Volume 48, Issue 4 pp. 1137-1148
Research Article

Crystal-induced neutrophil activation: VIII. Immediate production of prostaglandin E2 mediated by constitutive cyclooxygenase 2 in human neutrophils stimulated by urate crystals

Caroline Gilbert

Caroline Gilbert

Laval University, Ste-Foy, Quebec, Canada

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Patrice E. Poubelle

Patrice E. Poubelle

Laval University, Ste-Foy, Quebec, Canada

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Pierre Borgeat

Pierre Borgeat

Laval University, Ste-Foy, Quebec, Canada

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Marc Pouliot

Marc Pouliot

Laval University, Ste-Foy, Quebec, Canada

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Paul H. Naccache

Corresponding Author

Paul H. Naccache

Laval University, Ste-Foy, Quebec, Canada

CHUL, Room T1-49, 2705 Boulevard Laurier, Ste-Foy, Quebec G1V 4G2, CanadaSearch for more papers by this author
First published: 03 April 2003
Citations: 27

Abstract

Objective

To evaluate the impact of monosodium urate monohydrate (MSUM) crystals on the synthesis of prostaglandin E2 (PGE2) by human neutrophils, and to examine some of the mechanisms underlying these responses.

Methods

The amount of PGE2 released in the supernatants of stimulated human neutrophils was evaluated by enzyme immunoassay, and expression of cyclooxygenase 2 (COX-2) was monitored by immunoblot on cell lysates, as well as by cytofluorometry of buffy-coat cells.

Results

We observed that MSUM crystals rapidly stimulated the synthesis of PGE2, with levels peaking at 1 hour. This response was decreased by NS-398, a specific inhibitor of COX-2. We also detected a constitutive expression of COX-2 in unstimulated and unprimed neutrophils. This rapid COX-2–dependent PGE2 accumulation was independent of translation and transcription. We also observed that piceatannol, but not colchicine, blocked the synthesis of PGE2 stimulated by MSUM crystals.

Conclusion

These results show that the interaction of MSUM crystals with human neutrophils stimulates a significant synthesis of PGE2 mediated by constitutively expressed COX-2. The results of this study emphasize the potential importance of the neutrophil as a source of PGE2, which may modulate, positively or negatively, the inflammatory response.

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