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Bartolucci C, Mesirca P, Ricci E, Sales-Bellés C, Torre E, Louradour J, Mangoni ME, Severi S. Computational modelling of mouse atrio ventricular node action potential and automaticity. J Physiol 2024. [PMID: 39269369 DOI: 10.1113/jp285950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Accepted: 08/08/2024] [Indexed: 09/15/2024] Open
Abstract
The atrioventricular node (AVN) is a crucial component of the cardiac conduction system. Despite its pivotal role in regulating the transmission of electrical signals between atria and ventricles, a comprehensive understanding of the cellular electrophysiological mechanisms governing AVN function has remained elusive. This paper presents a detailed computational model of mouse AVN cell action potential (AP). Our model builds upon previous work and introduces several key refinements, including accurate representation of membrane currents and exchangers, calcium handling, cellular compartmentalization, dynamic update of intracellular ion concentrations, and calcium buffering. We recalibrated and validated the model against existing and unpublished experimental data. In control conditions, our model reproduces the AVN AP experimental features, (e.g. rate = 175 bpm, experimental range [121, 191] bpm). Notably, our study sheds light on the contribution of L-type calcium currents, through both Cav1.2 and Cav1.3 channels, in AVN cells. The model replicates several experimental observations, including the cessation of firing upon block of Cav1.3 or INa,r current. If block induces a reduction in beating rate of 11%. In summary, this work presents a comprehensive computational model of mouse AVN cell AP, offering a valuable tool for investigating pacemaking mechanisms and simulating the impact of ionic current blockades. By integrating calcium handling and refining formulation of ionic currents, our model advances understanding of this critical component of the cardiac conduction system, providing a platform for future developments in cardiac electrophysiology. KEY POINTS: This paper introduces a comprehensive computational model of mouse atrioventricular node (AVN) cell action potentials (APs). Our model is based on the electrophysiological data from isolated mouse AVN cells and exhibits an action potential and calcium transient that closely match the experimental records. By simulating the effects of blocking specific ionic currents, the model effectively predicts the roles of L-type Cav1.2 and Cav1.3 channels, T-type calcium channels, sodium currents (TTX-sensitive and TTX-resistant), and the funny current (If) in AVN pacemaking. The study also emphasizes the significance of other ionic currents, including IKr, Ito, IKur, in regulating AP characteristics and cycle length in AVN cells. The model faithfully reproduces the rate dependence of action potentials under pacing, opening the possibility of use in impulse propagation models. The population-of-models approach showed the robustness of this new AP model in simulating a wide spectrum of cellular pacemaking in AVN.
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Affiliation(s)
- Chiara Bartolucci
- Computational Physiopathology Unit, Department of Electrical, Electronic and Information Engineering 'Guglielmo Marconi,', University of Bologna, Cesena, Italy
| | - Pietro Mesirca
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
- LabEx Ion Channels Science and Therapeutics (ICST), Montpellier, France
| | - Eugenio Ricci
- Computational Physiopathology Unit, Department of Electrical, Electronic and Information Engineering 'Guglielmo Marconi,', University of Bologna, Cesena, Italy
| | - Clara Sales-Bellés
- BSICoS group, I3A Institute, University of Zaragoza, IIS Aragón, Zaragoza, Spain
| | - Eleonora Torre
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
- LabEx Ion Channels Science and Therapeutics (ICST), Montpellier, France
| | - Julien Louradour
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
- LabEx Ion Channels Science and Therapeutics (ICST), Montpellier, France
| | - Matteo Elia Mangoni
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
- LabEx Ion Channels Science and Therapeutics (ICST), Montpellier, France
| | - Stefano Severi
- Computational Physiopathology Unit, Department of Electrical, Electronic and Information Engineering 'Guglielmo Marconi,', University of Bologna, Cesena, Italy
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Clancy CE, Santana LF. Advances in induced pluripotent stem cell-derived cardiac myocytes: technological breakthroughs, key discoveries and new applications. J Physiol 2024; 602:3871-3892. [PMID: 39032073 PMCID: PMC11326976 DOI: 10.1113/jp282562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Accepted: 07/02/2024] [Indexed: 07/22/2024] Open
Abstract
A transformation is underway in precision and patient-specific medicine. Rapid progress has been enabled by multiple new technologies including induced pluripotent stem cell-derived cardiac myocytes (iPSC-CMs). Here, we delve into these advancements and their future promise, focusing on the efficiency of reprogramming techniques, the fidelity of differentiation into the cardiac lineage, the functional characterization of the resulting cardiac myocytes, and the many applications of in silico models to understand general and patient-specific mechanisms controlling excitation-contraction coupling in health and disease. Furthermore, we explore the current and potential applications of iPSC-CMs in both research and clinical settings, underscoring the far-reaching implications of this rapidly evolving field.
