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Pharmacological inhibitors of the cystic fibrosis transmembrane conductance regulator exert off-target effects on epithelial cation channels

Lookup NU author(s): JinHeng Lin, Sean Gettings, Professor Michael TaggartORCiD, Dr Mike Althaus, Dr Michael Gray



This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).


© 2022, The Author(s).The cystic fibrosis transmembrane conductance regulator (CFTR) anion channel and the epithelial Na+ channel (ENaC) play essential roles in transepithelial ion and fluid transport in numerous epithelial tissues. Inhibitors of both channels have been important tools for defining their physiological role in vitro. However, two commonly used CFTR inhibitors, CFTRinh-172 and GlyH-101, also inhibit non-CFTR anion channels, indicating they are not CFTR specific. However, the potential off-target effects of these inhibitors on epithelial cation channels has to date not been addressed. Here, we show that both CFTR blockers, at concentrations routinely employed by many researchers, caused a significant inhibition of store-operated calcium entry (SOCE) that was time-dependent, poorly reversible and independent of CFTR. Patch clamp experiments showed that both CFTRinh-172 and GlyH-101 caused a significant block of Orai1-mediated whole cell currents, establishing that they likely reduce SOCE via modulation of this Ca2+ release-activated Ca2+ (CRAC) channel. In addition to off-target effects on calcium channels, both inhibitors significantly reduced human αβγ-ENaC-mediated currents after heterologous expression in Xenopus oocytes, but had differential effects on δβγ-ENaC function. Molecular docking identified two putative binding sites in the extracellular domain of ENaC for both CFTR blockers. Together, our results indicate that caution is needed when using these two CFTR inhibitors to dissect the role of CFTR, and potentially ENaC, in physiological processes.

Publication metadata

Author(s): Lin JH, Gettings SM, Talbi K, Schreiber R, Taggart MJ, Preller M, Kunzelmann K, Althaus M, Gray MA

Publication type: Article

Publication status: Published

Journal: Pflugers Archiv European Journal of Physiology

Year: 2023

Volume: 475

Pages: 167-179

Print publication date: 01/02/2023

Online publication date: 07/10/2022

Acceptance date: 03/10/2022

Date deposited: 25/10/2022

ISSN (print): 0031-6768

ISSN (electronic): 1432-2013

Publisher: Springer Science and Business Media Deutschland GmbH


DOI: 10.1007/s00424-022-02758-9

PubMed id: 36205782


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Funder referenceFunder name
Cystic Fibrosis Trust (SRC013: MAG, KK).
Newcastle University JJ Hunter Bequest Scholarship (JL, MJT, MAG)