title: Readthrough-Promoting Drugs Gentamicin and PTC124 Fail to Rescue Nav1.5 Function of Human-Induced Pluripotent Stem Cell-Derived Cardiomyocytes Carrying Nonsense Mutations in the Sodium Channel Gene SCN5A.
abstract: Several compounds have been reported to induce translational readthrough of premature stop codons resulting in the production of full-length protein by interfering with ribosomal proofreading. Here we examined the effect of 2 of these compounds, gentamicin and PTC124, in human-induced pluripotent stem cell (hiPSC)-derived cardiomyocytes bearing nonsense mutations in the sodium channel gene SCN5A, which are associated with conduction disease and potential lethal arrhythmias.
  
  
  
  We generated hiPSC from 2 patients carrying the mutations R1638X and W156X. hiPSC-derived cardiomyocytes from both patients recapitulated the expected electrophysiological phenotype, as evidenced by reduced Na+currents and action potential upstroke velocities compared with hiPSC-derived cardiomyocytes from 2 unrelated control individuals. While we were able to confirm the readthrough efficacy of the 2 drugs in Human Embryonic Kidney 293 cells, we did not observe rescue of the electrophysiological phenotype in hiPSC-derived cardiomyocytes from the patients.
  
  
  
  We conclude that these drugs are unlikely to present an effective treatment for patients carrying the loss-of-function SCN5A gene mutations examined in this study.
authors: From the Department of Anatomy and Embryology, Leiden University Medical Center, Leiden (G.K., S.C., S.v.d.P., M.B., C.L.M.); and Heart Center, Department of Experimental and Clinical Cardiology (C.C.V., A.A.M.W., C.R.B.) and Department of Anatomy and Embryology, Academic Medical Center (A.O.V.), Amsterdam, The Netherlands.
authors: Georgios
authors: G
authors: Kosmidis
authors: From the Department of Anatomy and Embryology, Leiden University Medical Center, Leiden (G.K., S.C., S.v.d.P., M.B., C.L.M.); and Heart Center, Department of Experimental and Clinical Cardiology (C.C.V., A.A.M.W., C.R.B.) and Department of Anatomy and Embryology, Academic Medical Center (A.O.V.), Amsterdam, The Netherlands.
authors: Christiaan C
authors: CC
authors: Veerman
authors: From the Department of Anatomy and Embryology, Leiden University Medical Center, Leiden (G.K., S.C., S.v.d.P., M.B., C.L.M.); and Heart Center, Department of Experimental and Clinical Cardiology (C.C.V., A.A.M.W., C.R.B.) and Department of Anatomy and Embryology, Academic Medical Center (A.O.V.), Amsterdam, The Netherlands.
authors: Simona
authors: S
authors: Casini
authors: From the Department of Anatomy and Embryology, Leiden University Medical Center, Leiden (G.K., S.C., S.v.d.P., M.B., C.L.M.); and Heart Center, Department of Experimental and Clinical Cardiology (C.C.V., A.A.M.W., C.R.B.) and Department of Anatomy and Embryology, Academic Medical Center (A.O.V.), Amsterdam, The Netherlands.
authors: Arie O
authors: AO
authors: Verkerk
authors: From the Department of Anatomy and Embryology, Leiden University Medical Center, Leiden (G.K., S.C., S.v.d.P., M.B., C.L.M.); and Heart Center, Department of Experimental and Clinical Cardiology (C.C.V., A.A.M.W., C.R.B.) and Department of Anatomy and Embryology, Academic Medical Center (A.O.V.), Amsterdam, The Netherlands.
authors: Simone
authors: S
authors: van de Pas
authors: From the Department of Anatomy and Embryology, Leiden University Medical Center, Leiden (G.K., S.C., S.v.d.P., M.B., C.L.M.); and Heart Center, Department of Experimental and Clinical Cardiology (C.C.V., A.A.M.W., C.R.B.) and Department of Anatomy and Embryology, Academic Medical Center (A.O.V.), Amsterdam, The Netherlands.
authors: Milena
authors: M
authors: Bellin
authors: From the Department of Anatomy and Embryology, Leiden University Medical Center, Leiden (G.K., S.C., S.v.d.P., M.B., C.L.M.); and Heart Center, Department of Experimental and Clinical Cardiology (C.C.V., A.A.M.W., C.R.B.) and Department of Anatomy and Embryology, Academic Medical Center (A.O.V.), Amsterdam, The Netherlands.
authors: Arthur A M
authors: AA
authors: Wilde
authors: From the Department of Anatomy and Embryology, Leiden University Medical Center, Leiden (G.K., S.C., S.v.d.P., M.B., C.L.M.); and Heart Center, Department of Experimental and Clinical Cardiology (C.C.V., A.A.M.W., C.R.B.) and Department of Anatomy and Embryology, Academic Medical Center (A.O.V.), Amsterdam, The Netherlands.
authors: Christine L
authors: CL
authors: Mummery
authors: From the Department of Anatomy and Embryology, Leiden University Medical Center, Leiden (G.K., S.C., S.v.d.P., M.B., C.L.M.); and Heart Center, Department of Experimental and Clinical Cardiology (C.C.V., A.A.M.W., C.R.B.) and Department of Anatomy and Embryology, Academic Medical Center (A.O.V.), Amsterdam, The Netherlands. c.r.bezzina@amc.uva.nl.
authors: Connie R
authors: CR
authors: Bezzina
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000328:Adult; D053840:Brugada Syndrome / Q000188:drug therapy* / Q000235:genetics* / Q000378:metabolism; D000075224:Cardiac Conduction System Disease; D002478:Cells, Cultured; D018389:Codon, Nonsense; D022062:Electrophysiologic Techniques, Cardiac; D005839:Gentamicins / Q000494:pharmacology*; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D032383:Myocytes, Cardiac / Q000378:metabolism*; D062554:NAV1.5 Voltage-Gated Sodium Channel / Q000235:genetics / Q000378:metabolism*; D010069:Oxadiazoles / Q000494:pharmacology*; D010641:Phenotype
chemical_list: D018389:Codon, Nonsense; D005839:Gentamicins; D062554:NAV1.5 Voltage-Gated Sodium Channel; D010069:Oxadiazoles; C568320:SCN5A protein, human; C515878:ataluren
keywords: SCN5A; induced pluripotent stem cells; mutation; nonsense mutation; readthrough; sodium channels