1. Repolarization instability and arrhythmia by IKr block in single human-induced pluripotent stem cell-derived cardiomyocytes and 2D monolayers
- Author
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Antonio Zaza, Paul G.A. Volders, Roel L.H.M.G. Spätjens, Cristina Altrocchi, Tessa de Korte, Joyce Bernardi, Jordi Heijman, Stefan R. Braam, Cardiologie, RS: Carim - H04 Arrhythmogenesis and cardiogenetics, RS: Carim - H01 Clinical atrial fibrillation, MUMC+: MA Med Staf Spec Cardiologie (9), Altrocchi, C, de Korte, T, Bernardi, J, Spatjens, R, Braam, S, Heijman, J, Zaza, A, and Volders, P
- Subjects
CURRENTS ,Induced Pluripotent Stem Cells ,Action Potentials ,Dofetilide ,030204 cardiovascular system & hematology ,Multi-electrode array ,CALCIUM ,Afterdepolarization ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Basic Science ,Physiology (medical) ,medicine ,Human-induced pluripotent stem cell-derived cardiomyocyte ,Repolarization ,Humans ,Myocytes, Cardiac ,AcademicSubjects/MED00200 ,Calcium handling ,Induced pluripotent stem cell ,Arrhythmia inducibility ,Multi-electrode arrays ,Ion channel ,SODIUM CURRENT ,health care economics and organizations ,030304 developmental biology ,Human-induced pluripotent stem cell-derived cardiomyocytes ,0303 health sciences ,business.industry ,Cardiac arrhythmia ,Arrhythmias, Cardiac ,Electrophysiological Phenomena ,Electrophysiology ,chemistry ,Biophysics ,Cardiology and Cardiovascular Medicine ,Caffeine ,business ,Beat-to-beat variability of repolarization ,medicine.drug - Abstract
Aims Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) have proven valuable for studies in drug discovery and safety, although limitations regarding their structural and electrophysiological characteristics persist. In this study, we investigated the electrophysiological properties of Pluricyte® CMs, a commercially available hiPSC-CMs line with a ventricular phenotype, and assessed arrhythmia incidence by IKr block at the single-cell and 2D monolayer level. Methods and results Action potentials were measured at different pacing frequencies, using dynamic clamp. Through voltage-clamp experiments, we determined the properties of INa, IKr, and ICaL. Intracellular Ca2+ measurements included Ca2+-transients at baseline and during caffeine perfusion. Effects of IKr block were assessed in single hiPSC-CMs and 2D monolayers (multi-electrode arrays). Action-potential duration (APD) and its rate dependence in Pluricyte® CMs were comparable to those reported for native human CMs. INa, IKr, and ICaL revealed amplitudes, kinetics, and voltage dependence of activation/inactivation similar to other hiPSC-CM lines and, to some extent, to native CMs. Near-physiological Ca2+-induced Ca2+ release, response to caffeine and excitation–contraction coupling gain characterized the cellular Ca2+-handling. Dofetilide prolonged the APD and field-potential duration, and induced early afterdepolarizations. Beat-to-beat variability of repolarization duration increased significantly before the first arrhythmic events in single Pluricyte® CMs and 2D monolayers, and predicted pending arrhythmias better than action-potential prolongation. Conclusion Taking their ion-current characteristics and Ca2+ handling into account, Pluricyte® CMs are suitable for in vitro studies on action potentials and field potentials. Beat-to-beat variability of repolarization duration proved useful to evaluate the dynamics of repolarization instability and demonstrated its significance as proarrhythmic marker in hiPSC-CMs during IKr block.
- Published
- 2019