7 research outputs found

    Selective involvement of ERK and JNK mitogen-activated protein kinases in early rheumatoid arthritis (1987 ACR criteria compared to 2010 ACR/EULAR criteria): a prospective study aimed at identification of diagnostic and prognostic biomarkers as well as therapeutic targets

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    Objectives To investigate the expression and activation of mitogen-activated protein kinases in patients with early arthritis who are disease-modifying antirheumatic drug (DMARD) naive. Methods A total of 50 patients with early arthritis who were DMARD naive (disease duration <1 year) were prospectively followed and diagnosed at baseline and after 2 years for undifferentiated arthritis (UA), rheumatoid arthritis (RA) (1987 American College of Rheumatology (ACR) and 2010 ACR/European League Against Rheumatism (EULAR) criteria), or spondyloarthritis (SpA). Synovial biopsies obtained at baseline were examined for expression and phosphorylation of p38, extracellular signal regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) by immunohistochemistry and digital analysis. Synovial tissue mRNA expression was measured by quantitative PCR (qPCR). Results ERK and JNK activation was enhanced at inclusion in patients meeting RA criteria compared to other diagnoses. JNK activation was enhanced in patients diagnosed as having UA at baseline who eventually fulfilled 1987 ACR RA criteria compared to those who remained UA, and in patients with RA fulfilling 2010 ACR/EULAR criteria at baseline. ERK and JNK activation was enhanced in patients with RA developing progressive joint destruction. JNK activation in UA predicted 1987 ACR RA classification criteria fulfilment (R-2=0.59, p=0.02) after follow-up, and disease progression in early arthritis (R-2=0.16, p <0.05). Enhanced JNK activation in patients with persistent disease was associated with altered synovial expression of extracellular matrix components and CD44. Conclusions JNK activation is elevated in RA before 1987 ACR RA classification criteria are met and predicts development of erosive disease in early arthritis, suggesting JNK may represent an attractive target in treating RA early in the disease proces

    A Rac1 inhibitory peptide suppresses antibody production and paw swelling in the murine collagen-induced arthritis model of rheumatoid arthritis

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    Introduction: The Rho family GTPase Rac1 regulates cytoskeletal rearrangements crucial for the recruitment, extravasation and activation of leukocytes at sites of inflammation. Rac1 signaling also promotes the activation and survival of lymphocytes and osteoclasts. Therefore, we assessed the ability of a cell-permeable Rac1 carboxy-terminal inhibitory peptide to modulate disease in mice with collagen-induced arthritis (CIA). Methods: CIA was induced in DBA/1 mice, and in either early or chronic disease, mice were treated three times per week by intraperitoneal injection with control peptide or Rac1 inhibitory peptide. Effects on disease progression were assessed by measurement of paw swelling. Inflammation and joint destruction were examined by histology and radiology. Serum levels of anti-collagen type II antibodies were measured by enzyme-linked immunosorbent assay. T-cell phenotypes and activation were assessed by fluorescence-activated cell sorting analysis. Results were analyzed using Mann-Whitney U and unpaired Student t tests. Results: Treatment of mice with Rac1 inhibitory peptide resulted in a decrease in paw swelling in early disease and to a lesser extent in more chronic arthritis. Of interest, while joint destruction was unaffected by Rac1 inhibitory peptide, anti-collagen type II antibody production was significantly diminished in treated mice, in both early and chronic arthritis. Ex vivo, Rac1 inhibitory peptide suppressed T-cell receptor/CD28-dependent production of tumor necrosis factor a, interferon. and interleukin-17 by T cells from collagen-primed mice, and reduced induction of ICOS and CD154, T-cell costimulatory proteins important for B-cell help. Conclusions: The data suggest that targeting of Rac1 with the Rac1 carboxy-terminal inhibitory peptide may suppress T-cell activation and autoantibody production in autoimmune disease. Whether this could translate into clinically meaningful improvement remains to be show

    แƒ“แƒแƒ แƒ”แƒฏแƒแƒœ แƒ“แƒ”แƒ“แƒแƒคแƒšแƒ˜แƒก แƒกแƒแƒกแƒแƒฎแƒšแƒ˜แƒกแƒ แƒ“แƒ แƒกแƒแƒฉแƒ˜แƒœแƒแƒก แƒฎแƒ”แƒ“แƒ˜

