title: Some gating potentiators, including VX-770, diminish ΔF508-CFTR functional expression.
abstract: Cystic fibrosis (CF) is caused by mutations in the CF transmembrane regulator (CFTR) that result in reduced anion conductance at the apical membrane of secretory epithelia. Treatment of CF patients carrying the G551D gating mutation with the potentiator VX-770 (ivacaftor) largely restores channel activity and has shown substantial clinical benefit. However, most CF patients carry the ΔF508 mutation, which impairs CFTR folding, processing, function, and stability. Studies in homozygous ΔF508 CF patients indicated little clinical benefit of monotherapy with the investigational corrector VX-809 (lumacaftor) or VX-770, whereas combination clinical trials show limited but significant improvements in lung function. We show that VX-770, as well as most other potentiators, reduces the correction efficacy of VX-809 and another investigational corrector, VX-661. To mimic the administration of VX-770 alone or in combination with VX-809, we examined its long-term effect in immortalized and primary human respiratory epithelia. VX-770 diminished the folding efficiency and the metabolic stability of ΔF508-CFTR at the endoplasmic reticulum (ER) and post-ER compartments, respectively, causing reduced cell surface ΔF508-CFTR density and function. VX-770-induced destabilization of ΔF508-CFTR was influenced by second-site suppressor mutations of the folding defect and was prevented by stabilization of the nucleotide-binding domain 1 (NBD1)-NBD2 interface. The reduced correction efficiency of ΔF508-CFTR, as well as of two other processing mutations in the presence of VX-770, suggests the need for further optimization of potentiators to maximize the clinical benefit of corrector-potentiator combination therapy in CF.
authors.affiliation: Department of Physiology, McGill University, Montréal, Quebec H3G 1Y6, Canada.
authors.forename: Guido
authors.initials: G
authors.lastname: Veit
authors.affiliation: Department of Physiology, McGill University, Montréal, Quebec H3G 1Y6, Canada.
authors.forename: Radu G
authors.initials: RG
authors.lastname: Avramescu
authors.affiliation: Department of Physiology, McGill University, Montréal, Quebec H3G 1Y6, Canada.
authors.forename: Doranda
authors.initials: D
authors.lastname: Perdomo
authors.affiliation: Departments of Medicine and Physiology, University of California, San Francisco, San Francisco, CA 94143-0521, USA.
authors.forename: Puay-Wah
authors.initials: PW
authors.lastname: Phuan
authors.affiliation: Department of Physiology, McGill University, Montréal, Quebec H3G 1Y6, Canada.
authors.forename: Miklos
authors.initials: M
authors.lastname: Bagdany
authors.affiliation: Department of Physiology, McGill University, Montréal, Quebec H3G 1Y6, Canada.
authors.forename: Pirjo M
authors.initials: PM
authors.lastname: Apaja
authors.affiliation: Department of Physiology, McGill University, Montréal, Quebec H3G 1Y6, Canada.
authors.forename: Florence
authors.initials: F
authors.lastname: Borot
authors.affiliation: MTA-SE Molecular Biophysics Research Group, Hungarian Academy of Sciences, 1444 Budapest, Hungary. Department of Biophysics and Radiation Biology, Semmelweis University, 1444 Budapest P.O. Box 263, Hungary.
authors.forename: Daniel
authors.initials: D
authors.lastname: Szollosi
authors.affiliation: Department of Physiology, McGill University, Montréal, Quebec H3G 1Y6, Canada.
authors.forename: Yu-Sheng
authors.initials: YS
authors.lastname: Wu
authors.affiliation: Department of Pathology, University of California, San Francisco, San Francisco, CA 94143-0511, USA.
authors.forename: Walter E
authors.initials: WE
authors.lastname: Finkbeiner
authors.affiliation: MTA-SE Molecular Biophysics Research Group, Hungarian Academy of Sciences, 1444 Budapest, Hungary. Department of Biophysics and Radiation Biology, Semmelweis University, 1444 Budapest P.O. Box 263, Hungary.
authors.forename: Tamas
authors.initials: T
authors.lastname: Hegedus
authors.affiliation: Departments of Medicine and Physiology, University of California, San Francisco, San Francisco, CA 94143-0521, USA.
