scholarly journals 2-Cl-C.OXT-A Stimulates Contraction through the Suppression of Phosphodiesterase Activity in Human Induced Pluripotent Stem Cell-derived Cardiac Organoids

2019 ◽  
Author(s):  
Takahiro Kitsuka ◽  
Manabu Itoh ◽  
Sojiro Amamoto ◽  
Ken-ichi Arai ◽  
Junichi Oyama ◽  
...  

AbstractBackground2-Cl-C.OXT-A (COA-Cl) is a novel synthesized adenosine analog that activates S1P1 receptor (S1P1R) and combines with adenosine A1 receptor (A1R) in G proteins and was shown to enhance angiogenesis and improve the brain function in rat stroke models. However, the role of COA-Cl in hearts remains unclear. COA-Cl, which has a similar structure to xanthine derivatives, has the potential to suppress phosphodiesterase (PDE), which is an important factor involved in the beating of heart muscle.Methods and resultsCardiac organoids with fibroblasts, human induced pluripotent stem cell-derived cardiac myocytes (hiPSC-CMs), and hiPSC-derived endothelial cells (hiPSC-ECs) were cultured until they started beating. The beating and contraction of organoids were observed before and after the application of COA-Cl. COA-Cl significantly increased the beating rate and fractional area change in organoids. To elucidate the mechanism underlying these effects of COA-Cl on cardiac myocytes, pure hiPSC-CM spheroids were evaluated in the presence/absence of Suramin (antagonist of A1R). The effects of COA-Cl, SEW2871 (direct stimulator of S1P1R), two positive inotropes (Isoproterenol [ISO] and Forskolin [FSK]), and negative inotrope (Propranolol [PRP]) on spheroids were assessed based on the beating rates and cAMP levels. COA-Cl stimulated the beating rates about 1.5-fold compared with ISO and FSK, while PRP suppressed the beating rate. However, no marked changes were observed with SEW2871. COA-Cl, ISO, and FSK increased the cAMP level. In contrast, the level of cAMP did not change with PRP or SEW2871 treatment. The results were the same in the presence of Suramin as absence. Furthermore, an enzyme analysis showed that COA-Cl suppressed the PDE activity by half.ConclusionsCOA-Cl, which has neovascularization effects, suppressed PDE and increased the contraction of cardiac organoids, independent of S1P1R and A1R. These findings suggest that COA-Cl may be useful as an inotropic agent for promoting angiogenesis in the future.

2019 ◽  
Vol 116 (3) ◽  
pp. 671-685 ◽  
Author(s):  
Xi Lou ◽  
Meng Zhao ◽  
Chengming Fan ◽  
Vladimir G Fast ◽  
Mani T Valarmathi ◽  
...  

Abstract Aims In regenerative medicine, cellular cardiomyoplasty is one of the promising options for treating myocardial infarction (MI); however, the efficacy of such treatment has shown to be limited due to poor survival and/or functional integration of implanted cells. Within the heart, the adhesion between cardiac myocytes (CMs) is mediated by N-cadherin (CDH2) and is critical for the heart to function as an electromechanical syncytium. In this study, we have investigated whether the reparative potency of human-induced pluripotent stem cell-derived cardiac myocytes (hiPSC-CMs) can be enhanced through CDH2 overexpression. Methods and results CDH2-hiPSC-CMs and control wild-type (WT)-hiPSC-CMs were cultured in myogenic differentiation medium for 28 days. Using a mouse MI model, the cell survival/engraftment rate, infarct size, and cardiac functions were evaluated post-MI, at Day 7 or Day 28. In vitro, conduction velocities were significantly greater in CDH2-hiPSC-CMs than in WT-hiPSC-CMs. While, in vivo, measurements of cardiac functions: left ventricular (LV) ejection fraction, reduction in infarct size, and the cell engraftment rate were significantly higher in CDH2-hiPSC-CMs treated MI group than in WT-hiPSC-CMs treated MI group. Mechanistically, paracrine activation of ERK signal transduction pathway by CDH2-hiPSC-CMs, significantly induced neo-vasculogenesis, resulting in a higher survival of implanted cells. Conclusion Collectively, these data suggest that CDH2 overexpression enhances not only the survival/engraftment of cultured CDH2-hiPSC-CMs, but also the functional integration of these cells, consequently, the augmentation of the reparative properties of implanted CDH2-hiPSC-CMs in the failing hearts.