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Affiliation(s)
- Colleen E Clancy
- Department of Physiology & Membrane Biology, School of Medicine, University of California Davis, Davis, CA, USA
- Center for Precision Medicine and Data Sciences, University of California Davis, School of Medicine, Sacramento, CA, USA
| | - L Fernando Santana
- Department of Physiology & Membrane Biology, School of Medicine, University of California Davis, Davis, CA, USA
- Center for Precision Medicine and Data Sciences, University of California Davis, School of Medicine, Sacramento, CA, USA
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3
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Davies MR. Cardiac Safety Pharmacology Modeling. SYSTEMS MEDICINE 2021. [DOI: 10.1016/b978-0-12-801238-3.11545-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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Arrhythmia Mechanisms in Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes. J Cardiovasc Pharmacol 2020; 77:300-316. [PMID: 33323698 DOI: 10.1097/fjc.0000000000000972] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 12/08/2020] [Indexed: 12/30/2022]
Abstract
ABSTRACT Despite major efforts by clinicians and researchers, cardiac arrhythmia remains a leading cause of morbidity and mortality in the world. Experimental work has relied on combining high-throughput strategies with standard molecular and electrophysiological studies, which are, to a great extent, based on the use of animal models. Because this poses major challenges for translation, the progress in the development of novel antiarrhythmic agents and clinical care has been mostly disappointing. Recently, the advent of human induced pluripotent stem cell-derived cardiomyocytes has opened new avenues for both basic cardiac research and drug discovery; now, there is an unlimited source of cardiomyocytes of human origin, both from healthy individuals and patients with cardiac diseases. Understanding arrhythmic mechanisms is one of the main use cases of human induced pluripotent stem cell-derived cardiomyocytes, in addition to pharmacological cardiotoxicity and efficacy testing, in vitro disease modeling, developing patient-specific models and personalized drugs, and regenerative medicine. Here, we review the advances that the human induced pluripotent stem cell-derived-based modeling systems have brought so far regarding the understanding of both arrhythmogenic triggers and substrates, while also briefly speculating about the possibilities in the future.
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5
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Kernik DC, Morotti S, Wu H, Garg P, Duff HJ, Kurokawa J, Jalife J, Wu JC, Grandi E, Clancy CE. A computational model of induced pluripotent stem-cell derived cardiomyocytes incorporating experimental variability from multiple data sources. J Physiol 2019; 597:4533-4564. [PMID: 31278749 PMCID: PMC6767694 DOI: 10.1113/jp277724] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 07/05/2019] [Indexed: 12/22/2022] Open
Abstract
Key points Induced pluripotent stem cell‐derived cardiomyocytes (iPSC‐CMs) capture patient‐specific genotype–phenotype relationships, as well as cell‐to‐cell variability of cardiac electrical activity Computational modelling and simulation provide a high throughput approach to reconcile multiple datasets describing physiological variability, and also identify vulnerable parameter regimes We have developed a whole‐cell model of iPSC‐CMs, composed of single exponential voltage‐dependent gating variable rate constants, parameterized to fit experimental iPSC‐CM outputs We have utilized experimental data across multiple laboratories to model experimental variability and investigate subcellular phenotypic mechanisms in iPSC‐CMs This framework links molecular mechanisms to cellular‐level outputs by revealing unique subsets of model parameters linked to known iPSC‐CM phenotypes
Abstract There is a profound need to develop a strategy for predicting patient‐to‐patient vulnerability in the emergence of cardiac arrhythmia. A promising in vitro method to address patient‐specific proclivity to cardiac disease utilizes induced pluripotent stem cell‐derived cardiomyocytes (iPSC‐CMs). A major strength of this approach is that iPSC‐CMs contain donor genetic information and therefore capture patient‐specific genotype–phenotype relationships. A cited detriment of iPSC‐CMs is the cell‐to‐cell variability observed in electrical activity. We postulated, however, that cell‐to‐cell variability may constitute a strength when appropriately utilized in a computational framework to build cell populations that can be employed to identify phenotypic mechanisms and pinpoint key sensitive parameters. Thus, we have exploited variation in experimental data across multiple laboratories to develop a computational framework for investigating subcellular phenotypic mechanisms. We have developed a whole‐cell model of iPSC‐CMs composed of simple model components comprising ion channel models with single exponential voltage‐dependent gating variable rate constants, parameterized to fit experimental iPSC‐CM data for all major ionic currents. By optimizing ionic current model parameters to multiple experimental datasets, we incorporate experimentally‐observed variability in the ionic currents. The resulting population of cellular models predicts robust inter‐subject variability in iPSC‐CMs. This approach links molecular mechanisms to known cellular‐level iPSC‐CM phenotypes, as shown by comparing immature and mature subpopulations of models to analyse the contributing factors underlying each phenotype. In the future, the presented models can be readily expanded to include genetic mutations and pharmacological interventions for studying the mechanisms of rare events, such as arrhythmia triggers. Induced pluripotent stem cell‐derived cardiomyocytes (iPSC‐CMs) capture patient‐specific genotype–phenotype relationships, as well as cell‐to‐cell variability of cardiac electrical activity Computational modelling and simulation provide a high throughput approach to reconcile multiple datasets describing physiological variability, and also identify vulnerable parameter regimes We have developed a whole‐cell model of iPSC‐CMs, composed of single exponential voltage‐dependent gating variable rate constants, parameterized to fit experimental iPSC‐CM outputs We have utilized experimental data across multiple laboratories to model experimental variability and investigate subcellular phenotypic mechanisms in iPSC‐CMs This framework links molecular mechanisms to cellular‐level outputs by revealing unique subsets of model parameters linked to known iPSC‐CM phenotypes
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Affiliation(s)
- Divya C Kernik
- Department of Physiology and Membrane Biology, Department of Pharmacology, School of Medicine, University of California, Davis, Davis, CA, USA
| | - Stefano Morotti
- Department of Pharmacology, School of Medicine, University of California, Davis, CA, USA
| | - HaoDi Wu
- Stanford Cardiovascular Institute, Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Priyanka Garg
- Stanford Cardiovascular Institute, Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Henry J Duff
- Libin Cardiovascular Institute of Alberta, Faculty of Medicine, University of Calgary, Calgary, AB, Canada
| | - Junko Kurokawa
- Department of Bio-Informational Pharmacology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan
| | - José Jalife
- Department of Internal Medicine, Center for Arrhythmia Research, Cardiovascular Research Center, University of Michigan, Ann Arbor, MI, USA.,Centro Nacional de Investigaciones Cardiovasculares (CNIC), and CIBERV, Madrid, Spain
| | - Joseph C Wu
- Stanford Cardiovascular Institute, Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Eleonora Grandi
