title: Structure-based discovery of the novel antiviral properties of naproxen against the nucleoprotein of influenza A virus.
abstract: The nucleoprotein (NP) binds the viral RNA genome and associates with the polymerase in a ribonucleoprotein complex (RNP) required for transcription and replication of influenza A virus. NP has no cellular counterpart, and the NP sequence is highly conserved, which led to considering NP a hot target in the search for antivirals. We report here that monomeric nucleoprotein can be inhibited by a small molecule binding in its RNA binding groove, resulting in a novel antiviral against influenza A virus. We identified naproxen, an anti-inflammatory drug that targeted the nucleoprotein to inhibit NP-RNA association required for NP function, by virtual screening. Further docking and molecular dynamics (MD) simulations identified in the RNA groove two NP-naproxen complexes of similar levels of interaction energy. The predicted naproxen binding sites were tested using the Y148A, R152A, R355A, and R361A proteins carrying single-point mutations. Surface plasmon resonance, fluorescence, and other in vitro experiments supported the notion that naproxen binds at a site identified by MD simulations and showed that naproxen competed with RNA binding to wild-type (WT) NP and protected active monomers of the nucleoprotein against proteolytic cleavage. Naproxen protected Madin-Darby canine kidney (MDCK) cells against viral challenges with the H1N1 and H3N2 viral strains and was much more effective than other cyclooxygenase inhibitors in decreasing viral titers of MDCK cells. In a mouse model of intranasal infection, naproxen treatment decreased the viral titers in mice lungs. In conclusion, naproxen is a promising lead compound for novel antivirals against influenza A virus that targets the nucleoprotein in its RNA binding groove.
authors: Virologie et Immunologie Moléculaires, UR892, Institut National de la Recherche Agronomique, Domaine de Vilvert, 78350 Jouy en Josas, France.
authors: Nathalie
authors: N
authors: Lejal
authors: Bogdan
authors: B
authors: Tarus
authors: Edwige
authors: E
authors: Bouguyon
authors: Sylvie
authors: S
authors: Chenavas
authors: Nicolas
authors: N
authors: Bertho
authors: Bernard
authors: B
authors: Delmas
authors: Rob W H
authors: RW
authors: Ruigrok
authors: Carmelo
authors: C
authors: Di Primo
authors: Anny
authors: A
authors: Slama-Schwok
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000737:chemistry / Q000494:pharmacology*; D000998:Antiviral Agents / Q000737:chemistry / Q000494:pharmacology*; D001665:Binding Sites; D004285:Dogs; D055808:Drug Discovery; D058492:Drug Repositioning; D053118:Influenza A Virus, H1N1 Subtype / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D053122:Influenza A Virus, H3N2 Subtype / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D061985:Madin Darby Canine Kidney Cells; D051379:Mice; D062105:Molecular Docking Simulation; D056004:Molecular Dynamics Simulation; D009288:Naproxen / Q000737:chemistry / Q000494:pharmacology*; D009698:Nucleoproteins / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism; D009976:Orthomyxoviridae Infections / Q000188:drug therapy / Q000821:virology; D017354:Point Mutation; D011485:Protein Binding; D012367:RNA, Viral / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism; D014764:Viral Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D000998:Antiviral Agents; D009698:Nucleoproteins; D012367:RNA, Viral; D014764:Viral Proteins; D009288:Naproxen