Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Activity and protein expression of Na+/K+ ATPase are reduced in microvillous syncytiotrophoblast plasma membranes isolated from pregnancies complicated by intrauterine growth restriction

Johansson, Martin LU ; Karlsson, L. ; Wennergren, M. ; Jansson, T. and Powell, Theresa L. (2003) In Journal of Clinical Endocrinology and Metabolism 88(6). p.2831-2837
Abstract

In contrast to classical transporting epithelia, the Na+/K+ ATPase is distributed to both the microvillous membrane (MVM) and the basal membrane (BM) of the placental syncytiotrophoblast. Na+/K+ ATPase is important in maintaining the electrochemical gradient for Na+, which represents the driving force for Na+-coupled transport of nutrients. We hypothesized that syncytiotrophoblast Na+/K+-ATPase activity is reduced in intrauterine growth restriction (IUGR). We isolated MVM and BM from control (n = 10) and IUGR placentas (n = 11). The protein expression of Na+/K+-ATPase α1-subunit was determined by Western blotting and... (More)

In contrast to classical transporting epithelia, the Na+/K+ ATPase is distributed to both the microvillous membrane (MVM) and the basal membrane (BM) of the placental syncytiotrophoblast. Na+/K+ ATPase is important in maintaining the electrochemical gradient for Na+, which represents the driving force for Na+-coupled transport of nutrients. We hypothesized that syncytiotrophoblast Na+/K+-ATPase activity is reduced in intrauterine growth restriction (IUGR). We isolated MVM and BM from control (n = 10) and IUGR placentas (n = 11). The protein expression of Na+/K+-ATPase α1-subunit was determined by Western blotting and found to be slightly reduced in MVM isolated from IUGR (-10%; P < 0.05) placentas. Na+/K+ ATPase activity was measured as the ouabain-sensitive, K+-dependent cleavage of the fluorescent pseudosubstrate 3-O-methylfluorescein phosphate and was reduced by 35% in MVM obtained from IUGR placentas (P < 0.02). To assess the transcriptional levels of Na+/K+-ATPase mRNA, real time PCR was used. No significant changes in steady state mRNA levels for Na+/K+-ATPase were detected. The expression of the Na+/K+-ATPase α1-subunit and Na+/K+-ATPase activity in the BM were unaffected in cases of IUGR. These data suggest that Na+/K+-ATPase activity is reduced in the MVM of placentas from IUGR pregnancies. These changes might impair the function of Na+-coupled transporters and contribute to the reduced growth of these fetuses.

(Less)
Please use this url to cite or link to this publication:
author
; ; ; and
publishing date
type
Contribution to journal
publication status
published
in
Journal of Clinical Endocrinology and Metabolism
volume
88
issue
6
pages
2831 - 2837
publisher
Oxford University Press
external identifiers
  • pmid:12788896
  • scopus:0038239459
ISSN
0021-972X
DOI
10.1210/jc.2002-021926
language
English
LU publication?
no
id
39c67f2f-8261-4e79-9be9-f030643e2b96
date added to LUP
2017-04-10 16:16:13
date last changed
2024-06-23 15:04:24
@article{39c67f2f-8261-4e79-9be9-f030643e2b96,
  abstract     = {{<p>In contrast to classical transporting epithelia, the Na<sup>+</sup>/K<sup>+</sup> ATPase is distributed to both the microvillous membrane (MVM) and the basal membrane (BM) of the placental syncytiotrophoblast. Na<sup>+</sup>/K<sup>+</sup> ATPase is important in maintaining the electrochemical gradient for Na<sup>+</sup>, which represents the driving force for Na<sup>+</sup>-coupled transport of nutrients. We hypothesized that syncytiotrophoblast Na<sup>+</sup>/K<sup>+</sup>-ATPase activity is reduced in intrauterine growth restriction (IUGR). We isolated MVM and BM from control (n = 10) and IUGR placentas (n = 11). The protein expression of Na<sup>+</sup>/K<sup>+</sup>-ATPase α<sub>1</sub>-subunit was determined by Western blotting and found to be slightly reduced in MVM isolated from IUGR (-10%; P &lt; 0.05) placentas. Na<sup>+</sup>/K<sup>+</sup> ATPase activity was measured as the ouabain-sensitive, K<sup>+</sup>-dependent cleavage of the fluorescent pseudosubstrate 3-O-methylfluorescein phosphate and was reduced by 35% in MVM obtained from IUGR placentas (P &lt; 0.02). To assess the transcriptional levels of Na<sup>+</sup>/K<sup>+</sup>-ATPase mRNA, real time PCR was used. No significant changes in steady state mRNA levels for Na<sup>+</sup>/K<sup>+</sup>-ATPase were detected. The expression of the Na<sup>+</sup>/K<sup>+</sup>-ATPase α<sub>1</sub>-subunit and Na<sup>+</sup>/K<sup>+</sup>-ATPase activity in the BM were unaffected in cases of IUGR. These data suggest that Na<sup>+</sup>/K<sup>+</sup>-ATPase activity is reduced in the MVM of placentas from IUGR pregnancies. These changes might impair the function of Na<sup>+</sup>-coupled transporters and contribute to the reduced growth of these fetuses.</p>}},
  author       = {{Johansson, Martin and Karlsson, L. and Wennergren, M. and Jansson, T. and Powell, Theresa L.}},
  issn         = {{0021-972X}},
  language     = {{eng}},
  month        = {{06}},
  number       = {{6}},
  pages        = {{2831--2837}},
  publisher    = {{Oxford University Press}},
  series       = {{Journal of Clinical Endocrinology and Metabolism}},
  title        = {{Activity and protein expression of Na+/K+ ATPase are reduced in microvillous syncytiotrophoblast plasma membranes isolated from pregnancies complicated by intrauterine growth restriction}},
  url          = {{http://dx.doi.org/10.1210/jc.2002-021926}},
  doi          = {{10.1210/jc.2002-021926}},
  volume       = {{88}},
  year         = {{2003}},
}