Potentiators exert distinct effects on human, murine, and Xenopus CFTR.
VX-770 (Ivacaftor) has been approved for clinical usage in cystic fibrosis patients with several CFTR mutations. Yet the binding site(s) on CFTR for this compound and other small molecule potentiators are unknown. We hypothesize that insight into this question could be gained by comparing the effect of potentiators on CFTR channels from different origins, e.g., human, mouse, and Xenopus (frog). In the present study, we combined this comparative molecular pharmacology approach with that of computer-aided drug discovery to identify and characterize new potentiators of CFTR and to explore possible mechanism of action. Our results demonstrate that 1) VX-770, NPPB, GlyH-101, P1, P2, and P3 all exhibited ortholog-specific behavior in that they potentiated hCFTR, mCFTR, and xCFTR with different efficacies; 2) P1, P2, and P3 potentiated hCFTR in excised macropatches in a manner dependent on the degree of PKA-mediated stimulation; 3) P1 and P2 did not have additive effects, suggesting that these compounds might share binding sites. Also 4) using a pharmacophore modeling approach, we identified three new potentiators (IOWH-032, OSSK-2, and OSSK-3) that have structures similar to GlyH-101 and that also exhibit ortholog-specific potentiation of CFTR. These could potentially serve as lead compounds for development of new drugs for the treatment of cystic fibrosis. The ortholog-specific behavior of these compounds suggest that a comparative pharmacology approach, using cross-ortholog chimeras, may be useful for identification of binding sites on human CFTR.
Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis, and Sleep, Department of Pediatrics, Emory + Children's Center for Cystic Fibrosis and Airways Disease Research, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, Georgia; and.
Guiying
G
Cui
Department of Chemistry, Bar-Ilan University, Ramat-Gan, Israel.
Netaly
N
Khazanov
Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis, and Sleep, Department of Pediatrics, Emory + Children's Center for Cystic Fibrosis and Airways Disease Research, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, Georgia; and.
Brandon B
BB
Stauffer
Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis, and Sleep, Department of Pediatrics, Emory + Children's Center for Cystic Fibrosis and Airways Disease Research, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, Georgia; and.
Daniel T
DT
Infield
Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis, and Sleep, Department of Pediatrics, Emory + Children's Center for Cystic Fibrosis and Airways Disease Research, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, Georgia; and.
Barry R
BR
Imhoff
Department of Chemistry, Bar-Ilan University, Ramat-Gan, Israel.
Hanoch
H
Senderowitz
Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis, and Sleep, Department of Pediatrics, Emory + Children's Center for Cystic Fibrosis and Airways Disease Research, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, Georgia; and namccar@emory.edu.
Nael A
NA
McCarty
D000595:Amino Acid Sequence; D000627:Aminophenols / Q000494:pharmacology; D000818:Animals; D002478:Cells, Cultured; D065101:Chloride Channel Agonists / Q000494:pharmacology*; D003550:Cystic Fibrosis / Q000188:drug therapy / Q000235:genetics; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000502:physiology*; D004353:Drug Evaluation, Preclinical; D005998:Glycine / Q000031:analogs & derivatives / Q000494:pharmacology; D006834:Hydrazines / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice; D009579:Nitrobenzoates / Q000494:pharmacology; D018408:Patch-Clamp Techniques; D015363:Quinolones / Q000494:pharmacology; D017384:Sequence Deletion; D014982:Xenopus laevis
D000627:Aminophenols; C505032:CFTR protein, human; D065101:Chloride Channel Agonists; D006834:Hydrazines; C548779:N-(2-naphthalenyl)-((3,5-dibromo-2,4-dihydroxyphenyl)methylene)glycine hydrazide; D009579:Nitrobenzoates; D015363:Quinolones; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; C545203:ivacaftor; C058176:5-nitro-2-(3-phenylpropylamino)benzoic acid; D005998:Glycine
Xenopus CFTR; blocker; human CFTR; murine CFTR; pharmacophore model; potentiator