miR-9-1 gene methylation and DNMT3B (rs2424913) polymorphism may contribute to periodontitis

Genetic and epigenetic changes have been associated with periodontitis in various genes; however, little is known about genes involved in epigenetic mechanisms and in oxidative stress. Objective: This study aims to investigate the association of polymorphisms C677T in MTHFR (rs1801133) and −149C→T in DNMT3B (rs2424913), as well as the methylation profiles of MTHFR, miR-9-1, miR-9-3, SOD1, and CAT with periodontitis. The association between polymorphisms and DNA methylation profiles was also analyzed. Methodology: The population studied was composed of 100 nonsmokers of both sexes, divided into healthy and periodontitis groups. Genomic DNA was extracted from the epithelial buccal cells, which were collected through a mouthwash. Polymorphism analysis was performed through polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), while methylation-specific PCR (MSP) or combined bisulfite restriction analysis techniques were applied for methylation analysis. Results: For DNMT3B, the T allele and the TT genotype were detected more frequently in the periodontitis group, as well as the methylated profile on the miR-9-1 promoter region. There was also a tendency towards promoter region methylation on the CAT sequence of individuals with periodontal disease. Conclusion: The polymorphism −149C→T in DNMT3B (rs2424913) and the methylated profile of the miR-9-1 promoter region are associated with periodontitis

Genetic polymorphisms of genes involved in oxidative stress and inflammatory management in oncopediatric patients with chemo-induced oral mucositis

Oral mucositis (OM) is a painful inflammatory oral condition that affects children who undergo chemotherapy. Oxidative stress is a known OM mediator and pro-inflammatory cytokines contribute to the amplification of the immune response. Objective: To investigate the possible associations of rs4880 (superoxide dismutase 2, SOD2 47 C/T), rs7943316 (catalase, CAT −21 A/T), rs1800629 (tumor necrosis factor α, TNF- α −308 G/A), and rs1800795 (interleukin 6, IL-6 −174 G/C) polymorphisms with chemo-induced OM occurrence and severity in oncopediatric patients. Methodology: We conducted a single-center, observational cross-sectional study with sample collection of oral epithelial cells from 95 children and adolescents with hematological cancers who underwent chemotherapy, followed by genomic DNA extraction. Single-nucleotide polymorphisms (SNPs) were assessed with PCR-RFLP (Polymerase Chain Reaction-Restriction Fragment Length Polymorphism). Demographic data and information concerning OM occurrence were obtained from dental charts of the multidisciplinary oral care team. Information on OM severity was obtained from appropriately-filled Oral Assessment Guide records. Descriptive and inferential statistics were conducted with Student's T test, chi-squared test, and Fisher's exact test, with p≤0.05. Results: The mean age was 10 years-old and most patients were male individuals (57.89%). Female sex was considered a protective factor for OM occurrence (OR=4.83; CI=[1.14; 16.57]). The AA genotype for CAT was the most frequent amongst individuals with severe OM (p=0.04). The GA genotype for TNF- α was the most frequent amongst individuals without severe OM (p=0.03). For SOD2 and IL-6 , the most frequent genotypes were CT and GG respectively for all groups (p>0.05). Conclusion:The AA genotype for CAT −21 A/T was a tendency among the group with severe OM. Data on TNF- α −308 G/A were inconclusive. No associations were detected for SOD2 47 C/T and IL-6 −174 G/C polymorphisms in oncopediatric patients with chemo-induced oral mucositis

DNMT3B (rs2424913) polymorphism is associated with systemic lupus erythematosus alone and with co-existing periodontitis in a Brazilian population

