Effects of Cystamine on antioxidant activities and regulatory T cells in lupus-prone mice

Attenuated antioxidant activities, irregular cytokines expressions and reduced regulatory T cells, are strongly associated with the pathogenesis of systemic lupus erythematosus (SLE). Despite the well-established beneficial effects of cystamine on lupus-prone mice, the extent to which cystamine contributes to antioxidant activity and the reduction of regulatory T cells has seldom been investigated. Therefore, this study elucidates how cystamine affects anti-oxidant activities in NZB/W F1 mice by performing assays of Glutathione (GSH), 1,1-diphenyl-2- picryl-hydrazyl (DPPH) and malondialdehyde thiobarbituric acid (MDA). In addition, investigations of the effects of cystamine on CD4(+)/CD25(+) regulatory T cells and interleukin-6 (IL6)/STAT-3 signalling were performed with flow cytometry and immunoblots. Experimental results reveal more significantly reduced MDA and increased GSH and DPPH in NZB/W F1 mice receiving cystamine than in those mice receiving PBS. Meanwhile, CD4(+)/CD25(+) regulatory T cells more significantly increase in NZB/W F1 mice receiving cystamine than in those mice receiving PBS, accompanied by significantly reduced IL-6/phosphorylated STAT-3 expression. The above findings suggest the beneficial effects of cystamine in terms of increasing antioxidant activities and CD4(+)/CD25(+) regulatory T cells in lupus-prone mice by suppressing IL-6/STAT3 signalling.