- Department of Pharmacology, School of Medicine, University of California, Davis, CA, USA
| | - Colleen E Clancy
- Department of Physiology and Membrane Biology, Department of Pharmacology, School of Medicine, University of California, Davis, Davis, CA, USA
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Large-Scale Simulation of the Phenotypical Variability Induced by Loss-of-Function Long QT Mutations in Human Induced Pluripotent Stem Cell Cardiomyocytes. Int J Mol Sci 2018; 19:ijms19113583. [PMID: 30428582 PMCID: PMC6274824 DOI: 10.3390/ijms19113583] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 11/08/2018] [Accepted: 11/08/2018] [Indexed: 01/06/2023] Open
Abstract
Loss-of-function long QT (LQT) mutations inducing LQT1 and LQT2 syndromes have been successfully translated to human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) used as disease-specific models. However, their in vitro investigation mainly relies on experiments using small numbers of cells. This is especially critical when working with cells as heterogeneous as hiPSC-CMs. We aim (i) to investigate in silico the ionic mechanisms underlying LQT1 and LQT2 hiPSC-CM phenotypic variability, and (ii) to enable massive in silico drug tests on mutant hiPSC-CMs. We combined (i) data of control and mutant slow and rapid delayed rectifying K+ currents, IKr and IKs respectively, (ii) a recent in silico hiPSC-CM model, and (iii) the population of models paradigm to generate control and mutant populations for LQT1 and LQT2 cardiomyocytes. Our four populations contain from 1008 to 3584 models. In line with the experimental in vitro data, mutant in silico hiPSC-CMs showed prolonged action potential (AP) duration (LQT1: +14%, LQT2: +39%) and large electrophysiological variability. Finally, the mutant populations were split into normal-like hiPSC-CMs (with action potential duration similar to control) and at risk hiPSC-CMs (with clearly prolonged action potential duration). At risk mutant hiPSC-CMs carried higher expression of L-type Ca2+, lower expression of IKr and increased sensitivity to quinidine as compared to mutant normal-like hiPSC-CMs, resulting in AP abnormalities. In conclusion, we were able to reproduce the two most common LQT syndromes with large-scale simulations, which enable investigating biophysical mechanisms difficult to assess in vitro, e.g., how variations of ion current expressions in a physiological range can impact on AP properties of mutant hiPSC-CMs.
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7
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Paci M, Pölönen RP, Cori D, Penttinen K, Aalto-Setälä K, Severi S, Hyttinen J. Automatic Optimization of an in Silico Model of Human iPSC Derived Cardiomyocytes Recapitulating Calcium Handling Abnormalities. Front Physiol 2018; 9:709. [PMID: 29997516 PMCID: PMC6028769 DOI: 10.3389/fphys.2018.00709] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 05/22/2018] [Indexed: 12/20/2022] Open
Abstract
The growing importance of human induced pluripotent stem cell-derived cardiomyoyctes (hiPSC-CMs), as patient-specific and disease-specific models for studying cellular cardiac electrophysiology or for preliminary cardiotoxicity tests, generated better understanding of hiPSC-CM biophysical mechanisms and great amount of action potential and calcium transient data. In this paper, we propose a new hiPSC-CM in silico model, with particular attention to Ca2+ handling. We used (i) the hiPSC-CM Paci2013 model as starting point, (ii) a new dataset of Ca2+ transient measurements to tune the parameters of the inward and outward Ca2+ fluxes of sarcoplasmic reticulum, and (iii) an automatic parameter optimization to fit action potentials and Ca2+ transients. The Paci2018 model simulates, together with the typical hiPSC-CM spontaneous action potentials, more refined Ca2+ transients and delayed afterdepolarizations-like abnormalities, which the old Paci2013 was not able to predict due to its mathematical formulation. The Paci2018 model was validated against (i) the same current blocking experiments used to validate the Paci2013 model, and (ii) recently published data about effects of different extracellular ionic concentrations. In conclusion, we present a new and more versatile in silico model, which will provide a platform for modeling the effects of drugs or mutations that affect Ca2+ handling in hiPSC-CMs.
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Affiliation(s)
- Michelangelo Paci
- Faculty of Biomedical Sciences and Engineering, BioMediTech Institute, Tampere University of Technology, Tampere, Finland
| | - Risto-Pekka Pölönen
- Faculty of Medicine and Life Sciences, BioMediTech Institute, University of Tampere, Tampere, Finland
| | - Dario Cori
- Department of Electrical, Electronic and Information Engineering "Guglielmo Marconi", University of Bologna, Cesena, Italy
| | - Kirsi Penttinen
- Faculty of Medicine and Life Sciences, BioMediTech Institute, University of Tampere, Tampere, Finland
| | - Katriina Aalto-Setälä
- Faculty of Medicine and Life Sciences, BioMediTech Institute, University of Tampere, Tampere, Finland.,Heart Hospital, Tampere University Hospital, Tampere, Finland
| | - Stefano Severi
- Department of Electrical, Electronic and Information Engineering "Guglielmo Marconi", University of Bologna, Cesena, Italy
| | - Jari Hyttinen
- Faculty of Biomedical Sciences and Engineering, BioMediTech Institute, Tampere University of Technology, Tampere, Finland
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8
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Zhang C, Wang W, He W, Xi N, Wang Y, Liu L. Dynamic Model for Characterizing Contractile Behaviors and Mechanical Properties of a Cardiomyocyte. Biophys J 2018; 114:188-200. [PMID: 29320686 PMCID: PMC5773758 DOI: 10.1016/j.bpj.2017.11.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 11/01/2017] [Accepted: 11/02/2017] [Indexed: 01/27/2023] Open
Abstract
Studies on the contractile dynamics of heart cells have attracted broad attention for the development of both heart disease therapies and cardiomyocyte-actuated micro-robotics. In this study, a linear dynamic model of a single cardiomyocyte cell was proposed at the subcellular scale to characterize the contractile behaviors of heart cells, with system parameters representing the mechanical properties of the subcellular components of living cardiomyocytes. The system parameters of the dynamic model were identified with the cellular beating pattern measured by a scanning ion conductance microscope. The experiments were implemented with cardiomyocytes in one control group and two experimental groups with the drugs cytochalasin-D or nocodazole, to identify the system parameters of the model based on scanning ion conductance microscope measurements, measurement of the cellular Young's modulus with atomic force microscopy indentation, measurement of cellular contraction forces using the micro-pillar technique, and immunofluorescence staining and imaging of the cytoskeleton. The proposed mathematical model was both indirectly and qualitatively verified by the variation in cytoskeleton, beating amplitude, and contractility of cardiomyocytes among the control and the experimental groups, as well as directly and quantitatively validated by the simulation and the significant consistency of 90.5% in the comparison between the ratios of the Young's modulus and the equivalent comprehensive cellular elasticities of cells in the experimental groups to those in the control group. Apart from mechanical properties (mass, elasticity, and viscosity) of subcellular structures, other properties of cardiomyocytes have also been studied, such as the properties of the relative action potential pattern and cellular beating frequency. This work has potential implications for research on cytobiology, drug screening, mechanisms of the heart, and cardiomyocyte-based bio-syncretic robotics.
