STAT3 expression and its relationship with DNA methylation in patients with systemic lupus erythematosus / 中华皮肤科杂志

ABSTRACT

Objective To investigate DNA methylation status as well as signal transducer and activator of transcription 3 (STAT3) gene expression in peripheral blood T-lymphocytes from patients with systemic lupus erythematosus (SLE),and to explore their relationship.Methods Peripheral blood samples were obtained from 34 patients with SLE and 23 healthy controls followed by the isolation of T-lymphocytes.Flow cytometry was performed to evaluate DNA methylation status using antibodies against 5-methylcytosine (5-me),reverse transcription (RT)-PCR to detect the mRNA expression of STAT3 in T-lymphocytes.Results Compared with healthy controls,17 patients with active SLE showed significantly decreased DNA methylation levels (8.50 ± 1.42 vs.11.31 ± 1.34,P ＜ 0.01),but increased STAT3 mRNA expression levels (1.34 ± 0.32 vs.1.02 ± 0.28,P ＜ 0.01).However,there were no significant differences between 17 patients with stable SLE and healthy controls in DNA methylation levels (11.30 ± 1.34 vs.11.31 ±1.34,P ＞ 0.05) or STAT3 mRNA expression levels (1.01 ± 0.27 vs.1.02 ± 0.28,P ＞ 0.05).Patients with active SLE also showed significantly reduced DNA methylation levels,but enhanced STAT3 mRNA expression compared with those with stable SLE (both P ＜ 0.01).As Pearson correlation analysis showed,SLE disease activity index (SLE-DAI) was negatively correlated with DNA methylation levels in patients with SLE (r =-0.78,P ＜ 0.01),but positively correlated with STAT3 mRNA expression (r =0.50,P ＜ 0.01),and no significant correlation was observed between STAT3 mRNA expression and DNA methylation levels (r =-0.13,P ＞ 0.05).Conclusion The aberrant expression of STAT3 in peripheral blood T-lymphocytes may be related to disease activity in SLE,but unrelated to DNA methylation levels.