title: Pseudomonas aeruginosa Expresses a Functional Human Natriuretic Peptide Receptor Ortholog: Involvement in Biofilm Formation.
abstract: Considerable evidence exists that bacteria detect eukaryotic communication molecules and modify their virulence accordingly. In previous studies, it has been demonstrated that the increasingly antibiotic-resistant pathogen Pseudomonas aeruginosa can detect the human hormones brain natriuretic peptide (BNP) and C-type natriuretic peptide (CNP) at micromolar concentrations. In response, the bacterium modifies its behavior to adapt to the host physiology, increasing its overall virulence. The possibility of identifying the bacterial sensor for these hormones and interfering with this sensing mechanism offers an exciting opportunity to directly affect the infection process. Here, we show that BNP and CNP strongly decrease P. aeruginosa biofilm formation. Isatin, an antagonist of human natriuretic peptide receptors (NPR), prevents this effect. Furthermore, the human NPR-C receptor agonist cANF(4-23) mimics the effects of natriuretic peptides on P. aeruginosa, while sANP, the NPR-A receptor agonist, appears to be weakly active. We show in silico that NPR-C, a preferential CNP receptor, and the P. aeruginosa protein AmiC have similar three-dimensional (3D) structures and that both CNP and isatin bind to AmiC. We demonstrate that CNP acts as an AmiC agonist, enhancing the expression of the ami operon in P. aeruginosa. Binding of CNP and NPR-C agonists to AmiC was confirmed by microscale thermophoresis. Finally, using an amiC mutant strain, we demonstrated that AmiC is essential for CNP effects on biofilm formation. In conclusion, the AmiC bacterial sensor possesses structural and pharmacological profiles similar to those of the human NPR-C receptor and appears to be a bacterial receptor for human hormones that enables P. aeruginosa to modulate biofilm expression.
  
  
  OBJECTIVE
  The bacterium Pseudomonas aeruginosa is a highly dangerous opportunist pathogen for immunocompromised hosts, especially cystic fibrosis patients. The sites of P. aeruginosa infection are varied, with predominance in the human lung, in which bacteria are in contact with host molecular messengers such as hormones. The C-type natriuretic peptide (CNP), a hormone produced by lung cells, has been described as a bacterial virulence enhancer. In this study, we showed that the CNP hormone counteracts P. aeruginosa biofilm formation and we identified the bacterial protein AmiC as the sensor involved in the CNP effects. We showed that AmiC could bind specifically CNP. These results show for the first time that a human hormone could be sensed by bacteria through a specific protein, which is an ortholog of the human receptor NPR-C. The bacterium would be able to modify its lifestyle by favoring virulence factor production while reducing biofilm formation.
authors: Laboratory of Microbiology Signals and Microenvironment LMSM EA 4312, University of Rouen, Normandy University, Evreux, France.
authors: Thibaut
authors: T
authors: Rosay
authors: University of Bretagne-Sud, EA 3884, LBCM, IUEM, Lorient, France.
authors: Alexis
authors: A
authors: Bazire
authors: School of Biosciences, University of Exeter, Exeter, United Kingdom.
authors: Suraya
authors: S
authors: Diaz
authors: Laboratory of Microbiology Signals and Microenvironment LMSM EA 4312, University of Rouen, Normandy University, Evreux, France.
authors: Thomas
authors: T
authors: Clamens
authors: Laboratory of Microbiology Signals and Microenvironment LMSM EA 4312, University of Rouen, Normandy University, Evreux, France.
authors: Anne-Sophie
authors: AS
authors: Blier
authors: Laboratory of Microbiology Signals and Microenvironment LMSM EA 4312, University of Rouen, Normandy University, Evreux, France.
authors: Lily
authors: L
authors: Mijouin
authors: IMPMC, UMR7590, CNRS, Université Pierre et Marie Curie, Paris, France.
authors: Brice
authors: B
authors: Hoffmann
authors: Department of Biology, University of Cergy-Pontoise, Cergy-Pontoise, France.
authors: Jacques-Aurélien
authors: JA
authors: Sergent
authors: Laboratory of Microbiology Signals and Microenvironment LMSM EA 4312, University of Rouen, Normandy University, Evreux, France.
authors: Emeline
authors: E
authors: Bouffartigues
authors: Institut FEMTO-ST, Université de Franche Comté, CLIPP, Besançon, France.
authors: Wilfrid
authors: W
authors: Boireau
authors: UMR CNRS 6014 COBRA, University of Rouen, Evreux, France.
authors: Julien
authors: J
authors: Vieillard
authors: Laboratory of Microbiology Signals and Microenvironment LMSM EA 4312, University of Rouen, Normandy University, Evreux, France.
authors: Christian
authors: C
authors: Hulen
authors: University of Bretagne-Sud, EA 3884, LBCM, IUEM, Lorient, France.
authors: Alain
authors: A
authors: Dufour
authors: School of Biosciences, University of Exeter, Exeter, United Kingdom.
authors: Nicholas J
authors: NJ
authors: Harmer
authors: Laboratory of Microbiology Signals and Microenvironment LMSM EA 4312, University of Rouen, Normandy University, Evreux, France.
authors: Marc G J
authors: MG
authors: Feuilloley
authors: Laboratory of Microbiology Signals and Microenvironment LMSM EA 4312, University of Rouen, Normandy University, Evreux, France olivier.lesouhait@univ-rouen.fr.
authors: Olivier
authors: O
authors: Lesouhaitier
mesh_terms: D009320:Atrial Natriuretic Factor / Q000494:pharmacology; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development*; D003198:Computer Simulation; D018360:Crystallography, X-Ray; D006801:Humans; D008968:Molecular Conformation; D020097:Natriuretic Peptide, Brain / Q000378:metabolism / Q000494:pharmacology; D020098:Natriuretic Peptide, C-Type / Q000378:metabolism / Q000494:pharmacology; D010446:Peptide Fragments / Q000494:pharmacology; D033902:Periplasmic Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D011550:Pseudomonas aeruginosa / Q000737:chemistry / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*; D018000:Receptors, Peptide / Q000037:antagonists & inhibitors; D037521:Virulence Factors / Q000737:chemistry / Q000378:metabolism
chemical_list: D010446:Peptide Fragments; D033902:Periplasmic Binding Proteins; D018000:Receptors, Peptide; D037521:Virulence Factors; C065367:atrial natriuretic factor (4-23)NH2, de-Gln(18)-de-Ser(19)-de-Gly(20,22)-de-Leu(21)-; D020097:Natriuretic Peptide, Brain; D020098:Natriuretic Peptide, C-Type; C070135:AmiC protein, Pseudomonas aeruginosa; D009320:Atrial Natriuretic Factor