male and CT genotype may be the risk factors of chronic periodontitis in Uygur adults.

The effect of low-level diode laser on COX-2 gene expression in chronic periodontitis patients.

Adjunctive treatments to scaling and root planing (SRP) such as lasers, have been utilized in the treatment of chronic periodontitis, mainly aiming to suppress and eliminate the bacteria, as well as enhancing the healing response. Eighty gingival papilla biopsy samples were obtained from 60 patients diagnosed with chronic advanced periodontitis; randomly assigned to three treatment groups (n = 20), as well as 20 subjects with no periodontal disease [group A]. Group B received SRP on a single quadrant/day for four consecutive days. On day 5, all quadrants were rescaled. Groups C and D received the same treatment as group B plus laser application with the low-level diode laser (630-670 nm, 1.875 J/cm2) for five and ten consecutive days, respectively. Papilla biopsies were obtained from subjects and evaluated by RT-PCR for expression of COX-2. The values in the control group were 0.028 0.014 and baseline values for the examined groups were 0.16 0.18. Significantly decreased level of COX-2 expression for groups C and D was found after treatment, while lowest average expression was found in the group that had the 10 laser treatments supplemental to SRP (0,035 0,014). The results of this study show suppression of COX-2 in gingival tissue after low-level laser treatment as adjunct to SRP.

Diabetes may affect the expression of matrix metalloproteinases and their inhibitors more than smoking in chronic periodontitis.

BACKGROUND AND OBJECTIVE: No previous study has directly compared the levels of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMPs) between smokers and individuals with diabetes mellitus (DM) with periodontitis. Therefore, the aim of this study was to evaluate the gene expression of MMP-1, MMP-2, MMP-8, MMP-9, TIMP-1 and TIMP-2 in tissues with chronic periodontitis (ChP) of smokers and individuals with type 2 DM. MATERIAL AND METHODS: Gingival biopsies were harvested from: non-smokers and non-diabetic individuals with ChP (n = 18) (ChP group); non-diabetic smokers (≥ 10 cigarettes per day for at least the past 5 years) with ChP (n = 18) (SChP group); non-smoking individuals with type 2 diabetes (glycated hemoglobin levels ≥ 7.5%) and ChP (n = 18) (DMChP group). The tissue levels of mRNA of MMP-1, MMP-2, MMP-8, MMP-9, TIMP-1 and TIMP-2 were evaluated by quantitative real-time polymerase chain reaction. RESULTS: The MMP-8 expression was the lowest in the ChP group (p < 0.05). The DMChP group presented increased mRNA levels of MMP-2 and MMP-9, when compared to the SChP group (p < 0.05). MMP-1 expression and the MMP-1/TIMP-1, MMP-2/TIMP-1, MMP-8/TIMP-1, MMP-9/TIMP-1, MMP-1/TIMP-2 and MMP-2/TIMP-2 ratios were higher in the DMChP group than in the ChP and SChP groups (p < 0.05). The DMChP group presented lower mRNA levels of TIMP-1 than the ChP group (p < 0.05). The MMP-8/TIMP-2 ratio was the highest in the SChP group (p < 0.05). CONCLUSION: Uncontrolled type 2 DM upregulates the ratio of MMP/TIMPs in sites with ChP more than smoking, which may contribute to a greater extracellular matrix degradation and periodontal breakdown in DM-related periodontitis.

Production of endogenous hydrogen sulfide in human gingival tissue.

OBJECTIVE: Endogenous hydrogen sulfide (H2S) has recently been shown to play an important role in inflammation, but the role of endogenous H2S in the human gingival tissue is unknown. The aim of this study was to investigate whether gingiva had enzymes for H2S synthesis, and whether the effect of these enzymes for H2S production changed with periodontal inflammation. DESIGN: Gingival tissues were collected from patients undergoing periodontal operation including gingivitis, moderate chronic periodontitis, severe chronic periodontitis and normal controls. RT-PCR and western blotting were performed to measure mRNA and protein levels of cystathionine ß-synthase (CBS) and cystathionine γ-lyase (CSE) for H2S production. Immunohistochemistry was carried out to detect the location of the enzymes. H2S levels and synthesis in gingival tissue were evaluated with modified methylene blue method. RESULTS: The mRNA and protein of CBS and CSE were both expressed in human gingiva and raised significantly in moderate and severe periodontitis compared of that in healthy control. CBS, but not CSE, increased in gingivitis (p<0.05). However, there was no significant difference of H2S level and synthesis among these groups (p>0.05). CONCLUSIONS: Both CBS and CSE were expressed in human gingival tissue. The mRNA and protein levels of CBS and CSE were up-regulated in periodontitis.

