Mitochondrial dysfunction increases inflammatory responsiveness to cytokines in normal human chondrocytes
Article first published online: 27 AUG 2012
Copyright © 2012 by the American College of Rheumatology
Arthritis & Rheumatism
Volume 64, Issue 9, pages 2927–2936, September 2012
How to Cite
Vaamonde-García, C., Riveiro-Naveira, R. R., Valcárcel-Ares, M. N., Hermida-Carballo, L., Blanco, F. J. and López-Armada, M. J. (2012), Mitochondrial dysfunction increases inflammatory responsiveness to cytokines in normal human chondrocytes. Arthritis & Rheumatism, 64: 2927–2936. doi: 10.1002/art.34508
- Issue published online: 27 AUG 2012
- Article first published online: 27 AUG 2012
- Accepted manuscript online: 1 MAY 2012 11:49AM EST
- Manuscript Accepted: 12 APR 2012
- Manuscript Received: 22 JUL 2011
- Fondo Investigación Sanitaria, Spain. Grant Numbers: 06/1670, 06CP/00292, 09/02340
- Secretaría Xeral I+D+I. Grant Numbers: PXIB916357PR, INCITE 07PXI916207ES, INCITE 08E1R916069ES, INCITE 09E1R916139ES, 10CSA916035PR
- Fondo Investigación Sanitaria, Spain (Contrato Técnico de Apoyo). Grant Number: CA10/01497
- Dirección Xeral I+D+I. Grant Numbers: PS09/56, Programa María Barbeito 2008, IN845B2010/176
- Fondo Investigación Sanitaria, Spain (Contrato Investigadores). Grant Number: SNS 06CP/00292
Alterations in mitochondria play a key role in the pathogenesis of osteoarthritis (OA). The role of inflammation in the progression of OA has also acquired important new dimensions. This study was undertaken to evaluate the potential role of mitochondrial dysfunction in increasing the inflammatory response of normal human chondrocytes to cytokines.
Mitochondrial dysfunction was induced by commonly used inhibitors. Interleukin-1β (IL-1β) and tumor necrosis factor α (TNFα) were used as inflammatory mediators. IL-8 and cyclooxygenase 2 (COX-2) protein and messenger RNA (mRNA) expression and prostaglandin E2 (PGE2) levels were assessed. The chemotactic activity of neutrophils was assayed. Additionally, inhibitors of reactive oxygen species (ROS) and NF-κB were used to identify possible inflammatory response pathways induced by mitochondrial dysfunction, and the effects of the natural antioxidant resveratrol were tested.
Pretreatment with antimycin A or oligomycin (inhibitors of mitochondrial respiratory chain complexes III and V, respectively) triggered a strong potentiation of IL-1β–induced IL-8 mRNA and protein expression (mean ± SEM at 18 hours 5,932 ± 1,995 pg/50,000 cells for IL-1β alone versus 16,241 ± 5,843 pg/50,000 cells for antimycin A plus IL-1β and 20,087 ± 5,407 pg/50,000 cells for oligomycin plus IL-1β; P < 0.05). Similar results were observed with TNFα or when expression of the inflammatory mediator COX-2 or PGE2 production was assessed. Mitochondrial dysfunction increased the chemotactic activity induced by cytokines, and ROS and NF-κB inhibitors decreased the production of IL-8. Resveratrol significantly reduced the inflammatory response.
Our findings indicate that mitochondrial dysfunction could amplify the responsiveness to cytokine-induced chondrocyte inflammation through ROS production and NF-κB activation. This pathway might lead to the impairment of cartilage and joint function in OA.