title: Effect of VX-770 (ivacaftor) and OAG on Ca2+ influx and CFTR activity in G551D and F508del-CFTR expressing cells.
abstract: BACKGROUND
  TRPC6 has been proposed to be responsible for the abnormal OAG-dependent Ca(2+) influx in cystic fibrosis (CF) cells and we hypothesized that it interacts with CFTR. Here, we investigated how this functional complex operates in CF and non-CF epithelial cells.
  
  
  METHODS
  Chinese hamster ovary (CHO) cells stably transfected with pNut vector containing wild type CFTR (CHO-WT), F508del-CFTR (CHO-F508del) or G551D-CFTR(CHO-G551D) were used. Calcium channel activity was recorded using Fluo-4 probe and CFTR activity was measured by iodide efflux technique in the presence of CFTR activators (forskolin, genistein) and VX-770, CFTR inhibitor (GPinh5a) and TRPC non-selective modulators (OAG, SKF96365).
  
  
  RESULTS
  CFTR down regulates OAG Ca(2+) response and OAG Ca(2+) influx increases CFTR chloride efflux. Furthermore, we observed potentiation of G551D-CFTR activity when combining VX-770 and OAG.
  
  
  CONCLUSIONS
  Taking advantage of the functional coupling between OAG-dependent Ca(2+) influx and CFTR, a combination of OAG and VX-770 could be a therapeutic strategy for homozygote patients bearing the G551D-CFTR mutation.
authors.affiliation: Institut de Physiologie et Biologie Cellulaires, Université de Poitiers, CNRS FRE 3511, 86022 Poitiers, France.
authors.forename: Laura
authors.initials: L
authors.lastname: Vachel
authors.forename: Caroline
authors.initials: C
authors.lastname: Norez
authors.forename: Frédéric
authors.initials: F
authors.lastname: Becq
authors.forename: Clarisse
authors.initials: C
authors.lastname: Vandebrouck
mesh_terms: D000627:Aminophenols / Q000494:pharmacology*; D000818:Animals; D016466:CHO Cells; D002118:Calcium / Q000378:metabolism*; D003412:Cricetulus; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000378:metabolism*; D004075:Diglycerides / Q000494:pharmacology*; D015640:Ion Channel Gating / Q000187:drug effects; D008564:Membrane Potentials; D049990:Membrane Transport Modulators / Q000494:pharmacology*; D015363:Quinolones / Q000494:pharmacology*; D050052:TRPC Cation Channels / Q000378:metabolism; D014162:Transfection
chemical_list: C520323:1-oleoyl-2-acetoyl-sn-glycerol; D000627:Aminophenols; D004075:Diglycerides; D049990:Membrane Transport Modulators; D015363:Quinolones; D050052:TRPC Cation Channels; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; C545203:ivacaftor; D002118:Calcium
keywords: CFTR; Calcium signaling; Cystic fibrosis; G551D-CFTR; OAG; TRPC6; VX-770