A computational model of induced pluripotent stem-cell derived cardiomyocytes for high throughput risk stratification of KCNQ1 genetic variants

• Published in: PLoS computational biology Vol. 16; no. 8; p. e1008109
• Main Authors: Kernik, Divya C, Yang, Pei-Chi, Kurokawa, Junko, Wu, Joseph C, Clancy, Colleen E
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 01.08.2020; Public Library of Science (PLoS)
• Subjects: Aging; Analysis; Anomalies; Arrhythmias, Cardiac - genetics; Automation; Biology; Biology and Life Sciences; Cardiomyocytes; Computational Biology; Computer applications; Computer simulation; Electrophysiology; Funding; Gene mutation; Genetic disorders; Genetic diversity; Genetic Predisposition to Disease - genetics; Genetic variability; Genetic variance; Genetic variation; Genotype & phenotype; Genotypes; Health aspects; Heart; Heart cells; Humans; Induced Pluripotent Stem Cells - cytology; KCNQ1 Potassium Channel - genetics; KCNQ1 protein; Medicine; Medicine and Health Sciences; Models, Cardiovascular; Morphology; Mutants; Mutation; Mutation - genetics; Myocytes; Myocytes, Cardiac - classification; Myocytes, Cardiac - cytology; Patients; Pharmacology; Phenotypes; Physiology; Pluripotency; Population; Potassium channels (voltage-gated); Research and Analysis Methods; Risk; Risk factors; Stem cells; Variability; Ventricle; United States; United States > US; California
• ISSN: 1553-7358; 1553-734X; 1553-7358
• DOI: 10.1371/journal.pcbi.1008109

In the last decade, there has been tremendous progress in identifying genetic anomalies linked to clinical disease. New experimental platforms have connected genetic variants to mechanisms underlying disruption of cellular and organ behavior and the emergence of proarrhythmic cardiac phenotypes. The development of induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) signifies an important advance in the study of genetic disease in a patient-specific context. However, considerable limitations of iPSC-CM technologies have not been addressed: 1) phenotypic variability in apparently identical genotype perturbations, 2) low-throughput electrophysiological measurements, and 3) an immature phenotype which may impact translation to adult cardiac response. We have developed a computational approach intended to address these problems. We applied our recent iPSC-CM computational model to predict the proarrhythmic risk of 40 KCNQ1 genetic variants. An IKs computational model was fit to experimental data for each mutation, and the impact of each mutation was simulated in a population of iPSC-CM models. Using a test set of 15 KCNQ1 mutations with known clinical long QT phenotypes, we developed a method to stratify the effects of KCNQ1 mutations based on proarrhythmic markers. We utilized this method to predict the severity of the remaining 25 KCNQ1 mutations with unknown clinical significance. Tremendous phenotypic variability was observed in the iPSC-CM model population following mutant perturbations. A key novelty is our reporting of the impact of individual KCNQ1 mutant models on adult ventricular cardiomyocyte electrophysiology, allowing for prediction of mutant impact across the continuum of aging. This serves as a first step toward translating predicted response in the iPSC-CM model to predicted response of the adult ventricular myocyte given the same genetic mutation. As a whole, this study presents a new computational framework that serves as a high throughput method to evaluate risk of genetic mutations based-on proarrhythmic behavior in phenotypically variable populations.