TY - JOUR
T1 - Repolarization instability and arrhythmia by I-Kr block in single human-induced pluripotent stem cell-derived cardiomyocytes and 2D monolayers
AU - Altrocchi, Cristina
AU - de Korte, Tessa
AU - Bernardi, Joyce
AU - Spätjens, Roel L. H.
AU - Braam, Stefan R.
AU - Heijman, Jordi
AU - Zaza, Antonio
AU - Volders, Paul G. A.
N1 - Funding Information:
This work was supported by the Netherlands CardioVascular Research Initiative (CVON2012-10 PREDICT) and the Health Foundation Limburg, Maastricht, The Netherlands (to P.G.A.V.).
Publisher Copyright:
© The Author(s) 2020. Published by Oxford University Press on behalf of the European Society of Cardiology.
PY - 2020/9
Y1 - 2020/9
N2 - 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 (R) CMs, a commercially available hiPSC-CMs line with a ventricular phenotype, and assessed arrhythmia incidence by I-Kr 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 I-Na, I-Kr, and I-CaL. Intracellular Ca2+ measurements included Ca2+-transients at baseline and during caffeine perfusion. Effects of I-Kr block were assessed in single hiPSC-CMs and 2D monolayers (multi-electrode arrays). Action-potential duration (APD) and its rate dependence in Pluricyte (R) CMs were comparable to those reported for native human CMs. I-Na, I-Kr, and I-CaL 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 (R) 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 (R) 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 I-Kr block.
AB - 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 (R) CMs, a commercially available hiPSC-CMs line with a ventricular phenotype, and assessed arrhythmia incidence by I-Kr 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 I-Na, I-Kr, and I-CaL. Intracellular Ca2+ measurements included Ca2+-transients at baseline and during caffeine perfusion. Effects of I-Kr block were assessed in single hiPSC-CMs and 2D monolayers (multi-electrode arrays). Action-potential duration (APD) and its rate dependence in Pluricyte (R) CMs were comparable to those reported for native human CMs. I-Na, I-Kr, and I-CaL 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 (R) 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 (R) 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 I-Kr block.
KW - Human-induced pluripotent stem cell-derived cardiomyocytes
KW - Ion channel
KW - Calcium handling
KW - Beat-to-beat variability of repolarization
KW - Arrhythmia inducibility
KW - Multi-electrode arrays
KW - SODIUM CURRENT
KW - CALCIUM
KW - CURRENTS
U2 - 10.1093/europace/euaa111
DO - 10.1093/europace/euaa111
M3 - Article
C2 - 32770183
SN - 1099-5129
VL - 22
SP - 1431
EP - 1441
JO - EP Europace
JF - EP Europace
IS - 9
ER -