The use of chemical biology to evaluate targets associated with vascular inflammation: identification and targeted delivery of novel agents for targets

Abstract

The modulation of the resolution of inflammation (RoI) process represents a novel approach to treating inflammatory pathologies. The development of small molecule modulators which are able to promote resolution and the ability of tissues for self-recovery holds significant promise. Formyl peptide receptor 2 (FPR2) is a G-protein coupled receptor and expressed mainly by neutrophils. FPR2 is involved in the RoI process with implications in cardiovascular inflammation processes. The binding modes and structure-activity relationships of small molecule FPR2 agonists were investigated using in silico methods. Based on this a binding site with three hydrophobic subpockets and two polar clusters was proposed. The knowledge gained from SAR studies was used in finding alternative bioisosteric replacements and designing novel agonists. The second approach was screening the GPCR-Ligand Association database using our pharmacophore model. A new series of agonists was then synthesized and screened. The compounds activated the receptor in the nanomolar range, and they displayed promising in vitro ADMET profiles. Finally, using neutrophil adhesion assays we have shown that FPR2 agonists can reduce the number of adherent neutrophils which indicates their anti-inflammatory and pro-resolving properties. In the second part of project I focused on xanthine oxidoreductase (XOR) and its potential protective role in cardiovascular disease. XOR is a large homodimer enzyme with two possible binding sites: Molybdenum and Flavin Adenine Dinucleotide (FAD). The goal is to find selective inhibitors of the FAD active site and increase the NO bioavailability while lowering the production of superoxide. In the search for novel inhibitors a virtual screening approach with human XOR structure with potential FAD binding sites was used. The preliminary studies showed promising results. The selected inhibitors were able to reduce superoxide generation in the presence of either xanthine or NADH. At the same time, NADH driven nitrite-reductase activity of XOR was not affected.