Paradoxical effects of Zim3, a CRISPRi effector, on human iPSC-cardiomyocyte electrophysiology

Abstract

We show that Zim3, when used as Zim3-KRAB-dCas9 effector in interference CRISPR, without any guide RNAs, paradoxically upregulates key cardiac ion channel genes in human induced pluripotent stem-cell-derived cardiomyocytes, iPSC-CMs, responsible for healthy resting membrane potential, repolarization of the action potential and electrical transmission of signals. These were found to yield expected functional enhancements consistent with a more mature iPSC-CM phenotype, with anti-arrhythmic properties.

CRISPRi gene modulation and all-optical electrophysiology in post-differentiated human iPSC-cardiomyocytes

“…In addition, the Zim3 construct is smaller and therefore packaging for in vivo delivery may be easier. We envision high utility of this effector in future studies after proper baseline characterization 50 .…”

“…For this reason, all comparisons were between scramble gRNA and gRNA against a target of interest. Further baseline characterization of the effects of dCas9-KRAB-Zim3 in human iPSC-CMs, without gRNAs, is provided in a short report 50 . Virally delivered dCas9-KRAB-Zim3 appears to be potent CRISPRi effector, as we show for KCNJ2 as well 49 , and after proper characterization, it will likely find multiple applications in cardiac research.…”