Generation of cardiomyocytes from human-induced pluripotent stem cells resembling atrial cells with ability to respond to adrenoceptor agonists

Abstract

Atrial fibrillation (AF) is the most common chronic arrhythmia presenting a heavy disease burden. We report a new approach for generating cardiomyocytes (CMs) resembling atrial cells from human-induced pluripotent stem cells (hiPSCs) using a combination of Gremlin 2 and retinoic acid treatment. More than 40% of myocytes showed rod-shaped morphology, expression of CM proteins (including ryanodine receptor 2, α -actinin-2 and F-actin) and striated appearance, all of which were broadly similar to the characteristics of adult atrial myocytes (AMs). Isolated myocytes were electrically quiescent until stimulated to fire action potentials with an AM profile and an amplitude of approximately 100 mV, arising from a resting potential of approximately −70 mV. Single-cell RNA sequence analysis showed a high level of expression of several atrial-specific transcripts including NPPA , MYL7 , HOXA3 , SLN , KCNJ4 , KCNJ5 and KCNA5 . Amplitudes of calcium transients recorded from spontaneously beating cultures were increased by the stimulation of α -adrenoceptors (activated by phenylephrine and blocked by prazosin) or β -adrenoceptors (activated by isoproterenol and blocked by CGP20712A). Our new approach provides human AMs with mature characteristics from hiPSCs which will facilitate drug discovery by enabling the study of human atrial cell signalling pathways and AF. This article is part of the theme issue ‘The heartbeat: its molecular basis and physiological mechanisms’.

Cadherin‐5 facilitated the differentiation of human induced pluripotent stem cells into sinoatrial node‐like pacemaker cells by regulating β‐catenin

“…Pioneering studies have successfully recapitulated cardiac development in a dish, resulting in the generation of functional ventricular, atrial, and even specialized conduction system cells including SANPCs (Devalla et al, 2015; Hausburg et al, 2017; Lee et al, 2017; Li et al, 2021; Protze et al, 2017, 2019; Ren et al, 2019; Zhang et al, 2011; Zhao, Shao, et al, 2020). Despite significant strides in differentiating human pluripotent stem cells into ventricular or atrial myocytes (Ahmad et al, 2023; Cyganek et al, 2018; Devalla et al, 2015; Lee et al, 2017; Zhang et al, 2011), the directed differentiation toward SANPCs has relatively lagged behind. The distinct molecular and functional characteristics of cardiac pacemaker cells, which confer their cardiac pacemaking properties, present unique challenges in recreating these cells in vitro (Barbuti & Robinson, 2015; Christoffels et al, 2010; Kapoor et al, 2013; Liang et al, 2017).…”

Cardiac arrhythmogenesis: roles of ion channels and their functional modification

“…However, many human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) show immature embryonic-like rather than adult atrial/ventricular phenotypes ( Lee et al, 2012 ). Nevertheless, recent reports describe hiPSC-CMs with atrial AP properties and acetylcholine-activated K + current expression ( Ahmad et al, 2023 ). There are recent iPSC models for normal and disease changes in ion channel expression, Ca 2+ homeostasis, neurocardiac interactions, and hypertrophy ( Li et al, 2023 ; Chen et al, 2023 ; Langa et al, 2023 ; Zhou et al, 2023 ).…”

hiPSC-derived cardiomyocytes as a model to study the role of small-conductance Ca2+-activated K+ (SK) ion channel variants associated with atrial fibrillation

“…In hiPSC-aCMs derived from RA-guided differentiation, I Kur is relatively smaller than adult atrial cells but was sufficient to produce a shorter APD compared to hiPSC-vCMs ( Hilderink et al, 2020 ). Otherwise, I Ca,L , I Kr , and I Ks current densities and the expression of their encoding channels are considered comparable to adult cardiomyocytes ( Itzhaki et al, 2011 ; Ma et al, 2011 ; Lahti et al, 2012 ), and I KAch was recently shown to be comparable in hiPSC-aCMs ( Ahmad et al, 2023 ).…”