Phosphatase-1 and -2A inhibition modulates apoptosis in human osteoarthritis chondrocytes independently of nitric oxide production.
Ann Rheum Dis
; 64(7): 1079-82, 2005 Jul.
Article
em En
| MEDLINE
| ID: mdl-15958763
ABSTRACT
OBJECTIVE:
To characterise the role of phosphatase-1 and -2A (PP1/2A) in the modulation of apoptosis in human osteoarthritis (OA) chondrocytes.METHODS:
Human OA chondrocytes were isolated from cartilage obtained from the femoral heads of patients undergoing joint replacement surgery. Cell viability was evaluated by MTT assay. Apoptosis was quantified by ELISA, which measures DNA fragmentation. Nitric oxide (NO) production was evaluated by the Greiss method, and inducible nitric oxide synthase (iNOS) protein synthesis was studied by western blotting.RESULTS:
Inhibition of PP1/2A by the specific inhibitor okadaic acid (OKA) dose and time dependently caused a reduction of cell viability (OKA at 50 nmol/l a reduction to 60% and 43% at 48 and 72 hours, respectively). Genomic DNA from chondrocytes treated with OKA at 50 and 100 nmol/l for 48 hours displayed increased internucleosomal DNA fragmentation by 11 and 13 fields, respectively. Light microscopy and DAPI studies showed that OKA induced DNA condensation and fragmentation, typical of death by apoptosis. The caspase inhibitors Z-VAD-FMK and Z-DEVD-FMK increased cell viability, reduced by OKA at 50 nmol/l to 87% and 73%, respectively. OKA did not increase iNOS protein synthesis or NO production.CONCLUSION:
PP1/2A modulate apoptosis in human OA chondrocytes; this is independent of NO production but dependent on caspases.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Contexto em Saúde:
6_ODS3_enfermedades_notrasmisibles
Problema de saúde:
6_musculoskeletal_diseases_rheumatic_disorders
Assunto principal:
Osteoartrite do Quadril
/
Cartilagem Articular
/
Apoptose
/
Fosfoproteínas Fosfatases
/
Ácido Okadáico
/
Condrócitos
Limite:
Humans
Idioma:
En
Revista:
Ann Rheum Dis
Ano de publicação:
2005
Tipo de documento:
Article
País de afiliação:
Espanha