Study On Therapeutic Effects And Mechanisms Of Tripterygium Glycosides In Rheumatoid Arthritis By Regulating TRAF6

Objective To investigate whether Tripterygium glycosides(TG)regulate the expressing of(tumor necrosis factor receptor-associated factor 6,TRAF6),Inhibit the pathway activation of nuclear factor κB(NF-κB)and Mitogen activated protein kinase(MAPK),In turn,inhibit the inflammatory reaction and play a role in treating rheumatoid arthritis(RA).Methods 1.In vitro,fibroblast-like synoviocyte(FLS)cell line was treated with IL-1β to induce an inflammation model and then incubated with or without TG.The proliferation of FLS cells was detected by cell counting kit-8(CCK8);the release of inflammatory cytokines in FLS was detected by enzyme-linked immunosorbent assay(ELISA);The FLS cell apoptosis was detected by flow cytometry(FCM);The expression changes of TRAF6 and NF-κB and MAPK pathway key proteins(p-p65,p-IKBα,p-p38 and p-ERK)in FLS after TG treatment were detected by western blot(WB).The mechanism of TG alleviating inflammation in RA was explored from the cellular level.2.In vivo,collagen-induced arthritis(CIA)rat model was established,and TG was administered by gavage.Rthritis index(AI)and toe volume in CIA rats were used to evaluate the therapeutic effect of TG on CIA rat.The levels of inflammatory cytokines in synovial fluid and the expression levels of key proteins of TRAF6,NF-κB pathway and MAPK pathway in synovial tissue were detected by ELISA and WB respectively.In order to verify the mechanism of TG alleviating inflammation in vivo.Results 1.Compared with the control group,TG treatment could significant suppress FLS activity in a dose-dependent manner,and after 48 hours of 50ng/ml TG treatment,the survival of FLS was significantly inhibited.Compared with the module group,ELISA results showed that TG could significantly inhibits the express level of inflammatory cytokines such as IL-6,IL-17 and TNF-α in IL-1β treated FLS cells;CCK8 and FCM results showed that TG promotes the apoptosis of FLS and inhibits the proliferation of FLS;WB experiment results showed that TG inhibits the expression of TRAF6 in both transcription and protein level in FLS,and also inhibits the phosphorylation levels of p65,IKBα,p38 and ERK.2.Compared with the vehicle-treated control group,TG significantly reduces AI socre and toe volume in CIA rats;it inhibits the release of inflammatory cytokines such as IL-1β,IL-6,IL-17 and TNF-α in synovial fluid;it increases the activity of capspase3 in synovial tissue and promotes apoptosis of synovial cells;it inhibits the expression of TRAF6 in synovial tissue,and then inhibits the activation of NF-κB and MAPK pathways.Conclusion TG inhibits the inflammatory response in FLS cells induced by IL-β and inhibits the arthritis development in a CIA rat model significantly.Mechanistic studies have shown that TG inhibits the expression of TRAF6 and inhibits the activation of downstream NF-κB and MAPK signaling pathways,thereby inhibits the sustained release of inflammatory cytokines.In addition,TG treatment promotes the apoptosis of FLS cells and inhibits the proliferation of FLS.Taken together,TG playes an important role in inhibiting the progression of RA.