Am J Physiol Cell Physiol Email Content Delivery
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Cell Physiol 279: C762-C770, 2000;
0363-6143/00 $5.00
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Web of Science (36)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Lazrak, A.
Right arrow Articles by Matalon, S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Lazrak, A.
Right arrow Articles by Matalon, S.
Vol. 279, Issue 3, C762-C770, September 2000

Modification of biophysical properties of lung epithelial Na+ channels by dexamethasone

A. Lazrak1,*, A. Samanta1,*, K. Venetsanou3, P. Barbry4, and S. Matalon1,2

Departments of 1 Anesthesiology and 2 Physiology and Biophysics, University of Alabama at Birmingham, Birmingham, Alabama 35233; 3 Intensive Care Unit, Athens Trauma Center, Kephesia, Greece; and 4 Institut de Pharmacologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique UPR411, 06560 Sophia Antipolis, France

There is considerable interest in identifying the basic mechanisms by which dexamethasone alters ion transport across the adult alveolar epithelium. Herein, we incubated synchronized A549 cells, a human alveolar epithelial cell line, with dexamethasone (1 µM) for 24-48 h. When normalized to HPRT (a housekeeping gene), A549 beta - and gamma -subunit mRNA levels for the human amiloride-sensitive epithelial sodium channel (hENaC), assessed by RT-PCR, increased by 1.6- and 17-fold respectively, compared with control values (P < 0.05). These changes were abolished by actinomycin D, indicating transcriptional regulation. Western blotting studies revealed that dexamethasone also increased expression of beta - and gamma -hENaC protein levels. In contrast, alpha -hENaC mRNA increased by onefold (P > 0.05) and alpha -hENaC protein level was unchanged. Incubation of A549 cells with dexamethasone increased their whole cell amiloride-sensitive sodium currents twofold and decreased the K0.5 for amiloride from 833 ± 69 to 22 ± 5.4 nM (mean ± SE; P < 0.01). Single channel recordings in the cell-attached mode showed that dexamethasone treatment increased single channel open time and open probability threefold and decreased channel conductance from 8.63 ± 0.036 to 4.4 ± 0.027 pS (mean ± SE; P < 0.01). We concluded that dexamethasone modulates the amiloride-sensitive Na+ channels by differentially regulating the expression of beta - and gamma -subunits at the mRNA and protein levels in the human A549 cell line, with little effect on alpha -hENaC subunit.

ENaC; lung; whole cell currents; single channels; A549 cells; amiloride; reverse transcription-polymerase chain reaction; Western blots

* A. Lazrak and A. Samanta contributed equally to this work and are listed in alphabetical order.




This article has been cited by other articles:


Home page
 FASEB J.Home page
A. Lazrak, K. E. Iles, G. Liu, D. L. Noah, J. W. Noah, and S. Matalon
Influenza virus M2 protein inhibits epithelial sodium channels by increasing reactive oxygen species
FASEB J, November 1, 2009; 23(11): 3829 - 3842.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Respir. Cell Mol. Bio.Home page
E. Caci, R. Melani, N. Pedemonte, G. Yueksekdag, R. Ravazzolo, J. Rosenecker, L. J. V. Galietta, and O. Zegarra-Moran
Epithelial Sodium Channel Inhibition in Primary Human Bronchial Epithelia by Transfected siRNA
Am. J. Respir. Cell Mol. Biol., February 1, 2009; 40(2): 211 - 216.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Respir. Cell Mol. Bio.Home page
V. Shlyonsky, A. Goolaerts, F. Mies, and R. Naeije
Electrophysiological Characterization of Rat Type II Pneumocytes in Situ
Am. J. Respir. Cell Mol. Biol., July 1, 2008; 39(1): 36 - 44.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Lung Cell. Mol. Physiol.Home page
S. G. Brown, M. Gallacher, R. E. Olver, and S. M. Wilson
The regulation of selective and nonselective Na+ conductances in H441 human airway epithelial cells
Am J Physiol Lung Cell Mol Physiol, May 1, 2008; 294(5): L942 - L954.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Lung Cell. Mol. Physiol.Home page
S. Guney, A. Schuler, A. Ott, S. Hoschele, S. Zugel, E. Baloglu, P. Bartsch, and H. Mairbaurl
Dexamethasone prevents transport inhibition by hypoxia in rat lung and alveolar epithelial cells by stimulating activity and expression of Na+-K+-ATPase and epithelial Na+ channels
Am J Physiol Lung Cell Mol Physiol, November 1, 2007; 293(5): L1332 - L1338.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Lung Cell. Mol. Physiol.Home page
A. Dagenais, R. Frechette, M.-E. Clermont, C. Masse, A. Prive, E. Brochiero, and Y. Berthiaume
Dexamethasone inhibits the action of TNF on ENaC expression and activity
Am J Physiol Lung Cell Mol Physiol, December 1, 2006; 291(6): L1220 - L1231.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Respir. Cell Mol. Bio.Home page
H. G. Folkesson and M. A. Matthay
Alveolar Epithelial Ion and Fluid Transport: Recent Progress
Am. J. Respir. Cell Mol. Biol., July 1, 2006; 35(1): 10 - 19.
[Full Text] [PDF]

Home page
 Am. J. Physiol. Lung Cell. Mol. Physiol.Home page
G. M. Mutlu and J. I. Sznajder
Mechanisms of pulmonary edema clearance
Am J Physiol Lung Cell Mol Physiol, November 1, 2005; 289(5): L685 - L695.
[Abstract] [Full Text] [PDF]

Home page
 J. Physiol.Home page
M. T. Clunes, A. G. Butt, and S. M. Wilson
A glucocorticoid-induced Na+ conductance in human airway epithelial cells identified by perforated patch recording
J. Physiol., June 15, 2004; 557(3): 809 - 819.
[Abstract] [Full Text] [PDF]

