Kolahi Sousan, Rashtchizadeh Nadereh, Mahdavi Aida Malek, Farhadi Jafar, Khabbazi Alireza, Sakhinia Ebrahim, Bahavarnia Neda, Farajzadeh Polsangi Mohammad Jahed, Babaloo Zohreh, Estiar Mehrdad A
Connective Tissue Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
Division of Regenerative Medicine, School of Medicine, Faculty of Medical and Human Sciences, University of Manchester, Manchester, UK.
J Gene Med. 2020 Oct;22(10):e3234. doi: 10.1002/jgm.3234. Epub 2020 Jun 12.
Altered innate immune function plays an important role in the initiation of inflammatory response in Behcet's disease (BD). Toll-like receptors (TLRs) are the master regulators of the innate immune system. Because the role of TLRs remains unknown in the pathogenesis of BD, the present study aimed to evaluate the expression levels and methylation status of the TLR2 and TLR4 promoters in patients with BD.
In the present study, Iranian Azeri BD patients (n = 47) with an active (n = 22) and inactive (n = 25) period, and healthy controls (n = 61), were matched according to age, sex and ethnicity. TLR2 and TLR4 genes promoter CpG islands were predicted with the Eukaryotic Promoter Database (https://epd.vital-it.ch). Methylated DNA immunoprecipitation (MeDIP) was conducted.
The results showed that mRNA of TLR4 was significantly increased in the peripheral blood mononuclear cells (PBMCs) of BD patients with an active phase compared to the control group. Differences in mRNA of TLR4 between the inactive BD and control groups were not significant. Differences in TLR2 mRNA levels in the PBMCs of the active and inactive phase BD and control groups were not significant. The methylation rate of TLR4 gene promoter was significantly lower in the active and inactive BD groups compared to the control group. The difference between the active and inactive BD groups was not significant. There was no significant difference in the methylation rates of the TLR2 gene between studied groups.
Our preliminary findings suggest that the hypomethylation of TLR4 gene may be involved in the pathogenesis of BD via increasing TLR4 expression.
先天性免疫功能改变在白塞病（BD）炎症反应的启动中起重要作用。Toll样受体（TLR）是先天性免疫系统的主要调节因子。由于TLR在BD发病机制中的作用尚不清楚，本研究旨在评估BD患者中TLR2和TLR4启动子的表达水平和甲基化状态。
在本研究中，根据年龄、性别和种族匹配了处于活动期（n = 22）和非活动期（n = 25）的伊朗阿塞拜疆BD患者（n = 47）以及健康对照者（n = 61）。使用真核生物启动子数据库（https://epd.vital-it.ch）预测TLR2和TLR4基因启动子的CpG岛。进行甲基化DNA免疫沉淀（MeDIP）。
结果显示，与对照组相比，处于活动期的BD患者外周血单核细胞（PBMC）中TLR4的mRNA显著增加。非活动期BD组与对照组之间TLR4的mRNA差异不显著。活动期和非活动期BD组以及对照组的PBMC中TLR2 mRNA水平差异不显著。与对照组相比，活动期和非活动期BD组中TLR4基因启动子的甲基化率显著降低。活动期和非活动期BD组之间的差异不显著。研究组之间TLR2基因的甲基化率没有显著差异。
我们的初步研究结果表明，TLR4基因的低甲基化可能通过增加TLR4表达参与BD的发病机制。
