Dataset Information

Adult Human Primary Cardiomyocyte-Based Model for the Simultaneous Prediction of Drug-Induced Inotropic and Pro-arrhythmia Risk.

ABSTRACT: Cardiac safety remains the leading cause of drug development discontinuation. We developed a human cardiomyocyte-based model that has the potential to provide a predictive preclinical approach for simultaneously predicting drug-induced inotropic and pro-arrhythmia risk. Methods: Adult human primary cardiomyocytes from ethically consented organ donors were used to measure contractility transients. We used measures of changes in contractility parameters as markers to infer both drug-induced inotropic effect (sarcomere shortening) and pro-arrhythmia (aftercontraction, AC); contractility escape (CE); time to 90% relaxation (TR90). We addressed the clinical relevance of this approach by evaluating the effects of 23 torsadogenic and 10 non-torsadogenic drugs. Each drug was tested separately at four multiples of the free effective therapeutic plasma concentration (fETPC). Results: Human cardiomyocyte-based model differentiated between torsadogenic and non-torsadogenic drugs. For example, dofetilide, a torsadogenic drug, caused ACs and increased TR90 starting at 10-fold the fETPC, while CE events were observed at the highest multiple of fETPC (100-fold). Verapamil, a non-torsadogenic drug, did not change TR90 and induced no AC or CE up to the highest multiple of fETPCs tested in this study (222-fold). When drug pro-arrhythmic activity was evaluated at 10-fold of the fETPC, AC parameter had excellent assay sensitivity and specificity values of 96 and 100%, respectively. This high predictivity supports the translational safety potential of this preparation and of the selected marker. The data demonstrate that human cardiomyocytes could also identify drugs associated with inotropic effects. hERG channel blockers, like dofetilide, had no effects on sarcomere shortening, while multi-ion channel blockers, like verapamil, inhibited sarcomere shortening. Conclusions: Isolated adult human primary cardiomyocytes can simultaneously predict risks associated with inotropic activity and pro-arrhythmia and may enable the generation of reliable and predictive data for assessing human cardiotoxicity at an early stage in drug discovery.

SUBMITTER: Nguyen N

PROVIDER: S-EPMC5742250 | biostudies-literature | 2017

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Adult Human Primary Cardiomyocyte-Based Model for the Simultaneous Prediction of Drug-Induced Inotropic and Pro-arrhythmia Risk.

Nguyen Nathalie N Nguyen William W Nguyenton Brynna B Ratchada Phachareeya P Page Guy G Miller Paul E PE Ghetti Andre A Abi-Gerges Najah N

Frontiers in physiology 20171219

Cardiac safety remains the leading cause of drug development discontinuation. We developed a human cardiomyocyte-based model that has the potential to provide a predictive preclinical approach for simultaneously predicting drug-induced inotropic and pro-arrhythmia risk. <b>Methods:</b> Adult human primary cardiomyocytes from ethically consented organ donors were used to measure contractility transients. We used measures of changes in contractility parameters as markers to infer both drug-induced ...[more]

PMID: 29311989

Similar Datasets

Project description:BackgroundAtrial fibrillation is the most common arrhythmia syndrome and causes significant morbidity and mortality. Current therapeutics, however, have limited efficacy. Notably, many therapeutics shown to be efficacious in animal models have not proved effective in humans. Thus, there is a need for a drug screening platform based on human tissue. The aim of this study was to develop a robust protocol for generating atrial cardiomyocytes from human-induced pluripotent stem cells.MethodsA novel protocol for atrial differentiation, with optimized timing of retinoic acid during mesoderm formation, was compared to two previously published methods. Each differentiation method was assessed for successful formation of a contractile syncytium, electrical properties assayed by optical action potential recordings and multi-electrode array electrophysiology, and response to the G-protein-gated potassium channel activator, carbamylcholine. Atrial myocyte monolayers, derived using the new differentiation protocol, were further assessed for cardiomyocyte purity, gene expression, and the ability to form arrhythmic rotors in response to burst pacing.ResultsApplication of retinoic acid at day 1 of mesoderm formation resulted in a robust differentiation of atrial myocytes with contractile syncytium forming in 16/18 differentiations across two cell lines. Atrial-like myocytes produced have shortened action potentials and field potentials, when compared to standard application of retinoic acid at the cardiac mesoderm stage. Day 1 retinoic acid produced atrial cardiomyocytes are also carbamylcholine sensitive, indicative of active Ikach currents, which was distinct from ventricular myocytes and standard retinoic addition in matched differentiations. A current protocol utilizing reduced Activin A and BMP4 can produce atrial cardiomyocytes with equivalent functionality but with reduced robustness of differentiation; only 8/17 differentiations produced a contractile syncytium. The day 1 retinoic acid protocol was successfully applied to 6 iPSC lines (3 male and 3 female) without additional optimization or modification. Atrial myocytes produced could also generate syncytia with rapid conduction velocities, > 40 cm s-1, and form rotor style arrhythmia in response to burst pacing.ConclusionsThis method combines an enhanced atrial-like phenotype with robustness of differentiation, which will facilitate further research in human atrial arrhythmia and myopathies, while being economically viable for larger anti-arrhythmic drug screens.

