title: Mechanisms of Action of Novel Influenza A/M2 Viroporin Inhibitors Derived from Hexamethylene Amiloride.
abstract: The increasing prevalence of influenza viruses with resistance to approved antivirals highlights the need for new anti-influenza therapeutics. Here we describe the functional properties of hexamethylene amiloride (HMA)-derived compounds that inhibit the wild-type and adamantane-resistant forms of the influenza A M2 ion channel. For example, 6-(azepan-1-yl)-N-carbamimidoylnicotinamide ( 9: ) inhibits amantadine-sensitive M2 currents with 3- to 6-fold greater potency than amantadine or HMA (IC50 = 0.2 vs. 0.6 and 1.3 µM, respectively). Compound 9: competes with amantadine for M2 inhibition, and molecular docking simulations suggest that 9: binds at site(s) that overlap with amantadine binding. In addition, tert-butyl 4'-(carbamimidoylcarbamoyl)-2',3-dinitro-[1,1'-biphenyl]-4-carboxylate ( 27: ) acts both on adamantane-sensitive and a resistant M2 variant encoding a serine to asparagine 31 mutation (S31N) with improved efficacy over amantadine and HMA (IC50 = 0.6 µM and 4.4 µM, respectively). Whereas 9: inhibited in vitro replication of influenza virus encoding wild-type M2 (EC50 = 2.3 µM), both 27: and tert-butyl 4'-(carbamimidoylcarbamoyl)-2',3-dinitro-[1,1'-biphenyl]-4-carboxylate ( 26: ) preferentially inhibited viruses encoding M2(S31N) (respective EC50 = 18.0 and 1.5 µM). This finding indicates that HMA derivatives can be designed to inhibit viruses with resistance to amantadine. Our study highlights the potential of HMA derivatives as inhibitors of drug-resistant influenza M2 ion channels.
authors.affiliation: Department of Anesthesiology, Pharmacology, and Therapeutics, Faculty of Medicine, University of British Columbia, Vancouver (P.H.J., J.E., S.C.M., D.C.K., D.C., I.T., D.F.), and Faculty of Health Sciences, Simon Fraser University, Burnaby (S.S.-H.T., M.N., I.T.), British Columbia, Canada.
authors.forename: Pouria H
authors.initials: PH
authors.lastname: Jalily
authors.affiliation: Department of Anesthesiology, Pharmacology, and Therapeutics, Faculty of Medicine, University of British Columbia, Vancouver (P.H.J., J.E., S.C.M., D.C.K., D.C., I.T., D.F.), and Faculty of Health Sciences, Simon Fraser University, Burnaby (S.S.-H.T., M.N., I.T.), British Columbia, Canada.
authors.forename: Jodene
authors.initials: J
authors.lastname: Eldstrom
authors.affiliation: Department of Anesthesiology, Pharmacology, and Therapeutics, Faculty of Medicine, University of British Columbia, Vancouver (P.H.J., J.E., S.C.M., D.C.K., D.C., I.T., D.F.), and Faculty of Health Sciences, Simon Fraser University, Burnaby (S.S.-H.T., M.N., I.T.), British Columbia, Canada.
authors.forename: Scott C
authors.initials: SC
authors.lastname: Miller
authors.affiliation: Department of Anesthesiology, Pharmacology, and Therapeutics, Faculty of Medicine, University of British Columbia, Vancouver (P.H.J., J.E., S.C.M., D.C.K., D.C., I.T., D.F.), and Faculty of Health Sciences, Simon Fraser University, Burnaby (S.S.-H.T., M.N., I.T.), British Columbia, Canada.
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Kwan
authors.affiliation: Department of Anesthesiology, Pharmacology, and Therapeutics, Faculty of Medicine, University of British Columbia, Vancouver (P.H.J., J.E., S.C.M., D.C.K., D.C., I.T., D.F.), and Faculty of Health Sciences, Simon Fraser University, Burnaby (S.S.-H.T., M.N., I.T.), British Columbia, Canada.
authors.forename: Sheldon S-H
authors.initials: SS
authors.lastname: Tai
authors.affiliation: Department of Anesthesiology, Pharmacology, and Therapeutics, Faculty of Medicine, University of British Columbia, Vancouver (P.H.J., J.E., S.C.M., D.C.K., D.C., I.T., D.F.), and Faculty of Health Sciences, Simon Fraser University, Burnaby (S.S.-H.T., M.N., I.T.), British Columbia, Canada.
authors.forename: Doug
authors.initials: D
authors.lastname: Chou
authors.affiliation: Department of Anesthesiology, Pharmacology, and Therapeutics, Faculty of Medicine, University of British Columbia, Vancouver (P.H.J., J.E., S.C.M., D.C.K., D.C., I.T., D.F.), and Faculty of Health Sciences, Simon Fraser University, Burnaby (S.S.-H.T., M.N., I.T.), British Columbia, Canada.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Niikura
authors.affiliation: Department of Anesthesiology, Pharmacology, and Therapeutics, Faculty of Medicine, University of British Columbia, Vancouver (P.H.J., J.E., S.C.M., D.C.K., D.C., I.T., D.F.), and Faculty of Health Sciences, Simon Fraser University, Burnaby (S.S.-H.T., M.N., I.T.), British Columbia, Canada.
authors.forename: Ian
authors.initials: I
authors.lastname: Tietjen
authors.affiliation: Department of Anesthesiology, Pharmacology, and Therapeutics, Faculty of Medicine, University of British Columbia, Vancouver (P.H.J., J.E., S.C.M., D.C.K., D.C., I.T., D.F.), and Faculty of Health Sciences, Simon Fraser University, Burnaby (S.S.-H.T., M.N., I.T.), British Columbia, Canada David.Fedida@ubc.ca.
authors.forename: David
authors.initials: D
authors.lastname: Fedida
mesh_terms: D000547:Amantadine / Q000494:pharmacology; D000584:Amiloride / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D000818:Animals; D000998:Antiviral Agents / Q000737:chemistry / Q000494:pharmacology*; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D006146:Guanidines / Q000494:pharmacology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D053127:Influenza A Virus, H9N2 Subtype / Q000187:drug effects; D009980:Influenza A virus / Q000187:drug effects* / Q000378:metabolism*; D015640:Ion Channel Gating / Q000187:drug effects; D051379:Mice; D062105:Molecular Docking Simulation; D018408:Patch-Clamp Techniques; D014763:Viral Matrix Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000086082:Viroporin Proteins
chemical_list: D000547:Amantadine; D000584:Amiloride; D000998:Antiviral Agents; D006146:Guanidines; D014763:Viral Matrix Proteins; C488937:M2 protein, Influenza A virus; D000086082:Viroporin Proteins; C057360:5-(N,N-hexamethylene)amiloride