Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, iCeMS Research Building, Yoshida Honmachi, Kyoto 606-8501, Japan.
Eur Heart J. 2013 Apr;34(15):1147-56. doi: 10.1093/eurheartj/ehs418. Epub 2012 Nov 30.
Development of a human cell-derived reentrant arrhythmia model is needed for studying the mechanisms of disease and accurate drug response.
We differentiated human pluripotent stem cells (hPSCs) into cardiomyocytes, and then re-plated them into cell sheets that proved capable of forming electrically coupled assemblies. We monitored the function of these re-plated sheets optically with the Ca(2+) sensitive dye Fluo-4, and found that they generated characteristic waves of activity whose velocity and patterns of propagation depended upon the concentration of sodium channel blockers; lidocaine and tetrodotoxin, and also the time after re-plating, as well as the applied stimulation frequency. Importantly, reentrant spiral-wave propagation could be generated in these sheets by applying high-frequency stimulation, particularly when cell-density in the sheets was relatively low. This was because cardiac troponin T-positive cells were more non-homogeneously distributed at low cell densities. Especially in such sheets, we could terminate spiral waves by administering the anti-arrhythmic drugs; nifekalant, E-4031, sotalol, and quinidine. We also found that in these sheets, nifekalant showed a clear dose-dependent increase in the size of the unexcitable 'cores' of these induced spiral waves, an important parallel with the treatment for ventricular tachycardia in the clinical situation, which was not shown properly in cardiac-cell sheets derived from dissociated rodent hearts.
We have succeeded in creating from hPSCs a valuable type of cardiomyocyte sheet that is capable of generating reentrant arrhythmias, and thus is demonstrably useful for screening and testing all sorts of drugs with anti-arrhythmic potential.
需要开发一种基于人源细胞的折返性心律失常模型，用于研究疾病机制和药物的准确反应。
我们将人多能干细胞分化为心肌细胞，然后将其重新铺板成细胞片，证明这些细胞片能够形成电耦联的集合体。我们使用 Ca(2+) 敏感染料 Fluo-4 对这些重新铺板的细胞片进行光学监测，发现它们产生了特征性的活动波，其传播速度和模式取决于钠通道阻滞剂的浓度；利多卡因和河豚毒素，以及重新铺板后的时间，以及施加的刺激频率。重要的是，通过施加高频刺激，可以在这些细胞片中产生折返性螺旋波传播，尤其是当细胞片的细胞密度相对较低时。这是因为心肌肌钙蛋白 T 阳性细胞在较低的细胞密度下分布更加不均匀。特别是在这些细胞片中，我们可以通过给予抗心律失常药物，如尼非卡兰、E-4031、索他洛尔和奎尼丁，终止螺旋波。我们还发现，在这些细胞片中，尼非卡兰在诱导螺旋波的不可兴奋“核心”区域的大小上表现出明显的剂量依赖性增加，这与临床情况下治疗室性心动过速的情况相平行，而在源自分离的啮齿动物心脏的心肌细胞片中没有很好地表现出来。
我们已经成功地从 hPSCs 中创建了一种有价值的心肌细胞片类型，该类型能够产生折返性心律失常，因此在筛选和测试各种具有抗心律失常潜力的药物方面具有明显的应用价值。
