CysLT1 receptor antagonists pranlukast and zafirlukast inhibit LRRC8-mediated volume regulated anion channels independently of the receptor.
Am J Physiol Cell Physiol
; 317(4): C857-C866, 2019 10 01.
Article
en En
| MEDLINE
| ID: mdl-31390227
ABSTRACT
Volume-regulated anion channels (VRACs) encoded by the leucine-rich repeat containing 8 (LRRC8) gene family play critical roles in myriad cellular processes and might represent druggable targets. The dearth of pharmacological compounds available for studying VRAC physiology led us to perform a high-throughput screen of 1,184 of US Food and Drug Administration-approved drugs for novel VRAC modulators. We discovered the cysteinyl leukotriene receptor 1 (CysLT1R) antagonist, pranlukast, as a novel inhibitor of endogenous VRAC expressed in human embryonic kidney 293 (HEK293) cells. Pranlukast inhibits VRAC voltage-independently, reversibly, and dose-dependently with a maximal efficacy of only ~50%. The CysLT1R pathway has been implicated in activation of VRAC in other cell types, prompting us to test whether pranlukast requires the CysLT1R for inhibition of VRAC. Quantitative PCR analysis demonstrated that CYSLTR1 mRNA is virtually undetectable in HEK293 cells. Furthermore, the CysLT1R agonist leukotriene D4 had no effect on VRAC activity and failed to stimulate Gq-coupled receptor signaling. Heterologous expression of the CysLT1R reconstituted LTD4-CysLT1R- Gq-calcium signaling in HEK293 cells but had no effect on VRAC inhibition by pranlukast. Finally, we show the CysLT1R antagonist zafirlukast inhibits VRAC with an IC50 of ~17 µM and does so with full efficacy. Our data suggest that both pranlukast and zafirlukast are likely direct channel inhibitors that work independently of the CysLT1R. This study provides clarifying insights into the putative role of leukotriene signaling in modulation of VRAC and identifies two new chemical scaffolds that can be used for development of more potent and specific VRAC inhibitors.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Cromonas
/
Receptores de Leucotrienos
/
Antagonistas de Leucotrieno
/
Células Epiteliales
Límite:
Humans
Idioma:
En
Revista:
Am J Physiol Cell Physiol
Asunto de la revista:
FISIOLOGIA
Año:
2019
Tipo del documento:
Article