authors.forename: Alan S
authors.initials: AS
authors.lastname: Verkman
authors.affiliation: Department of Physiology, McGill University, Montréal, Quebec H3G 1Y6, Canada. Department of Biochemistry, McGill University, Montréal, Quebec H3G 1Y6, Canada. Groupe de Recherche Axé sur la Structure des Protéines (GRASP), McGill University, Montréal, Quebec H3G 1Y6, Canada. gergely.lukacs@mcgill.ca.
authors.forename: Gergely L
authors.initials: GL
authors.lastname: Lukacs
mesh_terms: D000627:Aminophenols / Q000494:pharmacology*; D001980:Bronchi / Q000473:pathology; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002712:Chlorides / Q000378:metabolism; D003550:Cystic Fibrosis / Q000188:drug therapy / Q000235:genetics / Q000503:physiopathology; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000378:metabolism*; D015536:Down-Regulation / Q000187:drug effects; D004705:Endocytosis / Q000187:drug effects; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D006801:Humans; D015640:Ion Channel Gating / Q000187:drug effects*; D009154:Mutation / Q000235:genetics; D015363:Quinolones / Q000494:pharmacology*; D013489:Suppression, Genetic / Q000187:drug effects; D013997:Time Factors
chemical_list: D000627:Aminophenols; D002712:Chlorides; D015363:Quinolones; C093349:cystic fibrosis transmembrane conductance regulator delta F508; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; C545203:ivacaftor
references.citation: Paediatr Drugs. 2013 Oct;15(5):393-402
references.pmid: 23757197
references.citation: J Phys Chem B. 1998 Apr 30;102(18):3586-616
references.pmid: 24889800
references.citation: Sci Transl Med. 2014 Jul 23;6(246):246ra96
references.pmid: 25101886
references.citation: J Biol Chem. 2010 Nov 12;285(46):35825-35
references.pmid: 20667826
references.citation: Cell Tissue Res. 2006 Mar;323(3):405-15
references.pmid: 16249874
references.citation: Cold Spring Harb Perspect Med. 2013 Jul 01;3(7):
references.pmid: 23818513
references.citation: Methods Mol Biol. 2011;741:39-54
references.pmid: 21594777
references.citation: Proc Natl Acad Sci U S A. 2011 Nov 15;108(46):18843-8
references.pmid: 21976485
references.citation: J Clin Invest. 2001 Dec;108(11):1705-15
references.pmid: 11733566
references.citation: J Physiol. 2014 May 1;592(9):1931-47
references.pmid: 24591578
references.citation: J Physiol. 2000 Apr 15;524 Pt 2:317-30
references.pmid: 10766914
references.citation: Proc Natl Acad Sci U S A. 2008 Mar 4;105(9):3256-61
references.pmid: 18305154
references.citation: J Clin Invest. 2005 Sep;115(9):2564-71
references.pmid: 16127463
references.citation: J Biol Chem. 2005 Jan 14;280(2):1346-53
references.pmid: 15528182
references.citation: Mol Biol Cell. 2012 Nov;23(21):4188-202
references.pmid: 22973054
references.citation: FASEB J. 2010 Nov;24(11):4178-86
references.pmid: 20581223
references.citation: Science. 2010 Aug 13;329(5993):805-10
references.pmid: 20595578
references.citation: Biochim Biophys Acta. 2006 May;1758(5):565-72
references.pmid: 16624253
references.citation: PLoS One. 2010 Nov 30;5(11):e15458
references.pmid: 21152102
references.citation: Nat Rev Drug Discov. 2012 Apr 30;11(5):349-50
references.pmid: 22543461
references.citation: Mol Pharmacol. 2014 Jul;86(1):42-51
references.pmid: 24737137
references.citation: Bioinformatics. 2013 Apr 1;29(7):845-54
references.pmid: 23407358
references.citation: J Cyst Fibros. 2014 Jan;13(1):29-36
references.pmid: 23891399
references.citation: Proc Natl Acad Sci U S A. 2009 Nov 3;106(44):18825-30