Matrix metalloproteinase-8 activity in gingival crevicular fluid: development of a novel assay.

BACKGROUND AND OBJECTIVE: The matrix metalloproteinases (MMPs) play a role in regulating turnover and metabolism of connective tissues in health but they have also been implicated in a wide variety of pathological conditions, including periodontal disease. MMP-8 has been extensively studied in periodontal health and disease using ELISA, although this technique is limited by its inability to determine enzyme activity. The aim was to develop an assay specifically to measure MMP-8 activity and to demonstrate its use in the analysis of gingival crevicular fluid samples. MATERIAL AND METHODS: A specific antibody was used to coat black 96-well microtitre plates to capture MMP-8 selectively. The activity of bound MMP-8 was measured using a fluorogenic substrate. Gingival crevicular fluid samples, from healthy and periodontally diseased sites, were collected using PerioPaper strips and tested for MMP-8 activity. RESULTS: Significantly higher MMP-8 activity was demonstrated in gingival crevicular fluid from periodontally diseased sites compared with healthy sites that exhibited basal or no MMP-8 activity. No cross-reactivity with other MMPs was noted. CONCLUSION: We show, for the first time, that MMP-8 activity can be specifically detected and quantified in gingival crevicular fluid samples. Measurement of MMP-8 activity could prove to be useful in monitoring periodontal disease progression.

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.

Gene-expression analysis of matrix metalloproteinases 1 and 2 and their tissue inhibitors in chronic periapical inflammatory lesions.

BACKGROUND: Periapical inflammatory lesions have been investigated previously, but understanding of pathogenesis of these lesions (granulomas and radicular cysts) at the molecular level is still questionable. Matrix metalloproteinases (MMPs) are enzymes involved in the development of periapical pathology, specifically inflammation and tissue destruction. To elucidate pathogenesis of periapical granulomas and radicular cysts, we undertook a detailed analysis of gene expression of MMP-1, MMP-2 and their tissue inhibitors, TIMP-1 and TIMP-2. METHODS: A total of 149 samples were analyzed using real-time PCR (59 radicular cysts, 50 periapical granulomas and 40 healthy gingiva samples as controls) for expression of MMP-1, MMP-2, TIMP-1 and TIMP-2 genes. The determination of best reference gene for expression analysis of periapical lesions was done using a panel of 12 genes. RESULTS: We have shown that ß-actin and GAPDH are not the most stable reference controls for gene expression analysis of inflammatory periapical tissues and healthy gingiva. The most suitable reference gene was determined to be SDHA (a succinate dehydrogenase complex, subunit A, flavoprotein [Fp]). We found that granulomas (n = 50) and radicular cysts (n = 59) exhibited significantly higher expression of all four examined genes, MMP-1, MMP-2, TIMP-1, and TIMP-2, when compared to healthy gingiva (n = 40; P < 0.05). CONCLUSION: This study has confirmed that the expression of MMP-1, MMP-2, TIMP-1, and TIMP-2 genes is important for the pathogenesis of periapical inflammatory lesions. Since the abovementioned markers were not differentially expressed in periapical granulomas and radicular cysts, the challenge of finding the genetic differences between the two lesions still remains.

The utility of gingival crevicular fluid matrix metalloproteinase-8 response patterns in prediction of site-level clinical treatment outcome.

