IntroductionChemerin is a chemotactic agonist identified as a ligand for ChemR23 that is expressed on macrophages and dendritic cells (DCs). In this study, we analyzed the expression of chemerin and ChemR23 in the synovium of rheumatoid arthritis (RA) patients and the stimulatory effects of chemerin on fibroblast-like synoviocytes (FLSs) from RA patients.MethodsChemerin and ChemR23 expression in the RA synovium was ascertained by immunohistochemistry and Western blot analysis. Chemerin expression on cultured FLSs was analyzed by ELISA. ChemR23 expression on FLSs was determined by immunocytochemistry and Western blot analysis. Cytokine production from FLSs was measured by ELISA. FLS cell motility was evaluated by utilizing a scrape motility assay. We also examined the stimulating effect of chemerin on the phosphorylation of mitogen-activated protein kinase (MAPK), p44/42 mitogen-activated protein kinase (ERK1/2), p38MAPK, c-Jun N-terminal kinase (JNK)1/2 and Akt, as well as on the degradation of regulator of NF-κB (IκBα) in FLSs, by Western blot analysis.ResultsChemerin was expressed on endothelial cells and synovial lining and sublining cells. ChemR23 was expressed on macrophages, immature DCs and FLSs and a few mature DCs in the RA synovium. Chemerin and ChemR23 were highly expressed in the RA synovium compared with osteoarthritis. Chemerin and ChemR23 were expressed on unstimulated FLSs. TNF-α and IFN-γ upregulated chemerin production. Chemerin enhanced the production of IL-6, chemokine (C-C motif) ligand 2 and matrix metalloproteinase 3 by FLSs, as well as increasing FLS motility. The stimulatory effects of chemerin on FLSs were mediated by activation of ERK1/2, p38MAPK and Akt, but not by JNK1/2. Degradation of IκB in FLSs was not promoted by chemerin stimulation. Inhibition of the ERK1/2, p38MAPK and Akt signaling pathways significantly suppressed chemerin-induced IL-6 production. Moreover, blockade of the p38MAPK and Akt pathways, but not the ERK1/2 pathway, inhibited chemerin-enhanced cell motility.ConclusionsThe interaction of chemerin and ChemR23 may play an important role in the pathogenesis of RA through the activation of FLSs.
Objective. The interaction between CXCL12 and its receptor, CXCR4, in the synovium of patients with rheumatoid arthritis (RA) is important for local inflammatory cell recruitment, angiogenesis, and cytokine production. CXCR7 was recently identified as an alternative receptor for CXCL12. We undertook this study to analyze the expression of CXCR7 in RA synovium and the pathogenic role of the CXCL12/CXCR7 pathway in RA.Methods. CXCR7 expression in RA synovial tissue was analyzed using immunohistochemistry, while expression of CXCR4 and CXCR7 on human umbilical vein endothelial cells (HUVECs) was examined using quantitative reverse transcription-polymerase chain reaction, and CXCR7 expression was also analyzed by flow cytometry. Tube formation and rat aortic ring angiogenesis assays were used to assess the effects of CCX733 (a CXCR7 antagonist) and AMD3100 (a CXCR4 antagonist) on CXCL12-induced angiogenesis. The effect of anti-CXCR4 monoclonal antibody (mAb) was also analyzed using a tube formation assay. The effects of CCX733 in a murine model of collagen-induced arthritis (CIA) were also evaluated.Results. CXCR7 was expressed on endothelial cells in RA synovium and also on unstimulated HUVECs. The expression of CXCR7 on HUVECs was markedly up-regulated by interleukin-1 (IL-1) stimulation, and this overexpression was further enhanced by CXCL12 treatment. Incubation with CXCL12 also promoted angiogenic activity, with addition of IL-1 again augmenting the effect. CXCL12-induced angiogenesis was inhibited by both CXCR4 and CXCR7 antagonists and by anti-CXCR4 mAb. Furthermore, treatment with CCX733 significantly reduced the clinical arthritis scores and the numbers of vessels in the inflamed synovial tissue in mice with CIA.
Research Methods and Procedures:Twenty-one Japanese adults were fitted with a triaxial accelerometer while also in a whole-body human calorimeter for 22.5 hours. The protocol time was composed of sleep (8 hours), four structured activity periods totaling 4 hours (sitting, standing, housework, and walking on a treadmill at speeds of 71 and 95 m/min, 2 ϫ 30 minutes for each activity), and residual time (10.5 hours). Acceleration data (milligausse) from the different periods and their relationship to physical activity ratio obtained from the human calorimeter allowed for the development of EE equations for each activity. The EE equations were validated on the residual times, and the percentage difference for the prediction errors was calculated as (predicted value Ϫ measured value)/measured value ϫ 100. Results: Using data from triaxial accelerations and the ratio of horizontal to vertical accelerations, there was relatively high accuracy in identifying the four different periods of activity. The predicted EE (882 Ϯ 150 kcal/10.5 hours) was strongly correlated with the actual EE measured by human calorimetry (846 Ϯ 146 kcal/10.5 hours, r ϭ 0.94 p Ͻ 0.01), although the predicted EE was slightly higher than the measured EE. Discussion: Triaxial accelerometry, when total, vertical, and horizontal accelerations are utilized, can effectively evaluate different types of activities and estimate EE for low-intensity physical activities associated with modern lifestyles.
