Human ex-vivo action potential model for pro-arrhythmia risk assessment

Page, Guy; Ratchada, Phachareeya; Miron, Yannick; Steiner, Guido; Ghetti, Andre; Miller, Paul E.; Reynolds, Jack; Wang, Ken; Greiter‐Wilke, Andrea; Polonchuk, Liudmila; Traebert, Martin; Gintant, Gary A.; Abi‐Gerges, Najah

doi:10.1016/j.vascn.2016.05.016

Cited by 36 publications

(65 citation statements)

References 51 publications

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“…There was no prominent effect on APD30 or APD50. These ndings were in line with the drug experiment in human ventricular trabeculae (35), indicating the pronounced blockade of potassium current especially hERG than the sodium current. Besides, we observed that adverse events were reduced or at least not added in the range of 3-fold the ETPC of quinidine in BrS-CMs, and were even newly emerged in control group.…”

Section: Pharmacologic Responses To Quinidinesupporting

confidence: 85%

Comparative Analysis of Genetic Variations in the Nav1.5 Sodium Channel Subunits that Underlie Brugada Syndrome Using Patient-Specific iPSC-CMs

Zhu

Wang

Cui

et al. 2020

Preprint

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Background: Brugada syndrome (BrS) is an autosomal dominant disorder that causes a high predisposition to sudden cardiac death. Several genes have been reported to be associated with BrS. Considering that the heterogeneity in clinical manifestations may result from genetic variations, the application of patient-specific induced pluripotent stem (iPS) cell-derived cardiomyocytes (CMs) may help to reveal cell phenotype characteristics resulting from different genetic backgrounds. The present study was to compare the structural and electrophysiological characteristics of sodium channel subunits with different genetic variations and evaluate the safety of quinidine for use with BrS patient-specific iPSC-derived cardiomyocytes.Methods: Two BrS patient-specific iPS cell lines were constructed that carried missense mutations in SCN5A and SCN1B. One iPS cell line from a healthy volunteer was used as a control. The differentiated cardiomyocytes from the three groups were evaluated by flow cytometry, immunofluorescence staining, electron microscopy, as well as calcium transient and patch clamp analyses to assess different pathological phenotypes. Finally, we evaluated the drug responses to varying concentrations of quinidine by measuring the action potential.Results: Compared to the control group, BrS-CMs showed a significant reduction in sodium current, prolonged action potential duration and varying degrees of decreased Vmax, but no structural difference was observed. After applying different concentrations of quinidine, the disease-specific groups and the control group had a downward trend in maximal upstroke velocity, resting membrane potential and action potential amplitude, and exhibited prolonged action potential duration without increasing incidence of arrhythmic events.Conclusion: Both patient-specific iPSC-CMs recapitulated the BrS phenotype at the cellular level. Although the SCN5A variation led to a markedly lower sodium current than what was observed with the SCN1B variation, their responses to quinidine were quite similar. The present study provides an advantageous platform for exploring disease mechanisms and evaluating drug safety in vitro.

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Section: Pharmacologic Responses To Quinidinesupporting

confidence: 85%

Comparative Analysis of Genetic Variations in the Nav1.5 Sodium Channel Subunits that Underlie Brugada Syndrome Using Patient-Specific iPSC-CMs

Zhu

Wang

Cui

et al. 2020

Preprint

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“…Microelectrode AP recordings from stimulated ex vivo human ventricular trabeculae at 1 and 2 Hz were obtained as described in detail in Page et al ( 2016 ). Briefly, undiseased donor hearts were obtained from organ donors in the United States with legal consent.…”

Section: Methodsmentioning

confidence: 99%

“…In this study, we systematically and quantitatively compare drug-induced changes in repolarization biomarkers predicted by human ventricular cell models against changes observed from AP recordings of human ventricular trabeculae (Page et al, 2016 ). We investigate four drugs commonly used as reference drugs, three of which are torsadogenic: dofetilide; dl-sotalol; and quinidine, and verapamil, which is a non-torsadogenic drug.…”

Section: Introductionmentioning

confidence: 99%

Quantitative Comparison of Effects of Dofetilide, Sotalol, Quinidine, and Verapamil between Human Ex vivo Trabeculae and In silico Ventricular Models Incorporating Inter-Individual Action Potential Variability