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Affiliation(s)
- Chuang Zhang
- State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang, China; University of Chinese Academy of Sciences, Beijing, China
| | - Wenxue Wang
- State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang, China.
| | - Wenhui He
- Department of Pharmacology, Shenyang Pharmaceutical University, Shenyang, China
| | - Ning Xi
- Emerging Technologies Institute, Department of Industrial and Manufacturing Systems Engineering, University of Hong Kong Pokfulam, Pokfulam, Hong Kong
| | - Yuechao Wang
- State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang, China
| | - Lianqing Liu
- State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang, China.
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9
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Lei CL, Wang K, Clerx M, Johnstone RH, Hortigon-Vinagre MP, Zamora V, Allan A, Smith GL, Gavaghan DJ, Mirams GR, Polonchuk L. Tailoring Mathematical Models to Stem-Cell Derived Cardiomyocyte Lines Can Improve Predictions of Drug-Induced Changes to Their Electrophysiology. Front Physiol 2017; 8:986. [PMID: 29311950 PMCID: PMC5732978 DOI: 10.3389/fphys.2017.00986] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 11/17/2017] [Indexed: 01/27/2023] Open
Abstract
Human induced pluripotent stem cell derived cardiomyocytes (iPSC-CMs) have applications in disease modeling, cell therapy, drug screening and personalized medicine. Computational models can be used to interpret experimental findings in iPSC-CMs, provide mechanistic insights, and translate these findings to adult cardiomyocyte (CM) electrophysiology. However, different cell lines display different expression of ion channels, pumps and receptors, and show differences in electrophysiology. In this exploratory study, we use a mathematical model based on iPSC-CMs from Cellular Dynamic International (CDI, iCell), and compare its predictions to novel experimental recordings made with the Axiogenesis Cor.4U line. We show that tailoring this model to the specific cell line, even using limited data and a relatively simple approach, leads to improved predictions of baseline behavior and response to drugs. This demonstrates the need and the feasibility to tailor models to individual cell lines, although a more refined approach will be needed to characterize individual currents, address differences in ion current kinetics, and further improve these results.
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Affiliation(s)
- Chon Lok Lei
- Computational Biology, Department of Computer Science, University of Oxford, Oxford, United Kingdom
| | - Ken Wang
- Roche Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| | - Michael Clerx
- Computational Biology, Department of Computer Science, University of Oxford, Oxford, United Kingdom
| | - Ross H Johnstone
- Computational Biology, Department of Computer Science, University of Oxford, Oxford, United Kingdom
| | | | - Victor Zamora
- Clyde Biosciences, BioCity Scotland, Newhouse, United Kingdom
| | - Andrew Allan
- Clyde Biosciences, BioCity Scotland, Newhouse, United Kingdom
| | - Godfrey L Smith
- Clyde Biosciences, BioCity Scotland, Newhouse, United Kingdom
| | - David J Gavaghan
- Computational Biology, Department of Computer Science, University of Oxford, Oxford, United Kingdom
| | - Gary R Mirams
- Centre for Mathematical Medicine and Biology, School of Mathematical Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Liudmila Polonchuk
- Roche Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
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10
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Sartiani L, Mannaioni G, Masi A, Novella Romanelli M, Cerbai E. The Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels: from Biophysics to Pharmacology of a Unique Family of Ion Channels. Pharmacol Rev 2017; 69:354-395. [PMID: 28878030 DOI: 10.1124/pr.117.014035] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 07/07/2017] [Indexed: 12/22/2022] Open
Abstract
Hyperpolarization-activated, cyclic nucleotide-gated (HCN) channels are important members of the voltage-gated pore loop channels family. They show unique features: they open at hyperpolarizing potential, carry a mixed Na/K current, and are regulated by cyclic nucleotides. Four different isoforms have been cloned (HCN1-4) that can assemble to form homo- or heterotetramers, characterized by different biophysical properties. These proteins are widely distributed throughout the body and involved in different physiologic processes, the most important being the generation of spontaneous electrical activity in the heart and the regulation of synaptic transmission in the brain. Their role in heart rate, neuronal pacemaking, dendritic integration, learning and memory, and visual and pain perceptions has been extensively studied; these channels have been found also in some peripheral tissues, where their functions still need to be fully elucidated. Genetic defects and altered expression of HCN channels are linked to several pathologies, which makes these proteins attractive targets for translational research; at the moment only one drug (ivabradine), which specifically blocks the hyperpolarization-activated current, is clinically available. This review discusses current knowledge about HCN channels, starting from their biophysical properties, origin, and developmental features, to (patho)physiologic role in different tissues and pharmacological modulation, ending with their present and future relevance as drug targets.
