Beat Rate Variability in Murine Embryonic Stem Cell-Derived Cardiomyocytes: Effect of Antiarrhythmic Drugs

Abstract

Background/Aims: Heart rate variability (HRV) refers to the fluctuation of the time interval between consecutive heartbeats in humans. It has recently been discovered that cardiomyocytes derived from human embryonic and induced pluripotent stem cells show beat rate variability (BRV) that is similar to the HRV in humans. In the present study, clinical aspects of HRV were transferred to an in vitro model. The aims of the study were to explore the BRV in murine embryonic stem cell (mESC)-derived cardiomyocytes and to demonstrate the influence of antiarrhythmic drugs on BRV as has been shown in clinical trials previously. Methods: The Microelectrode Array (MEA) technique was used to perform short-term recordings of extracellular field potentials (FPs) of spontaneously beating cardiomyocytes derived from mESCs (D3 cell line, αPig-44). Offline analysis was focused on time domain and nonlinear methods. Results: The Poincaré-Plot analysis of measurements without pharmacological intervention revealed that three different shapes of scatter plots occurred most frequently. Comparable shapes have been described in clinical studies before. The antiarrhythmic drugs Ivabradine, Verapamil and Sotalol augmented BRV, whereas Flecainide decreased BRV parameters at low concentrations (SDSD 79.0 ± 8.7% of control at 10^-9 M, p < 0.05) and increased variability measures at higher concentrations (SDNN 258.8 ± 42.7% of control at 10^-5 M, p < 0.05). Amiodarone and Metoprolol did not alter BRV significantly. Conclusions: Spontaneously beating cardiomyocytes derived from mESCs showed BRV that appears to be similar to the HRV known from humans. Antiarrhythmic drugs affected BRV parameters similar to clinical observations. Therefore, our study demonstrates that this in vitro model can contribute to a better understanding of electrophysiological properties of mESC-derived cardiomyocytes and might serve as a valuable tool for drug safety screening.

The Expression of Uncoupling Protein 3 Coincides With the Fatty Acid Oxidation Type of Metabolism in Adult Murine Heart

“…By using mESC-derived CM in this study, we have revealed that the appearance of UCP3 in heart cannot be attributed to the establishment of electrical/contractile activity in CM, which is the main criterion for the successful mESC differentiation in all protocols ( Seiler and Spielmann, 2011 ; Niehoff et al, 2016 ). UCP3′s presence is rather an indicator of CM’ maturity, which includes (i) the presence of specific CM markers – SERCA2, TnC and GATA4 ( Figure 1C ), (ii) an increase of cristae density in mitochondria ( Figure 3C ), (iii) the appearance of lipid droplets (LD) and the establishment of multiple contacts between LD and mitochondria ( Figure 3D , arrows), and, the most important, (iv) a switch to FAO as a main type of cell metabolism ( Figure 4 and ( Lopaschuk and Jaswal, 2010 ; Mdaki et al, 2016 )).…”

Embryonic stem‐like cells from rabbit blastocysts cultured with melatonin could differentiate into three germ layers in vitro and in vivo

“…For human pluripotent cells, embryoid body formation or other growth factors are essential for cardiomyocyte differentiation (Mummery et al, ). Murine or human ESC‐derived cardiomyocytes have already provided a promising source of material for cell therapy and drug screening (Zhang et al, ; Niehoff et al, ), so our rES‐like cells could be a source of material for heart disease and differentiation research.…”

Overexpression of Cardiac-Specific Kinase TNNI3K Promotes Mouse Embryonic Stem Cells Differentiation into Cardiomyocytes

“…The glass pipette was filled with the pipette solution (in mM): 120 KCl, 5 EGTA, 1 MgCl 2 , 5 Na2ATP, 10 HEPES, adjusted to pH = 7.4 with KOH. Experiments were performed at RT, as has been noted [31-33]. …”