Subtype-specific promoter-driven action potential imaging for precise disease modelling and drug testing in hiPSC-derived cardiomyocytes

Abstract

Translational perspectiveCardiomyocytes (CMs) generated from human induced pluripotent stem cells are an evolving platform to understand molecular disease mechanism and evaluate cardiovascular drugs. A major limitation of this system is that they represent a heterogeneous mix of ventricular-, atrial-, and nodal-like CMs. By expressing a voltage-sensitive fluorescent protein under the control of lineage-specific promoters, we developed a convenient system allowing high-throughput subtype-specific optical action potential (AP) imaging in these cells. This enables not only quantification of electrical phenotypes in patient-specific CMs but also subtype-specific investigation of drug effects, which may aid both drug development and safety pharmacology in the cardiovascular field.

Induced pluripotent stem-cell-derived cardiomyocytes: cardiac applications, opportunities, and challenges

“…They then compared action potential characteristics and specific cardiac chamber markers using single cell PCR. While this does not constitute definitive proof, this study clearly showed that cardiac chamber-specific hiPSC-CM subtypes do exist (Chen et al 2016). However, given the varied action potential morphologies and characteristics, appropriate and robust methods to compare chamber-specific hiPSC-CM subtypes are required.…”

“…However, a very elegant recent study that combined electrophysiology, single cell RT-PCR, and optical action potential recordings showed that action potential characteristics are related to the expression of ventricular-, atrial-, and nodal-specific markers (Chen et al 2016). Chen et al…”

“…Cell sorting is used in immunofluorescence studies where, for example, mlc2v, mlc2a, and HCN4 are often employed as ventricular-, atrial-, and nodal-specific markers, respectively (Chen et al 2016;Moreau et al 2017). However, this approach is terminal in that the cells are fixed and permeabilized, precluding further functional work.…”

Non-invasive phenotyping and drug testing in single cardiomyocytes or beta-cells by calcium imaging and optogenetics

“…As these tools are genetically encoded, and equivalents have already been utilised in transgenic models [9,37], genome knock-in lines with constitutive and homogeneous expression may become useful adjuncts to this approach. Indeed, further refinement identifying particular cardiomyocyte subtypes by targeting promoters active in the atrium or ventricle, as demonstrated for lentiviral promoter:transgene combinations in SC-CMs [38] may be possible.…”

The Future Role of Pharmacogenomics in Anticancer Agent-Induced Cardiovascular Toxicity

“…Applying minor modification to differentiation protocols such as adding neuregulin inhibitors [22] and retinoic acid regulators [23,24], and the usage of reporter gene constructs have proven successful in generating a relatively pure subtypes of cardiomyocytes including ventricular, atrial and nodal cardiomyocytes [25].…”