Joint damage and inflammation in c-Jun N-terminal kinase 2 knockout mice with passive murine collagen-induced arthritis
Autor: | Michael Karin, Lufen Chang, Yuji Yamanishi, Gary S. Firestein, Zuoning Han |
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Rok vydání: | 2002 |
Předmět: |
musculoskeletal diseases
Inflammatory arthritis Immunology Gene Expression Arthritis Inflammation Mice Rheumatology Western blot Animals Mitogen-Activated Protein Kinase 9 Protein Isoforms Immunology and Allergy Medicine Pharmacology (medical) Collagenases Northern blot Mice Knockout medicine.diagnostic_test business.industry c-jun JNK Mitogen-Activated Protein Kinases medicine.disease Arthritis Experimental Molecular biology Transcription Factor AP-1 Rheumatoid arthritis Knockout mouse Joints Mitogen-Activated Protein Kinases medicine.symptom business |
Zdroj: | Arthritis & Rheumatism. 46:818-823 |
ISSN: | 1529-0131 0004-3591 |
DOI: | 10.1002/art.10104 |
Popis: | Objective Previous studies have demonstrated that inhibition of c-Jun N-terminal kinase (JNK) decreases joint destruction in the rat adjuvant arthritis model. The present study was undertaken to investigate whether selective loss of JNK-2 function decreases joint destruction in JNK-2 knockout mice, in order to determine the role of this isoform in inflammatory arthritis. Methods Passive collagen-induced arthritis (CIA) was induced in Jnk2−/− and wild-type mice by administering anti–type II collagen antibodies. Arthritis was assessed daily using a semiquantitative clinical scoring system. Fibroblast-like synoviocytes (FLS) were prepared from Jnk2−/− and wild-type mice, and JNK protein expression was determined by Western blot analysis. Matrix metalloproteinase 13 (MMP-13) expression was determined by Northern blot analysis, and activator protein 1 (AP-1) binding activity by electromobility shift assay (EMSA). Results The JNK protein level in Jnk2−/− mice with CIA was 22% of that in wild-type mice with CIA (P < 0.001), and mainly the 46-kd isoform was expressed in the former group. Surprisingly, clinical arthritis was slightly more severe in the Jnk2−/− mice. Histologic scores for synovial inflammation were not significantly different. However, Safranin O–stained sections from the Jnk2−/− mice exhibited significantly less joint damage. Although joint destruction was decreased in Jnk2−/− mice with CIA, EMSA and Northern blot analysis of total joint extracts revealed similar levels of AP-1 binding and MMP-13 expression in Jnk2−/− and wild-type mice. The lack of correlation with AP-1 activity and MMP expression was probably because non-FLS cells in the joint may express more JNK-1 than do FLS. Conclusion JNK-2 is a determinant of matrix degradation, but it has little effect on inflammation in arthritis. Complete inhibition of MMP expression and joint destruction will likely require combined JNK-1 and JNK-2 inhibition. |
Databáze: | OpenAIRE |
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