Externalization of calpain (calcium-dependent neutral cysteine proteinase) in human arthritic cartilage.
Clin Exp Rheumatol
; 17(5): 569-74, 1999.
Article
em En
| MEDLINE
| ID: mdl-10544840
ABSTRACT
OBJECTIVE:
Calcium-dependent neutral cysteine proteinase (calpain) was originally referred to as an intracellular enzyme. However, recently it has come to be considered as an extracellular matrix proteinase, as well having a degrading effect on cartilage proteoglycan. In the present study we sought to determine whether human articular cartilage chondrocytes themselves have the capability to produce and secrete this interesting proteinase.METHODS:
Human articular cartilage tissue cultures from osteoarthritic (11 specimens from 7 patients) and rheumatoid arthritic (3 specimens from 2 patients) knee joints were established, and the m-calpain released into the culture medium was concentrated and detected by immunoelectrophoretic blotting. The presence of m-calpain in the arthritic cartilage was also examined by immunohistochemistry before and after culturing.RESULTS:
M-calpain was detectable in all of the cartilage tissue culture supernatants (conditioned medium) by western blotting. Positive intracellular immunostaining of m-calpain in chondrocytes was observed in all samples. Furthermore, m-calpain was found to be present in the matrix and on the articular surface of the cartilage in half of the specimens.CONCLUSION:
The findings of our experiment suggest that cartilage chondrocytes may actively take part in m-calpain production and that they may have the capacity to release it into the extracellular matrices.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Osteoartrite
/
Artrite Reumatoide
/
Calpaína
/
Cartilagem Articular
Limite:
Aged
/
Aged80
/
Humans
/
Middle aged
Idioma:
En
Revista:
Clin Exp Rheumatol
Ano de publicação:
1999
Tipo de documento:
Article
País de afiliação:
Japão