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

Aspectos morfologicos da apoptose induzida pelo tamoxifeno em linfocitos humanos cultivados in vitro

Orientadores: Mary Anne Heidi Dolder, Selma Candelaria GenariDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de BiologiaResumo: Alguns fármacos apresentam potencial quimioterápico contra neoplasias, por inibirem a proliferação celular e induzirem a morte celular. Muitos desses agentes podem apresentar efeitos citotóxicos em tecidos normais como linfopenia, devido à indução de apoptose com diminuição das células T CD4, podendo levar a implicações na resposta imune. O tamoxifeno (T AM) é um agente não esteróide antiestrógeno utilizado como quimioterápico coadjuvante no tratamento de câncer de mama. Trabalhos recentes têm demonstrado que o T AM pode causar câncer endometrial em pacientes pós-menopausa, como sério efeito colateral. O presente trabalho objetivou investigar a capacidade do T AM de induzir apoptose em linfócitos humanos cultivados in vitro. Para tanto, amostras de sangue de voluntárias jovens (grupo A= 25 a 30 anos;n=3) e idosas (grupo B= 58 a 77 anos;n=3), foram centrifugadas em gradiente de densidade de Percoll (percoll-50%) para separação de linfócitos e monócitos. Os monócitos foram excluídos por cultura dependente de adesão por 2 horas. O sobrenadante contendo linfócitos controle foram cultivados em meio RPMI suplementado com 10% de soro fetal bovino por 24 e 48 horas, enquanto linfócitos, denominados tratados, receberam 20J.1M de T AM no meio de cultura. Após a cultura, as células foram: 1) contadas em hemocitômetro, sendo estipulado a porcentagem de células viáveis para o total de células analisadas, utilizando-se o método de exclusão pelo Azul Tripan; 2) incubadas com anexina-biotina, que possui alta afinidade pela fosfatidilserina, seguido de incubação com anti-biotina conjugada à fluoresceína, para marcação das células em apoptose e analisadas ao microscópio de fluorescência; 3) fixadas em formaldeído e coradas com Leishman para estudos em microscopia de luz (ML); 4) depositadas em lamínulas, fixadas em glutaraldeído seguido de pós-fixação com tetróxido de ósmio e analisadas ao microscópio eletrônico de varredura (MEV); 5) fixadas em solução de glutaraldeído, ácido pícrico e formaldeído seguido de pós-fixação com tetróxido de ósmio e analisadas ao microscópio eletrônico de transmissão (MET); 6) a análise estatística foi realizada a partir de análise de variância one-way ANOV A com p< 0,05. As culturas tratadas demonstraram menor viabilidade celular e maior índice apoptótico que seus controles. Ainda, culturas controle e tratadas de linfócitos de mulheres idosas apresentaram maior porcentagem de células em apoptose quando comparadas com linfócitos de mulheres jovens. Os estudos em ML e MET revelaram maior condensação cromatínica e redução do volume celular, e ainda, ao MET foram observados vacúolos autofágicos no citoplasma. A MEV revelou células com perda de microvilosidades e perda da morfologia arredondada após 48 horas de tratamento. Conclui-se, então que os linfócitos foram afetados pelo tratamento com o TAM em ambos os grupos, embora o grupo de mulheres idosas se mostrou mais susceptível a apoptoseAbstract: Some drugs have a chemotherapic potential against neoplasms, through inhibition of proliferation and cell death induction. Many of these agents can display cytotoxic effects in normal tissues such as lymphopeny due apoptosis induction with a consequent decrease of T CD4 cells and its implications in the immune response. Tamoxifen is a synthetic non steroidal antiestrogenic drug which is currently being widely employed in the treatment of female breast cancer. Recent studies have shown that TAM can cause endometrial cancer in postmenopausal patients, considered a serious side effect. The purpose of this work was to investigate the capacity of T AM to induce apoptosis in human lymphocytes cultivated in vitro. Samples of peripheral blood were obtained from young (group A= 25-30 years 0Id;n=3) and old (group B= 58-77 years 01d;n=3) women and centrifuged in a Percoll density gradient, to separate lymphocytes and monocytes (percoll-50%). Monocytes were excluded by culturing for 2 hours. The supernatant with control lymphocytes was cultivated in RPMI containing 10% fetal bovine serum, for 24 and 48 h as controls, whereas treated lymphocytes received TAM (20JlM) added to the culture medium. After the culture, the cells were: 1) counted in a hemocytometer, and the viable cell number for each sample was obtained through an exclusion test of intact cells by using 1 % Tripan Blue and establishing the percentage of unstained, alive cells for the total of ressuspended cells; 2) incubated with annexin-biotin, which has high affinity for phosphatidilserine (PS), followed by incubation with FITC conjugated anti-biotin, to target apoptotic cells and examined by fluorescence microscopy; 3) fixed in formaldehyde and stained with Leishman and examined by light microscopy (LM); 4) placed on coverslips, where the cells were fixed, post fixed in osmium tetroxide and examined with the scanning electron microscope (SEM); 5) fixed in in glutaraldehyde, formaldehyde and picric acid, post fixed in osmium tetroxide, and examined in a transmission electron microscope (TEM); 6) statistical analysis was performed using one-way analysis of variance (ANOV A) with p< 0.05. The treated cultures showed less viable cells and more apoptotic cells than control cultures. Moreover, group B showed more apoptotic cells in comparison with group A, in both control and treated cultures. LM and TEM showed treated cells with more condensed chromatin and reduction of cell volume. In TEM some autophagic vacuoles in the cytoplasm were observed. SEM showed loss of microvilli and loss of spherical shape at 48 h, when compared with the controls. Thus, a response to TAM was observed in both groups, although group B was more susceptible to apoptosisMestradoBiologia CelularMestre em Biologia Celular e Estrutura