et al. 2017

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Background: In silico modeling could soon become a mainstream method of pro-arrhythmic risk assessment in drug development. However, a lack of human-specific data and appropriate modeling techniques has previously prevented quantitative comparison of drug effects between in silico models and recordings from human cardiac preparations. Here, we directly compare changes in repolarization biomarkers caused by dofetilide, dl-sotalol, quinidine, and verapamil, between in silico populations of human ventricular cell models and ex vivo human ventricular trabeculae.Methods and Results: Ex vivo recordings from human ventricular trabeculae in control conditions were used to develop populations of in silico human ventricular cell models that integrated intra- and inter-individual variability in action potential (AP) biomarker values. Models were based on the O'Hara-Rudy ventricular cardiomyocyte model, but integrated experimental AP variability through variation in underlying ionic conductances. Changes to AP duration, triangulation and early after-depolarization occurrence from application of the four drugs at multiple concentrations and pacing frequencies were compared between simulations and experiments. To assess the impact of variability in IC50 measurements, and the effects of including state-dependent drug binding dynamics, each drug simulation was repeated with two different IC50 datasets, and with both the original O'Hara-Rudy hERG model and a recently published state-dependent model of hERG and hERG block. For the selective hERG blockers dofetilide and sotalol, simulation predictions of AP prolongation and repolarization abnormality occurrence showed overall good agreement with experiments. However, for multichannel blockers quinidine and verapamil, simulations were not in agreement with experiments across all IC50 datasets and IKr block models tested. Quinidine simulations resulted in overprolonged APs and high incidence of repolarization abnormalities, which were not observed in experiments. Verapamil simulations showed substantial AP prolongation while experiments showed mild AP shortening.Conclusions: Results for dofetilide and sotalol show good agreement between experiments and simulations for selective compounds, however lack of agreement from simulations of quinidine and verapamil suggest further work is needed to understand the more complex electrophysiological effects of these multichannel blocking drugs.

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“…CIPA proposes a multimodal approach of cardiac safety screening based on the integrated effects of drugs on the multiple cardiac ion channels that define cardiac excitability and repolarization and that play a role in delayed ventricular repolarization. Reconstructions of the drug effects are evaluated in silico on a computationally reconstructed human ventricular cardiomyocyte action potential (AP) (Cavero and Holzgrefe, 2014 ; Fermini et al, 2016 ; Gintant et al, 2016 ; Page et al, 2016 ). Finally, predicted effects are verified with electrophysiological experiments in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM).…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Optogenetic Electrophysiology Tools in Human Stem Cell-Derived Cardiomyocytes

et al. 2017

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Current cardiac drug safety assessments focus on hERG channel block and QT prolongation for evaluating arrhythmic risks, whereas the optogenetic approach focuses on the action potential (AP) waveform generated by a monolayer of human cardiomyocytes beating synchronously, thus assessing the contribution of several ion channels on the overall drug effect. This novel tool provides arrhythmogenic sensitizing by light-induced pacing in combination with non-invasive, all-optical measurements of cardiomyocyte APs and will improve assessment of drug-induced electrophysiological aberrancies. With the help of patch clamp electrophysiology measurements, we aimed to investigate whether the optogenetic modifications alter human cardiomyocytes' electrophysiology and how well the optogenetic analyses perform against this gold standard. Patch clamp electrophysiology measurements of non-transduced stem cell-derived cardiomyocytes compared to cells expressing the commercially available optogenetic constructs Optopatch and CaViar revealed no significant changes in action potential duration (APD) parameters. Thus, inserting the optogenetic constructs into cardiomyocytes does not significantly affect the cardiomyocyte's electrophysiological properties. When comparing the two methods against each other (patch clamp vs. optogenetic imaging) we found no significant differences in APD parameters for the Optopatch transduced cells, whereas the CaViar transduced cells exhibited modest increases in APD-values measured with optogenetic imaging. Thus, to broaden the screen, we combined optogenetic measurements of membrane potential and calcium transients with contractile motion measured by video motion tracking. Furthermore, to assess how optogenetic measurements can predict changes in membrane potential, or early afterdepolarizations (EADs), cells were exposed to cumulating doses of E-4031, a hERG potassium channel blocker, and drug effects were measured at both spontaneous and paced beating rates (1, 2 Hz). Cumulating doses of E-4031 produced prolonged APDs, followed by EADs and drug-induced quiescence. These observations were corroborated by patch clamp and contractility measurements. Similar responses, although more modest were seen with the IKs potassium channel blocker JNJ-303. In conclusion, optogenetic measurements of AP waveforms combined with optical pacing compare well with the patch clamp gold standard. Combined with video motion contractile measurements, optogenetic imaging provides an appealing alternative for electrophysiological screening of human cardiomyocyte responses in pharmacological efficacy and safety testings.

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Human ex-vivo action potential model for pro-arrhythmia risk assessment

Cited by 36 publications

References 51 publications

Comparative Analysis of Genetic Variations in the Nav1.5 Sodium Channel Subunits that Underlie Brugada Syndrome Using Patient-Specific iPSC-CMs

Comparative Analysis of Genetic Variations in the Nav1.5 Sodium Channel Subunits that Underlie Brugada Syndrome Using Patient-Specific iPSC-CMs

Quantitative Comparison of Effects of Dofetilide, Sotalol, Quinidine, and Verapamil between Human Ex vivo Trabeculae and In silico Ventricular Models Incorporating Inter-Individual Action Potential Variability

Evaluation of Optogenetic Electrophysiology Tools in Human Stem Cell-Derived Cardiomyocytes

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