Abstract
Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM) are a promising tool for drug testing and modelling genetic disorders. Abnormally low upstroke velocity is a current limitation. Here we investigated the use of 3D engineered heart tissue (EHT) as a culture method with greater resemblance to human heart tissue in comparison to standard technique of 2D monolayer (ML) format. INa was measured in ML or EHT using the standard patch-clamp technique. INa density was ~1.8 fold larger in EHT (−18.5 ± 1.9 pA/pF; n = 17) than in ML (−10.3 ± 1.2 pA/pF; n = 23; p < 0.001), approaching densities reported for human CM. Inactivation kinetics, voltage dependency of steady-state inactivation and activation of INa did not differ between EHT and ML and were similar to previously reported values for human CM. Action potential recordings with sharp microelectrodes showed similar upstroke velocities in EHT (219 ± 15 V/s, n = 13) and human left ventricle tissue (LV, 253 ± 7 V/s, n = 25). EHT showed a greater resemblance to LV in CM morphology and subcellular NaV1.5 distribution. INa in hiPSC-CM showed similar biophysical properties as in human CM. The EHT format promotes INa density and action potential upstroke velocity of hiPSC-CM towards adult values, indicating its usefulness as a model for excitability of human cardiac tissue.
Highlights
Animal-heart tissue is commonly used as a model for human-heart tissue, but exhibits a significantly different action potential (AP) duration and shape, due to different ion channel contributions, interactions and regulation
We directly compared upstroke velocity in hiPSC-CM cultured in 3D (EHT) and in human heart tissue biopsies obtained during the implantation of left ventricular assist devices (LVAD) or heart transplantation, and studied INa properties in hiPSC-CM from 2D monolayers (ML) and engineered heart tissue (EHT) under the conditions published for human adult CM
We investigated whether culture of hiPSC-CM in the EHT format leads to a higher resemblance with adult human CM in terms of INa density, upstroke velocity, CM morphology and subcellular distribution of NaV1.5
Summary
Animal-heart tissue is commonly used as a model for human-heart tissue, but exhibits a significantly different action potential (AP) duration and shape, due to different ion channel contributions, interactions and regulation. Brought about by co-culture with non-cardiac cells[8], long-term culture[9], hormone stimulation[1], continuous field stimulation[10] and variation of substrate stiffness[11, 12], revealing upstroke velocities of up to 147 V/s12. While these values approach the expected range (200–300 V/s) for human adult ventricular tissue, differences remain and a head-to-head comparison under same conditions is lacking. We directly compared upstroke velocity in hiPSC-CM cultured in 3D (EHT) and in human heart tissue biopsies obtained during the implantation of left ventricular assist devices (LVAD) or heart transplantation, and studied INa properties in hiPSC-CM from 2D monolayers (ML) and EHT under the conditions published for human adult CM
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
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 callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
