Abstract
Cardiomyocytes (CMs) derived from human embryonic stem cells (hESCs) or human induced pluripotent stem cells (hiPSCs) are functionally heterogeneous, display insufficient biological efficacy and generally possess the electrophysiological properties seen in fetal CMs. However, a homogenous population of hESC/hiPSC-CMs, with properties similar to those of adult human ventricular cells, is required for use in drug cardiotoxicity screening. Unfortunately, despite the requirement for the functional characteristics of post-mitotic beating cell aggregates to mimic the behavior of mature cardiomyocytes in vitro, few technological improvements have been made in this field to date. Previously, we showed that culturing hESC-CMs under low-adhesion conditions with cyclic replating confers continuous contractility on the cells, leading to a functional increase in cardiac gene expression and electrophysiological properties over time. The current study reveals that culturing hESC/hiPSC-CMs under non-adhesive culture conditions enhances the electrophysiological properties of the CMs through an increase in the acetylation of histone H3 lysine residues, as confirmed by western blot analyses. Histone H3 acetylation was induced chemically by treating primitive hESC/hiPSC-CMs with Trichostatin A (TSA), a histone deacetylase (HDAC) inhibitor, resulting in an immediate increase in global cardiac gene expression. In functional analyses using multi-electrode array (MEA) recordings, TSA-treated hESC/hiPSC-CM colonies showed appropriate responses to particular concentrations of known potassium ion channel inhibitors. Thus, the combination of a cell-autonomous functional increase in response to non-adhesive culture and short-term TSA treatment of hESC/hiPSC-CM colonies cultured on MEA electrodes will help to make cardiac toxicity tests more accurate and reproducible via genome-wide chromatin activation.
Highlights
Human embryonic stem cells (ESCs) are pluripotent stem cells derived from the inner cell mass of the blastocyst, whereas induced pluripotent stem cells are a type of pluripotent stem cell artificially derived from reprogrammed somatic cells [1,2]
The quantitative RT-PCR (qRT-PCR) analysis revealed that the gene expression levels of alpha myosin heavy chain (aMHC), ERG1b and KCNQ1 were higher after 14 days of Sus culture than after the same period of Ad culture (Fig. S1C)
histone deacetylase (HDAC) Inhibitor Improves multi-electrode array (MEA) Testing in human embryonic stem cells (hESCs)-CMs we examined the effects of Trichostatin A (TSA)-mediated acetylation on the MEA testing of a transgenic hESC cell line expressing enhanced green fluorescent protein (EGFP) under the control of the aMHC promoter
Summary
Human embryonic stem cells (ESCs) are pluripotent stem cells derived from the inner cell mass of the blastocyst, whereas induced pluripotent stem cells (iPSCs) are a type of pluripotent stem cell artificially derived from reprogrammed somatic cells [1,2]. Both cell types can be used to generate vast numbers of cells, which can develop into human tissues. In in vitro cardiac toxicity tests with hESC-CMs/hiPSC-CMs, the developmental stage of the cells used is very important; the mechanisms involved in age-related functional development in post-mitotic cardiomyocytes are still uncertain
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
