Shifting the Biosynthesis of Leukotrienes Toward Specialized Pro-Resolving Mediators by the 5-Lipoxygenase-Activating Protein (FLAP) Antagonist BRP-201

Christian Kretzer,1 Paul M Jordan,1 Rossella Bilancia,2 Antonietta Rossi,2 Tuğçe Gür Maz,3 Erden Banoglu,3 Ulrich S Schubert,4,5 Oliver Werz1,5 1Department of Pharmaceutical/Medicinal Chemistry, Institute of Pharmacy, Friedrich Schiller University Jena, Jena, 07743, Germany; 2Department of Pharmacy, School of Medicine and Surgery, University of Naples Federico II, Naples, I-80131, Italy; 3Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Gazi University, Yenimahalle, 06560, Ankara, Turkey; 4Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Jena, 07743, Germany; 5Jena Center for Soft Matter (JCSM) Friedrich Schiller University Jena, Jena, 07743, GermanyCorrespondence: Oliver Werz, Email oliver.werz@uni-jena.deBackground and Purpose: Lipid mediators (LM) play crucial roles in the complex inflammation process with respect to initiation, maintenance, and resolution. Proinflammatory leukotrienes (LTs), generated by 5-lipoxygenase (LOX) and the 5-LOX-activating protein (FLAP), initiate and maintain inflammation while specialized pro-resolving mediators (SPMs) formed by various LOXs as key enzymes promote inflammation resolution and the return to homeostasis. Since 5-LOX also contributes to SPM biosynthesis, smart pharmacological manipulation of the 5-LOX pathway and accompanied activation of 12-/15-LOXs may accomplish suppression of LT formation but maintain or even elevate SPM formation. Here, we demonstrated that the FLAP antagonist BRP-201 possesses such pharmacological profile and causes a switch from LT toward SPM formation.Methods and Results: Comprehensive LM metabololipidomics with activated human monocyte-derived macrophages (MDM) of M1 or M2 phenotype showed that BRP-201 strongly inhibits LT formation induced by bacterial exotoxins. In parallel, SPM levels and 12/15-LOX-derived products were markedly elevated, in particular in M2-MDM. Intriguingly, in unstimulated MDM, BRP-201 induced formation of 12/15-LOX products including SPM and caused 15-LOX-1 subcellular redistribution without affecting 5-LOX. Experiments with HEK293 cells stably expressing either 5-LOX with or without FLAP, 15-LOX-1 or 15-LOX-2 confirmed suppression of 5-LOX product formation due to FLAP antagonism by BRP-201 but activated 15-LOX-1 in the absence of FLAP. Finally, in zymosan-induced murine peritonitis, BRP-201 (2 mg/kg, ip) lowered LT levels but elevated 12/15-LOX products including SPMs.Conclusion: BRP-201 acts as FLAP antagonist but also as 12/15-LOX activator switching formation of pro-inflammatory LTs toward inflammation-resolving SPM, which reflects a beneficial pharmacological profile for intervention in inflammation.Keywords: lipoxygenase, specialized pro-resolving mediators, leukotrienes, lipid mediators