Effects of AF3442 [N-(9-ethyl-9H-carbazol-3-yl)-2-(trifluoromethyl)benzamide], a novel inhibitor of human microsomal prostaglandin E synthase-1, on prostanoid biosynthesis in human monocytes in vitro

Annalisa Bruno , Luigia Di Francesco , Isabella Coletta , Giorgina Mangano , Maria Alessandra Alisi , Lorenzo Polenzani , Claudio Milanese , Paola Anzellotti , Emanuela Ricciotti , Melania Dovizio , Andrea Di Francesco , Stefania Tacconelli , Marta L Capone , Paola Patrignani

Inhibitors of microsomal prostaglandin(PG)E synthase-1(mPGES-1) are being developed for the relief of pain. Redirection of the PGH substrate to other PG synthases, found both in vitro and in vivo, in mPGES-1 knockout mice, may influence their efficacy and safety. We characterized the contribution of mPGES-1 to PGH metabolism in lipopolysaccharide(LPS)-stimulated isolated human monocytes and whole blood by studying the synthesis of prostanoids [PGE, thromboxane(TX)B, PGF and 6-keto-PGF] and expression of cyclooxygenase(COX)-isozymes and down-stream synthases in the presence of pharmacological inhibition by the novel mPGES-1 inhibitor AF3442 [-(9-ethyl-9-carbazol-3-yl)-2-(trifluoromethyl)benzamide]. AF3442 caused a concentration-dependent inhibition of PGE in human recombinant mPGES-1 with an IC of 0.06μM. In LPS-stimulated monocytes, AF3442 caused a concentration-dependent reduction of PGE biosynthesis with an IC of 0.41μM. At 1μM, AF3442 caused maximal selective inhibitory effect of PGE biosynthesis by 61±3.3%(mean±SEM, P<0.01 versus DMSO vehicle) without significantly affecting other prostanoids (i.e., TXB, PGF and 6-keto-PGF). In LPS-stimulated whole blood, AF3442 inhibited in a concentration-dependent fashion inducible PGE biosynthesis with an IC of 29μM. A statistically significant inhibition of mPGES-1 activity was detected at 10 and 100μM (38±14%, P<0.05, and 69±5%, P<0.01, respectively). Up to 100μM, the other prostanoids were not significantly affected. In conclusion, AF3442 is a selective mPGES-1 inhibitor which reduced monocyte PGE generation also in the presence of plasma proteins. Pharmacological inhibition of mPGES-1 did not translate into redirection of PGH metabolism towards other terminal PG synthases in monocytes. The functional relevance of this observation deserves to be investigated in vivo.

Mots clés: Life Sciences

Annalisa Bruno, Luigia Di Francesco, Isabella Coletta, Giorgina Mangano, Maria Alessandra Alisi, et al.. Effects of AF3442 [N-(9-ethyl-9H-carbazol-3-yl)-2-(trifluoromethyl)benzamide], a novel inhibitor of human microsomal prostaglandin E synthase-1, on prostanoid biosynthesis in human monocytes in vitro. Biochemical Pharmacology, 2010, 79 (7), pp.974. ⟨10.1016/j.bcp.2009.11.011⟩. ⟨hal-00560685⟩