RT Journal Article
SR Electronic
T1 Corticosteroid-Dependent Sodium Transport in a Novel Immortalized Mouse Collecting Duct Principal Cell Line
JF Journal of the American Society of Nephrology
JO J. Am. Soc. Nephrol.
FD American Society of Nephrology
SP 923
OP 934
VO 10
IS 5
A1 BENS, MARCELLE
A1 VALLET, VÉRONIQUE
A1 CLUZEAUD, FRANÇOISE
A1 PASCUAL-LETALLEC, LAURENT
A1 KAHN, AXEL
A1 RAFESTIN-OBLIN, MARIE E.
A1 ROSSIER, BERNARD C.
A1 VANDEWALLE, ALAIN
YR 1999
UL http://jasn.asnjournals.org/content/10/5/923.abstract
AB 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 (RT approximately 4700 Ω × cm2) and potential difference (PD approximately -50 mV) and have an amiloride-sensitive electrogenic sodium transport, as assessed by the short-circuit current method (Isc approximately 11 μA/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 11β-hydroxysteroid dehydrogenase type 2, which metabolizes glucocorticoids to inactive 11-dehydroderivates, carbenoxolone potentiated the corticosterone-stimulated Isc. Aldosterone (5 × 10-7 M)-induced Isc (fourfold) was associated with a three- to fivefold increase in α-ENaC mRNA (but not in those for β- or γ-ENaC) and three- to 10-fold increases in α-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.