title: Immunocytochemical localization of pendrin in intercalated cell subtypes in rat and mouse kidney.
abstract: Recent studies have demonstrated that a novel anion exchanger, pendrin, is expressed in the apical domain of type B intercalated cells in the mammalian collecting duct. The purpose of this study was 1) to determine the expression and distribution of pendrin along the collecting duct and connecting tubule of mouse and rat kidney and establish whether pendrin is expressed in the non-A-non-B intercalated cells and 2) to determine the intracellular localization of pendrin in the different populations of intercalated cells by immunoelectron microscopy. A peptide-derived affinity-purified antibody was generated that specifically recognized pendrin in immunoblots of rat and mouse kidney. Immunohistochemistry and confocal laser scanning microscopy demonstrated the presence of pendrin in apical domains of all type B intercalated cells in mouse and rat connecting tubule and collecting duct. In addition, strong pendrin immunostaining was observed in non-A-non-B intercalated cells. There was no labeling of type A intercalated cells. Immunoelectron microscopy demonstrated that pendrin was located in the apical plasma membrane and intracellular vesicles of both type B intercalated cells and non-A-non-B cells; the latter was identified by the presence of H(+)-ATPase in the apical plasma membrane. The results of this study demonstrate that both pendrin and H(+)-ATPase are expressed in the apical plasma membrane of non-A-non-B intercalated cells, suggesting that these cells are capable of both HCO and proton secretion. Furthermore, the presence of pendrin in both the apical plasma membrane and the apical intracellular vesicles of type B and non-A-non-B intercalated cells suggests that HCO secretion may be regulated by trafficking of pendrin between the two membrane compartments.
authors.affiliation: Department of Medicine, Hypertension and Transplantation, University of Florida, Gainesville 32610, USA.
authors.forename: Young-Hee
authors.initials: YH
authors.lastname: Kim
authors.forename: Tae-Hwan
authors.initials: TH
authors.lastname: Kwon
authors.forename: Sebastian
authors.initials: S
authors.lastname: Frische
authors.forename: Jin
authors.initials: J
authors.lastname: Kim
authors.forename: C Craig
authors.initials: CC
authors.lastname: Tisher
authors.forename: Kirsten M
authors.initials: KM
authors.lastname: Madsen
authors.forename: Søren
authors.initials: S
authors.lastname: Nielsen
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D002352:Carrier Proteins / Q000096:biosynthesis* / Q000235:genetics; D002478:Cells, Cultured; D004591:Electrophoresis, Polyacrylamide Gel; D007150:Immunohistochemistry; D007668:Kidney / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D007685:Kidney Tubules, Collecting / Q000166:cytology / Q000378:metabolism; D008297:Male; D008565:Membrane Proteins / Q000096:biosynthesis / Q000737:chemistry; D026901:Membrane Transport Proteins; D051379:Mice; D008810:Mice, Inbred C57BL; D018613:Microscopy, Confocal; D016253:Microscopy, Immunoelectron; D008969:Molecular Sequence Data; D006180:Proton-Translocating ATPases / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D013347:Subcellular Fractions / Q000378:metabolism; D000076988:Sulfate Transporters
chemical_list: D002352:Carrier Proteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; C085609:SLC26A4 protein, human; D000076988:Sulfate Transporters; D006180:Proton-Translocating ATPases