Referenced in: none

Automatically associated channels: Nav1.5

Title: Cardiomyocytes derived from pluripotent stem cells recapitulate electrophysiological characteristics of an overlap syndrome of cardiac sodium channel disease.

Authors: Richard P Davis, Simona Casini, Cathelijne W van den Berg, Maaike Hoekstra, Carol Ann Remme, Cheryl Dambrot, Daniela Salvatori, Dorien Ward-van Oostwaard, Arthur A M Wilde, Connie R Bezzina, Arie O Verkerk, Christian Freund, Christine L Mummery

Journal, date & volume: Circulation, 2012 Jun 26 , 125, 3079-91

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/22647976

Abstract
Pluripotent stem cells (PSCs) offer a new paradigm for modeling genetic cardiac diseases, but it is unclear whether mouse and human PSCs can truly model both gain- and loss-of-function genetic disorders affecting the Na(+) current (I(Na)) because of the immaturity of the PSC-derived cardiomyocytes. To address this issue, we generated multiple PSC lines containing a Na(+) channel mutation causing a cardiac Na(+) channel overlap syndrome.Induced PSC (iPSC) lines were generated from mice carrying the Scn5a(1798insD/+) (Scn5a-het) mutation. These mouse iPSCs, along with wild-type mouse iPSCs, were compared with the targeted mouse embryonic stem cell line used to generate the mutant mice and with the wild-type mouse embryonic stem cell line. Patch-clamp experiments showed that the Scn5a-het cardiomyocytes had a significant decrease in I(Na) density and a larger persistent I(Na) compared with Scn5a-wt cardiomyocytes. Action potential measurements showed a reduced upstroke velocity and longer action potential duration in Scn5a-het myocytes. These characteristics recapitulated findings from primary cardiomyocytes isolated directly from adult Scn5a-het mice. Finally, iPSCs were generated from a patient with the equivalent SCN5A(1795insD/+) mutation. Patch-clamp measurements on the derivative cardiomyocytes revealed changes similar to those in the mouse PSC-derived cardiomyocytes.Here, we demonstrate that both embryonic stem cell- and iPSC-derived cardiomyocytes can recapitulate the characteristics of a combined gain- and loss-of-function Na(+) channel mutation and that the electrophysiological immaturity of PSC-derived cardiomyocytes does not preclude their use as an accurate model for cardiac Na(+) channel disease.