Ajmaline blocks INa and IKr without eliciting differences between Brugada syndrome patient and control human pluripotent stem cell-derived cardiac clusters

Duncan C. Miller, Stephen C. Harmer, Ariel Poliandri, Muriel Nobles, Elizabeth C. Edwards, James S. Ware, Tyson V. Sharp, Tristan R. McKay, Leo Dunkel, Pier D. Lambiase, Andrew Tinker*

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)

7 Citations (Scopus)
258 Downloads (Pure)

Abstract

The class Ia anti-arrhythmic drug ajmaline is used clinically to unmask latent type I ECG in Brugada syndrome (BrS) patients, although its mode of action is poorly characterised. Our aims were to identify ajmaline's mode of action in human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes (CMs), and establish a simple BrS hiPSC platform to test whether differences in ajmaline response could be determined between BrS patients and controls. Control hiPSCs were differentiated into spontaneously contracting cardiac clusters. It was found using multi electrode array (MEA) that ajmaline treatment significantly lengthened cluster activation-recovery interval. Patch clamping of single CMs isolated from clusters revealed that ajmaline can block both INa and IKr. Following generation of hiPSC lines from BrS patients (absent of pathogenic SCN5A sodium channel mutations), analysis of hiPSC-CMs from patients and controls revealed that differentiation and action potential parameters were similar. Comparison of cardiac clusters by MEA showed that ajmaline lengthened activation-recovery interval consistently across all lines. We conclude that ajmaline can block both depolarisation and repolarisation of hiPSC-CMs at the cellular level, but that a more refined integrated tissue model may be necessary to elicit differences in its effect between BrS patients and controls.

Original languageEnglish
Pages (from-to)233-244
Number of pages12
JournalStem Cell Research
Volume25
Early online date7 Nov 2017
DOIs
Publication statusPublished - 1 Dec 2017

Bibliographical note

Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Keywords

  • Activation-recovery interval
  • Ajmaline
  • Brugada syndrome
  • hiPSC-cardiomyocytes
  • I

Fingerprint Dive into the research topics of 'Ajmaline blocks I<sub>Na</sub> and I<sub>Kr</sub> without eliciting differences between Brugada syndrome patient and control human pluripotent stem cell-derived cardiac clusters'. Together they form a unique fingerprint.

  • Profiles

    Cite this

    Miller, D. C., Harmer, S. C., Poliandri, A., Nobles, M., Edwards, E. C., Ware, J. S., Sharp, T. V., McKay, T. R., Dunkel, L., Lambiase, P. D., & Tinker, A. (2017). Ajmaline blocks INa and IKr without eliciting differences between Brugada syndrome patient and control human pluripotent stem cell-derived cardiac clusters. Stem Cell Research, 25, 233-244. https://doi.org/10.1016/j.scr.2017.11.003