Abstract: Objective To investigate the effects of DNA methylation inhibitor azacytidine on the gene expression of Th2 cytokines in peripheral T cells of patients with systemic lupus erythematosus(SLE) and healthy controls. Methods Peripheral blood T cells isolated from patients with active SLE(n=15), patients with inactive SLE(n=13),and healthy control individuals(n=14)were stimulated with PHA for 1 d and then cultured an additional 3 d with or without azacytidine. The expression of IL-4, IL-6, IL-10, and DNA methyltransferase 1(Dnmtl)mRNA were detected by semiquantitative reverse transcription polymerase chain reaction(RT-PCR). Results ①In the absence of azacytidine, the gene expression of IL-4, 6, 10 in T cells of patients with active or inactive SLE was significant higher than that in healthy controls(P<0.05),whereas the gene expression of Dnmtl in T cells of patients with active or inactive SLE was significant lower than that in healthy controls(P<0.05).Meanwhile, there was a significant inverse correlation between the expression of IL-4, 6, 10 genes and that of Dnmtl in T cells of SLE patients(P<0.05).②In the presence of azacytidine, T cells of healthy controls expressed a significant higher level of IL-4, 6, 10(P<0.05),and a significant lower level of Dnmtl(P<0.05).Nevertheless, there were no significant changes in the expression of IL-4, 6, 10, and Dnmtl in T cells of patients with active or inactive SLE before and after the treatment with azacytidine(P > 0.05). Conclusion These results suggest that the loss of DNA methylation may play an important role in the aberrant expression of Th2 cytokines in SLE.

Key words: Lupus erythematosus, systemic, DNA Methylation, Azacytidine, Interleukin-4, Interleukin-6, Interleukin-10