In vitro functional characterization of novel nociceptin/orphanin FQ receptor agonists in recombinant and native preparations

  • Eur J Pharmacol. 2016 Dec 15:793:1-13. doi: 10.1016/j.ejphar.2016.10.025.
Federica Ferrari  1 ,  Maria Camilla Cerlesi  1 ,  Davide Malfacini  1 ,  Laila Asth  2 ,  Elaine C Gavioli  2 ,  Blair V Journigan  3 ,  Uma Gayathri Kamakolanu  3 ,  Michael E Meyer  3 ,  Dennis Yasuda  3 ,  Willma E Polgar  4 ,  Anna Rizzi  1 ,  Remo Guerrini  5 ,  Chiara Ruzza  1 ,  Nurulain T Zaveri  3 ,  Girolamo Calo  6
Affiliations
  • 1. Section of Pharmacology, Department of Medical Sciences, and National Institute of Neurosciences, University of Ferrara, Italy.
  • 2. Behavioral Pharmacology Laboratory, Department of Biophysics and Pharmacology, Federal University of Rio Grande do Norte, Natal, RN, Brazil.
  • 3. Astraea Therapeutics, LLC. 320 Logue Avenue, Mountain View, CA, USA.
  • 4. SRI International, Biosciences Division, 333 Ravenswood Avenue, Menlo Park, CA, USA.
  • 5. Department of Chemical and Pharmaceutical Sciences and LTTA, University of Ferrara, Italy.
  • 6. Section of Pharmacology, Department of Medical Sciences, and National Institute of Neurosciences, University of Ferrara, Italy. Electronic address: [email protected].
PMID: 27780725 DOI: 10.1016/j.ejphar.2016.10.025
Abstract

Nociceptin/Orphanin FQ (N/OFQ) regulates several biological functions via selective activation of the N/OFQ receptor (NOP). In this study novel nonpeptide NOP ligands were characterized in vitro in receptor binding and [35S]GTPγS stimulated binding in membranes of cells expressing human NOP and classical opioid receptors, calcium mobilization assay in cells coexpressing the receptors and chimeric G proteins, bioluminescence resonance energy transfer (BRET) based assay for studying NOP receptor interaction with G protein and Arrestin, the electrically stimulated mouse vas deferens and the mouse colon bioassays. The action of the AT compounds were compared with standard NOP agonists (N/OFQ and Ro 65-6570) and the NOP selective antagonist SB-612111. AT compounds displayed high NOP affinity and behaved as NOP agonists in all the functional assays consistently showing the following rank order of potency AT-127≥AT-090≥AT-035>AT-004= AT-001. AT compounds behaved as NOP full agonists in the calcium mobilization and mouse colon assays and as partial agonists in the [35S]GTPγS and BRET assays. Interestingly AT-090 and AT-127, contrary to standard nonpeptide agonists that display G protein biased agonism, behaved as an unbiased agonists. AT-090 and AT-127 displayed higher NOP selectivity than Ro 65-6570 at native mouse receptors. AT-090 and AT-127 might be useful pharmacological tools for investigating the therapeutic potential of NOP partial agonists.

Keywords
Bioluminescence resonance energy transfer; Calcium mobilization and mouse colon vas deferens and assays; NOP and classical opioid receptors; Receptor and [(35)S]GTPγS binding.
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