| Autor: |
Moulin, David, Poleni, Paul-Emile, Kirchmeyer, Mélanie, Sebillaud, Sylvie, Koufany, Meriem, Netter, Patrick, Terlain, Bernard, Bianchi, Arnaud, Jouzeau, Jean-Yves |
| Předmět: |
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| Zdroj: |
Biorheology; Jun2006, Vol. 43 Issue 3/4, p561-575, 15p, 2 Diagrams, 2 Charts, 2 Graphs |
| Abstrakt: |
In response to inflammatory cytokines, chondrocytes and synovial fibroblasts produce high amounts of prostaglandins (PG) which self-perpetuate locally the inflammatory reaction. Prostaglandins act primarily through membrane receptors coupled to G proteins but also bind to nuclear Peroxisome Proliferator-Activated Receptors (PPARs). Amongst fatty acids, the cyclopentenone metabolite of PGD2, 15-deoxy-PGJ2 (15d-PGJ2), was shown to be a potent ligand of the PPARγ isotype prone to inhibit the production of inflammatory mediators. As the stimulated synthesis of PGE2 originates from the preferential coupling of inducible enzymes, cyclooxygenase-2 (COX-2) and membrane PGE synthase-1 (mPGES-1), we investigated the potency of 15d-PGJ2 to regulate prostaglandins synthesis in rat chondrocytes stimulated with interleukin-1β (IL-1β). We demonstrated that 15d-PGJ2, but not the high-affinity PPARγ ligand rosiglitazone, decreased almost completely PGE2 synthesis and mPGES-1 expression. The inhibitory potency of 15d-PGJ2 was unaffected by changes in PPARγ expression and resulted from inhibition of NF-κB nuclear binding and IκBα sparing, secondary to reduced phosphorylation of IKKβ. Consistently with 15d-PGJ2 being a putative endogenous regulator of the inflammatory reaction if synthesized in sufficient amounts, the present data confirm the variable PPARγ-dependency of its effects in joint cells while underlining possible species and cell types specificities. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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