Department of Applied Physics, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
Analyst. 2010 Jul;135(7):1624-30. doi: 10.1039/c0an00208a. Epub 2010 Jun 1.
The interest in cardiomyocytes derived from differentiation of embryonic stem (ES) cells or induced pluripotent stem (iPS) cells is increasing due to their potential for regenerative therapeutics and as a pharmaceutical model of drug screening. Characterization of ES or iPS derived cardiomyocytes is challenging and inevitable for the intended usage of such cells. In this paper we have outlined a novel, non-invasive method for evaluating in vitro beating properties of cardiomyocytes. The method is based on the analysis of time dependent variation in the total pixel intensities in derivative images obtained from the consecutive systolic and diastolic frames from the light microscopic video recordings of beating tissue. Fast Fourier transform (FFT) yielded the frequency domains for these images. The signal to noise ratio for the analysis met the Rose criterion. We have successfully applied our method for monitoring mouse ES cell (mESC) derived cardiac muscle cells to determine the initiation of beating, organization and maturation of beating tissue, calculating the beating rhythms in terms of beating interval or frequency and the strength of beating. We have shown the successful application of our image analysis method in direct monitoring of the responses of differentiated cardiomyocytes towards caffeine hydrate, p-hydroxyphenylacetamide and calcium chloride dehydrate - respectively as positive, neutral and negative inotropic agents. This non-invasive method of characterization will be useful in studying the response of these cells to various external stimulations, such as differentiation promoting agents or treatments, as well as in preliminary drug screening in a quick and inexpensive manner without needing much expertise.
由于胚胎干细胞（ES）或诱导多能干细胞（iPS）衍生的心肌细胞在再生治疗和作为药物筛选的药物模型方面具有潜在应用价值，因此人们对其的兴趣日益增加。对 ES 或 iPS 衍生的心肌细胞进行特征描述对于这些细胞的预期用途是具有挑战性且不可避免的。在本文中，我们概述了一种新颖的、非侵入性方法，用于评估心肌细胞的体外搏动特性。该方法基于分析从搏动组织的连续收缩和舒张帧的明场视频记录中获得的衍生图像中总像素强度随时间的变化。快速傅里叶变换（FFT）为这些图像提供了频域。分析的信噪比符合罗斯标准。我们已经成功地将我们的方法应用于监测小鼠胚胎干细胞（mESC）衍生的心肌细胞，以确定搏动的起始、搏动组织的组织和成熟，以及以搏动间隔或频率和搏动强度来计算搏动节律。我们已经证明，我们的图像分析方法可成功用于直接监测分化的心肌细胞对水合咖啡因、对羟基苯乙酰胺和无水氯化钙的反应——分别作为正性、中性和负性变力剂。这种非侵入性的特征描述方法将有助于研究这些细胞对各种外部刺激的反应，例如促进分化的试剂或治疗方法，以及以快速和廉价的方式进行初步药物筛选，而不需要太多的专业知识。
