Abrogation of skin disease in lupus-prone MRL/Fas^lpr mice by means of a novel tylophorine analog

Objective. To test the therapeutic effect of DCB-3503, a synthetic compound derived from a natural product that inhibits NF-κB, on end-organ disease in the MRL-Fas^lpr murine model of systemic lupus erythematosus (SLE). Methods. Eight-week-old female MRI/Fas^lpr mice were treated intraperitoneally with a low (2 mg/kg) or high (6 mg/kg) dose of DCB-3503 for 10 weeks. Control groups were administered vehicle treatment alone (negative control) or 25 mg/kg cyclopliosphamide (positive control). Mice were bled before (8 weeks) and during (13 weeks) treatment, and when they were killed (20 weeks), and serum samples were analyzed for total IgM and IgG levels and autoantibody titers. When the mice were killed, spleen and lymph nodes (axillary, brachial, and cervical) were examined by flow cytometric analysis. The presence of skin and renal disease was determined by histopathologic analysis. Results. DCB-3503 reduced anti-double-stranded DNA and antichromatin autoantibodies and nearly abrogated inflammatory skin disease in MRL/Fas ^lpr mice; however, it had little effect on histologic kidney disease. Treated mice did not have hematologic or hepatic toxicity. These data indicate that end-organ disease in MRL/Fas^lpr mice responds differentially to NF-κB inhibitor. Conclusion. DCB-3503 causes significant abrogation of skin disease in MHL/Fas^lpr mice and may potentially be beneficial in the treatment of inflammatory skin disease in SLE.