Variability in high-throughput ion-channel screening data and consequences for cardiac safety assessment

Elkins, Ryan C.; Davies, Mark R.; Brough, Stephen J.; Gavaghan, David J.; Cui, Yi; Abi-Gerges, Najah; Mirams, Gary R.

Abstract

Introduction: Unwanted drug interactions with ionic currents in the heart can lead to an increased pro-arrhythmic risk to patients in the clinic. It is therefore a priority for safety pharmacology teams to detect block of cardiac ion channels, and new technologies have enabled the development of automated and high-throughput screening assays using cell lines. As a result of screening multiple ion-channels there is a need to integrate information, particularly for compounds affecting more than one current, and mathematical electrophysiology in-silico action potential models are beginning to be used for this. Methods: We quantified the variability associated with concentration-effect curves fitted to recordings from high-throughput Molecular Devices IonWorks® Quattro™ screens when detecting block of IKr (hERG), INa (NaV1.5), ICaL (CaV1.2), IKs (KCNQ1/minK) and Ito (Kv4.3/KChIP2.2), and the Molecular Devices FLIPR® Tetra fluorescence screen for ICaL (CaV1.2), for control compounds used at AstraZeneca and GlaxoSmithKline. We examined how screening variability propagates through in-silico action potential models for whole cell electrical behaviour, and how confidence intervals on model predictions can be estimated with repeated simulations. Results: There are significant levels of variability associated with high-throughput ion channel electrophysiology screens. This variability is of a similar magnitude for different cardiac ion currents and different compounds. Uncertainty in the Hill coefficients of reported concentration-effect curves is particularly high. Depending on a compound's ion channel blocking profile, the uncertainty introduced into whole-cell predictions can become significant. Discussion: Our technique allows confidence intervals to be placed on computational model predictions that are based on high-throughput ion channel screens. This allows us to suggest when repeated screens should be performed to reduce uncertainty in a compound's action to acceptable levels, to allow a meaningful interpretation of the data. © 2013 The Authors.

• Journal Article Type: Article
• Acceptance Date: Apr 25, 2013
• Publication Date: Jul 1, 2013
• Deposit Date: Jan 14, 2020
• Publicly Available Date: Feb 28, 2020
• Journal: Journal of Pharmacological and Toxicological Methods
• Print ISSN: 1056-8719
• Electronic ISSN: 1873-488X
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 68
• Issue: 1
• Pages: 112-122
• DOI: https://doi.org/10.1016/j.vascn.2013.04.007
• Keywords: Toxicology; Pharmacology
• Public URL: https://nottingham-repository.worktribe.com/output/3217534
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S1056871913002475?via%3Dihub
• Additional Information: This article is maintained by: Elsevier; Article Title: Variability in high-throughput ion-channel screening data and consequences for cardiac safety assessment; Journal Title: Journal of Pharmacological and Toxicological Methods; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.vascn.2013.04.007; Content Type: article; Copyright: Copyright © 2013 The Authors. Published by Elsevier Inc.