DNA methylation analysis of the IL8, TLR2 and TLR4 gene promoters in oral mucosa cells and gingival tissue of smokers and non-smokers subjects with chronic periodontitis

Orientador: Ana Paula de Souza PardoTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de PiracicabaResumo: A doença periodontal crônica é caracterizada pela inflamação e destruição dos tecidos periodontais, podendo levar à perda dos dentes. Está claro que a periodontite é influenciada pela genética do hospedeiro, constituição do biofilme bucal e o hábito de fumar. Sabe-se que a interleucina 8 (IL-8) é a principal molécula atrativa de neutrófilos. Essas células são as primeiras a chegar aos locais inflamados e além de realizar fagocitose, participam também da destruição do tecido periodontal. Sabe-se também que os patógenos que causam a periodontite são reconhecidos por proteínas receptoras de membrana denominadas receptores Toll-like (TLR), que uma vez acionados iniciam a resposta imune inata. IL8 e TLRs são expressos constitutivamente por células bucais e estão superexpressos na periodontite. Em particular, a IL-8 está ainda aumentada em indivíduos com periodontite crônica fumantes. A expressão gênica é controlada por diferentes mecanismos, incluindo a metilação de DNA. A metilação em dinucleotídeos CpG presentes em promotores de genes inibe a expressão do gene, podendo silenciar por completo a expressão gênica. Assim, o objetivo deste estudo foi analisar o padrão de metilação no DNA nas regiões promotoras dos genes IL8, TLR2 e TLR4 em células bucais e sanguíneas de indivíduos com periodontite crônica fumantes e não fumantes. Também, analisar os níveis de transcritos destes genes quando encontrado diferença no padrão de metilação entre os grupos, a fim de associar o padrão de metilação com a transcrição gênica. Amostras de DNA foram purificadas de células da mucosa bucal, de tecido gengival e tecido sanguíneo de indivíduos saudáveis e com periodontite crônica fumantes e não fumantes. A metilação no gene IL8 foi investigada pela transformação com bissulfito de sódio seguida pela técnica de PCR Específica para Metilação. A análise de metilação nos genes TLR2 e TLR4 foi realizada utilizando o método de Digestão Enzimática Sensível à Metilação. Após o tratamento pelo bissulfito de sódio (IL8) ou digestão enzimática (TLRs), DNA foi amplificado por PCR, submetido à eletroforese em gel de poliacrilamida 10% corado pelo SYBR Gold. Os níveis de transcritos foram analisados utilizando PCR Quantitativo. A análise estatística foi realizada pelo teste de x2 e Kruskal-Wallis para metilação e expressão gênica, respectivamente. A correlação entre metilação versus expressão foi realizada a partir do teste de coeficiente não linear de Spearman. Os resultados indicam que para células epiteliais da mucosa bucal, a frequência de desmetilação no gene da IL8 é maior no grupo periodontite crônica, independente do hábito de fumar, em comparação ao grupo saudável (p0,05). Para o gene TLR2, não foram detectadas diferenças no padrão de metilação entre os grupos em nenhum tecido estudado (p>0,05). Para o gene TLR4, foi encontrada massiva desmetilação na mucosa bucal e para tecido gengival a desmetilação foi ainda maior, principalmente dentro do grupo periodontite (p=0,03).Abstract: Chronic periodontal disease is characterized by inflammation and destruction of periodontal tissues, culminating in teeth loss. It is clear that periodontitis is influenced by host genetic, biofilm, and smoking habit. There are some important molecules involved on the pathogenesis of periodontitis. Interleukin (IL-8) is responsible for inducing chemotaxis, which is the directed migration of neutrophil to a site of inflammation. Neutrophil contributes to the elimination of the infecting bacteria and tissue destruction. Infecting bacteria are recognized by transmembrane receptors called Toll-like receptors (TLR), which recognized molecular pattern of microorganisms. The recognition of a variety of microorganisms components by individual TLRs induces innate immune responses. IL8 and TLRs are constitutively expressed by buccal cells and they are upregulated during periodontitis. Genetic transcription is regulated by different pathways, including DNA methylation. Methylation in CpG dinucleotides of gene promoters downregulates the levels of transcription and may even silence the gene transcription completely. So, the objective of this study was to analyze the pattern of DNA methylation in the promoter region of IL8, TLR2 and TLR4 genes in oral cells and blood tissue from healthy subjects and subjects with chronic periodontitis smokers and non-smokers. We also investigated the levels of mRNA expressed when different methylation status were found amoung groups. DNA samples were purified from buccal mucosa, gingival tissue and blood tissue of healthy subjects and subjects with chronic periodontitis smokers and non-smokers. Methylation of IL8 gene was investigated using sodium bisulphite modification followed by Methylation Specific PCR. Methylation analysis of TLRs genes were performed using Specific Methylation-Sensitive Restriction Enzymes. After sodium bisulphate modification (IL8) or enzymatic digestion (TLR2 and TLR4), DNA was amplified by PCR and the results were visualized after electrophoresis on 10% polyacrylamide gels stained by SYBR Gold. Levels of mRNA were analised using Real Time PCR. The statistical analysis was performed using the test of x2 and Kruskal-Wallis test for methylation status and gene expression, respectively. The correlation among methylation status versus gene expression was performed using no linear coefficient test of Spearman. The results indicate that frequency of IL8 gene demethylation is higher in individuals with chronic periodontitis, independent of smoking habit, than healthy group (p0.05). TLR4 gene promoter showed massive demethylation in oral mucosa and for gingival tissue it was even higher, mainly in periodontitis group (p=0.03).DoutoradoHistologia e EmbriologiaDoutor em Biologia Buco-Denta

