Introduction

Juvenile idiopathic arthritis (JIA) is an autoimmune rheumatic disease, which affects primarily the joints in children under 16 years old. The etiology of JIA is yet unknown but research has shown that JIA is a multifactorial disease implicating several genes and environmental factors. Environmental factors affect immune cells via epigenetic mechanisms. One of the most important epigenetic mechanisms is DNA methylation catalyzed by DNA methyltransferases (DNMTs) and usually associated with gene silencing. In this study, we analyzed the expression of three DNA methyltransferases namely DNMT1, DNMT3a and DNMT3b in peripheral blood mononuclear cells (PBMCs) of patients with JIA and compared it with the expression of these genes in healthy young individuals.

Materials and methods

Peripheral blood mononuclear cells of 28 JIA patients and 28 healthy controls were isolated. Total RNA was extracted, cDNA was synthesized and the transcript levels of DNMTs were analyzed by quantitative PCR.

Results

Analysis of DNMT1, DNMT3a and DNMT3b relative gene expression in PBMCs of JIA patients and control individuals shows that the expression of DNMT1 and DNMT3a is reduced significantly by 7 folds and 5.5 folds, respectively, in JIA patients compared to healthy controls. Furthermore, the expression of all three DNMTs were significantly and drastically reduced in young affected males compared to healthy males.

Conclusion

This study shows that the expression of DNMTs is reduced in JIA patients and this reduction is severe in male JIA patients.

中文翻译：

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男性幼年特发性关节炎患者外周血单个核细胞中DNMTs表达显着降低

 介绍

幼年特发性关节炎 (JIA) 是一种自身免疫性风湿性疾病，主要影响 16 岁以下儿童的关节。 JIA 的病因尚不清楚，但研究表明 JIA 是一种多因素疾病，涉及多种基因和环境因素。环境因素通过表观遗传机制影响免疫细胞。最重要的表观遗传机制之一是 DNA 甲基化，由 DNA 甲基转移酶 (DNMT) 催化，通常与基因沉默相关。在这项研究中，我们分析了 JIA 患者外周血单核细胞 (PBMC) 中三种 DNA 甲基转移酶（DNMT1、DNMT3a 和 DNMT3b）的表达，并将其与健康年轻人中这些基因的表达进行比较。

 材料和方法

分离了 28 名 JIA 患者和 28 名健康对照者的外周血单核细胞。提取总RNA，合成cDNA，并通过定量PCR分析DNMT的转录水平。

 结果

对JIA患者和对照个体的PBMC中DNMT1 、 DNMT3a和DNMT3b相对基因表达的分析表明，与健康对照相比，JIA患者中DNMT1和DNMT3a的表达分别显着降低7倍和5.5倍。此外，与健康男性相比，年轻受影响男性中所有三种 DNMT 的表达均显着且急剧降低。

 结论

这项研究表明，JIA 患者中 DNMT 的表达减少，并且这种减少在男性 JIA 患者中更为严重。