ABSTRACT
Objective To investigate the mRNA expression of toll like receptor-9 (TLR9) and interferon regulatory factors-5 (IRF5) of AS2O3 on peripheral blood mononuclear cells (PBMCs) in systemic lupus erythematosus (SLE) patients.Methods PBMCs of 15 SLE patients and 15 healthy subjects were treated with different concentrations of AS2O3 and cyclophosphamide (CTX) in vitro.Real-time quantitative polymerase chain reaction was used to amplify TLR9 and IRF5 gene before and after 12 and 24 hours drug intervention and the mRNA expressions were measured.Differences between groups were analyzed by paired t test or variance analysis.Results The mRNA expression levels of TLR9 [12 h(1.38±0.26) and 24 h (1.28±0.35)] on PBMCs in SLE patients were significantly higher than those in healthy controls [12 h(1.05±0.35) and 24 h (0.97±0.19)](t=2.37,P=0.03; t=2.44,P=0.02).The IRF5 mRNA expression levels [12 h (0.95±0.27) and 24 h (0.91 ±0.35)] in SLE patients were obviously higher than those in healthy controls [12 h (0.62 ±0.23) and 24 h (0.60±0.39)] (t =3.07,P=0.01 ; t =3.45,P＜0.01).AS2O3 could suppress the mRNA expression of TLR9 on PBMCs and the effect was gradually increasing with the increasing concentration of AS2O3 and processing time [0.2 mg/L AS2O3 group 12 h (0.430±0.110) and 24 h(0.290±0.050),0.4 mg/L AS2O3 group 12 h (0.170±0.038) and 24 h (0.090±0.017),0.8 mg/L AS2O3 group 12 h (0.023±0.011) and 24 h (0.003±0.001)].Comparing with CTX [12 h (0.814±0.081) and 24 h(0.755±0.139)],AS2O3 had a more significant strong effect on inhibiting the expression of TLR9 mRNA in SLE patients [F=165.32(12 h),P＜0.01; F=99.20 (24 h),P＜0.01].The mRNA expression of IRF5 on PBMCs was not suppressed by AS2O3 and CTX and there was no statistically significant difference between groups (P＞0.05).Conclusion There is abnormal expression of IRF5 and TLR9 mRNA in SLE patients.AS2O3 may suppress the TLR9 mRNA expression in SLE patients,which may be one mechanism of clinical effectiveness.