Avaliação do padrão de metilação dos genes CD14 e NFkB e transcrição das DNAs metiltransferases na Periodontite Crônica

• Ano de defesa: 2016
• Autor(a) principal: Simone Angélica de Faria Amormino Carvalho
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; Brasil; Programa de Pós-Graduação em Biologia Celular; UFMG
• Palavras-chave em Português: Periodontite; DNA; DNA metiltransferases (DNMTs); CD14; NFkB; Metiltransferases; Receptores de Lipopolissacarídeos
• Link de acesso: http://hdl.handle.net/1843/65567

DNA methylation is an epigenetic mechanism catalyzed by a family of enzymes called DNA methyltransferases (DNMTs). This event is able to interfere with the expression of several genes involved in immune response and has been related to the pathogenesis of inflammatory diseases, like periodontitis. CD14 is a receptor with high affinity for LPS and this interaction promotes a cascade of intracellular signaling with NFkB activation and consequent expression of pro-inflammatory genes.The objectives of this study were to assess the pattern of methylation and transcription of CD14 and NFkB genes, as well as the transcription of DNMT on chronic periodontitis.The influenceof smoking was evaluated in these events.Gingival tissue samples were collected from 30 individuals with chronic periodontitis and 30 without periodontitis and submitted to histological analysis.The DNA was extracted by the QIAamp DNA Tissue kit Mini Kit and analyzed using the Methyl DNA Methylation qPCR Profiler. For the evaluation of transcription RNA extraction was performed by the method of trizol, followed by conversion to cDNA and further analysis by real-time PCR with specific probes. An unmethylated pattern was observed in all groups. The CD14 transcription was higher in periodontitis compared to control. The unmethylation of NFkB was also a usual event in gingival tissues from individuals with and without periodontitis. Increased transcription of NFkB was observed in the group without periodontitis compared to with periodontitis, considering the non-smokers. There was no difference in transcription of DNMT1 in all evaluated groups. Individuals with chronic periodontitis and smoker presented a higher expression of DNMT3A and DNMT3B than nonsmokers. DNMT3A and B were correlated with severity of periodontal disease.The results showed for the first time a unmethylated patternof the CD14 and NFkB genes as a common event in periodontal tissues. In addition the data suggest that the smoking can interfere in transcription of CD14 and DNMT3A/B. Additional studies are needed to determine the functional relevance of these changes on periodontitis.