Fabrice Guillier

Identification and pharmacological properties of E339-3D6, the first nonpeptidic apelin receptor agonist

Apelin plays a prominent role in body fluid and cardiovascular homeostasis. To explore further upstream the role played by this peptide, nonpeptidic agonists and antagonists of the apelin receptor are required. To identify such compounds that do not exist to date, we used an original fluorescence resonance energy transfer‐based assay to screen a G‐protein‐coupled receptor‐focused library of fluorescent compounds on the human EGFP‐tagged apelin receptor. This led to isolated E339–3D6 that displayed a 90 nM affinity and behaved as a partial agonist with regard to cAMP production and as a full agonist with regard to apelin receptor internalization. Finally, E339–3D6 induced vasorelaxation of rat aorta precontracted with noradrenaline and potently inhibited systemic vasopressin release in water‐deprived mice when intracerebroventricularly injected. This compound represents the first nonpeptidic agonist of the apelin receptor, the optimization of which will allow development of a new generation of vasodilator and aquaretic agents.—Iturrioz, X., Alvear‐Perez, R., De Mota, N., Franchet, C., Guillier, F., Leroux, V., Dabire, H., Le Jouan, M., Chabane, H., Gerbier, R., Bonnet, D., Berdeaux, A., Maigret, B., Galzi J.‐L., Hibert, M., Llorens‐Cortes, C. Identification and pharmacological properties of E339–3D6, FASEB J. 24, 1506–1517 (2010). www.fasebj.org

On the Use of Nonfluorescent Dye Labeled Ligands in FRET-Based Receptor Binding Studies

The efficiency of fluorescence resonance energy transfer (FRET) is dependent upon donor-acceptor proximity and spectral overlap, whether the acceptor partner is fluorescent or not. We report here on the design, synthesis, and characterization of two novel pirenzepine derivatives that were coupled to patent blue VF and pinacyanol dyes. These nonfluorescent compounds, when added to cells stably expressing enhanced green fluorescent protein (EGFP)-fused muscarinic M1 receptors, promote EGFP fluorescence extinction in a time-, concentration-, and atropine-dependent manner. They display nanomolar affinity for the muscarinic receptor, determined using either FRET or classical radioligand binding conditions. We provide evidence that these compounds behave as potent acceptors of energy from excited EGFP with quenching efficiencies comparable to those of analogous fluorescent bodipy or rhodamine red pirenzepine derivatives. The advantages they offer over fluorescent ligands are illustrated and discussed in terms of reliability, sensitivity, and wider applicability of FRET-based receptor binding assays.

Design, Synthesis, and Evaluation of a Novel Series of Indole Sulfonamide Peroxisome Proliferator Activated Receptor (PPAR) α/γ/δ Triple Activators: Discovery of Lanifibranor, a New Antifibrotic Clinical Candidate

Here, we describe the identification and synthesis of novel indole sulfonamide derivatives that activate the three peroxisome proliferator activated receptor (PPAR) isoforms. Starting with a PPARα activator, compound 4, identified during a high throughput screening (HTS) of our proprietary screening library, a systematic optimization led to the discovery of lanifibranor (IVA337) 5, a moderately potent and well balanced pan PPAR agonist with an excellent safety profile. In vitro and in vivo, compound 5 demonstrated strong activity in models that are relevant to nonalcoholic steatohepatitis (NASH) pathophysiology suggesting therapeutic potential for NASH patients.