title: Pseudomonas aeruginosa activates Cl- channels in host epithelial cells.
abstract: Exposure to Pseudomonas aeruginosa triggers the apoptotic cell death of Chang epithelial cells, and this depends on the expression of both the CD95 receptor and CD95 ligand. In lymphocytes CD95-mediated apoptosis is paralleled by the activation of outwardly rectifying Cl- channels. The present study was performed to explore whether P. aeruginosa-induced apoptosis of Chang epithelial cells is paralleled by activation of Cl- channels. According to whole-cell patch-clamp recordings, exposure of Chang epithelial cells to P. aeruginosa does lead to rapid activation of an outwardly rectifying Cl- -selective current. The current is inhibited by the Cl- channel blocker NPPB. Exposure of Chang epithelial cells to P. aeruginosa led to a significant decrease of cell membrane capacitance by 6%, pointing to a decrease in cell volume by 7%. Exposure to P. aeruginosa depolarized the mitochondrial membrane potential indicating apoptotic cell death. The decline of mitochondrial membrane potential was not significantly affected by NPPB. In conclusion, P. aeruginosa-induced apoptosis of Chang epithelial cells is paralleled by activation of Cl- channels. Activation of the channels participates in the alteration of cell volume but is not a prerequisite for P. aeruginosa-induced apoptosis.
authors.affiliation: Department of Physiology, University of Tübingen, Gmelinstr. 5, 72076 Tübingen, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Ullrich
authors.forename: Susanne
authors.initials: S
authors.lastname: Berchtold
authors.forename: Christoph
authors.initials: C
authors.lastname: Boehmer
authors.forename: Sophie
authors.initials: S
authors.lastname: Fillon
authors.forename: Verena
authors.initials: V
authors.lastname: Jendrossek
authors.forename: Monica
authors.initials: M
authors.lastname: Palmada
authors.forename: Torsten H
authors.initials: TH
authors.lastname: Schroeder
authors.forename: Gerald B
authors.initials: GB
authors.lastname: Pier
authors.forename: Florian
authors.initials: F
authors.lastname: Lang
mesh_terms: D002460:Cell Line; D018118:Chloride Channels / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism* / Q000382:microbiology; D006801:Humans; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009579:Nitrobenzoates / Q000494:pharmacology; D011550:Pseudomonas aeruginosa / Q000378:metabolism*
chemical_list: D018118:Chloride Channels; D009579:Nitrobenzoates; C058176:5-nitro-2-(3-phenylpropylamino)benzoic acid