Şivge Kurgan

High sensitivity detection of salivary 8-hydroxy deoxyguanosine levels in patients with chronic periodontitis

BACKGROUND Inflammation is associated with hydroxyl radical damage to DNA as a result of oxidative stress. 8-Hydroxy deoxyguanosine (8-OHdG) is a marker of this process and its levels in saliva could be linked to the severity of periodontal inflammation. The aim of this study was to test the sensitivity of liquid chromatography with tandem mass spectrometry (LC-MS/MS) in comparison to enzyme-linked immune sorbent assay (ELISA) for the detection of 8-OHdG in saliva in patients with chronic periodontitis before and after periodontal treatment. METHODS Saliva samples were collected from 23 patients (eight females and 15 males; 46.1 ± 5.1 years of age) with generalized chronic periodontitis and 25 (15 females and 10 males; 44.9 ± 6.8 years of age) periodontally healthy individuals. Patients received initial periodontal treatment consisting of scaling and root planing and were evaluated at baseline and after 6 wk of completion of non-surgical therapy. Salivary 8-OHdG levels were measured using ELISA and LC-MS/MS before and after the treatment. Clinically, plaque index, gingival index, clinical attachment level, bleeding on probing, gingival recession and probing pocket depth were measured at baseline and after 6 wk. RESULTS Salivary levels of 8-OHdG decreased significantly after the non-surgical periodontal treatment (p < 0.001). Statistically significant positive correlations were observed between plaque index, gingival index, probing pocket depth, clinical attachment level, bleeding on probing values and LC-MS/MS and ELISA levels of 8-OHdG (p < 0.001). CONCLUSION LC-MS/MS is a reliable and sensitive method for evaluating salivary 8-OHdG levels to monitor the treatment response of periodontitis.

Strain-Specific Impact of Fusobacterium nucleatum on Neutrophil Function

BACKGROUND Neutrophil function is critical for initiation and progression of infecto-inflammatory diseases. Key quorum-sensing plaque bacteria, such as Fusobacterium nucleatum, act as bridging species between early and late colonizer pathogens, such as Porphyromonas gingivalis, as the biofilm ages and periodontal inflammation increases. This study is designed to determine impact of different F. nucleatum strains on neutrophil function. METHODS Cells of human promyelocytic leukemia cell line-60 were differentiated into neutrophil-like cells and cultured with F. nucleatum strains of subspecies (ssp.) nucleatum ATCC 25586, ssp. polymorphum ATCC 10953, and ssp. vincentii ATCC 49256. Neutrophil phagocytosis of F. nucleatum strains and neutrophil apoptosis were analyzed by flow cytometry. Superoxide generation was measured by cytochrome C reduction in the presence and absence of N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP) (1 μM) stimulation. Proinflammatory cytokine release was determined after 2, 6, and 24 hours of culture in the presence/absence of different F. nucleatum strains. Expression of Toll-like receptor (TLR)2, TLR4, and nuclear factor (NF)-kappa B mRNA levels were analyzed using real-time quantitative polymerase chain reaction. Each experiment was repeated at least three times in triplicate. Data were analyzed using analysis of variance followed by post hoc Bonferroni correction. RESULTS All strains of F. nucleatum significantly increased phagocytic capacity of neutrophils. Neutrophil phagocytosis of F. nucleatum ssp. polymorphum was significantly greater than that of F. nucleatum ssp. vincentii and ssp. nucleatum (P <0.001). F. nucleatum ssp. nucleatum and ssp. polymorphum significantly blocked fMLP-induced superoxide generation (P <0.001). Although F. nucleatum vincentii also reduced superoxide generation (25%), the impact was not as strong as that of ssp. nucleatum (83%) and ssp. polymorphum (100%). All F. nucleatum strains stimulated significant increase in neutrophil apoptosis compared with control (P <0.001) and significantly increased expression of NF-κB mRNA in neutrophils (P <0.05). Levels of interleukin-8 and tumor necrosis factor-α produced by neutrophils were significantly increased in all F. nucleatum groups compared with control (P <0.001). CONCLUSIONS These findings suggest that different strains of F. nucleatum impact neutrophil function in different ways. Two of three subspecies blocked neutrophil superoxide generation in response to a secondary stimulus, preventing oxidative killing by neutrophils. The direct role of bridging species in pathogenesis of periodontitis may be greater than previously suspected in which they create a favorable environment for pathogenic transition of the dental ecosystem.

Gingival crevicular fluid tissue/blood vessel‐type plasminogen activator and plasminogen activator inhibitor‐2 levels in patients with rheumatoid arthritis: effects of nonsurgical periodontal therapy

BACKGROUND AND OBJECTIVE The aim of this study was to evaluate the effect of nonsurgical periodontal therapy on clinical parameters and gingival crevicular fluid levels of tissue/blood vessel-type plasminogen activator (t-PA) and plasminogen activator inhibitor-2 (PAI-2) in patients with periodontitis, with or without rheumatoid arthritis (RA). MATERIAL AND METHODS Fifteen patients with RA and chronic periodontitis (RA-P), 15 systemically healthy patients with chronic periodontitis (H-P) and 15 periodontally and systemically healthy volunteers (C) were included in the study. Plaque index, gingival index, probing pocket depth, clinical attachment level, bleeding on probing, gingival crevicular fluid t-PA and PAI-2 levels, erythrocyte sedimentation rate, serum C-reactive protein and disease activity score were evaluated at baseline and 3 mo after mechanical nonsurgical periodontal therapy. RESULTS All periodontal clinical parameters were significantly higher in the RA-P and H-P groups compared with the C group (p < 0.001) and decreased significantly after treatment (p < 0.001). Pretreatment t-PA levels were highest in the RA-P group and significantly decreased post-treatment (p = 0.047). Pre- and post-treatment PAI-2 levels were significantly lower in controls compared with both periodontitis groups (p < 0.05). Gingival crevicular fluid volume and the levels of t-PA and PAI-2 were significantly correlated. CONCLUSION In patients with periodontitis and RA, nonsurgical periodontal therapy reduced the pretreatment gingival crevicular fluid t-PA levels, which were significantly correlated with gingival crevicular fluid PAI-2 levels. The significantly higher t-PA and PAI-2 gingival crevicular fluid levels in periodontal patients, regardless of systemic status, suggest that the plasminogen activating system plays a role in the disease process of periodontitis.