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    แƒ“แƒแƒ แƒ”แƒฏแƒแƒœ แƒ“แƒ”แƒ“แƒแƒคแƒšแƒ˜แƒก แƒกแƒแƒกแƒแƒฎแƒšแƒ”, แƒกแƒแƒฉแƒ˜แƒœแƒ - แƒ”แƒ แƒ”แƒ™แƒšแƒ” II แƒ›แƒ”แƒฃแƒฆแƒšแƒ”แƒ› แƒ“แƒแƒ แƒ”แƒฏแƒแƒœ แƒ“แƒ”แƒ“แƒแƒคแƒแƒšแƒ›แƒ 1776 แƒฌแƒ”แƒšแƒก แƒแƒ•แƒšแƒแƒ‘แƒ แƒ˜แƒก แƒขแƒ”แƒ แƒ˜แƒขแƒแƒ แƒ˜แƒแƒ–แƒ” แƒซแƒ•แƒ”แƒšแƒ˜ แƒชแƒ˜แƒฎแƒ˜แƒก แƒœแƒแƒœแƒ’แƒ แƒ”แƒ•แƒ”แƒ‘แƒ–แƒ”, แƒกแƒแƒกแƒแƒฎแƒšแƒ” แƒแƒแƒ’แƒ. แƒ“แƒแƒ แƒ”แƒฏแƒแƒœ แƒ“แƒ”แƒ“แƒแƒคแƒšแƒ˜แƒก แƒกแƒแƒกแƒแƒฎแƒšแƒ”แƒก โ€žแƒ“แƒแƒ แƒ”แƒฏแƒแƒœแƒ˜แƒก แƒกแƒแƒกแƒแƒฎแƒšแƒ”แƒกโ€œ แƒฃแƒฌแƒแƒ“แƒ”แƒ‘แƒ“แƒœแƒ”แƒœ, แƒฎแƒแƒšแƒ แƒกแƒแƒกแƒแƒฎแƒšแƒ˜แƒก แƒ”แƒ แƒ— แƒจแƒ”แƒ›แƒแƒ แƒฉแƒ”แƒœแƒ˜แƒš แƒœแƒแƒฌแƒ˜แƒšแƒก, แƒ แƒแƒ›แƒ”แƒšแƒ˜แƒช แƒ›แƒแƒฎแƒ“แƒ”แƒœแƒ˜แƒšแƒแƒ“ แƒแƒ’แƒ•แƒ˜แƒ แƒ’แƒ•แƒ˜แƒœแƒ”แƒ‘แƒก แƒซแƒ•แƒ”แƒšแƒ˜ แƒแƒ•แƒšแƒแƒ‘แƒ แƒ˜แƒก แƒ’แƒแƒšแƒแƒ•แƒœแƒ˜แƒก แƒ”แƒ แƒ—-แƒ”แƒ แƒ— แƒ‘แƒฃแƒ แƒฏแƒก โ€“ แƒกแƒแƒฉแƒ˜แƒœแƒ

    Silencing the Expression of Ras Family GTPase Homologues Decreases Inflammation and Joint Destruction in Experimental Arthritis

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    Changes in the expression and activation status of Ras proteins are thought to contribute to the pathological phenotype of stromal fibroblast-like synoviocytes (FLS) in rheumatoid arthritis, a prototypical immune-mediated inflammatory disease. Broad inhibition of Ras and related proteins has shown protective effects in animal models of arthritis, but each of the Ras family homologues (ie, H-, K-, and N-Ras) makes distinct contributions to cellular activation. We examined the expression of each Ras protein in synovial tissue and FLS obtained from patients with rheumatoid arthritis and other forms of inflammatory arthritis. Each Ras protein was expressed in synovial tissue and cultured FLS. Each homolog was also activated following FLS stimulation with tumor necrosis factor-ฮฑ or interleukin (IL)-1ฮฒ. Constitutively active mutants of each Ras protein enhanced IL-1ฮฒ-induced FLS matrix metalloproteinase-3 production, while only active H-Ras enhanced IL-8 production. Gene silencing demonstrated that each Ras protein contributed to IL-1ฮฒ-dependent IL-6 production, while H-Ras and N-Ras supported IL-1ฮฒ-dependent matrix metalloproteinase-3 and IL-8 production, respectively. The overlap in contributions of Ras homologues to FLS activation suggests that broad targeting of Ras GTPases in vivo suppresses global inflammation and joint destruction in arthritis. Consistent with this, simultaneous silencing of H-Ras, K-Ras, and N-Ras expression significantly reduces inflammation and joint destruction in murine collagen-induced arthritis, while specific targeting of N-Ras alone is less effective in providing clinical benefits
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