Dataset Information

Crosstalk between epithelial sodium channels (ENaC) and basolateral potassium channels (K_ir 4.1/K_ir 5.1) in the cortical collecting duct.

ABSTRACT:

Background and purpose

Inwardly rectifying K⁺ (K_ir ) channels located on the basolateral membrane of epithelial cells of the distal nephron play a crucial role in K⁺ handling and BP control, making these channels an attractive target for the treatment of hypertension. The purpose of the present study was to determine how the inhibition of basolateral K_ir 4.1/K_ir 5.1 heteromeric K⁺ channel affects epithelial sodium channel (ENaC)-mediated Na⁺ transport in the principal cells of cortical collecting duct (CCD).

Experimental approach

The effect of fluoxetine, amitriptyline and recently developed K_ir inhibitor, VU0134992, on the activity of K_ir 4.1, K_ir 4.1/K_ir 5.1 and ENaC were tested using electrophysiological approaches in CHO cells transfected with respective channel subunits, cultured polarized epithelial mCCD_cl1 cells and freshly isolated rat and human CCD tubules. To test the effect of pharmacological K_ir 4.1/K_ir 5.1 inhibition on electrolyte homeostasis in vivo and corresponding changes in distal tubule transport, Dahl salt-sensitive rats were injected with amitriptyline (15 mg·kg^-1 ·day^-1 ) for 3 days.

Key results

We found that inhibition of K_ir 4.1/K_ir 5.1, but not the K_ir 4.1 channel, depolarizes the cell membrane, induces the elevation of intracellular Ca²⁺ concentration and suppresses ENaC activity. Furthermore, we demonstrate that amitriptyline administration leads to a significant drop in plasma K⁺ level, triggering sodium excretion and diuresis.

Conclusion and implications

The present data uncover a specific role of the K_ir 4.1/K_ir 5.1 channel in the modulation of ENaC activity and emphasize the potential for using K_ir 4.1/K_ir 5.1 inhibitors to regulate electrolyte homeostasis and BP.

SUBMITTER: Isaeva E

PROVIDER: S-EPMC9106811 | biostudies-literature | 2022 Jun

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Crosstalk between epithelial sodium channels (ENaC) and basolateral potassium channels (Kir 4.1/Kir 5.1) in the cortical collecting duct.

Isaeva Elena E Bohovyk Ruslan R Fedoriuk Mykhailo M Shalygin Alexey A Klemens Christine A CA Zietara Adrian A Levchenko Vladislav V Denton Jerod S JS Staruschenko Alexander A Palygin Oleg O

British journal of pharmacology 20220207 12

<h4>Background and purpose</h4>Inwardly rectifying K+ (Kir ) channels located on the basolateral membrane of epithelial cells of the distal nephron play a crucial role in K+ handling and BP control, making these channels an attractive target for the treatment of hypertension. The purpose of the present study was to determine how the inhibition of basolateral Kir 4.1/Kir 5.1 heteromeric K+ channel affects epithelial sodium channel ...[more]

PMID: 34904226

Similar Datasets

Project description:The transient receptor potential channel TRPC3 is exclusively expressed in the apical membrane of principal cells of the collecting duct (CD) both in vivo and in the mouse CD cell line IMCD-3. Previous studies revealed that ATP-induced apical-to-basolateral transepithelial Ca(2+) flux across IMCD-3 monolayers is increased by overexpression of TRPC3 and attenuated by a dominant negative TRPC3 construct, suggesting that Ca(2+) entry across the apical membrane occurs via TRPC3 channels. To test this hypothesis, we selectively measured the Ca(2+) permeability of the apical membrane of fura-2-loaded IMCD-3 cells using the Mn(2+) quench technique. Mn(2+) influx across the apical membrane was increased 12- to 16-fold by apical ATP and was blocked by the pyrazole derivative BTP2, a known inhibitor of TRPC3 channels, with an IC(50) value <100 nM. In contrast, Mn(2+) influx was only increased approximately 2-fold by basolateral ATP. Mn(2+) influx was also activated by apical, but not basolateral, 1-stearoyl-2-acetyl-sn-glycerol (SAG), a known activator of TRPC3 channels. Apical ATP- and SAG-induced Mn(2+) influx was increased by overexpression of TRPC3 and completely blocked by expression of the dominant negative TRPC3 construct. Mn(2+) influx was also stimulated approximately 2-fold by thapsigargin applied to either the apical or basolateral side. Thapsigargin-induced flux was blocked by BTP2 but was unaffected by overexpression of TRPC3 or by dominant negative TRPC3. Apical ATP, but not basolateral ATP, increased transepithelial (45)Ca(2+) flux. These results demonstrate that the apical membrane of IMCD-3 cells has two distinct Ca(2+) influx pathways: 1) a store-operated channel activated by thapsigargin and basolateral ATP and 2) TRPC3 channels activated by apical ATP. Only activation of TRPC3 leads to net transepithelial apical-to-basolateral Ca(2+) flux. Furthermore, these results demonstrate that native TRPC3 is not a store-operated channel in IMCD-3 cells.

Dataset Information

Crosstalk between epithelial sodium channels (ENaC) and basolateral potassium channels (K_ir 4.1/K_ir 5.1) in the cortical collecting duct.

Background and purpose

Experimental approach

Key results

Conclusion and implications

Publications

Crosstalk between epithelial sodium channels (ENaC) and basolateral potassium channels (K<sub>ir</sub> 4.1/K<sub>ir</sub> 5.1) in the cortical collecting duct.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

Dataset Information

Crosstalk between epithelial sodium channels (ENaC) and basolateral potassium channels (Kir 4.1/Kir 5.1) in the cortical collecting duct.

Background and purpose

Experimental approach

Key results

Conclusion and implications

Publications

Crosstalk between epithelial sodium channels (ENaC) and basolateral potassium channels (K&lt;sub&gt;ir&lt;/sub&gt; 4.1/K&lt;sub&gt;ir&lt;/sub&gt; 5.1) in the cortical collecting duct.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

Crosstalk between epithelial sodium channels (ENaC) and basolateral potassium channels (K_ir 4.1/K_ir 5.1) in the cortical collecting duct.

Crosstalk between epithelial sodium channels (ENaC) and basolateral potassium channels (K<sub>ir</sub> 4.1/K<sub>ir</sub> 5.1) in the cortical collecting duct.