Header

UZH-Logo

Maintenance Infos

The mineralocorticoid receptor (MR) regulates ENaC but not NCC in mice with random MR deletion


Czogalla, Jan; Vohra, Twinkle; Penton, David; Kirschmann, Moritz; Craigie, Eilidh; Loffing, Johannes (2016). The mineralocorticoid receptor (MR) regulates ENaC but not NCC in mice with random MR deletion. Pflügers Archiv : European Journal of Physiology, 468(5):849-858.

Abstract

Aldosterone binds to the mineralocorticoid receptor (MR) and increases renal Na+ reabsorption via up-regulation of the epithelial Na+ channel (ENaC) and the Na+-K+- ATPase in the collecting system (CS) and possibly also via the NaCl cotransporter (NCC) in the distal convoluted tubule (DCT). However, whether aldosterone directly regulates NCC via MR, or indirectly through systemic alterations remains controversial. We used mice with deletion of MR in ~20% of renal tubule cells (MR/X mice), in which MR-positive (MRwt) and -negative (MRko) cells can be studied sideby- side in the same physiological context. Adult MR/X mice showed similar mRNA and protein levels of renal ion transport proteins to control mice. In MR/X mice, no differences in NCC abundance and phosphorylation was seen between MRwt and MRko cells and dietary Na+ restriction up-regulated NCC to similar extent in both groups of cells. In contrast, MRko cells in the CS did not show any detectable alpha- ENaC abundance or apical targeting of ENaC neither on control diet nor in response to dietary Na+ restriction. Furthermore, Na+-K+-ATPase expression was unaffected in MRko cells of the DCT, while it was lost in MRko cells of the CS. In conclusion, MR is crucial for ENaC and Na+-K+-ATPase regulation in the CS, but is dispensable for NCC and Na+-K+-ATPase regulation in the DCT.

Abstract

Aldosterone binds to the mineralocorticoid receptor (MR) and increases renal Na+ reabsorption via up-regulation of the epithelial Na+ channel (ENaC) and the Na+-K+- ATPase in the collecting system (CS) and possibly also via the NaCl cotransporter (NCC) in the distal convoluted tubule (DCT). However, whether aldosterone directly regulates NCC via MR, or indirectly through systemic alterations remains controversial. We used mice with deletion of MR in ~20% of renal tubule cells (MR/X mice), in which MR-positive (MRwt) and -negative (MRko) cells can be studied sideby- side in the same physiological context. Adult MR/X mice showed similar mRNA and protein levels of renal ion transport proteins to control mice. In MR/X mice, no differences in NCC abundance and phosphorylation was seen between MRwt and MRko cells and dietary Na+ restriction up-regulated NCC to similar extent in both groups of cells. In contrast, MRko cells in the CS did not show any detectable alpha- ENaC abundance or apical targeting of ENaC neither on control diet nor in response to dietary Na+ restriction. Furthermore, Na+-K+-ATPase expression was unaffected in MRko cells of the DCT, while it was lost in MRko cells of the CS. In conclusion, MR is crucial for ENaC and Na+-K+-ATPase regulation in the CS, but is dispensable for NCC and Na+-K+-ATPase regulation in the DCT.

Statistics

Citations

11 citations in Web of Science®
13 citations in Scopus®
Google Scholar™

Altmetrics

Downloads

16 downloads since deposited on 08 Aug 2016
13 downloads since 12 months
Detailed statistics

Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:04 Faculty of Medicine > Institute of Anatomy
04 Faculty of Medicine > Center for Microscopy and Image Analysis
Dewey Decimal Classification:570 Life sciences; biology
610 Medicine & health
Language:English
Date:May 2016
Deposited On:08 Aug 2016 12:57
Last Modified:08 Dec 2017 20:08
Publisher:Springer
ISSN:0031-6768
Additional Information:The final publication is available at Springer via http://dx.doi.org/10.1007/s00424-016-1798-5
Publisher DOI:https://doi.org/10.1007/s00424-016-1798-5
PubMed ID:26898302

Download