Research Unit in Systemic Autoimmune Diseases, Vall d'Hebron Research Institute, Hospital Vall d'Hebron, Universitat Autónoma de Barcelona, Barcelona, Spain.
PLoS One. 2012;7(9):e45897. doi: 10.1371/journal.pone.0045897. Epub 2012 Sep 21.
We determined the expression of ITGAL, PRF1, KIR2DL4, CD70, and CD40LG in patients with SLE and performed correlations with the global DNA methylation status and the levels of three DNA methylation enzymes and two methyl CpG-binding domain (MBD) proteins.
CD4(+) T cells were isolated from 35 SLE patients and 30 healthy controls. DNA deoxymethylcytosine content was measured by an enzyme-linked immunosorbent assay (ELISA). Transcript levels of ITGAL, PRF1, KIR2DL4, CD70, CD40LG, DNMT1, DNMT3A, DNMT3B, MBD2, and MBD4 were quantified by real-time reverse-transcription polymerase chain reaction (RT-PCR).
SLE patients had significantly elevated transcript levels of ITGAL (18.61±22.17 vs. 7.33±9.17, p = 0.042), PRF1 (21.67±26.34 vs. 10.67±11.65, p = 0.039), and CD70 (1.45±1.63 vs. 0.67±0.28, p = 0.011). A positive correlation was observed between transcript levels of CD40LG and ITGAL (r = 0.477, p = 0.004) as well as between CD40LG and PRF1 (r = 0.557, p = 0.001). Transcript levels of KIR2DL4 were higher than controls' but it did not reach statistical significance (1.36±3.52 vs. 0.22±0.79, p = 0.560). A tight relationship with global DNA hypomethylation as well as with the expression of most of the DNA methylation-related genes was observed, especially for ITGAL, PRF1, and CD40LG.
ITGAL, PRF1, and CD70 are overexpressed in SLE CD4(+) T cells. The tight association of CD40LG with ITGAL and PRF1 leads us to infer that it probably contributes to the pathogenesis of the disease. The apparent simultaneous regulation between their expression and the global DNA hypomethylation as well as with the transcription of many DNA methylation-related enzymes, reinforces the idea that epigenetic mechanisms are responsible for the deregulation of ITGAL, PRF1, and CD40LG.
我们测定了 SLE 患者中 ITGAL、PRF1、KIR2DL4、CD70 和 CD40LG 的表达情况，并与全基因组 DNA 甲基化状态以及 3 种 DNA 甲基化酶和 2 种甲基 CpG 结合域（MBD）蛋白的水平进行了相关性分析。
从 35 例 SLE 患者和 30 例健康对照者中分离 CD4(+)T 细胞。采用酶联免疫吸附试验（ELISA）测定脱氧胞嘧啶含量。采用实时逆转录聚合酶链反应（RT-PCR）定量测定 ITGAL、PRF1、KIR2DL4、CD70、CD40LG、DNMT1、DNMT3A、DNMT3B、MBD2 和 MBD4 的转录水平。
SLE 患者的 ITGAL（18.61±22.17 与 7.33±9.17，p=0.042）、PRF1（21.67±26.34 与 10.67±11.65，p=0.039）和 CD70（1.45±1.63 与 0.67±0.28，p=0.011）的转录水平显著升高。CD40LG 的转录水平与 ITGAL（r=0.477，p=0.004）以及 CD40LG 与 PRF1（r=0.557，p=0.001）之间存在正相关。KIR2DL4 的转录水平高于对照组，但无统计学意义（1.36±3.52 与 0.22±0.79，p=0.560）。结果还发现 CD40LG 与全基因组低甲基化以及大多数 DNA 甲基化相关基因的表达之间存在紧密的关系，特别是与 ITGAL、PRF1 和 CD70。
SLE CD4(+)T 细胞中 ITGAL、PRF1 和 CD70 表达过度。CD40LG 与 ITGAL 和 PRF1 的紧密关联使我们推断其可能有助于疾病的发病机制。它们的表达与全基因组低甲基化以及许多 DNA 甲基化相关酶的转录之间的明显的同步调控，进一步证实了表观遗传机制负责 ITGAL、PRF1 和 CD40LG 的失调。
