Blebbistatin protects iPSC-CMs from hypercontraction and facilitates automated patch-clamp based electrophysiological study

Abstract

Recently, there have been great advances in cardiovascular channelopathy modeling and drug safety pharmacology using human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs). The automated patch-clamp (APC) technique overcomes the disadvantages of manual patch-clamp (MPC) such as labor intensive and low output. However, it was not clear whether the data generated by using the APC could be reliably used for iPSC-CM disease modeling. In this study, we improved the iPSC-CM preparation method by applying blebbistatin (BB, an excitation-contraction coupling uncoupler) in the whole APC procedures (dissociation, filtration, storage, and recording). Under non-BB buffered condition, iPSC-CMs in suspension showed a severe bleb-like morphology, however, BB-supplement leads to significant improvements in morphology and INa recording. We observe no effects of BB on action potential and field potential. Furthermore, APC faithfully recapitulates the single-cell electrophysiological phenotypes of iPSC-CMs derived from Brugada syndrome patients, as detected with MPC. Our study indicates that APC is capable of replacing MPC in the modeling of cardiac channelopathies using human iPSC-CMs by providing high quality data with higher throughput.