Immortalized cardiac cell line characterization and comparison (mouse/mouse-derived)

The aim of this study was to compare the most common immortalized cardiac cell lines (human: AC16, rat: H9C2, mouse: HL-1) to primary cultures (neonatal rat or mouse cardiomyocytes, and human induced pluripotent stem cells) and left ventricular tissues from the corresponding species. To characterize cardiac cell lines, cardiac cell lines were seeded onto plates, and their differentiation towards a more cardiac phenotype was induced on the basis of most commonly used protocols in literature. The cells were harvested either in stage of proliferation or differentiation, and left ventricular tissue from each corresponding species, and isolated neonatal primary cardiac myocytes (for mouse and rat) or human induced pluripotent stem cells were applied as references for comparison. Transcriptomic analysis was performed on all samples. Generally, the mRNA expression pattern of cardiac markers in the cell lines showed significant differences compared to corresponding tissue or primary cultures. mRNA profile of cell lines indicates poor cardiac characteristics regardless the differentiation protocol used. Limitations of these cell lines should be taken into account when these cells are used as in vitro platforms to model cardiomyocytes and cardiovascular diseases.

本研究旨在对比目前最常用的几类永生化心肌细胞系（人类细胞系：AC16，大鼠细胞系：H9C2，小鼠细胞系：HL-1）与原代培养样本（新生大鼠或小鼠心肌细胞，以及人类诱导多能干细胞（human induced pluripotent stem cells）），以及对应物种的左心室组织。为表征上述心肌细胞系，我们依照文献中通用的实验方案，将细胞系接种于培养板，并诱导其向成熟心肌表型分化。分别在增殖期与分化期收集细胞；同时采集各对应物种的左心室组织，以及分离得到的新生原代心肌细胞（小鼠与大鼠）或人类诱导多能干细胞作为对照参照。随后对所有样本开展转录组学分析。总体而言，与对应组织或原代培养细胞相比，各细胞系中心肌标志物的mRNA表达模式存在显著差异。无论采用何种分化方案，细胞系的mRNA表达谱均显示其心肌特性欠佳。当使用此类细胞作为模拟心肌细胞与心血管疾病的体外实验平台时，需充分考虑其上述局限性。