ZNRF3 Regulates Collagen-Induced Arthritis Through NF-kB and Wnt Pathways.

Although the E3 ubiquitin ligase Zinc and ring finger 3 (ZNRF3) negatively regulates the Wnt signaling pathway, its function in rheumatoid arthritis (RA) is elusive. Here, the effects and the mechanism of ZNRF3 on a mouse model of collagen-induced arthritis (CIA) and human fibroblast-like synoviocytes (FLS) obtained from RA patients were determined. Our results showed that ZNRF3 was highly expressed in tissues and FLSs compared to trauma patients. Lentivirus-mediated silencing of ZNRF3 induced apoptosis decreased cell viability and significantly attenuated inflammation in RA-FLSs via tumor necrosis-α (TNF-α). Additionally, silencing of ZNRF3 reduced knee joint damage and also decreased the level of TNF-α, IL-1ß, and IL-6 in the CIA mouse model. These effects were mediated by the crosstalk between Wnt and NF-κB pathways in RA-FLS.

Diallyl Trisulfide can induce fibroblast-like synovial apoptosis and has a therapeutic effect on collagen-induced arthritis in mice via blocking NF-κB and Wnt pathways.

BACKGROUND: Diallyl Trisulfide (DATS) is an organosulfur compound extracted from garlic bulb, and exerts cardioprotective, anti-inflammatory, antioxidant, antimicrobial and anticancer effects. But its role in the pathogenesis of rheumatoid arthritis (RA) is unknown. Here we explored the influence of DATS on human fibroblast-like synoviocytes (FLS) isolated from RA patients and a mouse model of collagen-induced arthritis (CIA) and the underlying mechanism. METHODS: RA-FLS were cultured and treated with different concentrations of DATS. The CCK8 assay was used to assess cell proliferation while cell apoptosis was detected by flow cytometry and western blot. The IL-8, IL-6 and IL-1ß levels were determined using RT-qPCR and ELISA assay. The expression of proteins of the NF-κB and Wnt pathways were measured using western blot. Furthermore, the effect of DATS was also explored in vivo using the collagen-induced arthritis mouse model. The Th17/Treg pattern obtain from cells of spleen of collagen-induced arthritis mouse model was detected by flow cytometry. RESULTS: Our results showed that DATS could decrease cell viability and introduce apoptosis in RA-FLS. Furthermore, DATS significantly attenuated the production of key inflammatory cytokines induced by RA-FLS cells following treatment with tumor necrosis α (TNF-α) at a concentration of 100 µM or higher. This was due to its inhibitory effect on the NF-κB and Wnt pathway signaling in RA-FLS. Additionally, DATS decreased the production of inflammatory cytokines and regulated the immune function by restoring the balance between Th17 and Treg in CIA mouse model. CONCLUSIONS: In conclusion, DATS may serve as a potential curative agent for RA.

Dishevelled2 promotes apoptosis and inhibits inflammatory cytokine secretion in rheumatoid arthritis fibroblast-like synoviocytes through crosstalk with the NF-κB pathway.

Dishevelled (Dvl) not only links the canonical Wnt and non-canonical Wnt pathways but can also crosstalk with other pathways. As there is no systematic study to date on Dvl in rheumatoid arthritis (RA), we explored the impact of Dvl2 on proliferation and inflammatory cytokine secretion in RA fibroblast-like synoviocytes (FLSs). Expression of Dvl2 in RA synovial tissue and RA-FLSs was measured. Dvl2 was overexpressed in collagen-induced arthritis rats and human RA-FLSs,. the apoptosis and secretion of inflammatory cytokines were observed. Genetic changes and corresponding mechanisms caused by overexpressing Dvl2 in RA-FLSs were assessed. Dvl2 was found to be overexpressed in RA synovial tissue and RA-FLSs. Overexpression of Dvl2 increased apoptosis and inhibited inflammatory cytokine secretion by RA-FLSs in vivo and in vitro, and Dvl2 inhibited expression of anti-apoptotic and inflammatory genes. One possible mechanism is that Dvl2 decreases the nuclear translocation of P65 and inhibits its ability to bind to the promoters of NF-κB target genes. Our findings reveal an underappreciated role of Dvl2 in regulating inflammation and RA-FLS apoptosis and provide insight into crosstalk between the Wnt and nuclear factor-κB (NF-κB) pathways.

Prevalence of rheumatic symptoms, rheumatoid arthritis, ankylosing spondylitis, and gout in Shanghai, China: a COPCORD study.

OBJECTIVE: To carry out a cross-sectional survey on prevalence of musculoskeletal symptoms, rheumatoid arthritis (RA), ankylosing spondylitis (AS), and gout. METHODS: In Shanghai, 4 communities comprising 7603 inhabitants over 15 years of age in an urban population were randomly selected from 13 communities. Interviews were conducted from September 1997 to March 1998 by trained physicians using the COPCORD Core Questionnaire. Physical and radiographic examinations and serologic tests were carried out when required to classify categories of rheumatic diseases. The diagnoses of RA, systemic lupus erythematosus (SLE), and gout were based on American Rheumatism Association criteria. The diagnosis of AS strictly followed the modified New York criteria of 1984. Crude prevalence rates were standardized according to a standard Chinese population for age and sex structure. RESULTS: A total of 6584 adults (3394 women, 3190 men) were interviewed, and response rate was 86.6%. The age and sex standardized prevalence rate of rheumatic symptoms at any site amounted to 13.3% (95% CI 12.5-14.1%). Symptoms occurred more frequently in the following sites: knee 7.0% (95% CI 6.4-7.6%), lower back 5.6% (95% CI 5.0-6.2%), shoulder 4.7% (95% CI 4.2-5.2%), and neck 2.4% (95% CI 2.0-2.8%). Women complained of rheumatic symptoms more frequently than men. The standardized rates of RA, AS, gout, symptomatic knee osteoarthritis, and soft tissue rheumatism were 0.28% (95% CI 0.15-0.41%), 0.11% (95% CI 0.03-0.19%), 0.22% (95% CI 0.11-0.33%), 4.1% (95% CI 3.6-4.6%), and 3.4% (95% CI 3.0-3.8%), respectively. Two cases of SLE, one case of dermatomyositis, and one case of systemic sclerosis were found. CONCLUSION: Compared with rates in European and Western countries the prevalence rates of RA, AS, and gout are low in Shanghai, China, although the prevalence rates of rheumatic symptoms are high.