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Affiliation(s)
- Laura Sartiani
- Department of Neurosciences, Psychology, Drug Research, and Child Health, University of Florence, Firenze, Italy
| | - Guido Mannaioni
- Department of Neurosciences, Psychology, Drug Research, and Child Health, University of Florence, Firenze, Italy
| | - Alessio Masi
- Department of Neurosciences, Psychology, Drug Research, and Child Health, University of Florence, Firenze, Italy
| | - Maria Novella Romanelli
- Department of Neurosciences, Psychology, Drug Research, and Child Health, University of Florence, Firenze, Italy
| | - Elisabetta Cerbai
- Department of Neurosciences, Psychology, Drug Research, and Child Health, University of Florence, Firenze, Italy
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11
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Sala L, Bellin M, Mummery CL. Integrating cardiomyocytes from human pluripotent stem cells in safety pharmacology: has the time come? Br J Pharmacol 2017; 174:3749-3765. [PMID: 27641943 PMCID: PMC5647193 DOI: 10.1111/bph.13577] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2016] [Revised: 07/27/2016] [Accepted: 08/11/2016] [Indexed: 12/20/2022] Open
Abstract
Cardiotoxicity is a severe side effect of drugs that induce structural or electrophysiological changes in heart muscle cells. As a result, the heart undergoes failure and potentially lethal arrhythmias. It is still a major reason for drug failure in preclinical and clinical phases of drug discovery. Current methods for predicting cardiotoxicity are based on guidelines that combine electrophysiological analysis of cell lines expressing ion channels ectopically in vitro with animal models and clinical trials. Although no new cases of drugs linked to lethal arrhythmias have been reported since the introduction of these guidelines in 2005, their limited predictive power likely means that potentially valuable drugs may not reach clinical practice. Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) are now emerging as potentially more predictive alternatives, particularly for the early phases of preclinical research. However, these cells are phenotypically immature and culture and assay methods not standardized, which could be a hurdle to the development of predictive computational models and their implementation into the drug discovery pipeline, in contrast to the ambitions of the comprehensive pro-arrhythmia in vitro assay (CiPA) initiative. Here, we review present and future preclinical cardiotoxicity screening and suggest possible hPSC-CM-based strategies that may help to move the field forward. Coordinated efforts by basic scientists, companies and hPSC banks to standardize experimental conditions for generating reliable and reproducible safety indices will be helpful not only for cardiotoxicity prediction but also for precision medicine. LINKED ARTICLES This article is part of a themed section on New Insights into Cardiotoxicity Caused by Chemotherapeutic Agents. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.21/issuetoc.
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Affiliation(s)
- Luca Sala
- Department of Anatomy and EmbryologyLeiden University Medical CenterLeidenZAThe Netherlands
| | - Milena Bellin
- Department of Anatomy and EmbryologyLeiden University Medical CenterLeidenZAThe Netherlands
| | - Christine L Mummery
- Department of Anatomy and EmbryologyLeiden University Medical CenterLeidenZAThe Netherlands
- Department of Applied Stem Cell TechnologiesUniversity of TwenteEnschedeThe Netherlands
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12
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Saxena P, Hortigon‐Vinagre MP, Beyl S, Baburin I, Andranovits S, Iqbal SM, Costa A, IJzerman AP, Kügler P, Timin E, Smith GL, Hering S. Correlation between human ether-a-go-go-related gene channel inhibition and action potential prolongation. Br J Pharmacol 2017; 174:3081-3093. [PMID: 28681507 PMCID: PMC5573420 DOI: 10.1111/bph.13942] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 06/08/2017] [Accepted: 06/16/2017] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND AND PURPOSE Human ether-a-go-go-related gene (hERG; Kv 11.1) channel inhibition is a widely accepted predictor of cardiac arrhythmia. hERG channel inhibition alone is often insufficient to predict pro-arrhythmic drug effects. This study used a library of dofetilide derivatives to investigate the relationship between standard measures of hERG current block in an expression system and changes in action potential duration (APD) in human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). The interference from accompanying block of Cav 1.2 and Nav 1.5 channels was investigated along with an in silico AP model. EXPERIMENTAL APPROACH Drug-induced changes in APD were assessed in hiPSC-CMs using voltage-sensitive dyes. The IC50 values for dofetilide and 13 derivatives on hERG current were estimated in an HEK293 expression system. The relative potency of each drug on APD was estimated by calculating the dose (D150 ) required to prolong the APD at 90% (APD90 ) repolarization by 50%. KEY RESULTS The D150 in hiPSC-CMs was linearly correlated with IC50 of hERG current. In silico simulations supported this finding. Three derivatives inhibited hERG without prolonging APD, and these compounds also inhibited Cav 1.2 and/or Nav 1.5 in a channel state-dependent manner. Adding Cav 1.2 and Nav 1.2 block to the in silico model recapitulated the direction but not the extent of the APD change. CONCLUSIONS AND IMPLICATIONS Potency of hERG current inhibition correlates linearly with an index of APD in hiPSC-CMs. The compounds that do not correlate have additional effects including concomitant block of Cav 1.2 and/or Nav 1.5 channels. In silico simulations of hiPSC-CMs APs confirm the principle of the multiple ion channel effects.
