Vaidyanathan Ravi, Markandeya Yogananda S, Kamp Timothy J, Makielski Jonathan C, January Craig T, Eckhardt Lee L
Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin, Madison, Wisconsin.
Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin, Madison, Wisconsin
Am J Physiol Heart Circ Physiol. 2016 Jun 1;310(11):H1611-21. doi: 10.1152/ajpheart.00481.2015. Epub 2016 Apr 8.
Currently available induced pluripotent stem cell-derived cardiomyocytes (iPS-CMs) do not ideally model cellular mechanisms of human arrhythmic disease due to lack of a mature action potential (AP) phenotype. In this study, we create and characterize iPS-CMs with an electrically mature AP induced by potassium inward rectifier (IK1) enhancement. The advantages of IK1-enhanced iPS-CMs include the absence of spontaneous beating, stable resting membrane potentials at approximately -80 mV and capability for electrical pacing. Compared with unenhanced, IK1-enhanced iPS-CMs calcium transient amplitudes were larger (P < 0.05) with a typical staircase pattern. IK1-enhanced iPS-CMs demonstrated a twofold increase in cell size and membrane capacitance and increased DNA synthesis compared with control iPS-CMs (P < 0.05). Furthermore, IK1-enhanced iPS-CMs expressing the F97C-CAV3 long QT9 mutation compared with wild-type CAV3 demonstrated an increase in AP duration and late sodium current. IK1-enhanced iPS-CMs represent a more mature cardiomyocyte model to study arrhythmia mechanisms.
目前可用的诱导多能干细胞衍生的心肌细胞（iPS-CMs）由于缺乏成熟的动作电位（AP）表型，无法理想地模拟人类心律失常疾病的细胞机制。在本研究中，我们创建并表征了通过增强内向整流钾电流（IK1）诱导出电成熟AP的iPS-CMs。IK1增强的iPS-CMs的优点包括无自发搏动、在约-80 mV处有稳定的静息膜电位以及具备电起搏能力。与未增强的相比，IK1增强的iPS-CMs的钙瞬变幅度更大（P < 0.05），呈现典型的阶梯模式。与对照iPS-CMs相比，IK1增强的iPS-CMs细胞大小和膜电容增加了两倍，DNA合成增加（P < 0.05）。此外，与野生型CAV3相比，表达F97C-CAV3长QT9突变的IK1增强的iPS-CMs的动作电位时程和晚钠电流增加。IK1增强的iPS-CMs代表了一种更成熟的心肌细胞模型，用于研究心律失常机制。
