Ballan Nimer, Shaheen Naim, Keller Gordon M, Gepstein Lior
Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, POB 9649, Haifa 3109601, Israel.
McEwen Stem Cell Institute and Princess Margaret Cancer Center, UHN, Toronto, ON, Canada; Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada.
Stem Cell Reports. 2020 Sep 8;15(3):587-596. doi: 10.1016/j.stemcr.2020.07.006. Epub 2020 Aug 6.
Current platforms for studying the mechanical properties of human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) as single cells do not measure forces directly, require numerous assumptions, and cannot study cell mechanics at different loading conditions. We present a method for directly measuring the active and passive forces generated by single-cell hPSC-CMs at different stretch levels. Utilizing this technique, single hPSC-CMs exhibited positive length-tension relationship and appropriate inotropic, klinotropic, and lusitropic changes in response to pharmacological treatments (isoproterenol and verapamil). The unique potential of the approach for drug testing and disease modeling was exemplified by doxorubicin and omecamtiv mecarbil drug studies revealing their known actions to suppress (doxorubicin) or augment (omecamtiv mecarbil at low dose) cardiomyocyte contractility, respectively. Finally, mechanistic insights were gained regarding the cellular effects of these drugs as doxorubicin treatment led to cellular mechanical alternans and high doses of omecamtiv mecarbil suppressed contractility and worsened the cellular diastolic properties.
当前用于研究人多能干细胞衍生心肌细胞（hPSC-CMs）单细胞力学特性的平台无法直接测量力，需要大量假设，且不能在不同加载条件下研究细胞力学。我们提出了一种直接测量单细胞hPSC-CMs在不同拉伸水平下产生的主动和被动力的方法。利用该技术，单个hPSC-CMs表现出正长度-张力关系，并对药物治疗（异丙肾上腺素和维拉帕米）产生适当的变力性、变时性和变松弛性变化。阿霉素和奥米卡替麦卡比药物研究分别揭示了它们抑制（阿霉素）或增强（低剂量奥米卡替麦卡比）心肌细胞收缩力的已知作用，例证了该方法在药物测试和疾病建模方面的独特潜力。最后，获得了关于这些药物细胞效应的机制性见解，因为阿霉素治疗导致细胞机械交替，高剂量奥米卡替麦卡比抑制收缩力并恶化细胞舒张特性。
