title: TRPC6 channel translocation into phagosomal membrane augments phagosomal function.
abstract: Defects in the innate immune system in the lung with attendant bacterial infections contribute to lung tissue damage, respiratory insufficiency, and ultimately death in the pathogenesis of cystic fibrosis (CF). Professional phagocytes, including alveolar macrophages (AMs), have specialized pathways that ensure efficient killing of pathogens in phagosomes. Phagosomal acidification facilitates the optimal functioning of degradative enzymes, ultimately contributing to bacterial killing. Generation of low organellar pH is primarily driven by the V-ATPases, proton pumps that use cytoplasmic ATP to load H(+) into the organelle. Critical to phagosomal acidification are various channels derived from the plasma membrane, including the anion channel cystic fibrosis transmembrane conductance regulator, which shunt the transmembrane potential generated by movement of protons. Here we show that the transient receptor potential canonical-6 (TRPC6) calcium-permeable channel in the AM also functions to shunt the transmembrane potential generated by proton pumping and is capable of restoring microbicidal function to compromised AMs in CF and enhancement of function in non-CF cells. TRPC6 channel activity is enhanced via translocation to the cell surface (and then ultimately to the phagosome during phagocytosis) in response to G-protein signaling activated by the small molecule (R)-roscovitine and its derivatives. These data show that enhancing vesicular insertion of the TRPC6 channel to the plasma membrane may represent a general mechanism for restoring phagosome activity in conditions, where it is lost or impaired.
authors.affiliation: Department of Pharmacological and Physiological Sciences and Department of Medicine, University of Chicago, Chicago, IL 60637;
authors.forename: Vladimir
authors.initials: V
authors.lastname: Riazanski
authors.affiliation: Department of Pharmacological and Physiological Sciences and Department of Medicine, University of Chicago, Chicago, IL 60637;
authors.forename: Aida G
authors.initials: AG
authors.lastname: Gabdoulkhakova
authors.affiliation: Department of Pharmacological and Physiological Sciences and Department of Medicine, University of Chicago, Chicago, IL 60637;
authors.forename: Lin S
authors.initials: LS
authors.lastname: Boynton
authors.affiliation: Department of Pharmacological and Physiological Sciences and Department of Medicine, University of Chicago, Chicago, IL 60637;
authors.forename: Raphael R
authors.initials: RR
authors.lastname: Eguchi
authors.affiliation: Department of Pharmacological and Physiological Sciences and Department of Medicine, University of Chicago, Chicago, IL 60637;
authors.forename: Ludmila V
authors.initials: LV
authors.lastname: Deriy
authors.affiliation: Department of Pharmacological and Physiological Sciences and Department of Medicine, University of Chicago, Chicago, IL 60637;
authors.forename: D Kyle
authors.initials: DK
authors.lastname: Hogarth
authors.affiliation: Department of Research and Development, ManRos Therapeutics, Hôtel de Recherche, Centre de Perharidy, 29680 Roscoff, France;
authors.forename: Nadège
authors.initials: N
authors.lastname: Loaëc
authors.affiliation: Department of Research and Development, ManRos Therapeutics, Hôtel de Recherche, Centre de Perharidy, 29680 Roscoff, France;
authors.forename: Nassima
authors.initials: N
authors.lastname: Oumata
authors.affiliation: Unité de Technologies Chimiques et Biologiques pour la Santé, Université Paris Descartes UMR-S 1022 INSERM 75270, Paris Cedex 06, France;
authors.forename: Hervé
authors.initials: H
authors.lastname: Galons
authors.affiliation: Department of Pharmacological and Physiological Sciences and Department of Medicine, University of Chicago, Chicago, IL 60637;
authors.forename: Mary E
authors.initials: ME
authors.lastname: Brown
authors.affiliation: Department of Pharmacological and Physiological Sciences and Department of Medicine, University of Chicago, Chicago, IL 60637;
authors.forename: Pavel
authors.initials: P
authors.lastname: Shevchenko
authors.affiliation: Department of Pharmacological and Physiological Sciences and Department of Medicine, University of Chicago, Chicago, IL 60637;
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: Gallan
authors.affiliation: Department of Pharmacological and Physiological Sciences and Department of Medicine, University of Chicago, Chicago, IL 60637;
authors.forename: Sang Gune
authors.initials: SG
authors.lastname: Yoo
authors.affiliation: Department of Pediatrics, Division of Pulmonary Medicine and Gastroenterology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229;
authors.forename: Anjaparavanda P
authors.initials: AP
authors.lastname: Naren
authors.affiliation: Department of Pharmacological and Physiological Sciences and Department of Medicine, University of Chicago, Chicago, IL 60637;
authors.forename: Mitchel L
authors.initials: ML
authors.lastname: Villereal
authors.affiliation: Molecular Probes, Thermo Scientific, Eugene, OR 97402;
authors.forename: Daniel W
authors.initials: DW
authors.lastname: Beacham
authors.affiliation: Department of Pharmacological and Physiological Sciences and Department of Medicine, University of Chicago, Chicago, IL 60637;
authors.forename: Vytautas P
authors.initials: VP
authors.lastname: Bindokas
authors.affiliation: Laboratory of Neurobiology, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709 Birnbau1@gmail.com nelson@uchicago.edu.
authors.forename: Lutz
authors.initials: L
authors.lastname: Birnbaumer
authors.affiliation: Department of Research and Development, ManRos Therapeutics, Hôtel de Recherche, Centre de Perharidy, 29680 Roscoff, France;
authors.forename: Laurent
authors.initials: L
authors.lastname: Meijer
authors.affiliation: Department of Pharmacological and Physiological Sciences and Department of Medicine, University of Chicago, Chicago, IL 60637; Birnbau1@gmail.com nelson@uchicago.edu.
authors.forename: Deborah J
authors.initials: DJ
authors.lastname: Nelson
mesh_terms: D000143:Acids / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling / Q000187:drug effects; D002460:Cell Line; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000378:metabolism; D004075:Diglycerides / Q000378:metabolism; D005089:Exocytosis / Q000187:drug effects; D005455:Fluorescent Antibody Technique; D006801:Humans; D007425:Intracellular Membranes / Q000187:drug effects / Q000378:metabolism*; D015640:Ion Channel Gating / Q000187:drug effects; D016676:Macrophages, Alveolar / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D050296:Microbial Viability / Q000187:drug effects; D008954:Models, Biological; D018408:Patch-Clamp Techniques; D037342:Pertussis Toxin / Q000494:pharmacology; D010588:Phagosomes / Q000187:drug effects / Q000378:metabolism*; D021381:Protein Transport / Q000187:drug effects; D011687:Purines / Q000737:chemistry / Q000494:pharmacology; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism; D000077546:Roscovitine; D054852:Small Molecule Libraries / Q000737:chemistry / Q000494:pharmacology; D050052:TRPC Cation Channels / Q000378:metabolism*; D000074287:TRPC6 Cation Channel
chemical_list: D000143:Acids; D004075:Diglycerides; D011687:Purines; D043562:Receptors, G-Protein-Coupled; D054852:Small Molecule Libraries; D050052:TRPC Cation Channels; D000074287:TRPC6 Cation Channel; C117032:TRPC6 protein, human; C492146:Trpc6 protein, mouse; D000077546:Roscovitine; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D037342:Pertussis Toxin; D002118:Calcium
keywords: TRPC6; alveolar macrophage; cystic fibrosis; phagosome; roscovitine