Oya Türkoğlu

Expression and regulation of the NALP3 inflammasome complex in periodontal diseases

Periodontitis is an infectious process characterized by inflammation affecting the supporting structures of the teeth. Porphyromonas gingivalis is a major oral bacterial species implicated in the pathogenesis of periodontitis. Processing of interleukin (IL)‐1 family cytokines is regulated by an intracellular innate immune response system, known as the NALP3 [nacht domain‐, leucine‐rich repeat‐, and pyrin domain (PYD)‐containing protein 3] inflammasome complex. The aim of the present study was to investigate by quantitative real‐time polymerase chain reaction (PCR) the mRNA expression of NALP3, its effector molecule apoptosis associated speck‐like protein (ASC), its putative antagonist NLRP2 (NLR family, PYD‐containing protein 2), IL‐1β and IL‐18 (i) in gingival tissues from patients with gingivitis (n = 10), chronic periodontitis (n = 18), generalized aggressive periodontitis (n = 20), as well as in healthy subjects (n = 20), (ii) in vitro in a human monocytic cell line (Mono‐Mac‐6), in response to P. gingivalis challenge for 6 h. The clinical data indicate that NALP3 and NLRP2, but not ASC, are expressed at significantly higher levels in the three forms of inflammatory periodontal disease compared to health. Furthermore, a positive correlation was revealed between NALP3 and IL‐1β or IL‐18 expression levels in these tissues. The in vitro data demonstrate that P. gingivalis deregulates the NALP3 inflammasome complex in Mono‐Mac‐6 cells by enhancing NALP3 and down‐regulating NLRP2 and ASC expression. In conclusion, this study reveals a role for the NALP3 inflammasome complex in inflammatory periodontal disease, and provides a mechanistic insight to the host immune responses involved in the pathogenesis of the disease by demonstrating the modulation of this cytokine‐signalling pathway by bacterial challenge.

Gingival Crevicular Fluid Levels of Cathelicidin LL-37 and Interleukin-18 in Patients With Chronic Periodontitis

BACKGROUND Cathelicidin LL-37, an antimicrobial peptide, is part of the host innate immune response in the oral cavity. Interleukin (IL)-18, a proinflammatory cytokine, could play a role in the progression of the inflammatory response. The aim of the present study was to determine the levels of cathelicidin LL-37 and IL-18 in the gingival crevicular fluid (GCF) of patients with gingivitis and chronic periodontitis. METHODS Fifty-nine subjects were included in the present study. Probing depth (PD), clinical attachment level (CAL), plaque index (PI), bleeding on probing, and papilla bleeding index (PBI) were assessed in patients with chronic periodontitis or gingivitis and in healthy controls. GCF levels of cathelicidin LL-37 and IL-18 were analyzed by enzyme-linked immunosorbent assay. RESULTS GCF levels of cathelicidin LL-37 were significantly elevated in patients with chronic periodontitis compared to the other groups (P <0.05). No significant difference was found in the total amount of GCF IL-18 among the study groups (P >0.05). Spearman correlation analysis revealed a positive relationship between levels of GCF cathelicidin LL-37 and PD, CAL, PI, and PBI at the sampled sites (P <0.01), whereas no correlation was found between the total amount of GCF IL-18 and clinical periodontal parameters at the sampled sites (P >0.05). CONCLUSION Elevated levels of GCF cathelicidin LL-37 in chronic periodontitis suggest that it may play a role in the host innate immune response during periodontal inflammation.

Antimicrobial peptide hCAP-18/LL-37 protein and mRNA expressions in different periodontal diseases.

OBJECTIVE To investigate the levels of antimicrobial peptide hCAP-18/LL-37 protein and mRNA expression in gingival tissues with different periodontal disease. MATERIALS AND METHODS Ten patients with generalized aggressive periodontitis, 10 patients with chronic periodontitis, and 10 healthy controls were included in this study. Periodontal parameters including probing depth, clinical attachment level, plaque index, and papilla bleeding index were assessed in study subjects. hCAP-18/LL-37 mRNA analysis by RT-PCR and immunohistochemistry were performed in 19 samples provided enough RNA in terms of concentration and integrity. RESULTS This study demonstrated that hCAP-18/LL-37 was a product of neutrophils. Tissue samples of chronic periodontitis patients had significantly higher immunostaining of hCAP-18/LL-37 on neutrophils infiltrating in both epithelium and connective tissue compared with controls. hCAP-18/LL-37 mRNA expression levels in tissue samples of chronic periodontitis patients seemed to be upregulated compared with controls. While two generalized aggressive periodontitis patients showed downregulated hCAP-18/LL-37 mRNA expression levels, one generalized aggressive periodontitis patient showed slightly increased hCAP-18/LL-37 mRNA level compared with controls. CONCLUSIONS hCAP-18/LL-37 has an important role in innate response during periodontal inflammation. Local deficiency in hCAP-18/LL-37 might be a confounding effect in the pathogenesis of generalized aggressive periodontitis.

