Laboratory of Molecular Biology, Department of Oral Surgery and Pathology, School of Dentistry, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
Immunobiology. 2011 Aug;216(8):936-41. doi: 10.1016/j.imbio.2011.01.006. Epub 2011 Jan 12.
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.
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.
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.
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.
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.
DNA 甲基化的特征是在 CpG 岛中的胞嘧啶内添加甲基基团。未甲基化的 CpG 与转录活跃的结构有关，而甲基化的 CpG 募集甲基结合蛋白，促进染色质紧缩。DNA 甲基化可以影响细胞因子的表达，并影响牙周病的发展。
本研究旨在评估干扰素 γ（IFN-γ）和白细胞介素 10（IL-10）基因在牙周组织中的甲基化状态。
分别使用甲基化特异性聚合酶链反应（MSP）和 DNA 测序分析来验证无牙周炎受试者和慢性牙周炎患者样本中 IFN-γ 和 IL-10 基因的 DNA 甲基化状态。苏木精-伊红染色的组织学切片用于样本的组织病理学评估。
IFN-γ 和 IL-10 基因的甲基化状态在各组之间相似。大多数样本的 IFN-γ 甲基化呈阳性。只有 11%的牙周炎组显示未甲基化 DNA。考虑到 IL-10 基因，未观察到未甲基化的样本。在评估的 CpG 中检测到总或部分甲基化的图谱。
结果表明 IFN-γ 和 IL-10 基因的甲基化是牙周组织的常见特征。需要进一步研究来确定这些改变的功能相关性。