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Affiliation(s)
- P Saxena
- Institute of Pharmacology and ToxicologyUniversity of ViennaViennaAustria
- Institute of Cardiovascular and Medical SciencesUniversity of GlasgowGlasgowUK
| | - M P Hortigon‐Vinagre
- Institute of Cardiovascular and Medical SciencesUniversity of GlasgowGlasgowUK
- Clyde Biosciences LtdGlasgowUK
| | - S Beyl
- Institute of Pharmacology and ToxicologyUniversity of ViennaViennaAustria
| | - I Baburin
- Institute of Pharmacology and ToxicologyUniversity of ViennaViennaAustria
| | - S Andranovits
- Institute of Pharmacology and ToxicologyUniversity of ViennaViennaAustria
| | - S M Iqbal
- Institute of Pharmacology and ToxicologyUniversity of ViennaViennaAustria
| | - A Costa
- Institute of Cardiovascular and Medical SciencesUniversity of GlasgowGlasgowUK
| | - A P IJzerman
- Division of Medicinal Chemistry, Leiden Academic Centre for Drug ResearchLeiden UniversityLeidenNetherlands
| | - P Kügler
- Institute for Applied Mathematics and StatisticsUniversity of HohenheimStuttgartGermany
- Radon Institute for Computational and Applied MathematicsAustrian Academy of SciencesViennaAustria
| | - E Timin
- Institute of Pharmacology and ToxicologyUniversity of ViennaViennaAustria
| | - G L Smith
- Institute of Cardiovascular and Medical SciencesUniversity of GlasgowGlasgowUK
- Clyde Biosciences LtdGlasgowUK
| | - S Hering
- Institute of Pharmacology and ToxicologyUniversity of ViennaViennaAustria
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13
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Overexpression of KCNJ2 in induced pluripotent stem cell-derived cardiomyocytes for the assessment of QT-prolonging drugs. J Pharmacol Sci 2017; 134:75-85. [DOI: 10.1016/j.jphs.2017.05.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 05/14/2017] [Accepted: 05/17/2017] [Indexed: 02/05/2023] Open
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14
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Sano HI, Toki T, Naito Y, Tomita M. Developmental changes in the balance of glycolytic ATP production and oxidative phosphorylation in ventricular cells: A simulation study. J Theor Biol 2017; 419:269-277. [PMID: 28237394 DOI: 10.1016/j.jtbi.2017.02.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 02/13/2017] [Accepted: 02/16/2017] [Indexed: 11/19/2022]
Abstract
The developmental program of the heart requires accurate regulation to ensure continuous circulation and simultaneous cardiac morphogenesis, because any functional abnormalities may progress to congenital heart malformation. Notably, energy metabolism in fetal ventricular cells is regulated in a manner that differs from adult ventricular cells: fetal cardiomyocytes generally have immature mitochondria and fetal ventricular cells show greater dependence on glycolytic ATP production. However, although various characteristics of energy metabolism in fetal ventricular cells have been reported, to our knowledge, a quantitative description of the contributions of these factors to fetal ventricular cell functions has not yet been established. Here, we constructed a mathematical model to integrate various characteristics of fetal ventricular cells and predicted the contribution of each characteristic to the maintenance of intracellular ATP concentration and sarcomere contraction under anoxic conditions. Our simulation results demonstrated that higher glycogen content, higher hexokinase activity, and lower creatine concentration helped prolong the time for which ventricular cell contraction was maintained under anoxic conditions. The integrated model also enabled us to quantitatively assess the contributions of factors related to energy metabolism in ventricular cells. Because fetal cardiomyocytes exhibit similar energy metabolic profiles to stem cell-derived cardiomyocytes and those in the failing heart, an improved understanding of these fetal ventricular cells will contribute to a better comprehension of the processes in stem cell-derived cardiomyocytes or under pathological conditions.
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Affiliation(s)
- Hitomi I Sano
- Institute for Advanced Biosciences, Keio University, 5322 Endo, Fujisawa, Kanagawa 252-0882, Japan; Department of Environment and Information Studies, Keio University, 5322 Endo, Fujisawa, Kanagawa 252-0882, Japan.
| | - Tamami Toki
- Institute for Advanced Biosciences, Keio University, 5322 Endo, Fujisawa, Kanagawa 252-0882, Japan; Systems Biology Program, Graduate School of Media and Governance, Keio University, 5322 Endo, Fujisawa, Kanagawa 252-0882, Japan.
| | - Yasuhiro Naito
- Institute for Advanced Biosciences, Keio University, 5322 Endo, Fujisawa, Kanagawa 252-0882, Japan; Systems Biology Program, Graduate School of Media and Governance, Keio University, 5322 Endo, Fujisawa, Kanagawa 252-0882, Japan; Department of Environment and Information Studies, Keio University, 5322 Endo, Fujisawa, Kanagawa 252-0882, Japan.
| | - Masaru Tomita
- Institute for Advanced Biosciences, Keio University, 5322 Endo, Fujisawa, Kanagawa 252-0882, Japan; Systems Biology Program, Graduate School of Media and Governance, Keio University, 5322 Endo, Fujisawa, Kanagawa 252-0882, Japan; Department of Environment and Information Studies, Keio University, 5322 Endo, Fujisawa, Kanagawa 252-0882, Japan.
