From Early Embryonic to Adult Stage: Comparative Study of Action Potentials of Native and Pluripotent Stem Cell-Derived Cardiomyocytes

Abstract

Cardiomyocytes (CMs) derived from induced pluripotent stem cells (iPS-CMs) are promising candidates for cell therapy, drug screening, and developmental studies. It is known that iPS-CMs possess immature electrophysiological properties, but an exact characterization of their developmental stage and subtype differentiation is hampered by a lack of knowledge of electrophysiological properties of native CMs from different developmental stages and origins within the heart. Thus, we sought to systematically investigate action potential (AP) properties of native murine CMs and to establish a database that allows classification of stem cell-derived CMs. Hearts from 129S2PasCrl mice were harvested at days 9-10, 12-14, and 16-18 postcoitum, as well as 1 day, 3-4 days, 1-2 weeks, 3-4 weeks, and 6 weeks postpartum. AP recordings in left and right atria and at apical, medial, and basal left and right ventricles were performed with sharp glass microelectrodes. Measurements revealed significant changes in AP morphology during pre- and postnatal murine development and significant differences between atria and ventricles, enabling a classification of developmental stage and subtype differentiation of stem cell-derived CMs based on their AP properties. For iPS-CMs derived from cell line TiB7.4, a typical ventricular phenotype was demonstrated at later developmental stages, while there were electrophysiological differences from atrial as well as ventricular native CMs at earlier stages. This finding supports that iPS-CMs can develop AP properties similar to native CMs, but points to differences in the maturation process between iPS-CMs and native CMs, which may be explained by dissimilar conditions during in vitro differentiation and in vivo development.

A Multiwell Cardiac μGMEA Platform for Action Potential Recordings from Human iPSC-Derived Cardiomyocyte Constructs

“…Nonetheless, our hiPSC-CMs are still in the early stage of development and are structurally immature ( Figure 1 B) compared with adult cardiomyocytes. Excitation-contraction coupling studies on hiPSC-CMs at day 30 post differentiation ( Figures 1 D–1G) suggest that they straddle along the embryonic to neonatal stage as seen in other studies ( Lundy et al., 2013 , Peinkofer et al., 2016 ). Cardiac μGMEA electrophysiological data reported in this study also demonstrate electrical maturational plasticity.…”

Optimizing the Use of iPSC-CMs for Cardiac Regeneration in Animal Models

“…Studies investigating iPSC-CM metabolism have also found iPSC-CM have a fetal phenotype. iPSC-CMs utilize glucose to meet its energy demands whereas adult CMs preferentially use fatty acids oxidation [37,[143][144][145][146]216].…”

“…Characterization of iPSC-CM metabolism shows that they mostly rely on glucose and amino acids and to a lesser extent on fatty acids whereas in adult CMs, the dominant metabolic pathway is fatty acid oxidation [143][144][145][146]. Figure 1 compares the different metabolic substrates and pathways used by iPSC-CMs and adult CMs.…”

Kinin B2-Receptor in human iPSC differentiation into cardiomyocytes

“…Unfortunately, due to our inability to standardize working antibodies for atrial and nodal subtypes during this project, it was not possible to report whether such shift can also be verified in the molecular level. However, it could be argued that the parameters that support AP classification into different subtypes would only be valid during a limited period of development, rather than throughout the entire cardiogenesis, with eventual (and confounding) overlapping of AP properties (112). Moreover, it has been proposed that the AP kinetic parameters fail in efficiently clustering differentiated hiPSC-CM into discrete subpopulations (64).…”

“…The functionality of ion channel matures as in vivo cardiogenesis progresses (113)(114)(115) and this culminates in electrophysiological alterations on AP kinetic parameters (112).…”