Regulation of B cell activating factor (BAFF) receptor expression by NF-kappaB signaling in rheumatoid arthritis B cells

B cells play an important role in the pathogenesis of rheumatoid arthritis (RA). High levels of B cell activating factor (BAFF) are detected in autoimmune diseases. BAFF and BAFF receptor (BAFF-R) are expressed in B and T cells of RA synovium. The study was undertaken to identify the NF-kappaB signal pathway involved in the induction of BAFF-R in human B cells. Immunohistochemical staining of NF-kappaB p65, NF-kappaB p50, BAFF, and BAFF-R was performed on sections of synovium from severe and mild RA and osteoarthritis (OA) patients. Peripheral blood mononuclear cells (PBMCs) were isolated from control and RA patients and B cells were isolated from controls. BAFF-R was analyzed by flow cytometry, realtime PCR and confocal staining after treatment with NF-kappaB inhibitors. NF-kappaB p65, NF-kappaB p50, BAFF, and BAFF-R were highly expressed in severe RA synovium relative to mild RA synovium or OA synovium. BAFF-R expression was reduced by NF-kappaB inhibitors in PBMCs and B cells from normal controls. We also showed reduction in expression of BAFF-R via inhibition of the NF-kappaB pathway in PBMCs of RA patients. BAFF/BAFF-R signaling is an important mechanism of pathogenesis in RA and that BAFF-R reduction by NF-kappaB blocking therapy is another choice for controlling B cells in autoimmune diseases such as RA.

Grape seed proanthocyanidin extract ameliorates monosodium iodoacetate-induced osteoarthritis

Osteoarthritis (OA) is an age-related joint disease that is characterized by degeneration of articular cartilage and chronic pain. Oxidative stress is considered one of the pathophysiological factors in the progression of OA. We investigated the effects of grape seed proanthocyanidin extract (GSPE), which is an antioxidant, on monosodium iodoacetate (MIA)-induced arthritis of the knee joint of rat, which is an animal model of human OA. GSPE (100 mg/kg or 300 mg/kg) or saline was given orally three times per week for 4 weeks after the MIA injection. Pain was measured using the paw withdrawal latency (PWL), the paw withdrawal threshold (PWT) and the hind limb weight bearing ability. Joint damage was assessed using histological and microscopic analysis and microcomputerized tomography. Matrix metalloproteinase-13 (MMP13) and nitrotyrosine were detected using immunohistochemistry. Administration of GSPE to the MIA-treated rats significantly increased the PWL and PWT and this resulted in recovery of hind paw weight distribution (P < 0.05). GSPE reduced the loss of chondrocytes and proteoglycan, the production of MMP13, nitrotyrosine and IL-1beta and the formation of osteophytes, and it reduced the number of subchondral bone fractures in the MIA-treated rats. These results indicate that GSPE is antinociceptive and it is protective against joint damage in the MIA-treated rat model of OA. GSPE could open up novel avenues for the treatment of OA.

Grape seed proanthocyanidin extract ameliorates monosodium iodoacetate-induced osteoarthritis

Osteoarthritis (OA) is an age-related joint disease that is characterized by degeneration of articular cartilage and chronic pain. Oxidative stress is considered one of the pathophysiological factors in the progression of OA. We investigated the effects of grape seed proanthocyanidin extract (GSPE), which is an antioxidant, on monosodium iodoacetate (MIA)-induced arthritis of the knee joint of rat, which is an animal model of human OA. GSPE (100 mg/kg or 300 mg/kg) or saline was given orally three times per week for 4 weeks after the MIA injection. Pain was measured using the paw withdrawal latency (PWL), the paw withdrawal threshold (PWT) and the hind limb weight bearing ability. Joint damage was assessed using histological and microscopic analysis and microcomputerized tomography. Matrix metalloproteinase-13 (MMP13) and nitrotyrosine were detected using immunohistochemistry. Administration of GSPE to the MIA-treated rats significantly increased the PWL and PWT and this resulted in recovery of hind paw weight distribution (P < 0.05). GSPE reduced the loss of chondrocytes and proteoglycan, the production of MMP13, nitrotyrosine and IL-1beta and the formation of osteophytes, and it reduced the number of subchondral bone fractures in the MIA-treated rats. These results indicate that GSPE is antinociceptive and it is protective against joint damage in the MIA-treated rat model of OA. GSPE could open up novel avenues for the treatment of OA.

IL-17 and Toll-like Receptor 2 or Toll-like Receptor 4 Combined Engagement Upregulates RANKL and IL-6 in Human Rheumatoid Synovial Fibroblasts / 대한류마티스학회지

OBJECTIVE: The aim of this study was to clarify whether stimulation of recombinant IL-17, TLR2 and TLR4 by their specific ligands induces the production of RANKL and IL-6 in the fibroblast-like synoviocytes (FLSs) from RA patients. METHODS: FLSs were isolated from RA synovial tissues and they were stimulated with the IL-17, TLR2 ligand bacterial peptidoglycan (PGN) and TLR4 ligand lipopolysaccharide (LPS). The RANKL levels were assessed by RT-PCR and western blotting. The expressions of IL-17, TLR2, TLR4, RANKL and IL-6 in the RA synovium were quantified by immunohistochemistry and these values were compared with the values obtained in the osteoarthritis synovium. The increased IL-6 production in the culture supernatants of the RA FLSs was quantified by sandwich ELISA. RESULTS: The mRNA and protein levels of RANKL and IL-6 increased in the RA FLSs stimulated with PGN, LPS and IL-17, or PGN plus IL-17 or LPS plus IL-17. The expressions of IL-17, TLR2, TLR4, RANKL and IL-6 were much higher in the RA synovium than those in the osteoarthritis (OA) synovium. CONCLUSION: We observed synergistic effects of TLR-2, TLR-4 and IL-17 upon the induction of RANKL. In conclusion, our data supports the previous evidence of an important role of TLR-2, TLR-4 and IL-17 in the pathogenesis of RA.

The Marginal Zone B Cells have an Increased Antibody Expression in Mice with Collagen-induced Arthritis / 대한류마티스학회지

OBJECTIVE: Mature B cells in the spleen of mouse can be divide into two main subsets: the follicular (FO) B cells and the marginal zone (MZ) B cells. In this study, we investigated which subtype of B cells is involved in the production of costimulatory molecules, cytokine and antibody during the induction of autoimmune arthritis. METHODS: The MZB and FOB cells isolated from DBA/1J induced- and collagen-induced arthritis (CIA) mice were stimulated with LPS or CpG. The costimulatory molecules were measured by flow cytometry (FACs). The cytokines were measured by ELISA. Production of antibodies by the MZB cells or FOB cells was measured by ELISA and the results were observed by confocal microscopy. RESULTS: The expression of co-stimulatory molecules was stronger in the MZB cells than that in the FOB cells. The production of cytokines (IL-10, IL-6) and antibodies was higher in the MZB cells. The IgG expression of the MZB cells, which is known to be associated with the acceleration of autoimmunity, was higher in the CIA mice than that in the DBA/1J mice. CONCLUSION: We observed that the MZB cells were increased in the CIA mice. The costimulatory molecules, cytokine and auto-antibodies were increased in the MZB cells compared to that of the FOB cells. Our results suggest that MZB cells mainly produce autoantibodies, and they play a key role in development of autoimmune arthritis.

Expression of Programmed Death Ligand-1 (PD-L1) on B Cells Regulates IL-17 Production of Activated CD4+ T Cells / 대한류마티스학회지

No abstract available.