Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) represent an attractive model to investigate CM function and disease mechanisms. One characteristic marker of ventricular specificity of human CMs is expression of the ventricular, slow β-myosin heavy chain (MyHC), as opposed to the atrial, fast α-MyHC. The main aim of this study was to investigate at the single-cell level whether contraction kinetics and electrical activity of hESC-CMs are influenced by the relative expression of α-MyHC versus β-MyHC. For effective assignment of functional parameters to the expression of both MyHC isoforms at protein and mRNA levels in the very same hESC-CMs, we developed a single-cell mapping technique. Surprisingly, α- versus β-MyHC was not related to specific contractile or electrophysiological properties of the same cells. The multiparametric cell-by-cell analysis suggests that in hESC-CMs the expression of genes associated with electrical activity, contraction, calcium handling, and MyHCs is independently regulated.

人多能干细胞衍生的心肌细胞（hPSC-CMs）是研究CM功能和疾病机制的有吸引力的模型。人CM的心室特异性的一个特征性标志是心室慢β-肌球蛋白重链（MyHC）的表达，而不是心房快速α-MyHC。这项研究的主要目的是在单细胞水平上研究hESC-CMs的收缩动力学和电活动是否受α-MyHC与β-MyHC相对表达的影响。为了在相同的hESC-CM中有效分配功能参数，以同时在蛋白质和mRNA水平表达MyHC异构体，我们开发了一种单细胞作图技术。出乎意料的是，α-与β-MyHC与相同细胞的特异性收缩或电生理特性无关。