BACKGROUND: Different gingival crevicular fluid (GCF) matrix metalloproteinase (MMP)-8 response patterns were studied among non-smoking and smoking patients with chronic periodontitis (CP) and generalized aggressive periodontitis (GAgP) to test the utility of GCF MMP-8 levels predicting the site-level treatment outcome. METHODS: Data from four independent longitudinal studies were combined. Altogether, the studies included 158 periodontal sites from 67 patients with CP and 32 patients with GAgP, and GCF samples were collected at baseline, after the treatment, and during the 6-month maintenance period. All GCF samples were analyzed by immunofluorometric assay for MMP-8. Different site-level MMP-8 response patterns were explored by the cluster analysis. Most optimal MMP-8 cutoff levels were searched with receiver operating characteristic analyses, and the predictive utility of defined levels was tested. RESULTS: Distinct types of MMP-8 response patterns were found in both smokers and non-smokers. MMP-8 levels exceeding the optimal cutoff levels separately defined for smokers and non-smokers indicated increased risk for compromised treatment outcome at baseline and during the maintenance period. Seventy-one percent of non-smokers (positive likelihood ratio of 4.22) and 88% of smokers (positive likelihood ratio of 5.00) with positive test results at both baseline and the maintenance period had compromised treatment outcome. The double-positive result indicated 46% and 39% point risk increase for the compromised outcome, respectively. CONCLUSION: GCF MMP-8 analysis with defined cutoff levels could be used to predict the site-level treatment outcome and for longitudinal monitoring of the disease status during the maintenance period.

Telomerase expression in individuals with chronic and aggressive periodontitis.

BACKGROUND: The aim of this study is to evaluate the expression of human telomerase reverse transcription (hTERT) enzyme in chronic periodontitis (CP) and aggressive periodontitis (AgP) compared with healthy individuals. METHODS: A total of 79 individuals consented to participate in the study. The study sample comprised healthy individuals (n = 30), patients with CP (n = 30), and patients with AgP (n = 19). Gingival tissue was collected and evaluated for hTERT expression by Western blot and immunohistochemical methods. Reverse transcription polymerase chain reaction was performed using the gingival crevicular fluid (GCF) samples. RESULTS: The hTERT messenger RNA (mRNA) and protein expression was significantly higher in AgP compared with CP (P <0.001). In GCF, 53.33% of patients with CP and 68.42% of patients with AgP were showing hTERT mRNA expression, but it was not detected in the control group. The AgP tissue showed higher hTERT expression compared with CP (P <0.001). The hTERT mRNA expression did not show a correlation with gingival index (GI), plaque index (PI), probing depth (PD), and clinical attachment loss (AL) in patients with AgP, whereas hTERT protein expression was strongly correlated with GI, PI, PD, and AL in patients with AgP. The protein expression of hTERT shows significant but moderate correlation with GI and AL in patients with CP. CONCLUSION: High expression of hTERT might be associated with periodontal disease progression, suggesting that hTERT could be a potential prognostic marker.

Effect of phase 1 periodontal therapy on gingival crevicular fluid levels of matrix metalloproteinases-3 and -13 in chronic periodontitis patients.

AIM: The aim of the present study was to estimate the gingival crevicular fluid (GCF) levels of matrix metalloproteinases (MMP)-3 and -13 in periodontally-healthy controls and chronic periodontitis (CP) patients, and also to investigate the effect of phase 1 periodontal therapy on MMP-3 and -13 levels in CP patients. METHODS: Fifty-five systemically-healthy patients were divided into two groups: group 1 (healthy) and group 2 (CP). The recording of clinical parameters and GCF sampling was done at baseline for both groups and again at 6 weeks post-therapy for group 2. The MMP level was determined by ELISA. RESULTS: A significant increase in the mean MMP-3 and -13 was found between healthy and CP patients. There was a statistically-significant reduction of GCF MMP-3 and -13 concentration after periodontal therapy in the CP group. A positive correlation was found between clinical parameters and GCF MMP-3 and -13 levels. CONCLUSIONS: A lower concentration of GCF MMP-3 and -13 was found in healthy patients, and a higher concentration was noted for CP patients, which was reduced after periodontal therapy. This indicates the important role played by these MMP in periodontal destruction. Thus, MMP-3 and -13 could be used as inflammatory biomarkers in diagnosing periodontal disease severity.

