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Rat lung alveolar type II cell line maintains sodium transport characteristics of primary culture
Author(s) -
Michaut Patrick,
Planes Carole,
Escoubet Brigitte,
Clement Annick,
Amiel Claude,
Clerici Christine
Publication year - 1996
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/(sici)1097-4652(199610)169:1<78::aid-jcp8>3.0.co;2-b
Subject(s) - amiloride , epithelial sodium channel , ouabain , microbiology and biotechnology , cell culture , transfection , cotransporter , biology , sodium , chemistry , genetics , organic chemistry
Abstract Culture of primary alveolar type II cells has been widely used to investigate the Na + transport characteristics of alveolar epithelium. However, this model was restricted by early morphological and physiological dedifferentiation in culture. Recently, a cell line has been obtained by transfection of neonatal type II cells with the simian virus SV40 large T antigen gene (SV40‐T2). SV40‐T2 cells have retained proliferative characteristics of the primary type II cells (Clement et al., 1991, Exp. Cell Res., 196 :198–205.) In the present study, we have characterized Na + transport pathways in SV40‐T2 cells. SV40‐T2 cells retained most cardinal properties of the original alveolar epithelial cells. Na + entry occurred, as in primary cultures, through both Na + ‐cotransporters and amiloride‐sensitive Na + channels. SV40‐T2 cells expressed Na + ‐phosphate, Na + ‐amino acid and Na + ‐K + ‐Cl − cotransports which are quantitatively similar to that of primary cultures. The existence of amiloride‐sensitive Na + channels was supported by molecular and functional data. SV40‐T2 expressed the cloned α‐and γ‐mRNAs for the rat epithelial Na + channel (rENaC), whereas β subunit was not detected, and 22 Na + influx was significantly inhibited by 10 μM amiloride. Na + , which enters SV40‐T2 cells, is extruded through a Na + , K + ‐ATPase: mRNA for α 1 and β 1 isoforms of Na + , K + ‐ATPase were present and Na + , K + ‐ATPase activity was evidenced either on intact cells by the presence of a ouabain‐sensitive component of 86 Rb + influx or on cell homogenates by the measurement of ouabain‐inhibitable ATP hydrolysis. These results indicate that SV40‐T2 cell line displays most of the Na + transport characteristics of well‐differentiated primary cells in the first days of culture. We conclude that the SV40‐T2 cell line provides a model of differentiated alveolar type II cells and may be a powerful tool to study, in vitro, the modulation of Na + transport in pathophysiological conditions. © 1996 Wiley‐Liss, Inc.