Exogenous IFN-beta regulates the RANKL-c-Fos-IFN-beta signaling pathway in the collagen antibody-induced arthritis model

Rong Zhao, Ni-Nan Chen, Xiao-Wei Zhou, Ping Miao, Chao-Ying Hu, Liu Qian, Qi-Wen Yu, Ji-Ying Zhang, Hong Nie, Xue-hua Chen, Pu Li, Rong Xu, Lian-Bo Xiao, Xin Zhang, Jian-Ren Liu, Dong-Qing Zhang

BackgroundAlthough a variety of drugs have been used to treat the symptoms of rheumatoid arthritis (RA), none of them are able to cure the disease. Interferon ß (IFN-ß) has pleiotropic effects on RA, but whether it can be used to treat RA remains globally controversial. Thus, in this study we tested the effects of IFN-ß on RA patients and on collagen antibody-induced arthritis (CAIA) model mice.MethodsThe cytokine and auto-antibody expression profiles in the serum and synovial fluid (SF) from RA patients were assessed using enzyme-linked immunosorbent assay (ELISA) and compared with the results from osteoarthritis (OA) patients. Exogenous IFN-ß was administered to RA patients and CAIA model mice, and the therapeutic effects were evaluated. Endogenous IFN-ß expression in the joint bones of CAIA model mice was evaluated by quantitative real-time PCR (qRT-PCR). The effects of exogenous IFN-ß on CAIA model mice were assessed using a clinical scoring system, hematoxylin eosin and safranin-O with fast green counterstain histology, molybdenum target X-ray, and tartrate-resistant acid phosphatase (TRAP) staining. The RANKL-RANK signaling pathway was analyzed using qRT-PCR. The RAW 264.7 cell line was differentiated into osteoclasts with RANKL stimulation and then treated with exogenous IFN-ß.ResultsThe expression of inflammatory cytokines (IFN-¿, IL-17, MMP-3, and RANKL) and auto-antibodies (CII antibodies, RF-IgM, and anti-CCP/GPI) were significantly higher in RA compared with OA patients. After IFN-ß intervention, some clinical symptoms in RA patients were partially alleviated, and the expression of IFN-¿, IL-17, MMP-3, and OPG) returned to normal levels. In the CAIA model, the expression of endogenous IFN-ß in the joint bones was decreased. After IFN-ß administration, the arthritis scores were decreased; synovial inflammation, cartilage, and bone destruction were clearly attenuated; and the expression of c-Fos and NFATc1 were reduced, while RANKL and TRAF6 expression was unchanged. In addition, exogenous IFN-ß directly inhibited RANKL-induced osteoclastogenesis.ConclusionsExogenous IFN-ß administration immunomodulates CAIA, may reduce joint inflammation and, perhaps more importantly, bone destruction by inhibiting the RANKL-c-Fos signaling pathway. Exogenous IFN-ß intervention should be selectively used on RA patients because it may only be useful for RA patients with low endogenous IFN-ß expression.