references.pmid: 19846789
references.citation: Proc Natl Acad Sci U S A. 2012 Dec 4;109(49):20035-40
references.pmid: 23169653
references.citation: J Cyst Fibros. 2012 May;11(3):237-45
references.pmid: 22293084
references.citation: J Comput Chem. 2009 Dec;30(16):2785-91
references.pmid: 19399780
references.citation: Bioinformatics. 2003 Dec 12;19(18):2500-1
references.pmid: 14668246
references.citation: J Gen Physiol. 2005 Apr;125(4):377-94
references.pmid: 15767296
references.citation: J Biol Chem. 2002 Sep 27;277(39):35896-905
references.pmid: 12110684
references.citation: Nat Struct Mol Biol. 2005 Jan;12(1):17-25
references.pmid: 15619635
references.citation: J Biol Chem. 2003 Sep 12;278(37):35079-85
references.pmid: 12832418
references.citation: Biochem Pharmacol. 2013 Sep 1;86(5):612-9
references.pmid: 23835419
references.citation: J Biol Chem. 1999 Jul 30;274(31):21873-7
references.pmid: 10419506
references.citation: Nat Med. 2013 Jul;19(7):939-45
references.pmid: 23727931
references.citation: Methods Mol Biol. 2011;741:301-17
references.pmid: 21594793
references.citation: Int J Biochem Cell Biol. 2014 Jul;52:83-93
references.pmid: 24569122
references.citation: N Engl J Med. 2011 Nov 3;365(18):1663-72
references.pmid: 22047557
references.citation: Chest. 2011 Jun;139(6):1480-1490
references.pmid: 21652558
references.citation: J Cell Biol. 2010 Nov 1;191(3):553-70
references.pmid: 20974815
references.citation: Expert Opin Emerg Drugs. 2014 Mar;19(1):143-55
references.pmid: 24479826
references.citation: Mol Biol Cell. 2010 Aug 1;21(15):2639-48
references.pmid: 20554763
references.citation: Cell. 2012 Jan 20;148(1-2):164-74
references.pmid: 22265409
references.citation: Cell. 2012 Jan 20;148(1-2):150-63
references.pmid: 22265408
references.citation: N Engl J Med. 2005 May 12;352(19):1992-2001
references.pmid: 15888700
references.citation: Cell Biol Int. 2011 May;35(5):463-6
references.pmid: 21476987
references.citation: Cell. 1993 Jul 2;73(7):1251-4
references.pmid: 7686820
references.citation: J Med Chem. 2011 Aug 11;54(15):5468-77
references.pmid: 21707078
references.citation: J Physiol. 2006 Apr 15;572(Pt 2):347-58
references.pmid: 16484308
references.citation: Mol Biol Cell. 2013 Oct;24(19):3016-24
references.pmid: 23924900
references.citation: Protein Sci. 2010 Oct;19(10):1917-31
references.pmid: 20687133
references.citation: Thorax. 2012 Jan;67(1):12-8
references.pmid: 21825083
references.citation: N Engl J Med. 2010 Nov 18;363(21):1991-2003
references.pmid: 21083385
references.citation: Methods Mol Med. 2005;107:183-206
references.pmid: 15492373
references.citation: Science. 1992 May 8;256(5058):774-9
references.pmid: 1375392
references.citation: Am J Physiol. 1992 Jun;262(6 Pt 1):L713-24
references.pmid: 1616056
references.citation: Am J Respir Crit Care Med. 2006 Oct 1;174(7):787-94
references.pmid: 16840743
references.citation: J Gen Physiol. 1998 Mar;111(3):477-90
references.pmid: 9482713
references.citation: Nat Chem Biol. 2013 Jul;9(7):444-54
references.pmid: 23666117
references.citation: J Clin Invest. 1994 Feb;93(2):461-6
references.pmid: 8113384
references.citation: Chest. 2012 Sep;142(3):718-724
references.pmid: 22383668
references.citation: Chem Biol. 2013 Jul 25;20(7):943-55
references.pmid: 23890012
references.citation: Annu Rev Biochem. 2008;77:701-26
references.pmid: 18304008
references.citation: J Clin Invest. 1999 May 15;103(10):1379-89
references.pmid: 10330420