title: Hydrogen peroxide suppresses TRPM4 trafficking to the apical membrane in mouse cortical collecting duct principal cells.
abstract: A Ca2+-activated nonselective cation channel (NSCCa) is found in principal cells of the mouse cortical collecting duct (CCD). However, the molecular identity of this channel remains unclear. We used mpkCCDc14cells, a mouse CCD principal cell line, to determine whether NSCCarepresents the transient receptor potential (TRP) channel, the melastatin subfamily 4 (TRPM4). A Ca2+-sensitive single-channel current was observed in inside-out patches excised from the apical membrane of mpkCCDc14cells. Like TRPM4 channels found in other cell types, this channel has an equal permeability for Na+and K+and has a linear current-voltage relationship with a slope conductance of ~23 pS. The channel was inhibited by a specific TRPM4 inhibitor, 9-phenanthrol. Moreover, the frequency of observing this channel was dramatically decreased in TRPM4 knockdown mpkCCDc14cells. Unlike those previously reported in other cell types, the TRPM4 in mpkCCDc14cells was unable to be activated by hydrogen peroxide (H2O2). Conversely, after treatment with H2O2, TRPM4 density in the apical membrane of mpkCCDc14cells was significantly decreased. The channel in intact cell-attached patches was activated by ionomycin (a Ca2+ionophore), but not by ATP (a purinergic P2receptor agonist). These data suggest that the NSCCacurrent previously described in CCD principal cells is actually carried through TRPM4 channels. However, the physiological role of this channel in the CCD remains to be further determined.
authors.affiliation: Departments of Cardiology and Clinic Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Harbin, China; and.|Department of Physiology, Emory University School of Medicine, Atlanta, Georgia.
authors.forename: Ming-Ming
authors.initials: MM
authors.lastname: Wu
authors.affiliation: Department of Physiology, Emory University School of Medicine, Atlanta, Georgia.
authors.forename: Yu-Jia
authors.initials: YJ
authors.lastname: Zhai
authors.affiliation: Departments of Cardiology and Clinic Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Harbin, China; and.
authors.forename: Yu-Xia
authors.initials: YX
authors.lastname: Li
authors.affiliation: Departments of Cardiology and Clinic Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Harbin, China; and.
authors.forename: Qing-Qing
authors.initials: QQ
authors.lastname: Hu
authors.affiliation: Departments of Cardiology and Clinic Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Harbin, China; and.
authors.forename: Zhi-Rui
authors.initials: ZR
authors.lastname: Wang
authors.affiliation: Department of Physiology, Emory University School of Medicine, Atlanta, Georgia.
authors.forename: Shi-Peng
authors.initials: SP
authors.lastname: Wei
authors.affiliation: Department of Physiology, Emory University School of Medicine, Atlanta, Georgia.
authors.forename: Li
authors.initials: L
authors.lastname: Zou
authors.affiliation: Department of Physiology, Emory University School of Medicine, Atlanta, Georgia.
authors.forename: Abdel A
authors.initials: AA
authors.lastname: Alli
authors.affiliation: Department of Physiology, Emory University School of Medicine, Atlanta, Georgia.
authors.forename: Tiffany L
authors.initials: TL
authors.lastname: Thai
authors.affiliation: Departments of Cardiology and Clinic Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Harbin, China; and zhirenz@yahoo.com.
authors.forename: Zhi-Ren
authors.initials: ZR
authors.lastname: Zhang
authors.affiliation: Department of Physiology, Emory University School of Medicine, Atlanta, Georgia.
authors.forename: He-Ping
authors.initials: HP
authors.lastname: Ma
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D015759:Ionomycin / Q000494:pharmacology; D007685:Kidney Tubules, Collecting / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D010616:Phenanthrenes / Q000494:pharmacology; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D021381:Protein Transport / Q000187:drug effects; D050053:TRPM Cation Channels / Q000378:metabolism*
chemical_list: D010616:Phenanthrenes; D047428:Protein Kinase Inhibitors; D050053:TRPM Cation Channels; C476766:TRPM4 protein, mouse; D015759:Ionomycin; D000255:Adenosine Triphosphate; C091375:9-phenanthrol; D006861:Hydrogen Peroxide; D002118:Calcium
keywords: Ca2+-activated nonselective cation channel; confocal microscopy; intracellular calcium; patch clamp; reactive oxygen species