hERG-deficient human embryonic stem cell-derived cardiomyocytes for modelling QT prolongation

Abstract

Background Long-QT syndrome type 2 (LQT2) is a common malignant hereditary arrhythmia. Due to the lack of suitable animal and human models, the pathogenesis of LQT2 caused by human ether-a-go-go-related gene (hERG) deficiency is still unclear. In this study, we generated an hERG-deficient human cardiomyocyte (CM) model that simulates ‘human homozygous hERG mutations’ to explore the underlying impact of hERG dysfunction and the genotype–phenotype relationship of hERG deficiency. Methods The KCNH2 was knocked out in the human embryonic stem cell (hESC) H9 line using the CRISPR/Cas9 system. Using a chemically defined differentiation protocol, we obtained and verified hERG-deficient CMs. Subsequently, high-throughput microelectrode array (MEA) assays and drug interventions were performed to characterise the electrophysiological signatures of hERG-deficient cell lines. Results Our results showed that KCNH2 knockout did not affect the pluripotency or differentiation efficiency of H9 cells. Using high-throughput MEA assays, we found that the electric field potential duration and action potential duration of hERG-deficient CMs were significantly longer than those of normal CMs. The hERG-deficient lines also exhibited irregular rhythm and some early afterdepolarisations. Moreover, we used the hERG-deficient human CM model to evaluate the potency of agents (nifedipine and magnesium chloride) that may ameliorate the phenotype. Conclusions We established an hERG-deficient human CM model that exhibited QT prolongation, irregular rhythm and sensitivity to other ion channel blockers. This model serves as an important tool that can aid in understanding the fundamental impact of hERG dysfunction, elucidate the genotype–phenotype relationship of hERG deficiency and facilitate drug development.

The Role of METTL3-Mediated N6-Methyladenosine (m6A) of JPH2 mRNA in Cyclophosphamide-Induced Cardiotoxicity

“…MEA recording in cardiomyocytes was performed as described previously ( 23 ). In brief, 2 × 10 4 cells were plated on CytoView MEA plates (Axion Biosystems, USA) pre-coated with 5% matrigel, followed by treatment with CYP at different concentrations (0 and 500 μmoL/L).…”

Human Engineered Heart Tissue Models for Disease Modeling and Drug Discovery

“…Itzhaki et al revealed that LQTS2 disease models show a significant prolongation of the APD due to a reduction in I Kr and evaluated the effects of some pharmacological agents on the disease phenotype ( Itzhaki et al, 2011 ). Chang et al (2021) used CRISPR/Cas9 editing to generate a KCNH2-KO hiPSC-CM model and showed that the model exhibited QT prolongation, irregular rhythm, and sensitivity to ion channel blockers such as L-type Ca channel blockers. Bellin et al (2013) demonstrated that correction of the KCNH2 mutation normalized the I Kr current conducted by the hERG channel and APD.…”

Gene Editing in Pluripotent Stem Cells and Their Derived Organoids

“…Both long-QT syndrome and short-QT syndrome are fatal inherited arrhythmogenic syndromes, which can cause apopsychia and death. A human ether-a-go-go-related gene-deficient CM model [ 6 ] with a pathogenic mutation, or mutation-corrected hiPSC-CMs [ 86 ], was established separately using CRISPR/Cas9, providing clues for malignant hereditary arrhythmia [ 6 ]. Moreover, the underlying molecular mechanism of congenital hepatic fibrosis (CHF) remains unclear.…”

“…Gene editing is broadly applied in disease modeling [ 6 ], exploring disease mechanisms [ 7 ] and disease targeting treatments [ 8 ]. Jennifer Doudna and Emmanuelle Charpentier, who pioneered gene-editing technology, were awarded the 2020 Nobel Prize in Chemistry, driving an unprecedented boom in the field [ 9 ].…”