Osteoarthritis Research Today is a free monthly online journal that collates and summarizes the latest research about Osteoarthritis, including details on treatment, symptoms, causes, medication. | ||||||||
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The regulation of human MMP-13 by licofelone, an inhibitor of cyclo-oxygenases and 5-lipoxygenase, in human osteoarthritic chondrocytes is mediated by the inhibition of the p38 MAP kinase signalling pathway.Boileau C, Pelletier JP, Tardif G, Fahmi H, Laufer S, Lavigne M, Martel-Pelletier J Osteoarthritis Research Unit, University of Montreal Hospital Centre, Notre-Dame Hospital, 1560 Sherbrooke St East, Montreal, Quebec, Canada H2L 4M1. BACKGROUND: MMP-13 is one of the most important metalloproteases (MMP) involved in osteoarthritis. Licofelone, a novel dual inhibitor of cyclo-oxygenases (COX) and 5-lipoxygenase (5-LOX), can modulate MMP-13 production in human osteoarthritis chondrocytes. OBJECTIVE: To evaluate the impact of licofelone on MMP-13 expression/production, promoter, and major MAP kinase signalling pathways and transcription factors. METHODS: Human osteoarthritis chondrocytes were stimulated by interleukin 1beta (IL1beta) and treated with or without: licofelone (0.3, 1, or 3 mug/ml); NS-398 (10 muM; a specific COX-2 inhibitor); or BayX-1005 (10 muM; a specific 5-LOX inhibitor). MMP-13 synthesis was determined by specific enzyme linked immunosorbent assay, and expression by real time polymerase chain reaction. The effect of licofelone on the MMP-13 promoter was studied through transient transfection; dexamethasone (10(-7) M) was used as comparison. The effect on IL1beta induced MMP-13 signalling pathways was determined using specific ELISA for phosphorylated MAP kinases and transcription factors. RESULTS: Licofelone dose dependently inhibited the IL1beta stimulated production and expression of MMP-13. NS-398 and BayX-1005 had very little effect. Licofelone also inhibited MMP-13 transcription on each of the promoter constructs used. The licofelone inhibition was comparable to that obtained with dexamethasone. Licofelone had no effect on phosphorylated p44/42 or JNK1/2; however, it decreased phosphorylated c-jun and inhibited phosphorylated p38, CREB, and AP-1 activity. CONCLUSIONS: Licofelone inhibited MMP-13 production under proinflammatory conditions on human osteoarthritis chondrocytes, through inhibition of the p38/AP-1 pathway and the transcription factor CREB. This may explain some of the mechanisms whereby licofelone exerts its positive effect on osteoarthritic changes. Published 17 May 2005 in Ann Rheum Dis, 64(6): 891-8.
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