Evaluation of Gingival Crevicular Fluid Adrenomedullin and Human Neutrophil Peptide 1–3 Levels of Patients With Different Periodontal Diseases

BACKGROUND Antimicrobial peptides participating in the innate host response are important contributors for maintaining the balance between health and disease. The aim of the present study is to investigate the levels of gingival crevicular fluid (GCF) adrenomedullin and human neutrophil peptides 1 through 3 (HNP1-3) in patients with different periodontal diseases. METHODS A total of 77 subjects, including 20 patients with chronic periodontitis, 18 patients with generalized aggressive periodontitis, 20 patients with gingivitis, and 19 healthy subjects, were included in the present study. The probing depth, clinical attachment level, plaque index, and papilla bleeding index were assessed in all study subjects. GCF samples were analyzed for evaluating adrenomedullin and HNP1-3 levels by enzyme-linked immunosorbent assay. RESULTS The present study demonstrated that the periodontitis groups had a significantly higher total amount of GCF adrenomedullin compared to the gingivitis and healthy control groups after adjusting for age and gender (P <0.05). Additionally, GCF adrenomedullin levels were positively correlated with clinical periodontal parameters of sampling sites (P <0.05). The total amount of GCF HNP1-3 was not different among the study groups, and there was no correlation between the total amount of GCF HNP1-3 and clinical periodontal parameters (P >0.05). CONCLUSIONS Our results suggest a defensive role for adrenomedullin during the host response in periodontal disease. Additionally, the lack of the HNP1-3 antimicrobial peptide might point to the deficiency of one of the protective mechanisms for periodontal tissues.

The effect of adjunctive chlorhexidine mouthrinse on clinical parameters and gingival crevicular fluid cytokine levels in untreated plaque-associated gingivitis.

Abstract.Objective and design:To examine the effectiveness of chlorhexidine mouthrinse (CHX) in addition to daily plaque control on gingival inflammation.Methods:Fifty gingivitis patients were randomized to CHX or placebo groups. In addition to proper plaque control, CHX group rinsed with CHX, while placebo group rinsed with placebo mouthrinse for 4 weeks. Gingival crevicular fluid (GCF) samples were collected and clinical parameters including plaque index (PI), papillary bleeding index (PBI), calculus index and probing depth (PD) were recorded at baseline and repeated at 4 week. GCF IL-1α, IL-1β, IL-1Ra, and IL-8 levels were determined by ELISA.Results:Whole mouth clinical parameters were significantly improved in both groups at 4 weeks. CHX group showed greater reduction in the mean PI scores than placebo at 4 weeks (p < 0.05). GCF IL-8 levels of anterior sites significantly reduced in CHX and placebo group at 4 weeks (p < 0.05). GCF IL-1α, IL-1β, IL-1Ra levels remained unchanged at 4 weeks in both groups. GCF cytokine levels of CHX group were similar to those of placebo at 4 weeks.Conclusions:Within the limitations of this study, CHX mouthrinse as adjuncts to daily plaque control could be useful in management of plaque-associated gingivitis, although ineffective on GCF cytokine levels.

