DNA methylation profile of genes related to immune response in generalized periodontitis.

BACKGROUND AND OBJECTIVE: Epigenetic events, as the DNA methylation, may be related to development of inflammatory diseases. Due to the important role of host's response in the pathogenesis of periodontitis, the purpose of the present study was to investigate the methylation profile of genes related to immune response in gingival tissues from patients with generalized periodontitis (GP) compared to healthy individuals. METHODS: Gingival tissues were collected from 20 individuals with GP and 20 healthy individuals. Genomic DNA was extracted and submitted to enzymatic digestions. An initial screening using a panel of genes involved with the response immune was performed in pools containing six samples of each group. Genes that presented different levels of methylation between the groups were selected for individual assays for validation. RESULTS: The array results showed an unmethylated profile in the majority of genes evaluated in both groups. MALT1, LTB, and STAT5 genes presented a profile of partial methylation in the control compared with GP group. Validation individual assays using a larger number of samples (n = 20, each group) confirmed the hypomethylation of STAT5 in the GP group compared with control group (P < .001). CONCLUSION: Generalized periodontitis is associated with hypomethylation of the STAT5 gene. Further studies are necessary to evaluate the functional impact these findings.

Effect of Periodontal Therapy on Serum Levels of IL-6 in Type 2 Diabetics: A Systematic Review.

The objective of this systematic review was to search for scientific evidence regarding the impact of periodontal therapy on serum levels of interleukin 6 (IL-6) in type 2 diabetics. A survey was conducted in five databases. Two researchers read titles and abstracts for initial selection and full text for inclusion. Data extraction and methodological quality assessment were performed. Four hundred and fifty-five studies were identified and 15 were included. Significant divergence on the effect of periodontal intervention on IL-6 levels in diabetics was observed among studies. The evaluation results of studies that controlled obesity indicate that periodontal therapy seems to have beneficial effects on IL-6 levels.

Hypermethylation and low transcription of TLR2 gene in chronic periodontitis.

Periodontitis is an inflammatory disorder characterized by interactions between periodontal pathogens and host's immune response. Epigenetic may contribute to disease development and outcome by influencing the expression of genes involved in the immune response. It has been shown that Toll-like receptors (TLR) play an important role in the response to periodontopathic bacteria. The aim of study was to evaluate the methylation status and the expression of TLR2 gene in gingival samples from individuals with and without periodontitis. DNA was analyzed using the Methyl Profiler DNA Methylation qPCR assay. DNA methylation and transcript levels were evaluated by real-time polymerase chain reaction. The periodontitis group showed a hypermethylated profile and a low expression of gene. Positive correlation between the TLR2 methylation frequency and probing depth was observed. This study gives the first evidence of methylation frequency in inflamed periodontal tissues and of the possible participation of methylation in the development of periodontitis.

Transcription factor STAT1 gene polymorphism is associated with the development of severe forms of periodontal disease.

INTRODUCTION: Periodontal disease (PD) is one of the most common inflammatory diseases, affecting about 10 % of the world population. The establishment of PD is influenced by polymorphisms in genes involved with the inflammatory response. Signal Transducer and Activator of Transcription (STAT)-1 is a transcription factor that plays a key role in the intracellular signaling triggered by cytokines and, thus, its activation is critical in inflammatory diseases. AIM AND METHODS: We aim to evaluate the occurrence of association between STAT-1 (rs3771300) polymorphism and distinct clinical forms and severity of PD; we genotyped 180 subjects using realtime PCR. RESULTS AND CONCLUSION: We observed that the presence of the G allele for STAT-1 was associated with twice as high of a chance to develop aggressive periodontitis, and the most severe form of the disease.

Expression, polymorphism and methylation pattern of interleukin-6 in periodontal tissues.

Periodontitis is considered an inflammatory disorder of bacterial etiology that results in periodontal tissue destruction, as a result of complex interactions between periodontal pathogens, host and immune response. Genetic and epigenetic mechanisms may modulate the individual response since it is able to influence the gene expression. The aim of this study was to evaluate the impact of -174 G/C polymorphism and the methylation status of the promoter region of IL-6 gene on the expression of IL-6 in gingival samples from individuals with chronic periodontitis. Gingival biopsies were collected from 21 patients with chronic periodontitis and 21 controls. Histologic sections stained by hematoxylin-eosin were used for histopathological evaluation. The IL-6 gene expression was assessed by quantitative real-time PCR. The polymorphism IL-6 -174 C/G was studied by polymerase chain reaction (PCR) amplification and restriction endonuclease digestion (HspII). Methylation-specific polymerase chain reaction was used to verify the DNA methylation pattern. The number of inflammatory cells in tissue fragments from individuals with chronic periodontitis was higher than in the control group and the inflammatory infiltrate was predominantly mononuclear. The expression of IL-6 was higher in the group with periodontitis. In polymorphism assay, no statistical difference in the distribution of genotypes and alleles in both groups were observed. The most of samples were partially methylated. No difference was observed in methylation pattern from two different regions of the IL-6 gene among groups. The high expression of IL-6 is an important factor related to chronic periodontitis, but was not associated with methylation status or the -174 (G/C) genetic polymorphism, suggesting that other mechanisms are involved in this gene transcription regulation.

Halitosis in obese patients and those undergoing bariatric surgery.