Home page
 PediatricsHome page
O. Helve, O. M. Pitkanen, S. Andersson, H. O'Brodovich, T. Kirjavainen, and G. Otulakowski
Low Expression of Human Epithelial Sodium Channel in Airway Epithelium of Preterm Infants With Respiratory Distress
Pediatrics, May 1, 2004; 113(5): 1267 - 1272.
[Abstract] [Full Text] [PDF]

Home page
 Proc Am Thorac SocHome page
D. C. Eaton, J. Chen, S. Ramosevac, S. Matalon, and L. Jain
Regulation of Na+ Channels in Lung Alveolar Type II Epithelial Cells
Proceedings of the ATS, January 1, 2004; 1(1): 10 - 16.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Renal Physiol.Home page
O. A. Weisz and J. P. Johnson
Noncoordinate regulation of ENaC: paradigm lost?
Am J Physiol Renal Physiol, November 1, 2003; 285(5): F833 - F842.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Renal Physiol.Home page
J. Lebowitz, B. An, R. S. Edinger, M. L. Zeidel, and J. P. Johnson
Effect of altered Na+ entry on expression of apical and basolateral transport proteins in A6 epithelia
Am J Physiol Renal Physiol, September 1, 2003; 285(3): F524 - F531.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Lung Cell. Mol. Physiol.Home page
A. Lazrak and S. Matalon
cAMP-induced changes of apical membrane potentials of confluent H441 monolayers
Am J Physiol Lung Cell Mol Physiol, August 1, 2003; 285(2): L443 - L450.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Lung Cell. Mol. Physiol.Home page
S. M. O'Grady and S. Y. Lee
Chloride and potassium channel function in alveolar epithelial cells
Am J Physiol Lung Cell Mol Physiol, May 1, 2003; 284(5): L689 - L700.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Respir. Cell Mol. Bio.Home page
S. Jovanovic, R. M. Crawford, H. J. Ranki, and A. Jovanovic
Large Conductance Ca2+-Activated K+ Channels Sense Acute Changes in Oxygen Tension in Alveolar Epithelial Cells
Am. J. Respir. Cell Mol. Biol., March 1, 2003; 28(3): 363 - 372.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Lung Cell. Mol. Physiol.Home page
U. H. Thome, I. C. Davis, S. V. Nguyen, B. J. Shelton, and S. Matalon
Modulation of sodium transport in fetal alveolar epithelial cells by oxygen and corticosterone
Am J Physiol Lung Cell Mol Physiol, February 1, 2003; 284(2): L376 - L385.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Endocrinol. Metab.Home page
O. A. Itani, K. Z. Liu, K. L. Cornish, J. R. Campbell, and C. P. Thomas
Glucocorticoids stimulate human sgk1 gene expression by activation of a GRE in its 5'-flanking region
Am J Physiol Endocrinol Metab, November 1, 2002; 283(5): E971 - E979.
[Abstract] [Full Text] [PDF]

Home page
 Physiol. Rev.Home page
M. A. Matthay, H. G. Folkesson, and C. Clerici
Lung Epithelial Fluid Transport and the Resolution of Pulmonary Edema
Physiol Rev, July 1, 2002; 82(3): 569 - 600.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Lung Cell. Mol. Physiol.Home page
M. A. Matthay
Editorial: Alveolar Epithelial Ion and Fluid Transport: Regulation of ion and fluid transport across the distal pulmonary epithelia: new insights
Am J Physiol Lung Cell Mol Physiol, April 1, 2002; 282(4): L595 - L598.
[Full Text] [PDF]

Home page
 Am. J. Physiol. Lung Cell. Mol. Physiol.Home page
K. M. Hardiman, J. R. Lindsey, and S. Matalon
Lack of amiloride-sensitive transport across alveolar and respiratory epithelium of iNOS({-}/{-}) mice in vivo
Am J Physiol Lung Cell Mol Physiol, September 1, 2001; 281(3): L722 - L731.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Lung Cell. Mol. Physiol.Home page
A. Dagenais, C. Denis, M.-F. Vives, S. Girouard, C. Masse, T. Nguyen, T. Yamagata, C. Grygorczyk, R. Kothary, and Y. Berthiaume
Modulation of {alpha}-ENaC and {alpha}1-Na+-K+-ATPase by cAMP and dexamethasone in alveolar epithelial cells
Am J Physiol Lung Cell Mol Physiol, July 1, 2001; 281(1): L217 - L230.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Lung Cell. Mol. Physiol.Home page
L. Jain, X.-J. Chen, S. Ramosevac, L. A. Brown, and D. C. Eaton
Expression of highly selective sodium channels in alveolar type II cells is determined by culture conditions
Am J Physiol Lung Cell Mol Physiol, April 1, 2001; 280(4): L646 - L658.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Lung Cell. Mol. Physiol.Home page
O. A. Itani, S. D. Auerbach, R. F. Husted, K. A. Volk, S. Ageloff, M. A. Knepper, J. B. Stokes, and C. P. Thomas
Alveolar Epithelial Ion and Fluid Transport: Glucocorticoid-stimulated lung epithelial Na+ transport is associated with regulated ENaC and sgk1 expression
Am J Physiol Lung Cell Mol Physiol, April 1, 2002; 282(4): L631 - L641.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Renal Physiol.Home page
C. P. Thomas, R. W. Loftus, K. Z. Liu, and O. A. Itani
Genomic organization of the 5' end of human beta -ENaC and preliminary characterization of its promoter
Am J Physiol Renal Physiol, May 1, 2002; 282(5): F898 - F909.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online