Activity and protein expression of Na+/K+ ATPase are reduced in microvillous syncytiotrophoblast plasma membranes isolated from pregnancies complicated by intrauterine growth restriction
(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)
- author
- Johansson, Martin LU ; Karlsson, L. ; Wennergren, M. ; Jansson, T. and Powell, Theresa L.
- publishing date
- 2003-06-01
- 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
-
- scopus:0038239459
- pmid:12788896
- 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
- 2024-10-01 01:05:21
@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 < 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 < 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}}, }