A novel NF-κB inhibitor, DHMEQ, ameliorates pristane-induced lupus in mice

Nuclear factor (NF)-κB is strongly associated with the development of immune regulation and inflammation. The aim of the present study was to identify whether a NF-κB inhibitor, dehydroxymethylepoxyquinomicin (DHMEQ), ameliorates systemic lupus erythematosus (SLE) in a pristane-induced mouse model. SLE was induced in 8-week-old female BALB/c mice by the injection of 0.5 ml pristane. The therapeutic effect of 12 mg/kg DHMEQ on the pristane-induced BALB/c mouse model of lupus was investigated to elucidate the effects on SLE. The intraperitoneal administration of DHMEQ three times per week was initiated when the mice were 16 weeks-old (8 weeks following the pristane injection) and the treatment was continued for 16 weeks. Serum IgG autoantibodies against nucleosomes, dsDNA and histones were detected at weeks 8, 16 and 32. In addition, the expression levels of interleukin (IL)-1β, 6 and 17, as well as tumor necrosis factor (TNF)-α, were analyzed at week 32. Renal lesions were also observed. DHMEQ was shown to antagonize the increasing levels of anti-nucleosome, anti-dsDNA and anti-histone autoantibodies, as well as the increasing levels of IL-1β, 6 and 17 and TNF-α. In addition, DHMEQ reduced the number of renal lesions caused by pristane, as reflected by milder proteinuria and reduced renal pathology. The renal expression levels of phosphorylated-p38 mitogen-activated protein kinase (MAPK), phosphorylated-c-Jun N-terminal kinase (JNK) and NF-κB p65 were significantly downregulated. Therefore, the results of the present study indicate that DHMEQ has a beneficial effect on pristane-induced lupus through regulating cytokine levels and the MAPK/JNK/NF-κB signaling pathway.