The association between Periodontitis and Systemic Lupus Erythematosus (SLE) has been primarily based on their similar pathophysiology and both are associated with genetic polymorphisms. Objectives: To investigate an association between the methylation-related gene polymorphisms DNMT3B (rs2424913) and MTHFR (rs1801133) to Systemic Lupus Erythematosus (SLE) and Periodontitis. Methodology: In total, 196 individuals of all genders aged 24 to 60 years old were allocated into four groups based on their systemic and periodontal status, namely: Healthy control (n=60), periodontitis (n=51), SLE (n=47), and SLE + periodontitis (n=38). Individuals with SLE were stratified according to disease activity (SLEDAI) in inactive or active. We performed polymorphism analysis using PCR-RFLP with genomic DNA from mouthwash. We analyzed data using Fisher’s Exact, Chi-square test, and regression models. Results: Periodontal status were similar in subjects with periodontitis alone and combined with SLE. SLE patients with periodontitis had a longer SLE diagnosis than SLE only (p=0.001). For DNMT3 B polymorphism, the periodontitis, SLE, and Inactive SLE + periodontitis groups showed a higher frequency of T allele and TT genotypes compared to healthy controls (p<0.05). Regression analyses showed that the TT genotype is a strong risk factor for periodontitis (OR=4.53; CI95%=1.13–18.05) and also for SLE without periodontitis (OR=11.57; CI95%=3.12–42.84) and SLE with periodontitis (OR=5.27; CI95%=1.25–22.11) when compared to control. Conclusion: SLE patients with periodontitis had a longer length of SLE diagnosis. The DNMT3B (rs2424913) polymorphism was associated with periodontitis and SLE alone or combined with periodontitis. Our study contributes to understanding the genetic mechanisms involved in periodontitis and SLE susceptibility

Frequency of MTHFR G1793A polymorphism in individuals with early coronary artery disease: cross-sectional study

CONTEXT AND OBJECTIVE: Atherosclerotic disease is the leading cause of death in Brazil. It is a complex disease and its prevention involves identification and control of risk factors. Moderately increased plasma homocysteine concentration (hyperhomocysteinemia) has been considered to be a risk factor for several vascular diseases. Mutations in the methylenetetrahydrofolate reductase (MTHFR) enzyme, which is involved in homocysteine metabolism, have been investigated as potential vascular disease risk factors. G1793A polymorphism was described in 2002 and there are few studies analyzing its involvement in diseases. The objective of this study was to investigate the prevalence of G1793A polymorphism in subjects with early coronary artery disease (CAD). DESIGN AND SETTING: Cross-sectional study with control group conducted at a private cardiology clinic and a molecular biology laboratory (Universidade do Vale do Itajaí). METHODS: We studied 74 early-onset CAD+ patients and 40 CAD- individuals with normal angiography results. DNA was extracted from blood samples. Molecular data were obtained via PCR/RFLP and agarose gel electrophoresis. RESULTS: The occurrence of G1793A heterozygotes was similar in the control (5%) and test (6.25%) groups, thus showing that in the population studied there was no correlation between the marker and occurrences of early CAD. There was also no association between the polymorphism and the risk factors for atherosclerosis. CONCLUSIONS: The frequency of the 1793A allele in the test group (3.4%) was similar to what was found in the control individuals (2.5%). There was no correlation between G1793A polymorphism and occurrences of early CAD in this population

The MTHFR C677T polymorphism and global DNA methylation in oral epithelial cells

DNA methylation is mediated by DNA methyltransferases (DNMTs) that add a methyl group to the 5'-carbon of cytosine. The enzyme methylenetetrahydrofolate reductase (MTHFR) catalyzes the reduction of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate in the rate-limiting step of the cycle involving the methyl donor S-adenosyl-L-methionine (SAM). The MTHFR C677T polymorphism results in a thermolabile enzyme with reduced activity that is predicted to influence the DNA methylation status. In this study, we investigated the impact of the MTHFR C677T polymorphism on the global DNA methylation of oral epithelial cells obtained from 54 healthy subjects. There were no significant differences in global DNA methylation among the MTHFR CC, CT and TT genotypes (p = 0.75; Kruskal-Wallis test)