Decoding Ca2+ signals as a non-electrophysiological method for assessing drug toxicity in stem cell-derived cardiomyocytes

George, Christopher H. and Edwards, David H. 2016. Decoding Ca2+ signals as a non-electrophysiological method for assessing drug toxicity in stem cell-derived cardiomyocytes. Clements, Michael and Roquemore, Elizabeth P., eds. Stem Cell-derived models in Toxicology, Springer, Item availability restricted.

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Abstract

We describe a new method to profile the Ca2+ signalling fingerprint of stem-cell-derived cardiomyocytes (CM) under drug-naïve and drug-exposed conditions. This method, termed SALVO, takes into account 1) the quantification of very low amplitude Ca2+ fluxes that occur between large Ca2+ spikes, that in the absence of any effect on Ca2+ spikes per se, may have a profound impact on cell phenotype, and 2) the statistical assessment of the variability in the amplitude and temporal components of Ca2+ spike trains. In a previous study, SALVO identified the potential cardiovascular (CV) risk of drugs that had no measurable impact on cellular electrophysiological profile and also yielded a toxicity score that exhibited a better correlation with human QT prolongation liabilities than other conventional electrophysiological readouts. This chapter sets out a step-by-step protocol for establishing phenotypically-consistent CM populations and our method for performing the Ca2+ signalling analysis in which the output data are reconciled with phenotypic endpoints (e.g. cytotoxicity and susceptibility to apoptosis). We present a worked example using two drugs that disrupt Ca2+ signalling via different mechanisms; drug A causes the cessation of spontaneous Ca2+ oscillation via progressive attenuation in Ca2+ spike amplitude whereas drug B elicits different periodic behaviour. Both drugs have comparable effects on the frequency of Ca2+ spikes, but SALVO analysis discriminates their actions. An extensive set of notes is included that will help the reader reproduce our methods with high fidelity.

Item Type:	Book Section
Date Type:	Published Online
Status:	In Press
Schools:	Medicine
Subjects:	R Medicine > RM Therapeutics. Pharmacology
Publisher:	Springer
Funders:	British Heart Foundation
Date of First Compliant Deposit:	30 June 2016
Last Modified:	28 Jun 2019 02:47
URI:	https://orca.cardiff.ac.uk/id/eprint/91953

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