Ion Channel Expression and Characterization in Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes.

BACKGROUND: Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are providing new possibilities for the biological study, cell therapies, and drug discovery. However, the ion channel expression and functions as well as regulations in hiPSC-CMs still need to be fully characterized.

METHODS: Cardiomyocytes were derived from hiPS cells that were generated from two healthy donors. qPCR and patch clamp techniques were used for the study.

RESULTS: In addition to the reported ion channels, INa , ICa-L , ICa-T , If , INCX , IK1 , Ito , IKr , IKs IKATP , IK-pH , ISK1-3 , and ISK4 , we detected both the expression and currents of ACh-activated (KACh) and Na+ -activated (KNa) K+ , volume-regulated and calcium-activated (Cl-Ca) Cl- , and TRPV channels. All the detected ion currents except IK1 , IKACh , ISK , IKNa , and TRPV1 currents contribute to AP duration. Isoprenaline increased ICa-L , If , and IKs but reduced INa and INCX , without an effect on Ito , IK1 , ISK1-3 , IKATP , IKr , ISK4 , IKNa , ICl-Ca , and ITRPV1 . Carbachol alone showed no effect on the tested ion channel currents.

CONCLUSION: Our data demonstrate that most ion channels, which are present in healthy or diseased cardiomyocytes, exist in hiPSC-CMs. Some of them contribute to action potential performance and are regulated by adrenergic stimulation.