Open Access Research article

Endothelin-1 in osteoarthritic chondrocytes triggers nitric oxide production and upregulates collagenase production

Christina Alexandra Manacu1, Johanne Martel-Pelletier2, Marjolaine Roy-Beaudry1, Jean-Pierre Pelletier2, Julio C Fernandes3, Fazool S Shipkolye1, Dragoslav R Mitrovic4 and Florina Moldovan15*

Author Affiliations

1 Research Center, Sainte-Justine Hospital, Montreal, Quebec, Canada

2 Osteoarthritis Research Unit, Centre Hospitalier de l'Université de Montréal, Hopital Notre-Dame, Montreal, Quebec, Canada

3 Orthopaedics Research Laboratory, Department of Orthopaedics, Centre hospitalier Sacre-Coeur, Montreal, Quebec, Canada

4 INSERM U-606, Hôpital Lariboisière, Paris, France

5 Faculty of Dentistry, Université de Montréal, Quebec, Canada

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Arthritis Res Ther 2005, 7:R324-R332  doi:10.1186/ar1489

Published: 17 January 2005

Abstract

The mechanism of endothelin-1 (ET-1)-induced nitric oxide (NO) production, MMP-1 production and MMP-13 production was investigated in human osteoarthritis chondrocytes. The cells were isolated from human articular cartilage obtained at surgery and were cultured in the absence or presence of ET-1 with or without inhibitors of protein kinase or LY83583 (an inhibitor of soluble guanylate cyclase and of cGMP). MMP-1, MMP-13 and NO levels were then measured by ELISA and Griess reaction, respectively. Additionally, inducible nitric oxide synthase (iNOS) and phosphorylated forms of p38 mitogen-activated protein kinase, p44/42, stress-activated protein kinase/Jun-N-terminal kinase and serine-threonine Akt kinase were determined by western blot. Results show that ET-1 greatly increased MMP-1 and MMP-13 production, iNOS expression and NO release. LY83583 decreased the production of both metalloproteases below basal levels, whereas the inhibitor of p38 kinase, SB202190, suppressed ET-1-stimulated production only. Similarly, the ET-1-induced NO production was partially suppressed by the p38 kinase inhibitor and was completely suppressed by the protein kinase A kinase inhibitor KT5720 and by LY83583, suggesting the involvement of these enzymes in relevant ET-1 signalling pathways. In human osteoarthritis chondrocytes, ET-1 controls the production of MMP-1 and MMP-13. ET-1 also induces NO release via iNOS induction. ET-1 and NO should thus become important target molecules for future therapies aimed at stopping cartilage destruction.

Keywords:
endothelin-1; metalloproteases; nitric oxide; osteoarthritis; signalling pathways