[Effect of oral intervention on matrix metalloproteinase-2, 9 expression in carotid arteries and serum interleukin-6 in rats with chronic periodontitis].

OBJECTIVE: To establish chronic periodontitis model in SD rats, and to investigate the effect of oral intervention on atherosclerosis. METHODS: Fifty male SD rats were randomly divided into three groups, group A (normal control), group B (atherosclerosis,As) and group C (chronic periodontitis, CP). Group C was further divided into group C1 (natural process), group C2 (simple mechanical treatment), group C3 (systemic antibiotics), group C4-1 (teeth extraction) and group C4-2 (teeth extraction+systemic antibiotics), each group consisted of 7 rats. Every group received oral intervention. Serum interleukin (IL)- 6 levels were detected in five different time points (1, 3, 5, 7, 9 weeks after a successful modeling) by enzyme linked immunosorbent assay. All animals were killed after 24 weeks. Matrix metalloproteinase (MMP)- 2, 9 in the proximal aorta was detected by immuno histochemistry. RESULTS: The levels of serum IL-6 in groups B and C1 increased gradually with time and became significantly higher than that in group A (P < 0.01). Levels of serum IL-6 were increased gradually in each intervention group (C2, C3, C4-1, C4-2) and reached its peak at 5 weeks after modeling [C2:(62.3 ± 14.3) ng/L, C3:(58.2 ± 8.7) ng/L, C4-1:(127.0 ± 29.9) ng/L, C4-2:(120.6 ± 23.1) ng/L]. Compared with group B, group C4- 1 and C4- 2 increased most significantly (P < 0.01). Levels of serum IL- 6 decreased gradually. Eventually, group C2 [(28.6 ± 8.1) ng/L], C3 [(40.8 ± 15.1) ng/L] and C4-2 [(32.7 ± 11.1) ng/L] were significantly lower than group B (P < 0.05), and in group C2 IL- 6 was the lowest. Although levels of serum of IL-6 significantly decreased in group C4-1 [(72.8 ± 16.4) ng/L], but remained the highest. Immunohistochemistry showed that MMP-2, 9 were expressed in group B, C1 and C4-1, and significantly higher than in group A (183.0 ± 2.0, 181.3 ± 2.0), the gray value differences were statistically significant (P < 0.01). Group C4-1 (123.1 ± 2.9, 121.0 ± 3.2) was the strongest, group B (126.4 ± 2.0, 124.8 ± 2.8) and C1 (140.0 ± 2.2, 139.7 ± 3.2) were decreased (P < 0.01). While group C2(169.3 ± 3.4, 169.7 ± 2.3), C3 (149.0 ± 1.7, 145.1 ± 2.5) and C4-2 (157.7 ± 1.2, 155.8 ± 2.7) were significantly lower than group C1 (P < 0.01), and group C2 was close to normal. CONCLUSIONS: Periodontitis could increase the risk of atherosclerosis in rats with chronic periodontitis. Periodontal mechanical treatment and teeth extraction may increase the risk of As in the short time. However, the risk would gradually reduce in a long time.

Immunolocalization of heme oxygenase-1 in periodontal diseases.

CONTEXT: Chronic periodontitis is an inflammatory condition of supporting tissues initiated by organisms in dental plaque. The reactive oxygen species and free radicals mediate connective tissue destruction in periodontitis. In order to counteract the free radical mediated tissue damage, numerous antioxidant mechanisms exist within the host. One such system is heme oxygenase enzymes. Heme oxygenase is the key enzyme involved in catabolism of heme. It cleaves the heme molecule to yield equimolar amounts of biliverdin, carbon monoxide, and iron. These end products act as important scavengers of reactive oxygen metabolites. Increased heme oxygenase expression has been identified in inflammatory condition, such as pancreatitis, diabetes, nephritis, and atherosclerosis. Since chronic periodontitis is one such inflammatory condition, we assessed the expression of heme oxygenase-1, in smokers and periodontitis group using immunohistochemistry technique. AIMS: The aim of this study is to compare the expression of heme oxygenase-1 in patients with healthy periodontium, periodontitis and smokers. MATERIALS AND METHODS: Gingival tissue samples were taken from 30 patients, who were divided into three groups healthy controls (n = 10), chronic periodontitis (n = 10), and smokers with chronic periodontitis (n = 10). All the samples were subjected to immunohistochemical staining using the antiheme oxygenase-1 antibody and were tested for efficiency by staining a positive control (prostate cancer tissue sections) and a negative control. The results were tabulated and analyzed. RESULTS: Our results showed increased expression of heme oxygenase-1 in the gingival tissue samples taken from smokers compared with periodontitis and healthy tissue. CONCLUSION: The results of our study is an increasing evidence of involvement of antioxidant enzymes like heme oxygenase-1 in periodontal inflammation and their implication for treatment of chronic periodontitis.

