Dasatinib, a selective tyrosine kinase inhibitor, prevents joint destruction in rheumatoid arthritis animal model.

AIM: We aimed to evaluate the preventive role of the tyrosine kinase inhibitor dasatinib in an animal model of rheumatoid arthritis (RA). METHODS: DBA/1J mice were injected with bovine type II collagen to induce arthritis (collagen-induced arthritis [CIA]). There were four experimental groups of mice, namely negative control (non-CIA), vehicle-treated CIA, dasatinib-pretreated CIA, and dasatinib-treated CIA. After collagen immunization, arthritis progression in the mice was clinically scored twice weekly for 5 weeks. Flow cytometry was used to evaluate in vitro CD4+ T-cell differentiation and ex vivo mast cell/CD4+ T-cell differentiation. Osteoclast formation was evaluated using tartrate-resistant acid phosphatase (TRAP) staining and by estimating the resorption pit area. RESULTS: We found that the clinical arthritis histological scores were lower in the dasatinib pretreatment group than in the vehicle and dasatinib post-treatment groups. Flow cytometry showed that FcεR1+ cells were downregulated and regulatory T cells were upregulated in splenocytes of the dasatinib pretreatment group compared with those in the vehicle group. Additionally, there was a decline in IL-17+ CD4+ T-cell differentiation and an increase in CD4+ CD24high Foxp3+ T-cell differentiation with in vitro dasatinib treatment of human CD4+ T cells. The number of TRAP+ osteoclasts and the area of the resorption were decreased in the bone marrow cells derived from dasatinib-pretreated mice compared with those derived from vehicle group. CONCLUSION: Dasatinib protected against arthritis in an animal model of RA by regulating the differentiation of regulatory T cells and IL-17+ CD4+ T cells and inhibiting osteoclastogenesis, indicating the therapeutic potential of dasatinib in the treatment of early RA.

Regulation of Th17 Cytokine-Induced Osteoclastogenesis via SKI306X in Rheumatoid Arthritis.

This study aimed to investigate the regulatory effect of SKI305X, a mixed extract of three herbs, in T helper (Th)17 cytokine-induced inflammation and joint destruction in rheumatoid arthritis (RA). Synovial fibroblasts were isolated from RA patients and cultured with Th17 cytokines including interleukin (IL)-17, IL-21, and IL-22 and SKI306X, and tumor necrosis factor (TNF)-, IL-1, and receptor activator of nuclear factor kappa-Β ligand (RANKL) expression and production were investigated using real-time PCR and ELISA of culture media. After peripheral blood (PB) cluster of differentiation (CD)14+ monocytes were cultured in media supplemented with Th17 cytokines and SKI306X, tartrate-resistant acid phosphatase positive (TRAP+) multinucleated giant cells (mature osteoclasts) were enumerated and gene expression associated with osteoclast maturation was assessed via real-time PCR analysis. After PB monocytes were co-cultured with IL-17-stimulated RA synovial fibroblasts in the presence of SKI306, osteoclast differentiation was assessed. When RA synovial fibroblasts were cultured with IL-17, IL-21, and IL-22, TNF-, IL-1, and RANKL expression and production were increased; however, SKI306X reduced cytokine expression and production. When PB monocytes were cultured in media supplemented with Th17 cytokines, osteoclast differentiation was stimulated; however, SKI306X decreased osteoclast differentiation and osteoclast maker expression. When PB monocytes were co-cultured with IL-17-stimulated RA synovial fibroblasts, osteoclast differentiation was increased; however, SKI306X decreased osteoclast differentiation and osteoclast maker expression. SKI306X reduced Th17 cytokine-induced TNF-, IL-1, and RANKL expression and osteoclast differentiation, providing novel insights into adjuvant therapy for regulating inflammation and joint destruction in RA.

Quercetin, a Plant Polyphenol, Has Potential for the Prevention of Bone Destruction in Rheumatoid Arthritis.

We investigated the immune-regulatory function of quercetin, in interleukin (IL)-17-produced osteoclastogenesis in rheumatoid arthritis (RA). RA fibroblasts-like synoviocytes (RA-FLS) were stimulated with IL-17, and the mRNA expression and secretion of receptor activator of nuclear factor kappa-B ligand (RANKL) were detected by real-time polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. CD14+ monocytes (osteoclast precursors) were stimulated with IL-17, RANKL, with/without quercetin, and tartrate-resistant acid phosphatase activity was evaluated to assess osteoclast differentiation. Osteoclast differentiation was investigated after coculturing IL-17-stimulated RA-FLS and Th17 cells with monocytes. CD4+ T cells were cocultured with quercetin under Th17-inducing conditions, and their differentiation to Th17 cells and Treg cells was determined by flow cytometry analysis. We found that IL-17 stimulated RA-FLS to produce RANKL and quercetin decreased the IL-17-induced RANKL protein levels. Quercetin decreased the IL-17-produced activation of mammalian target of rapamycin, extracellular signal-regulated kinase and inhibitor of kappa B-alpha. When monocytes were stimulated with IL-17, macrophage colony-stimulating factor or RANKL, mature osteoclasts were formed, and quercetin decreased this osteoclastogenesis. When monocytes were cultured with IL-17-prestimulated RA-FLS or Th17 cells, osteoclasts were produced, and quercetin decreased this osteoclast differentiation. In Th17-differentiation conditions, quercetin suppressed Th17 cell and the production of IL-17, but quercetin did not affect Treg cells. Quercetin inhibits IL-17-stimulated RANKL production in RA-FLS and IL-17-stimulated osteoclast formation. Quercetin reduces Th17 differentiation. Quercetin could be an additional therapeutic option for bone destructive processes in RA.