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15
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Spontaneous inward currents reflecting oscillatory activation of Na+/Ca2+ exchangers in human embryonic stem cell-derived cardiomyocytes. Pflugers Arch 2015; 468:609-22. [DOI: 10.1007/s00424-015-1769-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Revised: 11/30/2015] [Accepted: 12/03/2015] [Indexed: 11/25/2022]
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16
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Paci M, Hyttinen J, Rodriguez B, Severi S. Human induced pluripotent stem cell-derived versus adult cardiomyocytes: an in silico electrophysiological study on effects of ionic current block. Br J Pharmacol 2015; 172:5147-60. [PMID: 26276951 PMCID: PMC4629192 DOI: 10.1111/bph.13282] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 07/29/2015] [Accepted: 08/03/2015] [Indexed: 12/28/2022] Open
Abstract
Background and Purpose Two new technologies are likely to revolutionize cardiac safety and drug development: in vitro experiments on human‐induced pluripotent stem cell‐derived cardiomyocytes (hiPSC‐CMs) and in silico human adult ventricular cardiomyocyte (hAdultV‐CM) models. Their combination was recently proposed as a potential replacement for the present hERG‐based QT study for pharmacological safety assessments. Here, we systematically compared in silico the effects of selective ionic current block on hiPSC‐CM and hAdultV‐CM action potentials (APs), to identify similarities/differences and to illustrate the potential of computational models as supportive tools for evaluating new in vitro technologies. Experimental Approach In silico AP models of ventricular‐like and atrial‐like hiPSC‐CMs and hAdultV‐CM were used to simulate the main effects of four degrees of block of the main cardiac transmembrane currents. Key Results Qualitatively, hiPSC‐CM and hAdultV‐CM APs showed similar responses to current block, consistent with results from experiments. However, quantitatively, hiPSC‐CMs were more sensitive to block of (i) L‐type Ca2+ currents due to the overexpression of the Na+/Ca2+ exchanger (leading to shorter APs) and (ii) the inward rectifier K+ current due to reduced repolarization reserve (inducing diastolic potential depolarization and repolarization failure). Conclusions and Implications In silico hiPSC‐CMs and hAdultV‐CMs exhibit a similar response to selective current blocks. However, overall hiPSC‐CMs show greater sensitivity to block, which may facilitate in vitro identification of drug‐induced effects. Extrapolation of drug effects from hiPSC‐CM to hAdultV‐CM and pro‐arrhythmic risk assessment can be facilitated by in silico predictions using biophysically‐based computational models.
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Affiliation(s)
- M Paci
- Department of Electronics and Communications Engineering, Tampere University of Technology, BioMediTech, Tampere, Finland
| | - J Hyttinen
- Department of Electronics and Communications Engineering, Tampere University of Technology, BioMediTech, Tampere, Finland
| | - B Rodriguez
- Department of Computer Science, University of Oxford, Oxford, UK
| | - S Severi
- Department of Electrical, Electronic and Information Engineering 'Guglielmo Marconi', University of Bologna, Cesena (FC), Italy
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17
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Bosman A, Letourneau A, Sartiani L, Del Lungo M, Ronzoni F, Kuziakiv R, Tohonen V, Zucchelli M, Santoni F, Guipponi M, Dumevska B, Hovatta O, Antonarakis SE, Jaconi ME. Perturbations of Heart Development and Function in Cardiomyocytes from Human Embryonic Stem Cells with Trisomy 21. Stem Cells 2015; 33:1434-46. [DOI: 10.1002/stem.1961] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 12/19/2014] [Indexed: 12/31/2022]
Affiliation(s)
- Alexis Bosman
- Department of Pathology and Immunology; Faculty of Medicine; University of Geneva; Geneva Switzerland
- Victor Chang Cardiac Research Institute; Darlinghurst New South Wales Australia
| | - Audrey Letourneau
- Department of Genetic Medicine and Development; Faculty of Medicine, University of Geneva; Geneva Switzerland
| | - Laura Sartiani
- Department of Neuroscience; Psychology, Drug Research and Child Health, Center of Molecular Medicine, University of Florence; Florence Italy
| | - Martina Del Lungo
- Department of Neuroscience; Psychology, Drug Research and Child Health, Center of Molecular Medicine, University of Florence; Florence Italy
| | - Flavio Ronzoni
- Department of Pathology and Immunology; Faculty of Medicine; University of Geneva; Geneva Switzerland
| | - Rostyslav Kuziakiv
- Department of Pathology and Immunology; Faculty of Medicine; University of Geneva; Geneva Switzerland
| | - Virpi Tohonen
- Department of Biosciences and Nutrition; Karolinska Institute; Huddinge Sweden
| | - Marco Zucchelli
- Department of Biosciences and Nutrition; Karolinska Institute; Huddinge Sweden
| | - Federico Santoni
- Department of Genetic Medicine and Development; Faculty of Medicine, University of Geneva; Geneva Switzerland
| | - Michel Guipponi
- Department of Genetic Medicine and Development; Faculty of Medicine, University of Geneva; Geneva Switzerland
| | | | - Outi Hovatta
- Division of Obstetrics and Gynecology; Department of Clinical Science; Karolinska Institute; Huddinge Stockholm Sweden
| | - Stylianos E. Antonarakis
- Department of Genetic Medicine and Development; Faculty of Medicine, University of Geneva; Geneva Switzerland
- iGE3 Institute of Genetics and Genomics of Geneva; Geneva Switzerland
| | - Marisa E. Jaconi
- Department of Pathology and Immunology; Faculty of Medicine; University of Geneva; Geneva Switzerland
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18
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Zaniboni M, Cacciani F. Instantaneous current-voltage relationships during the course of the human cardiac ventricular action potential: new computational insights into repolarization dynamics. Europace 2014; 16:774-84. [PMID: 24798968 DOI: 10.1093/europace/eut397] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AIMS To adopt a novel three-dimensional (3D) representation of cardiac action potential (AP) to compactly visualize dynamical properties of human cellular ventricular repolarization. METHODS AND RESULTS We have recently established a novel 3D representation of cardiac AP, which is based on the iterative measurement of instantaneous ion current-voltage profiles during the course of an AP. Such an approach has been originally developed on real patch-clamped ventricular cells, and subsequently improved in silico on several cardiac ventricular AP models of different mammals, and on models of different AP types of the human heart. We apply it here on two different models of human ventricular AP, and show that it compactly provides further insights into repolarization dynamics. The 3D representation of the AP includes equilibrium points during repolarization, and can be screened in terms of what we have shown to be a region, during late repolarization, when membrane conductance becomes negative and repolarization therefore auto-regenerative. We have called this time window auto-regenerative-repolarization-phase (ARRP). CONCLUSION In addition to previous findings obtained through the same procedure, we show here that 3D current-voltage-time representations of human ventricular AP allow compact visualization of dynamical properties, which are relevant for the physiology and pathology of ventricular repolarization. In particular, we suggest that the volume under the current surface corresponding to the ARRP might be used as a predictor of safety of repolarization, in single cells and during AP conduction in cell pairs.