Project description:Background Sodium-calcium (Ca2+) exchanger isoform 1 (NCX1) is the dominant Ca2+ efflux mechanism in cardiomyocytes and is critical to maintaining Ca2+ homeostasis during excitation-contraction coupling. NCX1 activity has been implicated in the pathogenesis of cardiovascular diseases, but a lack of specific NCX1 blockers complicates experimental interpretation. Our aim was to develop a tamoxifen-inducible NCX1 knockout (KO) mouse to investigate compensatory adaptations of acute ablation of NCX1 on excitation-contraction coupling and intracellular Ca2+ regulation, and to examine whether acute KO of NCX1 confers resistance to triggered arrhythmia and ischemia/reperfusion injury. Methods and Results We used the α-myosin heavy chain promoter (Myh6)-MerCreMer promoter to create a tamoxifen-inducible cardiac-specific NCX1 KO mouse. Within 1 week of tamoxifen injection, NCX1 protein expression and current were dramatically reduced. Diastolic Ca2+ increased despite adaptive reductions in Ca2+ current and action potential duration and compensatory increases in excitation-contraction coupling gain, sarcoplasmic reticulum Ca2+ ATPase 2 and plasma membrane Ca2+ ATPase. As these adaptations progressed over 4 weeks, diastolic Ca2+ normalized and SR Ca2+ load increased. Left ventricular function remained normal, but mild fibrosis and hypertrophy developed. Transcriptomics revealed modification of cardiovascular-related gene networks including cell growth and fibrosis. NCX1 KO reduced spontaneous action potentials triggered by delayed afterdepolarizations and reduced scar size in response to ischemia/reperfusion. Conclusions Tamoxifen-inducible NCX1 KO mice adapt to acute genetic ablation of NCX1 by reducing Ca2+ influx, increasing alternative Ca2+ efflux pathways, and increasing excitation-contraction coupling gain to maintain contractility at the cost of mild Ca2+-activated hypertrophy and fibrosis and decreased survival. Nevertheless, KO myocytes are protected against spontaneous action potentials and ischemia/reperfusion injury.

Project description:RationaleThe capacity for cardiomyocyte regeneration in the healthy adult human heart is fundamentally relevant for both myocardial homeostasis and cardiomyopathy therapeutics. However, estimates of cardiomyocyte turnover rates conflict greatly, with a study employing C14 pulse-chase methodology concluding 1% annual turnover in youth declining to 0.5% with aging and another using cell population dynamics indicating substantial, age-increasing turnover (4% increasing to 20%).ObjectiveCreate a hybrid mathematical model to critically examine rates of cardiomyocyte turnover derived from alternative methodologies.Methods and resultsExamined in isolation, the cell population analysis exhibited severe sensitivity to a stem cell expansion exponent (20% variation causing 2-fold turnover change) and apoptosis rate. Similarly, the pulse-chase model was acutely sensitive to assumptions of instantaneous incorporation of atmospheric C14 into the body (4-fold impact on turnover in young subjects) while numerical restrictions precluded otherwise viable solutions. Incorporating considerations of primary variable sensitivity and controversial model assumptions, an unbiased numerical solver identified a scenario of significant, age-increasing turnover (4-6% increasing to 15-22% with age) that was compatible with data from both studies, provided that successive generations of cardiomyocytes experienced higher attrition rates than predecessors.ConclusionsAssignment of histologically-observed stem/progenitor cells into discrete regenerative phenotypes in the cell population model strongly influenced turnover dynamics without being directly testable. Alternatively, C14 trafficking assumptions and restrictive models in the pulse-chase model artificially eliminated high-turnover solutions. Nevertheless, discrepancies among recent cell turnover estimates can be explained and reconciled. The hybrid mathematical model provided herein permits further examination of these and forthcoming datasets.

Dataset Information

Adult Human Primary Cardiomyocyte-Based Model for the Simultaneous Prediction of Drug-Induced Inotropic and Pro-arrhythmia Risk.

Publications

Adult Human Primary Cardiomyocyte-Based Model for the Simultaneous Prediction of Drug-Induced Inotropic and Pro-arrhythmia Risk.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets