Relationship between DNA methylation of glucocort icoid receptor gene promotor and glucocorticoid receptor gene mRNA expression in systemic lupus erythematosus patients / 中华风湿病学杂志

ABSTRACT

Objective To investigate the relatio nship between the DNA methylation status of gluco-corticoid receptor (GR) gene promoter and mRNA expression level of GRα gene of peripheral blood mononuclear cells (PBMCs) in patients with systemic lupus erythematosus (SLE). Methods Fifteen new onset SLE patients and fifteen healthy controls were enrolled in this study. The DNA methylation status of GR gene promoter 1 of PBMCs was detected through bisulfite sequencing polymerase chain reaction (PCR). The mRNA expression of GRα, DNA methyltransferases, growth arrest and DNA damage-induced 45α (GADD45α) of PBMCs was detected using the quantitative real-time polymerase chain reaction method. T-test and χ2-test were used to detect the differences between the two groups, Pearson's correlation coefficient was used to analyze the linear correlation between two variables. Results Compared with healthy controls, the mRNA expression of GRα was signi-ficantly declined in SLE patients (10±5, 17±7, t=2.69, P<0.05), and the mRNA expression of DNMT1 and GADD45α was significantly elevated in SLE patients (t=3.11, P<0.05 and t=2.98, P<0.05). The overall mean methylation status of the 142 CpG islands of the four promoters was significantly elevated in SLE patients [(16±8)%vs (11±6)%, t=2.75, P<0.05]. The global methylation status of PBMCs in SLE patients was obviously lower than healthy controls (t=4.39, P<0.05). Conclusion Hypermethylation of GRα promoter may result in GRαgene low expression in PBMCs of patients with SLE.