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Affiliation(s)
- Massimiliano Zaniboni
- Department of Life Sciences, University of Parma, Italy, Parco Area delle Scienze 11A, 43124 Parma, Italy
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19
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Kolaja K. Stem cells and stem cell-derived tissues and their use in safety assessment. J Biol Chem 2013; 289:4555-61. [PMID: 24362027 DOI: 10.1074/jbc.r113.481028] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Toxicology has long relied on animal models in a tedious approach to understanding risk of exposure to an uncharacterized molecule. Stem cell-derived tissues can be made in high purity, quality, and quantity to enable a new approach to this problem. Currently, stem cell-derived tissues are primarily "generic" genetic backgrounds; the future will see the integration of various genetic backgrounds and complex three-dimensional models to create truly unique in vitro organoids. This minireview focuses on the state of the art of a number of stem cell-derived tissues and details their application in toxicology.
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Affiliation(s)
- Kyle Kolaja
- From Cellular Dynamics International, Montclair, New Jersey 07042
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20
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Paci M, Hyttinen J, Aalto-Setälä K, Severi S. Computational models of ventricular- and atrial-like human induced pluripotent stem cell derived cardiomyocytes. Ann Biomed Eng 2013; 41:2334-48. [PMID: 23722932 DOI: 10.1007/s10439-013-0833-3] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Accepted: 05/21/2013] [Indexed: 02/06/2023]
Abstract
The clear importance of human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) as an in-vitro model highlights the relevance of studying these cells and their function also in-silico. Moreover, the phenotypical differences between the hiPSC-CM and adult myocyte action potentials (APs) call for understanding of how hiPSC-CMs are maturing towards adult myocytes. Using recently published experimental data, we developed two computational models of the hiPSC-CM AP, distinguishing between the ventricular-like and atrial-like phenotypes, emerging during the differentiation process of hiPSC-CMs. Also, we used the computational approach to quantitatively assess the role of ionic mechanisms which are likely responsible for the not completely mature phenotype of hiPSC-CMs. Our models reproduce the typical hiPSC-CM ventricular-like and atrial-like spontaneous APs and the response to prototypical current blockers, namely tetrodotoxine, nifedipine, E4041 and 3R4S-Chromanol 293B. Moreover, simulations using our ventricular-like model suggest that the interplay of immature I Na, I f and I K1 currents has a fundamental role in the hiPSC-CM spontaneous beating whereas a negative shift in I CaL activation causes the observed long lasting AP. In conclusion, this work provides two novel tools useful in investigating the electrophysiological features of hiPSC-CMs, whose importance is growing fast as in-vitro models for pharmacological studies.
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Affiliation(s)
- Michelangelo Paci
- Biomedical Engineering Laboratory-DEI, University of Bologna, Via Venezia 52, 47521, Cesena, FC, Italy
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21
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Bosman A, Sartiani L, Spinelli V, Del Lungo M, Stillitano F, Nosi D, Mugelli A, Cerbai E, Jaconi M. Molecular and functional evidence of HCN4 and caveolin-3 interaction during cardiomyocyte differentiation from human embryonic stem cells. Stem Cells Dev 2013; 22:1717-27. [PMID: 23311301 DOI: 10.1089/scd.2012.0247] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Maturation of human embryonic stem cell-derived cardiomyocytes (hESC-CM) is accompanied by changes in ion channel expression, with relevant electrophysiological consequences. In rodent CM, the properties of hyperpolarization-activated cyclic nucleotide-gated channel (HCN)4, a major f-channel isoform, depends on the association with caveolin-3 (Cav3). To date, no information exists on changes in Cav3 expression and its associative relationship with HCN4 upon hESC-CM maturation. We hypothesize that Cav3 expression and its compartmentalization with HCN4 channels during hESC-CM maturation accounts for the progression of f-current properties toward adult phenotypes. To address this, hESC were differentiated into spontaneously beating CM and examined at ∼30, ∼60, and ∼110 days of differentiation. Human adult and fetal CM served as references. HCN4 and Cav3 expression and localization were analyzed by real time PCR and immunocyto/histochemistry. F-current was measured in patch-clamped single cells. HCN4 and Cav3 colocalize in adult human atrial and ventricular CM, but not in fetal CM. Proteins and mRNA for Cav3 were not detected in undifferentiated hESC, but expression increased during hESC-CM maturation. At 110 days, HCN4 appeared to be colocalized with Cav3. Voltage-dependent activation of the f-current was significantly more positive in fetal CM and 60-day hESC-CM (midpoint activation, V1/2, ∼ -82 mV) than in 110-day hESC-CM or adult CM (V1/2∼-100 mV). In the latter cells, caveolae disruption reversed voltage dependence toward a more positive or an immature phenotype, with V1/2 at -75 mV, while in fetal CM voltage dependence was not affected. Our data show, for the first time, a developmental change in HCN4-Cav3 association in hESC-CM. Cav3 expression and its association with ionic channels likely represent a crucial step of cardiac maturation.
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Affiliation(s)
- Alexis Bosman
- Department of Pathology and Immunology, Faculty of Medicine, Geneva University, Geneva, Switzerland
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