A Preliminary Study Of The Role Of NRAGE In Rheumatoid Arthritis

RA is a chronic,systemic,inflammatory autoimmune disease characterised by joint iflammation,synovial hyperplasia,and erosion of bone and cartilage.Its exact cause is unknown,some antirheumatic drugs including immunosuppressive and antiinflammatory drugs can interfere with the disease process clinically,but can not terminate.IL-1 ? and TNF-? antagonists for the treatment of RA has brought a revolutionary change.Unfortunately,only 40%of patients using IL-1 ? and TNF-? antagonists can achieve ACR50 criteria,but for 20-40%of the patients there is no effect.Therefore,explore the pathogenesis of RA and find new regulatory genes and intervention targets is still the urgent problem.As we all know.the external stimulus(eg.cytokines,viral and bacterial proteins,etc.)act on the target cells which must be activated through a specific signaling pathway to cause biochemical reaction.So if we find a key role in these signaling pathways,and clarify its regulatory role in the pathogenesis of RA,it may provide a new approach for the treatment of RA.NRAGE(neurotrophin receptor-interacting MAGE ho mo log)also known as MAGED1 or Dlxin-1,it is a member of MAGE(melanoma antigen)family.The molecule is a multifunctional cytoplasmic scaffolding proteins,located in the nodes of multiple signaling pathways,through different signaling pathways to regulate cell proliferation,apoptosis and inflammation(unpublished date of our laboratory,see in Li hao jie' s paper)and osteoclast differentiation(Our previous study,see in xu li juan' s papers).It is worth noting that as we said before,the most typical pathological feature of rheumatoid arthritis that is chronic inflammation,synovial hyperplasia and destruction of bone and cartilage.Therefore,we proposed:Is NRAGE involved in regulation of the rheumatoid arthritis development?To figure it out,we have established type ?collagen-induced arthritis(type ? collagen-induced arthritis,CIA)rat model,and detected NRAGE expression of CIA rats in RNA and protein levels;we used the NRAGE gene knockout mice to establish collagen antibody induced arthritis mouse model,further confirmed the role of NRAGE in RA.The main contents are as follows:1.Detected the expression of NRAGE in CIA rats;2.Establish collagen antibody induced arthritis mouse model in NRAGE gene knockout mice to clarified the regulation function of NRAGE in rheumatoid arthritis.The major experiments:Part one:Establish collagen induced arthritis rat model to detected the expression of NRAGE in CIA ratsIn this study,we intradermal injected the mixture of collagen type ? and complete Freund's adjuvantto to establish CIA rat model,detected NRAGE expression of CIA rats in RNA and protein level by RT-PCR and immunohistochemical methods.The results showed that,NRAGE express in normal rat synovium,and the expression in the synovium of CIA rats was significantly higher than in normal rats,suggesting that NRAGE may positively regulate the pathogenesis of rheumatoid arthritis.Part two:Used the NRAGE gene knockout mice to establish collagen antibody induced arthritis mouse model to confirmed the role of NRAGE in RAWe used collagen antibody induced arthritis method to establish RA model in wild type and NRAGE knockout mice.Through arthritis index score,p.aw thickness and pathology slice to compare the illness of RA in two genotype mice.It was found that in both of the incidence and severity of RA,knockout mice was significantly lower than wild type mice.This result further defined the positive regulation of NRAGE in RA.The main conclusions:1.NRAGE expression in synovium of rat CIA model,and the expression was significantly higher than in normal rats.2.Appearance and staining tissue sections showed that NRAGE gene knockout reduced the incidence and severity of RA in mouse CAIA model.