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Maneiro 2005 Ann Rheum Dis

From Bioblast
Publications in the MiPMap
Maneiro E, López-Armada MJ, de Andres MC, Caramés B, Martín MA, Bonilla A, Del Hoyo P, Galdo F, Arenas J, Blanco FJ (2005) Effect of nitric oxide on mitochondrial respiratory activity of human articular chondrocyte. Ann Rheum Dis 64:388-95.

» PMID: 15708893 Open Access

Maneiro E, Lopez-Armada MJ, de Andres MC, Carames B, Martin MA, Bonilla A, Del Hoyo P, Galdo F, Arenas J, Blanco FJ (2005) Ann Rheum Dis

Abstract: OBJECTIVE: To investigate the effect of nitric oxide (NO) on mitochondrial activity and its relation with the apoptosis of human articular chondrocytes.


MATERIALS AND METHODS: Mitochondrial function was evaluated by analysing respiratory chain enzyme complexes, citrate synthase (CS) activities, and mitochondrial membrane potential (Delta psi m). The activities of the mitochondrial respiratory chain (MRC) complexes (Complex I: NADH CoQ(1) reductase, Complex II: succinate dehydrogenase, Complex III: ubiquinol cytochrome c reductase, Complex IV: cytochrome c oxidase) and CS were measured in human articular chondrocytes isolated from normal cartilage. The Delta psi m was measured by 5,5',6,6'-tetracholoro-1,1',3,3'-tetraethylbenzimidazole carbocyanide iodide (JC-1) using flow cytometry. Apoptosis was analysed by flow cytometry. The mRNA expression of caspases was analysed by ribonuclease protection analysis and the detection of protein synthesis by western blotting. Sodium nitroprusside (SNP) was used as an NO compound donor.


RESULTS: SNP at concentrations higher than 0.5 mmol/l for 24 hours induced cellular changes characteristic of apoptosis. SNP elicited mRNA expression of caspase-3 and caspase-7 and down regulated bcl-2 synthesis in a dose and time dependent manner. Furthermore, 0.5 mM SNP induced depolarisation of the mitochondrial membrane at 5, 12, and 24 hours. Analysis of the MRC showed that at 5 hours, 0.5 mM SNP reduced the activity of Complex IV by 33%. The individual inhibition of mitochondrial Complex IV with azide modified the Delta psi m and induced apoptosis.


CONCLUSIONS: This study suggests that the effect of NO on chondrocyte survival is mediated by its effect on Complex IV of the MRC.


Labels:

Stress:Oxidative stress;RONS  Organism: Human 

Preparation: Intact cells  Enzyme: Complex I, Complex II;succinate dehydrogenase, Complex III, Complex IV;cytochrome c oxidase, Marker enzyme  Regulation: mt-Membrane potential 



Chondrocyte