title: Allele-specific RNA interference rescues the long-QT syndrome phenotype in human-induced pluripotency stem cell cardiomyocytes.
abstract: OBJECTIVE
  Long-QT syndromes (LQTS) are mostly autosomal-dominant congenital disorders associated with a 1:1000 mutation frequency, cardiac arrest, and sudden death. We sought to use cardiomyocytes derived from human-induced pluripotency stem cells (hiPSCs) as an in vitro model to develop and evaluate gene-based therapeutics for the treatment of LQTS.
  
  
  RESULTS
  We produced LQTS-type 2 (LQT2) hiPSC cardiomyocytes carrying a KCNH2 c.G1681A mutation in a IKr ion-channel pore, which caused impaired glycosylation and channel transport to cell surface. Allele-specific RNA interference (RNAi) directed towards the mutated KCNH2 mRNA caused knockdown, while leaving the wild-type mRNA unaffected. Electrophysiological analysis of patient-derived LQT2 hiPSC cardiomyocytes treated with mutation-specific siRNAs showed normalized action potential durations (APDs) and K(+) currents with the concurrent rescue of spontaneous and drug-induced arrhythmias (presented as early-afterdepolarizations).
  
  
  CONCLUSIONS
  These findings provide in vitro evidence that allele-specific RNAi can rescue diseased phenotype in LQTS cardiomyocytes. This is a potentially novel route for the treatment of many autosomal-dominant-negative disorders, including those of the heart.
authors.affiliation: Wolfson Centre for Stem Cells, Tissue Engineering and Modelling (STEM), University of Nottingham, Nottingham NG7 2RD, UK.
authors.forename: Elena
authors.initials: E
authors.lastname: Matsa
authors.forename: James E
authors.initials: JE
authors.lastname: Dixon
authors.forename: Christopher
authors.initials: C
authors.lastname: Medway
authors.forename: Orestis
authors.initials: O
authors.lastname: Georgiou
authors.forename: Minal J
authors.initials: MJ
authors.lastname: Patel
authors.forename: Kevin
authors.initials: K
authors.lastname: Morgan
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Kemp
authors.forename: Andrew
authors.initials: A
authors.lastname: Staniforth
authors.forename: Ian
authors.initials: I
authors.lastname: Mellor
authors.forename: Chris
authors.initials: C
authors.lastname: Denning
mesh_terms: D000072237:ERG1 Potassium Channel; D055724:Electrophysiological Phenomena / Q000235:genetics; D051638:Ether-A-Go-Go Potassium Channels / Q000235:genetics*; D015870:Gene Expression / Q000235:genetics; D055785:Gene Knockdown Techniques; D015316:Genetic Therapy; D006801:Humans; D008133:Long QT Syndrome / Q000235:genetics* / Q000503:physiopathology / Q000628:therapy; D020125:Mutation, Missense / Q000235:genetics; D032383:Myocytes, Cardiac / Q000502:physiology*; D010641:Phenotype; D039904:Pluripotent Stem Cells / Q000502:physiology*; D034622:RNA Interference / Q000502:physiology*; D014162:Transfection
chemical_list: D000072237:ERG1 Potassium Channel; D051638:Ether-A-Go-Go Potassium Channels; C000606913:KCNH2 protein, human
keywords: Arrhythmia; Electrophysiology; Gene therapy; Long-QT syndrome; iPS cells