A novel p.S34N mutation of CAMP gene in patients with periodontal disease

OBJECTIVE Recent studies have showed that genetic factors involved in the host responses might determine the severity of periodontitis. hCAP-18/LL-37 is a part of the innate immune response in the oral cavity. The aim of the present study was to investigate the mutation of CAMP gene encoding hCAP-18/LL-37 in the patients with different periodontal diseases. DESIGN Seventy-eight chronic periodontitis, 72 generalized aggressive periodontitis, and 149 controls were analysed for mutation of CAMP gene using direct DNA sequencing method. Frequencies of p.S34N mutation were compared by Pearson chi-square test. Logistic regression analysis was used to analyse the association between periodontitis and p.S34N mutation adjusting for bleeding on probing, age and gender. RESULTS Twenty-five subjects had a novel missense mutation of CAMP gene. Single base substitution (c.101G>A) in exon 1 led to p.S34N mutation. All amino acid substitutions were heterozygous mutation. The patients with generalized aggressive periodontitis had significantly higher p.S34N mutation prevalence compared to the others, whilst there was no significant difference in prevalence of p.S34N mutation between the patients with chronic periodontitis and the control subjects. Logistic regression analysis adjusted for BOP, age and gender revealed that the patients with generalized aggressive periodontitis were 5.32 times more likely to have p.S34N mutation compared to the controls (OR=5.32, 95% CI: 1.3-22.1). CONCLUSION We report a novel missense mutation of CAMP gene. p.S34N mutation in CAMP gene seems to be contributing factor for generalized aggressive periodontitis, but not for chronic periodontitis.

Gene expression of transcription factor NFATc1 in periodontal diseases

Belibasakis GN, Emingil G, Saygan B, Turkoglu O, Atilla G, Bostanci N. Gene expression of transcription factor NFATc1 in periodontal diseases. APMIS 2011; 119: 167–172.

Does smoking affect gingival crevicular fluid LL-37 levels following non-surgical periodontal treatment in chronic periodontitis?

OBJECTIVE LL-37 contributes to maintaining the balance between health and disease. Smoking is a risk factor for periodontitis that impairs neutrophil functions. The aim of the present study was to comparatively evaluate gingival crevicular fluid (GCF) LL-37 levels in smoker and non-smoker chronic periodontitis (CP) patients and controls, as well as the effect of non-surgical periodontal treatment on GCF LL-37 levels. DESIGN Thirty-one CP patients (16 smokers, 15 non-smokers) and thirty-one controls (16 smokers, 15 non-smokers) were included in the study. CP patients received non-surgical treatment. GCF LL-37 levels and periodontal parameters were assessed at baseline, 1 and 3 months after completion of non-surgical periodontal treatment. GCF LL-37 levels were analyzed by ELISA. RESULTS No significant difference was observed in GCF LL-37 levels between smoker and non-smoker controls (p>0.05). Smoker CP group had significantly lower GCF LL-37 level than non-smoker CP group at baseline (p<0.05). GCF LL-37 levels significantly decreased in non-smoker CP group at first week, 1 and 3 months after completion of non-surgical periodontal treatment (p<0.05) although no significant decrease in GCF LL-37 levels was observed in smoker CP group (p>0.05). Periodontal parameters were correlated with GCF LL-37 levels in non-smoker CP group (p<0.05), but not in smoker CP group (p>0.05). CONCLUSIONS GCF LL-37 levels do not seem to be affected from smoking in periodontal health. However, smoking might have a suppressive effect on GCF LL-37 levels in CP. Non-surgical treatment is effective in decreasing GCF LL-37 levels in non-smoker CP patients but not in smokers with CP.

Are antimicrobial peptides related to cyclosporine A-induced gingival overgrowth?

OBJECTIVE The aim of the present study was to investigate the effect of cyclosporine-A (CsA) medication on gingival crevicular fluid (GCF) LL-37, human neutrophil peptide (HNP)1-3 and adrenomedullin (ADM) levels. DESIGN CsA-treated renal transplant recipients with GO (CsA GO+) and without GO (CsA GO-), tacrolimus-medicated renal transplant recipients (n = 20/group), systemically healthy subjects with gingivitis (n = 21) and individuals free of periodontal and systemic diseases (n = 20) were included in the present study. Periodontal parameters were recorded and GCF samples were obtained from the study participants. GCF LL-37, HNP1-3 and ADM levels were analyzed by enzyme-linked immunosorbent assay. RESULTS GCF LL-37 total amount was higher at GO+ sites than the other study sites (p < 0.05). Total amount of GCF HNP1-3 was higher in immunosuppressive treatment groups than healthy and gingivitis groups, regardless of GO presence (p < 0.05). GCF ADM total amount was similar in all study groups. GCF volume, papillary bleeding index and hyperplastic index (p < 0.05) were significantly correlated with GCF LL-37 total amounts (p < 0.05), but not with GCF HNP1-3 and ADM total amount at GO+ sites (p > 0.05). CONCLUSION Neutrophil infiltration due to extended inflammation might have increased GCF LL-37 levels at GO+ sites and contributed to the pathogenesis of CsA-induced GO.

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.