Evaluation of systemic levels of neutrophilic enzymes in patients with hypertension and chronic periodontitis.

BACKGROUND: Inflammation stimulates neutrophils to release their enzymes into the extracellular matrix. The aim of the present study is to investigate the serum levels of matrix metalloproteinase (MMP)-8, MMP-9, tissue inhibitor of MMP (TIMP)-1, myeloperoxidase (MPO), and neutrophil elastase (NE) in patients with hypertension and chronic periodontitis (CP). METHODS: A total of 95 patients were included in the study. Patients were categorized into three groups: healthy control (n = 29), hypertensive control (n = 32), and hypertensive CP (n = 34). Periodontal parameters were recorded, and serum samples were collected from each participant. Serum MMP-8, MMP-9, TIMP-1, MPO, and NE levels in circulation were assessed by enzyme-linked immunosorbent assay. RESULTS: The hypertensive CP group had significantly higher serum MMP-8, MMP-9, and NE levels than the healthy control group (P <0.05). All study groups had similar serum TIMP-1 levels (P >0.05). Significantly higher serum MPO levels were detected in patients with hypertension and CP than healthy controls and hypertensive controls (P <0.05); however, the difference in serum MPO levels was not significant between the healthy controls and hypertensive controls (P >0.05). There was no significant difference in MMP-8/TIMP-1 ratio among the study groups (P >0.05). MMP-9/TIMP-1 ratio was significantly higher in patients with hypertension and CP than healthy controls (P <0.05). CONCLUSIONS: The presence of hypertension along with CP has a considerable effect on serum neutrophilic enzyme levels, except TIMP-1. However, the levels of these enzymes do not seem to be affected by the presence of hypertension only. Further studies including patients who have only CP might help illuminate the effect of CP on these enzymes in patients with hypertension.

Evaluation of antioxidant enzymes activity and malondialdehyde levels in patients with chronic periodontitis and diabetes mellitus.

BACKGROUND: The aim of this study is to investigate the impact of diabetes, a known risk factor for periodontitis, on activities of antioxidant enzymes superoxide dismutase (SOD), glutathione reductase (GR), and catalase (CAT) as well as levels of free radical damage marker malondialdehyde (MDA) in blood and saliva of individuals with chronic periodontitis (CP). METHODS: Sixty patients with CP (30 patients with type 2 diabetes mellitus [DMCP] and 30 systemically healthy patients [CP]) and 60 periodontally healthy individuals (30 patients with type 2 diabetes mellitus and 30 systemically healthy patients [PH]) were included in this study. After clinical measurements, blood and saliva samples were collected. SOD, GR, and CAT activities in red blood cell lysate and saliva and MDA levels in plasma and saliva samples were spectrophotometrically assayed. An analysis of variance test followed by a post hoc test was used to compare the intragroup and intergroup variances among the study groups. RESULTS: MDA levels in both the periodontitis groups were higher than in the periodontally healthy groups, but the difference between the CP and DMCP groups did not reach statistical significance (P >0.05). There was a highly significant difference between the CP and PH groups for all the enzymes studied except for SOD in blood. Only salivary SOD and GR activities were significantly different in the CP and DMCP groups. CONCLUSIONS: This study favors the role of oxidative stress in both diabetes and periodontitis. It shows that the compensatory mechanism of the body is partially collapsed because of excessive production of free radicals during periodontitis and is not able to cope with increased free radical generation attributable to diabetes, thereby worsening the situation.