Zhu Renjun, Millrod Michal A, Zambidis Elias T, Tung Leslie
Department of Biomedical Engineering, The Johns Hopkins University, Baltimore, MD 21205.
Institute for Cell Engineering and Division of Pediatric Oncology, Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University, Baltimore, MD 21205.
Sci Rep. 2016 Jan 5;6:18544. doi: 10.1038/srep18544.
Electrophysiological variability in cardiomyocytes derived from pluripotent stem cells continues to be an impediment for their scientific and translational applications. We studied the variability of action potentials (APs) recorded from clusters of human embryonic stem cell-derived cardiomyocytes (hESC-CMs) using high-resolution optical mapping. Over 23,000 APs were analyzed through four parameters: APD30, APD80, triangulation and fractional repolarization. Although measures were taken to reduce variability due to cell culture conditions and rate-dependency of APs, we still observed significant variability in APs among and within the clusters. However, similar APs were found in spatial locations with close proximity, and in some clusters formed distinct regions having different AP characteristics that were reflected as separate peaks in the AP parameter distributions, suggesting multiple electrophysiological phenotypes. Using a recently developed automated method to group cells based on their entire AP shape, we identified distinct regions of different phenotypes within single clusters and common phenotypes across different clusters when separating APs into 2 or 3 subpopulations. The systematic analysis of the heterogeneity and potential phenotypes of large populations of hESC-CMs can be used to evaluate strategies to improve the quality of pluripotent stem cell-derived cardiomyocytes for use in diagnostic and therapeutic applications and in drug screening.
多能干细胞来源的心肌细胞的电生理变异性仍然是其科学和转化应用的障碍。我们使用高分辨率光学映射研究了从人胚胎干细胞来源的心肌细胞（hESC-CMs）簇记录的动作电位（APs）的变异性。通过四个参数分析了超过23,000个APs：APD30、APD80、三角测量和复极化分数。尽管采取了措施来减少由于细胞培养条件和APs的速率依赖性引起的变异性，但我们仍然观察到簇间和簇内APs存在显著变异性。然而，在空间位置接近的地方发现了相似的APs，并且在一些簇中形成了具有不同AP特征的不同区域，这些区域在AP参数分布中表现为单独的峰值，表明存在多种电生理表型。使用最近开发的基于整个AP形状对细胞进行分组的自动化方法，当将APs分为2或3个亚群时，我们在单个簇内识别出不同表型的不同区域以及不同簇间的共同表型。对大量hESC-CMs的异质性和潜在表型进行系统分析，可用于评估提高多能干细胞来源的心肌细胞质量的策略，以用于诊断和治疗应用以及药物筛选。
