Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, MI, USA.
Department of Human Genetics, University of Michigan, Ann Arbor, MI, USA.
Nat Commun. 2021 Oct 25;12(1):6167. doi: 10.1038/s41467-021-26496-1.
Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) allow investigations in a human cardiac model system, but disorganized mechanics and immaturity of hPSC-CMs on standard two-dimensional surfaces have been hurdles. Here, we developed a platform of micron-scale cardiac muscle bundles to control biomechanics in arrays of thousands of purified, independently contracting cardiac muscle strips on two-dimensional elastomer substrates with far greater throughput than single cell methods. By defining geometry and workload in this reductionist platform, we show that myofibrillar alignment and auxotonic contractions at physiologic workload drive maturation of contractile function, calcium handling, and electrophysiology. Using transcriptomics, reporter hPSC-CMs, and quantitative immunofluorescence, these cardiac muscle bundles can be used to parse orthogonal cues in early development, including contractile force, calcium load, and metabolic signals. Additionally, the resultant organized biomechanics facilitates automated extraction of contractile kinetics from brightfield microscopy imaging, increasing the accessibility, reproducibility, and throughput of pharmacologic testing and cardiomyopathy disease modeling.
人多能干细胞衍生的心肌细胞（hPSC-CMs）允许在人类心脏模型系统中进行研究，但 hPSC-CMs 在标准二维表面上的组织结构紊乱和不成熟一直是障碍。在这里，我们开发了一种微尺度心肌束平台，用于在二维弹性体基底上控制数千个纯化的、独立收缩的心肌条带的生物力学，其通量远远超过单细胞方法。通过在这个简化平台中定义几何形状和工作量，我们表明肌原纤维的排列和生理工作量下的辅助收缩驱动收缩功能、钙处理和电生理的成熟。使用转录组学、报告 hPSC-CMs 和定量免疫荧光，这些心肌束可用于解析早期发育中的正交线索，包括收缩力、钙负荷和代谢信号。此外，由此产生的组织生物力学有助于从明场显微镜成像中自动提取收缩动力学，提高了药理学测试和心肌病疾病建模的可及性、可重复性和通量。
