Stable formyl peptide receptor agonists that activate the neutrophil NADPH-oxidase identified through screening of a compound library

Abstract

The neutrophil formyl peptide receptors (FPR1 and FPR2) are G-protein coupled receptors that can induce pro-inflammatory as well as anti-inflammatory activities when activated. Accordingly, these receptors may become therapeutic targets for the development of novel drugs to be used for reducing the inflammation induced injuries in asthma, rheumatoid arthritis, Alzheimer's disease, cardiovascular diseases and traumatic shock. We screened a library of more then 50 K small compounds for an ability of the compounds to induce a transient rise in intracellular Ca 2+ in cells transfected to express FPR2 (earlier called FPRL1 or the lipoxin A 4 receptor). Ten agonists hits were selected for further analysis representing different chemical series and five new together with five earlier described molecules were further profiled.. Compounds 1 -10 gave rise to a calcium response in the FPR2 transfectants with EC 50 values ranging from 4 x 10 -9 M to 2 x 10 -7 M. All 10 compounds activated human neutrophils to release superoxide , and based on the potency of their activity, the three most potent activators of the neutrophil NADPH-oxidase were further characterized. These three agonists were largely resistant to inactivation by neutrophil produced reactive oxygen species and shown to trigger the same functional repertoire in neutrophils as earlier described peptide agonists. Accordingly they induced chemotaxis, granule mobilization and secretion of superoxide. Interestingly, the oxidase activity was largely inhibited by cyclosporine H, an FPR1 selective antagonist, but not by PBP10, an FPR2 selective inhibitor, suggesting that FPR1 is the preferred receptor in neutrophils for all three agonists.

3-(1H-indol-3-yl)-2-[3-(4-nitrophenyl)ureido]propanamide enantiomers with human formyl-peptide receptor agonist activity: Molecular modeling of chiral recognition by FPR2

“…The surface consists of three regions (H 1 , H 2 , and H 3 ), which correlate with subpockets I, II, and III in the FPR2 binding site, respectively ([12] and Figure 5) . Enantiomeric FPR2 agonists and their active/inactive counterparts reported here and published previously [9;13;15] were then compared to the pharmacophore model. All molecules were overlaid in the three-subpocket model, and the highest-score superimpositions together with values of calculated similarity are shown in Table 3 .…”

FPR2/ALXR Agonists and the Resolution of Inflammation

“…166 All 90 compounds with a given EC 50 were aniline derivatives covered by formula II and, according to the chemistry, were either cis-endo or cis-exo. 144 and 15, a FPR2 agonist discovered earlier 165 and used as comparator. In further studies, 11, 13, and Amgen compound 6 were shown to activate neutrophils preferentially through FPR1.…”

Beyond the detergent effect: a binding site for sodium dodecyl sulfate (SDS) in mammalian apoferritin

“…This means that SDS might provide useful information about ligand-binding sites for particular protein targets. For example, SDS modulates the activity of the neutrophil formyl-peptide receptor (Thoré n et al, 2010); this G-protein-coupled receptor is an important therapeutic target for anti-inflammatory agents and selective antagonists have potential utility in the treatment of many pathological processes, including rheumatoid arthritis, sepsis, septic shock, asthma and Alzheimer's disease (Forsman et al, 2011). SDS might provide a useful new lead compound in the effort to develop such agents.…”