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

Autor: Lin J; Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.; Department of Pharmacology, University of Oxford, Oxford, OX1 3QT, UK., Gettings SM; School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK., Talbi K; Physiological Institute, University of Regensburg, 93053, Regensburg, Germany., Schreiber R; Physiological Institute, University of Regensburg, 93053, Regensburg, Germany., Taggart MJ; Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK., Preller M; Department of Natural Sciences/Institute for Functional Gene Analytics, Structural Biology Group, Bonn-Rhein-Sieg University of Applied Sciences, 53359, Rheinbach, Germany., Kunzelmann K; Physiological Institute, University of Regensburg, 93053, Regensburg, Germany., Althaus M; School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK.; Department of Natural Sciences /Institute for Functional Gene Analytics, Ion Transport Physiology Group, Bonn-Rhein-Sieg University of Applied Sciences, 53359, Rheinbach, Germany., Gray MA; Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK. m.a.gray@newcastle.ac.uk.
Jazyk: angličtina
Zdroj: Pflugers Archiv : European journal of physiology [Pflugers Arch] 2023 Feb; Vol. 475 (2), pp. 167-179. Date of Electronic Publication: 2022 Oct 07.
DOI: 10.1007/s00424-022-02758-9
Abstrakt: 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, CFTR inh -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 CFTR inh -172 and GlyH-101 caused a significant block of Orai1-mediated whole cell currents, establishing that they likely reduce SOCE via modulation of this Ca 2+ release-activated Ca 2+ (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.
(© 2022. The Author(s).)
Databáze: MEDLINE
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