Cell death induced by tamoxifen in human blood lymphocytes cultivated in vitro = Morte celular induzida pelo tamoxifeno em linfócitos humanos cultivados in vitro

Many chemotherapeutic agents with a potential against solid tumors or leukemia can cause lymphopenia. Tamoxifen (TAM) is a synthetic non-steroidal anti-estrogen drug employed in female breast cancer treatment. The present study investigated the capacity of TAM to induce cell death in human lymphocytes cultivated in vitro. Lymphocytes were obtained from young (25-30 years; n = 3) and elderly women (58-77 years; n = 3) and cultivated for 24 or 48h, with or without TAM (20 ƒÊM). After the culture, cell viability, immunocytochemical response and ultrastructure were evaluated. TAM affected lymphocytes in a time- dependent manner, and cells obtained from elderly women were the most sensitive to TAM. Immunocytochemicalanalysis evidenced higher frequency of apoptosis in treated cells, and the ultrastructural study revealed autophagic vacuoles, differing from the controls. In summary, the treated lymphocytes were affected by TAM, leading to cell death by apoptosis and autophagy.<br><br>Muitos agentes quimioterapicos com potencial contra tumores solidos ou leucemias podem causar linfopenia. O Tamoxifeno (TAM) e um agente antiestrogeno nao-esteroidal empregado no tratamento de cancer de mama feminino. O presente trabalho investigou a capacidade do TAM em induzir morte celular em linfocitos humanos cultivados in vitro. Oslinfocitos foram obtidos de mulheres jovens (25-30 anos; n = 3) e idosas (58-77 anos; n = 3) e cultivados por 24 ou 48h, com ou sem TAM (20 ƒÊM). Apos a cultura, foram analisadas a viabilidade celular, a resposta imunocitoquimica e a ultraestrutura. Os resultados indicam que o Tamoxifeno induziu morte celular em linfocitos de ambos os grupos, entretanto, as celulas das mulheres idosas apresentaram-se mais sensiveis ao tratamento. A analise imunocitoquimica mostrou maior frequencia de apoptose nas celulas tratadas e o estudo ultraestrutural revelou vacuolos autofagicos nos linfocitos expostos ao Tamoxifeno. Em conclusao, nosso estudo revelou que o TAM induziu morte celular por apoptose e autofagia

Cell death induced by tamoxifen in human blood lymphocytes cultivated in vitro - doi: 10.4025/actascibiolsci.v32i4.7015

Many chemotherapeutic agents with a potential against solid tumors or leukemia can cause lymphopenia. Tamoxifen (TAM) is a synthetic non-steroidal anti-estrogen drug employed in female breast cancer treatment. The present study investigated the capacity of TAM to induce cell death in human lymphocytes cultivated in vitro. Lymphocytes were obtained from young (25-30 years; n = 3) and elderly women (58-77 years; n = 3) and cultivated for 24 or 48h, with or without TAM (20 µM). After the culture, cell viability, immunocytochemical response and ultrastructure were evaluated. TAM affected lymphocytes in a time- dependent manner, and cells obtained from elderly women were the most sensitive to TAM. Immunocytochemical analysis evidenced higher frequency of apoptosis in treated cells, and the ultrastructural study revealed autophagic vacuoles, differing from the controls. In summary, the treated lymphocytes were affected by TAM, leading to cell death by apoptosis and autophagy