Sirenko Oksana, Crittenden Carole, Callamaras Nick, Hesley Jayne, Chen Yen-Wen, Funes Carlos, Rusyn Ivan, Anson Blake, Cromwell Evan F
Molecular Devices, LLC, Sunnyvale, CA, USA.
J Biomol Screen. 2013 Jan;18(1):39-53. doi: 10.1177/1087057112457590. Epub 2012 Sep 12.
A large percentage of drugs fail in clinical studies due to cardiac toxicity; thus, development of sensitive in vitro assays that can evaluate potential adverse effects on cardiomyocytes is extremely important for drug development. Human cardiomyocytes derived from stem cell sources offer more clinically relevant cell-based models than those presently available. Human-induced pluripotent stem cell-derived cardiomyocytes are especially attractive because they express ion channels and demonstrate spontaneous mechanical and electrical activity similar to adult cardiomyocytes. Here we demonstrate techniques for measuring the impact of pharmacologic compounds on the beating rate of cardiomyocytes with ImageXpress Micro and FLIPR Tetra systems. The assays employ calcium-sensitive dyes to monitor changes in Ca(2+) fluxes synchronous with cell beating, which allows monitoring of the beat rate, amplitude, and other parameters. We demonstrate here that the system is able to detect concentration-dependent atypical patterns caused by hERG inhibitors and other ion channel blockers. We also show that both positive and negative chronotropic effects on cardiac rate can be observed and IC(50) values determined. This methodology is well suited for safety testing and can be used to estimate efficacy and dosing of drug candidates prior to clinical studies.
很大一部分药物在临床研究中因心脏毒性而失败；因此，开发能够评估对心肌细胞潜在不良影响的灵敏体外检测方法对于药物研发极为重要。源自干细胞的人类心肌细胞比目前可用的细胞模型提供了更具临床相关性的基于细胞的模型。人类诱导多能干细胞衍生的心肌细胞尤其具有吸引力，因为它们表达离子通道，并表现出与成年心肌细胞相似的自发机械和电活动。在此，我们展示了使用ImageXpress Micro和FLIPR Tetra系统测量药物化合物对心肌细胞搏动率影响的技术。这些检测方法使用钙敏染料来监测与细胞搏动同步的Ca(2+)通量变化，从而能够监测搏动率、幅度和其他参数。我们在此证明，该系统能够检测由hERG抑制剂和其他离子通道阻滞剂引起的浓度依赖性非典型模式。我们还表明，可以观察到对心率的正性和负性变时作用，并确定IC(50)值。这种方法非常适合安全性测试，可用于在临床研究之前估计候选药物的疗效和剂量。
