Cathepsins B and L in synovial fluids from patients with rheumatoid arthritis and the effect of cathepsin B on the activation of pro-urokinase.
J Med Invest
; 47(1-2): 61-75, 2000 Feb.
Article
em En
| MEDLINE
| ID: mdl-10740981
ABSTRACT
To clarify the pathophysiological role of cathepsins in rheumatoid arthritis (RA), we investigated whether cathepsin B or cathepsin L was increased in synovial fluid (SF) of RA joints, and whether the cathepsin isolated from SF of RA patients activated pro-urokinase or not. Thus, we estimated the content of cathepsins in SF of RA patients by measuring their activities by fluorospectrometry, using Z-Phe-Arg-MCA as the substrate. Cathepsin activity was approximately 4-fold higher in the SF of RA patients than in those of patients with osteoarthritis. Cathepsin B and cathepsin L were separated by cation-exchange column chromatography. As a result, a large peak corresponding to cathepsin B and a very small peak corresponding to cathepsin L were detected. Biochemical sequential fractionation of the cathepsin purified from the SF showed that the large peak was mainly composed of cathepsin B. This purified enzyme induced conversion of pro-urokinase to urokinase, and the Km for pro-urokinase was approximately 8.27 microM. These findings indicated that an imbalance between cathepsin B and its inhibitors occurred due to increased concentrations of active cathepsin B in RA articular lesions, and that cathepsin B might be related to the degradation of cartilage in RA by activating the fibrinolytic cascade.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Endopeptidases
/
Artrite Reumatoide
/
Líquido Sinovial
/
Catepsina B
/
Ativador de Plasminogênio Tipo Uroquinase
/
Catepsinas
/
Precursores Enzimáticos
Limite:
Adult
/
Aged
/
Aged80
/
Female
/
Humans
/
Male
/
Middle aged
Idioma:
En
Revista:
J Med Invest
Assunto da revista:
MEDICINA
Ano de publicação:
2000
Tipo de documento:
Article
País de afiliação:
Japão