Jacqueline A Treat1, Robert J Goodrow1, Corina T Bot2, Rodolfo J Haedo2, Jonathan M Cordeiro3. 1. Department of Experimental Cardiology, Masonic Medical Research Institute, Utica, NY 13501 USA. 2. Nanion Technologies, 1 Naylon Ave. Suite C, Livingston, NJ 07039, USA. 3. Department of Experimental Cardiology, Masonic Medical Research Institute, Utica, NY 13501 USA. Electronic address: jcordeiro@mmri.edu.
Abstract
BACKGROUND: Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are used for many applications including safety pharmacology. However, a deficiency or complete absence of several K+ currents suggests repolarization reserve is low in hiPSC-CMs. We determined whether a dual Ito and IKr activator can improve repolarization reserve in hiPSC-CMs resulting in a more electrophysiologically mature phenotype. METHODS AND RESULTS: Human iPSC were maintained on growth factor and differentiated into the cardiac phenotype by addition of selective Wnt molecules. Current and voltage clamp recordings in single cells were made using patch electrodes. Extracellular field potentials were made using a microelectrode array on hiPSC monolayers. Action potential recordings from hiPSC-CMs following application of an IKr inhibitor resulted in depolarization of the membrane potential and prolongation of the APD. A flattening of the T-wave was noted on the pseudo-ECG. In contrast, application of the IKr and Ito agonist, NS3623, resulted in hyperpolarization of the membrane, slowing of the spontaneous rate and shortening of the APD. Voltage clamp recording showed a significant increase in IKr; no enhancement of Ito in hiPSC-CMs was noted. AP clamp experiments revealed that IKr plays a role in both phase 3 repolarization and phase 4 depolarization. mRNA analysis revealed that KCNH2 is abundantly expressed in hiPSC-CM, consistent with electrophysiological recordings. CONCLUSIONS: Although NS3623 is a dual Ito and IKr activator in ventricular myocytes, application of this compound to hiPSC-CMs enhanced only IKr and no effect on Ito was noted. Our results suggest IKr enhancement can improve repolarization reserve in this cell type. The disconnect between a dramatic increase in Ito in adult myocytes versus the lack of effect in hiPSC-CMs suggest that the translation of pharmacological effects in hiPSC-CM to adult myocytes should be viewed with caution.
BACKGROUND:Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are used for many applications including safety pharmacology. However, a deficiency or complete absence of several K+ currents suggests repolarization reserve is low in hiPSC-CMs. We determined whether a dual Ito and IKr activator can improve repolarization reserve in hiPSC-CMs resulting in a more electrophysiologically mature phenotype. METHODS AND RESULTS:Human iPSC were maintained on growth factor and differentiated into the cardiac phenotype by addition of selective Wnt molecules. Current and voltage clamp recordings in single cells were made using patch electrodes. Extracellular field potentials were made using a microelectrode array on hiPSC monolayers. Action potential recordings from hiPSC-CMs following application of an IKr inhibitor resulted in depolarization of the membrane potential and prolongation of the APD. A flattening of the T-wave was noted on the pseudo-ECG. In contrast, application of the IKr and Ito agonist, NS3623, resulted in hyperpolarization of the membrane, slowing of the spontaneous rate and shortening of the APD. Voltage clamp recording showed a significant increase in IKr; no enhancement of Ito in hiPSC-CMs was noted. AP clamp experiments revealed that IKr plays a role in both phase 3 repolarization and phase 4 depolarization. mRNA analysis revealed that KCNH2 is abundantly expressed in hiPSC-CM, consistent with electrophysiological recordings. CONCLUSIONS: Although NS3623 is a dual Ito and IKr activator in ventricular myocytes, application of this compound to hiPSC-CMs enhanced only IKr and no effect on Ito was noted. Our results suggest IKr enhancement can improve repolarization reserve in this cell type. The disconnect between a dramatic increase in Ito in adult myocytes versus the lack of effect in hiPSC-CMs suggest that the translation of pharmacological effects in hiPSC-CM to adult myocytes should be viewed with caution.
Authors: Akwasi Darkwah Akwaboah; Pascal Yamlome; Jacqueline A Treat; Jonathan M Cordeiro; Makarand Deo Journal: Annu Int Conf IEEE Eng Med Biol Soc Date: 2020-07
Authors: Michelangelo Paci; Jussi T Koivumäki; Hua Rong Lu; David J Gallacher; Elisa Passini; Blanca Rodriguez Journal: Front Pharmacol Date: 2021-03-15 Impact factor: 5.810
Authors: Akwasi D Akwaboah; Bright Tsevi; Pascal Yamlome; Jacqueline A Treat; Maila Brucal-Hallare; Jonathan M Cordeiro; Makarand Deo Journal: Front Physiol Date: 2021-06-16 Impact factor: 4.566
Authors: Hector Barajas-Martinez; Maya Smith; Dan Hu; Robert J Goodrow; Colleen Puleo; Can Hasdemir; Charles Antzelevitch; Ryan Pfeiffer; Jacqueline A Treat; Jonathan M Cordeiro Journal: Stem Cells Int Date: 2020-09-01 Impact factor: 5.443
Authors: Jacqueline A Treat; Ryan Pfeiffer; Hector Barajas-Martinez; Robert J Goodrow; Corina Bot; Rodolfo J Haedo; Ronald Knox; Jonathan M Cordeiro Journal: Int J Mol Sci Date: 2021-07-01 Impact factor: 5.923