系统性红斑狼疮患者低甲基化DNA活化浆细胞样树突状细胞的研究  

Activation of hypomethylated DNA on plasmacytoid dendritic cells in patients with systemic lupus erythematosus

作　　者：周晶晶[1,2] 汪国生[1] 李向培[1] 厉小梅[1] 钱龙[1] 

机构地区：[1]安徽医科大学附属省立医院风湿免疫科,合肥230001 [2]安徽省六安市第二人民医院神经内科

出　　处：《中华医学杂志》2013年第39期3119-3121,共3页National Medical Journal of China

基　　金：国家自然科学基金（81072462）;安徽省高校省级自然科学研究（KJ2010A188）

摘　　要：目的研究系统性红斑狼疮（SLE）患者低甲基化DNA对浆细胞样树突状细胞（pDC）的活化作用。方法提取SLE患者和正常对照外周血单核细胞（PBMC），抽提基因组DNA，检测DNA甲基化水平；提取总RNA，实时荧光定量PCR检测DNMT1mRNA表达；流式细胞术检测pDC表面CD32分子表达；酶联免疫吸附法（ELISA）检测血清IFN-α浓度。结果SLE患者DNA甲基化水平为（1．4±0．6）％，正常对照组为（1．8±0．7）％，两者比较P〈0．01。SLE患者DNMT1mRNA相对表达量为0．06±0．03，正常对照为0．09±0．02，两者比较P〈0．01。SLE患者pDC表面CD32表达为（29±19）％，正常对照组（18±8）％，两者比较P〈0．01。SLE患者血清IFN-α浓度（4．5±6．7）ng／L，正常对照（2．1±2．0）ng／L，两者比较P〈0．01。SLE患者DNA甲基化水平与DNMT1mRNA表达呈显著正相关（r=0．257，P〈0．05），而与CD32表达（r=-0．358，P〈0．01）、血清IFN-α浓度（r=-0．280，P〈0．05）呈显著负相关。结论SLE患者基因组DNA呈低甲基化状态，可能与DNMTl基因表达下调有关；低甲基化DNA可能由pDC表面内吞受体（CD32）转运至胞内，诱导pDC活化产生大量IFN-α，从而参与SLE的发病。Objective To explore the activation of hypomethylated DNA on plasmacytoid dendritic cells （pDC） in patients with systemic lupus erythematosus （SLE）. Methods Peripheral blood mononuclear cells （ PBMC ） were isolated from whole blood of SLE patients and healthy controls. The methylation level of DNA and the expression of DNA methyhransferase 1 （ DNMT1 ） mRNA were detected. Flow cytometry was used to detect the expression of CD32 on pDC and the serum concentration of interferonalpha （IFN-α） measured by enzyme-linked immunosorbent assay （ELISA）. Results The DNA methylation level from SLE patients （ 1.4 ±0. 6） % was lower than that of controls （ 1.8 ± 0. 7 ） % （ P 〈 0. 01 ）. The expression of DNMT1 mRNA significantly decreased in SLE patients （0. 06 ±0. 03） versus the controls （0.09 ±0.02） （P 〈0.0l）. The CD32 expression on pDC from SLE patients （29 ± 19）% was higher than that from controls （ 18.02 ± 7.80） % （ P 〈 0. 01 ）. The serum level of IFN-ct in SLE patients （4.5 ±6.7） ng/L was significantly higher than that of controls （ 2. 1 ± 2.0 ） ng/L （ P 〈 0.01 ） . The methylation level of DNA in SLE patients was positively correlated with the expression of DNMT1 mRNA （r = 0. 257, P 〈 0. 05 ） and negatively with the expression of CD32 （ r = - 0. 358, P 〈 0. 01 ） and IFN-α （r = - 0. 280, P 〈 0. 05）. Conclusions The methylation level of genomic DNA decreases in SLE patients due to the down-regulated expression of DNMT1 gene. Hypomethylated DNA may be translocated intracellularly via endocytic receptor （ CD32 ） on pDC. And the activation of pDC is induced to produce IFN-c~ so as to participate in the onset of SLE.

关 键 词：红斑狼疮 系统性 DNA甲基化 浆细胞样树突状细胞 干扰素Α 

分 类 号：R593.241[医药卫生—内科学]