IntroductionBiological drugs are effective in patients with rheumatoid arthritis (RA), but increase severe infections. The CC chemokine receptor (CCR) 9 antagonist was effective for Crohn’s disease without critical adverse effects including infections in clinical trials. The present study was carried out to explore the pathogenic roles of chemokine (C-C motif) ligand (CCL) 25 and its receptor, CCR9, in autoimmune arthritis and to study if the CCR9 antagonist could be a new treatment for RA.MethodsCCL25 and CCR9 expression was examined with immunohistochemistry and Western blotting. Concentration of interleukin (IL)-6, matrix metalloproteinase (MMP)-3 and tumor necrosis factor (TNF)-α was measured with enzyme-linked immunosorbent assays. Effects of abrogating CCR9 on collagen-induced arthritis (CIA) was evaluated using CCR9-deficient mice or the CCR9 antagonist, CCX8037. Fluorescence labeled-CD11b+ splenocytes from CIA mice were transferred to recipient CIA mice and those infiltrating into the synovial tissues of the recipient mice were counted.ResultsCCL25 and CCR9 proteins were found in the RA synovial tissues. CCR9 was expressed on macrophages, fibroblast-like synoviocytes (FLS) and dendritic cells in the synovial tissues. Stimulation with CCL25 increased IL-6 and MMP-3 production from RA FLS, and IL-6 and TNF-α production from peripheral blood monocytes. CIA was suppressed in CCR9-deficient mice. CCX8037 also inhibited CIA and the migration of transferred CD11b+ splenocytes into the synovial tissues.ConclusionsThe interaction between CCL25 and CCR9 may play important roles in cell infiltration into the RA synovial tissues and inflammatory mediator production. Blocking CCL25 or CCR9 may represent a novel safe therapy for RA.
We sent questionnaires to the major dermatological institutions in Japan concerning the course and associations of dermatomyositis (DM). Of 637 cases observed between 1973 and 1983, 68 were children. The mortality rate was 2.9% in children, 47.1% in adult males, and 30.0% in adult females. Associations with malignancies were noted in 30.1% of adults; 112 cases (19.7% of adults) died from these, but surgery improved the signs of DM in 22 cases. The main neoplasms were cancer of the stomach, lung, colon, and breast. Association with pulmonary fibrosis (PF) was observed in 85 cases (14.9% of adults) and, in spite of intensive treatment, 38 cases (6.7%) died from it. In the majority of PF cases who died within 2 months, pulmonary symptoms started within 6 months of the onset of DM. All cases of PF which occurred before the onset of DM survived. The concurrence of PF and malignancies was exceptional. Death from myocardial disease occurred in only 3 cases.
RNA interference, mediated by small interfering RNA (siRNA), is effective in silencing genes with a high degree of specificity. To explore the therapeutic potential of systemically administered siRNA for rheumatoid arthritis (RA), we tested the complex of siRNA and the recently developed wrapsome (siRNA/WS) containing siRNA-encapsulated liposome in mice with collageninduced arthritis (CIA). Mice with CIA received an intravenous injection of Cy5-labeled siRNA/WS. Fluorescence stereoscopic microscopy and flow cytometry were used to assess the siRNA/WS tissue distribution. The efficacy of siRNA-targeting tumor necrosis factor (TNF)-␣/WS in CIA was evaluated by arthritis score. TNF-␣ mRNA levels in the joints were measured by real-time reverse transcriptase-polymerase chain reaction. The intensity of Cy5 fluorescence was higher in arthritic joints than in nonarthritic sites in Cy5-siRNA/WS-treated mice and remained higher up to 48 h after injection, compared with that in naked Cy5-siRNA-treated mice. Cy5 fluorescence intensity was higher in synovial cells than in splenocytes, bone marrow cells, and peripheral blood leukocytes. The majority of Cy5-positive synovial cells were CD11b ϩ with only a few CD3 ϩ cells. Treatment with TNF-␣ siRNA/WS resulted in significant decreases in severity of arthritis and TNF-␣ mRNA level in the joints compared with control siRNA/WS. In conclusion, the use of our WS allowed efficient and targeted delivery of siRNAs to arthritic joints. The siRNA/WS was mainly incorporated into CD11b ϩ cells, including macrophages and neutrophils, in the inflamed synovium, suggesting its potential therapeutic effects in RA by silencing the expression of inflammatory molecules produced by these cells.
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