BACKGROUND: Patients undergoing bariatric surgery often complain of bad breath. However, the relationship between bariatric surgery and halitosis is relatively unknown. The purpose of the present study was to evaluate and compare the occurrence of halitosis among patients before and after a specific type of bariatric surgery, Roux-en-Y gastric bypass, and its relationship with the tongue coating index, plaque index, and salivary flow rate. METHODS: A total of 62 patients with good oral health and in treatment for obesity at the walk-in clinic of Santa Casa Hospital, Belo Horizonte, Brazil, were selected. Of this sample, 31 were bariatric surgery candidates (control group) and 31 had already undergone Roux-en-Y gastric bypass surgery (case group). After completing a questionnaire, all patients underwent an oral clinical examination. Halitosis was measured using an organoleptic scale and a portable sulfide monitor. RESULTS: The Spearman correlation demonstrated a strong positive relation between the organoleptic rates and the concentration of volatile sulfur compounds determined using the sulfide monitor (rs = .58; P = .0001). No difference was found in the prevalence of halitosis between the 2 groups (P = .48). Only the salivary flow rate was significantly reduced in the control group compared with the case group (P = .02). In the case group, the concentration of volatile sulfur compounds correlated negatively with the salivary flow rate (P = .04) and positively with the tongue coating index (P = .005). The tongue coating index was significantly increased in those patients who did not brush the tongue (P < .04) and who had had episodes of vomiting (P = .02). CONCLUSION: These data suggest that no significant association exists between halitosis and Roux-en-Y gastric bypass. However, they do highlight the possible effect of this surgery on the oral cavity.

Evaluation of IL17A expression and of IL17A, IL17F and IL23R gene polymorphisms in Brazilian individuals with periodontitis.

The IL23/Th17 axis plays an important role in the pathogenesis of cell-mediated tissue damage caused either by autoimmunity or immune responses against bacterial infection. Single nucleotide polymorphisms in the IL17A, IL17F and IL23R genes have been associated with several inflammatory diseases. However, these polymorphisms have not yet been studied in periodontitis. The aim of present study was to evaluate the expression of IL17A and occurrence of the IL17A (rs2275913), IL17F (rs763780) and IL23R (rs11209026) gene polymorphisms in different clinical forms or severity of periodontitis in a sample of Brazilian individuals. Peripheral blood was obtained from 30 non-smoker individuals and analyzed by flow cytometry to determine IL-17 expression. Genomic DNA was obtained from oral swabs in 180 individuals and analyzed by Real-time PCR. The study group was composed by individuals without periodontitis (control), with aggressive periodontitis (AP) and with chronic periodontitis (CP). Higher frequency of IL17A+CD4+ T cells was observed in control group. The A+ genotype from IL17A (rs2275913) was associated with lack of disease. No association was found considering the IL17F and IL23R polymorphisms. Our data suggest that IL17A and the presence of IL17A (rs2275913) A allele are associated with the absence of periodontal disease.

Methylation pattern of IFN-γ and IL-10 genes in periodontal tissues.

UNLABELLED: DNA methylation is characterized by the addition of methyl groups in cytosines within CpG islands. Unmethylated CpGs are related to transcriptionally active structure, whereas methylated CpG recruits methyl-binding proteins that promote chromatin compaction. DNA methylation can influence the expression of cytokines and affect the development of periodontal disease. OBJECTIVES: The purpose of the present study was to evaluate the methylation status of the interferon gamma (IFN-γ) and interleukin-10 (IL-10) genes in periodontal tissues. DESIGN: Methylation-specific polymerase chain reaction (MSP) and DNA sequencing analysis were used to verify the DNA methylation status of the IFN-γ and IL-10 genes, respectively, in samples from subjects without periodontitis and individuals with chronic periodontitis. Histological sections stained by hematoxylin-eosin were used for histopathological evaluation of samples. RESULTS: The methylation status of the IFN-γ and IL-10 genes was similar among the groups. Most of the samples were positive for IFN-γ methylation. Only 11% of the periodontitis group showed unmethylated DNA. Considering the IL-10 gene, no unmethylated sample was observed. The profile of total or partial methylation was detected in CpGs evaluated. CONCLUSIONS: The results showed evidence that methylation of IFN-γ and IL-10 genes is a usual feature on periodontal tissues. Further studies are needed to determine the functional relevance of these alterations.

Prevalence, severity, and risk variables associated with gingival overgrowth in renal transplant subjects treated under tacrolimus or cyclosporin regimens.

BACKGROUND: Some reports suggest that the prevalence and severity of gingival overgrowth (GO) is lower in patients taking tacrolimus (Tcr) than in those taking cyclosporin A (CsA). The present study was conducted to determine the prevalence and severity of GO in a group of renal transplant recipients treated with Tcr in comparison to those treated with CsA and to evaluate the risk variables associated with the development of GO in these two drug regimens. METHODS: A cross-sectional study was conducted in a public hospital in Belo Horizonte City, Brazil. Demographic, pharmacological, and periodontal data were recorded for each subject. Variables from 134 subjects taking Tcr were compared to 451 subjects taking CsA using independent sample t, chi(2) statistic, or Mann-Whitney tests. The effects of potential risk factors on GO severity were determined using forward and backward stepwise regression analysis. RESULTS: Subjects taking CsA showed a higher mean GO score (29.03% +/- 22.9%) compared to subjects taking Tcr (16.9% +/- 3.4%) (P = 0.0038). In the Tcr group, 17.9% of the subjects had clinically significant GO compared to 38.1% in the CsA group (P = 0.045). In the multivariate final model, papillary bleeding index, azathioprine dosage, and concomitant use of calcium channel blockers (CCB) were significant variables associated with severity of GO in Tcr and CsA groups. In addition, previous CsA use also remained significant for GO in subjects under a Tcr regimen. CONCLUSIONS: The prevalence and severity of GO is lower in transplant subjects taking Tcr compared to CsA. GO severity in both groups was strongly associated with the papillary bleeding index, highlighting the role of inflammation in this condition. Concomitant CCB use, azathioprine dosage, and previous CsA use in the Tcr group reinforces the possible synergistic effects of these pharmacological variables on GO severity.