2020 ◽  
pp. 247255522095320
Author(s):  
Shuyun Bai ◽  
Junjie Pei ◽  
Kan Chen ◽  
Ya Zhao ◽  
Henghua Cao ◽  
...  

Human induced pluripotent stem cell–derived cardiomyocytes (hiPSC-CMs) have been widely used for the assessment of drug proarrhythmic potential through multielectrode array (MEA). HiPSC-CM cultures beat spontaneously with a wide range of frequencies, however, which could affect drug-induced changes in repolarization. Pacing hiPSC-CMs at a physiological heart rate more closely resembles the state of in vivo ventricular myocytes and permits the standardization of test conditions to improve consistency. In this study, we systematically investigated the time window of stable ion currents in high-purity hiPSC-derived ventricular cardiomyocytes (hiPSC-vCMs) and confirmed that these cells could be used to correctly predict the proarrhythmic risk of Comprehensive In Vitro Proarrhythmia Assay (CiPA) reference compounds. To evaluate drug proarrhythmic potentials at a physiological beating rate, we used a MEA to electrically pace hiPSC-vCMs, and we recorded regular field potential waveforms in hiPSC-vCMs treated with DMSO and 10 CiPA reference drugs. Prolongation of field potential duration was detected in cells after exposure to high- and intermediate-risk drugs; in addition, drug-induced arrhythmia-like events were observed. The results of this study provide a simple and feasible method to investigate drug proarrhythmic potentials in hiPSC-CMs at a physiological beating rate.


2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Derek Schocken ◽  
Jayna Stohlman ◽  
Xiaoyu Zhang ◽  
Yama Abassi ◽  
Lars Johannesen ◽  
...  

Background: Inhibiting late sodium current (I NaL ) reduced drug-induced QTc prolongation in a recent clinical trial. Induced pluripotent stem cell derived cardiomyocytes (iPSC-CMs) have emerged as a valuable tool in preclinical assessment of multichannel blocking drugs’ potential to prolong QT and induce arrhythmias. However, sodium channels in commercially available iPSC-CMs are known to be under expressed, necessitating investigation into the presence and effects of I NaL in this electrophysiological model. Methods and Results: A platform combining simultaneous measurements of field potential and contraction (xCELLigence RTCA CardioECR, ACEA Biosciences) was used to assess the acute effects of three I NaL enhancing drugs, ATX-II, ibutilide, and alfuzosin, given alone or in combination with an I NaL blocker, lidocaine in iPSC-CMs (iCell Cardiomyocytes 2 , Cellular Dynamics). Additionally, dofetilide, diltiazem, and lidocaine alone were included as positive controls for hERG, L-type calcium, and sodium channel block. ATX-II, a potent and specific I NaL enhancer, caused significant dose dependent rate-corrected field potential duration (FPDc) prolongation, which was then subsequently reduced in a dose dependent manner by the addition of lidocaine. At 100 nM ATX-II prolonged the FPDc by 1153.8 ± 135.8 ms from 360.5 ± 16.4 ms at the baseline, which was then reduced to 537 ± 37.4 ms with the addition of 30 μM lidocaine. Ibutilide (0.1-1 μM), a class III antiarrhythmic, caused beating rate decreases and early after depolarizations (EADs) that were not affected by lidocaine addition. Alfuzosin, which increases both peak and late sodium currents, caused dose-dependent reduction of beating rate, FPDc prolongation, and EADs at 5 μM and 10 μM. Alfuzosin-induced EADs were mitigated by addition of lidocaine (5-15 μM). Conclusions: Late sodium current enhancers prolonged repolarization and induced arrhythmias in human iPSC-CMs. These effects were reversed by addition of lidocaine, a specific late sodium current blocker. These results are consistent with the late sodium current being present in iPSC-CMs in the presence of a late sodium current enhancer, which may have implications for drug safety testing.


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