title: Corticosteroid-dependent sodium transport in a novel immortalized mouse collecting duct principal cell line.
abstract: The final control of sodium balance takes place in the cortical collecting duct (CCD) of the nephron, where corticosteroid hormones regulate sodium reabsorption by acting through mineralocorticoid (MR) and/or glucocorticoid (GR) receptors. A clone of principal CCD cells (mpkCCDc14) has been established that is derived from a transgenic mouse (SV40 large T antigen under the control of the SV40 enhancer/L-type pyruvate kinase promoter). Cells grown on filters form polarized monolayers with high electrical transepithelial resistance (R(T) approximately 4700 ohm x cm2) and potential difference (P(D) approximately -50 mV) and have an amiloride-sensitive electrogenic sodium transport, as assessed by the short-circuit current method (Isc approximately 11 microA/cm2). Reverse transcription-PCR experiments using rat MR primers, [3H]aldosterone, and [3H]dexamethasone binding and competition studies indicated that the mpkCCDc14 cells exhibit specific MR and GR. Aldosterone increased Isc in a dose- (10(-10) to 10(-6) M) and time-dependent (2 to 72 h) manner, whereas corticosterone only transiently increased Isc (2 to 6 h). Consistent with the expression of 11beta-hydroxysteroid dehydrogenase type 2, which metabolizes glucocorticoids to inactive 11-dehydroderivates, carbenoxolone potentiated the corticosterone-stimulated Isc. Aldosterone (5x10(-7) M)-induced Isc (fourfold) was associated with a three- to fivefold increase in alpha-ENaC mRNA (but not in those for beta- or gamma-ENaC) and three- to 10-fold increases in alpha-ENaC protein synthesis. In conclusion, this new immortalized mammalian CCD clonal cell line has retained a high level of epithelial differentiation and sodium transport stimulated by aldosterone and therefore represents a useful mammalian cell system for identifying the genes controlled by aldosterone.
authors.affiliation: Institut National de la Santé et de la Recherche Médicale, Unité 478, Institut Fédératif de Recherche 02, Faculté de Médecine Xavier Bichat, Paris, France.
authors.forename: M
authors.initials: M
authors.lastname: Bens
authors.forename: V
authors.initials: V
authors.lastname: Vallet
authors.forename: F
authors.initials: F
authors.lastname: Cluzeaud
authors.forename: L
authors.initials: L
authors.lastname: Pascual-Letallec
authors.forename: A
authors.initials: A
authors.lastname: Kahn
authors.forename: M E
authors.initials: ME
authors.lastname: Rafestin-Oblin
authors.forename: B C
authors.initials: BC
authors.lastname: Rossier
authors.forename: A
authors.initials: A
authors.lastname: Vandewalle
mesh_terms: D000241:Adenosine / Q000494:pharmacology; D000305:Adrenal Cortex Hormones / Q000494:pharmacology*; D000584:Amiloride / Q000494:pharmacology; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002229:Carbenoxolone / Q000494:pharmacology; D002461:Cell Line, Transformed; D002478:Cells, Cultured; D003345:Corticosterone / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004594:Electrophysiology; D053503:Epithelial Sodium Channels; D007685:Kidney Tubules, Collecting / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D008297:Male; D051379:Mice; D011965:Receptors, Glucocorticoid / Q000502:physiology; D018161:Receptors, Mineralocorticoid / Q000502:physiology; D012964:Sodium / Q000378:metabolism*; D015222:Sodium Channels / Q000502:physiology; D013379:Substrate Specificity; D013997:Time Factors
chemical_list: D000305:Adrenal Cortex Hormones; D053503:Epithelial Sodium Channels; D011965:Receptors, Glucocorticoid; D018161:Receptors, Mineralocorticoid; D015222:Sodium Channels; D000584:Amiloride; D012964:Sodium; D000241:Adenosine; D002229:Carbenoxolone; D003345:Corticosterone