title: Production of cytokines by chondrocytes and its role in proteoglycan degradation.
abstract: Increased populations of interleukin 1 (IL-1), tumor necrosis factor alpha (TNF-alpha), interleukin 6 (IL-6) and stromelysin (MMP-3) positive chondrocytes were found in osteoarthritic cartilage with immunoperoxidase microscopy using monospecific antibodies. Chondrocytic cytokine and MMP-3 productions were confirmed with tissue cultures of human osteoarthritic and healthy cartilage and monolayer cultures of rabbit articular chondrocytes. IL-6 production was induced by IL-1 alpha and TNF-alpha. The effects of these cytokines on proteoglycan degradation was also studied. While IL-1 alpha and TNF-alpha accelerated proteoglycan release and caseinase production by chondrocytes, IL-6 had no effect by itself and even depressed the effect of IL-1 alpha. Our results suggest that the cytokine network plays a crucial role in the chondrocyte mediated breakdown of cartilage.
authors.affiliation: Department of Orthopaedic Surgery, National Defense Medical College, Saitama, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Shinmei
authors.forename: K
authors.initials: K
authors.lastname: Masuda
authors.forename: T
authors.initials: T
authors.lastname: Kikuchi
authors.forename: Y
authors.initials: Y
authors.lastname: Shimomura
authors.forename: Y
authors.initials: Y
authors.lastname: Okada
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000378:metabolism* / Q000473:pathology / Q000502:physiology; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism* / Q000502:physiology; D006801:Humans; D007150:Immunohistochemistry; D007375:Interleukin-1 / Q000378:metabolism / Q000502:physiology; D015850:Interleukin-6 / Q000378:metabolism; D019278:Matrix Metalloproteinase 3; D008666:Metalloendopeptidases / Q000378:metabolism; D010003:Osteoarthritis / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D010447:Peptide Hydrolases / Q000378:metabolism; D011509:Proteoglycans / Q000378:metabolism*; D011817:Rabbits; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism / Q000502:physiology
chemical_list: D016207:Cytokines; D007375:Interleukin-1; D015850:Interleukin-6; D011509:Proteoglycans; D014409:Tumor Necrosis Factor-alpha; D010447:Peptide Hydrolases; D008666:Metalloendopeptidases; C030895:caseinase; D019278:Matrix Metalloproteinase 3