目的:通过检测外周血肿瘤坏死因子样凋亡弱诱导剂(tumor necrosis factor-like weak inducer of apoptosis,TWEAK)基因DNA甲基化水平、mRNA表达水平及血清蛋白浓度,探究TWEAK基因与类风湿关节炎(rheumatoid arthritis,RA)发病机制的关联。方法:采用MassARRAY法检测112例RA患者和86例匹配的健康志愿者外周血TWEAK基因DNA甲基化水平,采用实时荧光定量PCR法检测外周血TWEAK基因mRNA表达水平,采用酶联免疫吸附测定法检测血清TWEAK蛋白浓度。比较RA组和健康对照组TWEAK基因DNA甲基化水平、mRNA表达水平及血清蛋白浓度,并分析其与疾病活动度的关系。结果:RA组TWEAK基因总体甲基化水平和CpG_11、CpG_17.18.19.20、CpG_40.41.42位点甲基化水平高于健康对照组(P=0.002,P=0.01,P=0.006,P=0.002),高疾病活动度组CpG_55.56位点甲基化水平高于中低疾病活动度组(P=0.041)。RA组外周血TWEAK基因mRNA表达水平低于健康对照组(P=0.023),高疾病活动度组TWEAK基因mRNA表达水平低于中低疾病活动度组(P=0.035)。RA组血清TWEAK蛋白浓度与健康对照组差异无统计学意义(P=0.508), 但其与mRNA表达水平呈正相关(r=0.482,P<0.001)。结论:TWEAK基因与RA的发病和病情活动程度密切相关,其高甲基化状态可能为调控mRNA低表达的表观遗传学机制之一,可作为临床监测和评价RA病情的重要指标之一。

Objective: To explore the relationship between tumor necrosis factor like weak inducer of apoptosis (TWEAK) gene and the pathogenesis of rheumatoid arthritis (RA) by detecting the DNA methylation level, mRNA expression level and serum protein concentration of TWEAK gene in peripheral blood. Methods: The MassARRAY method was used to detect the DNA methylation level of the TWEAK gene in the peripheral blood of 112 RA patients and 86 matched healthy volunteers. The real-time quantitative polymerase chain reaction method was used to detect the mRNA expression level of the TWEAK gene in the peripheral blood of the subjects. The enzyme-linked immunosorbent assay method was used to detect the serum TWEAK protein concentration of the subjects. The TWEAK gene DNA methylation level, mRNA expression level and serum protein concentration between the RA group and the healthy control group were compared, and the relationship between it and the degree of disease activity analyzed. Results: The overall DNA methylation level of TWEAK gene and the DNA methylation levels of CpG_11, CpG_17.18.19.20, CpG_40.41.42 site in the RA group were higher than those in the healthy control group (P=0.002, P=0.01, P=0.006, P=0.002, respectively). The DNA methylation level of CpG_55.56 site in the high disease activity group was higher than that in the medium and low disease activity group (P=0.041). The expression level of TWEAK gene mRNA in the peripheral blood of the RA group was lower than that of the healthy control group (P=0.023). The expression level of TWEAK gene mRNA in the high disease activity group was lower than that in the medium and low disease activity group (P=0.035). The serum TWEAK protein concentration of the RA group was not significantly different from that of the healthy control group (P=0.508), but it was positively correlated with the mRNA expression level (r=0.482, P<0.001). Conclusion: The TWEAK gene is closely related to the onset and progression of RA, and its hypermethylation state may be one of the epigenetic mechanisms regulating its low mRNA expression, and it can be used as one of the important indicators for clinical monitoring and evaluation of RA.