Department of Cell and Molecular Biology, Karolinska Institutet, SE-171 77 Stockholm, Sweden.
Exp Cell Res. 2011 Jan 15;317(2):188-94. doi: 10.1016/j.yexcr.2010.08.017. Epub 2010 Sep 7.
Assays to quantify myocardial renewal rely on the accurate identification of cardiomyocyte nuclei. We previously ¹⁴C birth dated human cardiomyocytes based on the nuclear localization of cTroponins T and I. A recent report by Kajstura et al. suggested that cTroponin I is only localized to the nucleus in a senescent subpopulation of cardiomyocytes, implying that ¹⁴C birth dating of cTroponin T and I positive cell populations underestimates cardiomyocyte renewal in humans. We show here that the isolation of cell nuclei from the heart by flow cytometry with antibodies against cardiac Troponins T and I, as well as pericentriolar material 1 (PCM-1), allows for isolation of close to all cardiomyocyte nuclei, based on ploidy and marker expression. We also present a reassessment of cardiomyocyte ploidy, which has important implications for the analysis of cell turnover, and iododeoxyuridine (IdU) incorporation data. These data provide the foundation for reliable analysis of cardiomyocyte turnover in humans.
检测心肌更新依赖于对心肌细胞核的准确识别。我们之前¹⁴C 标记了基于 c 肌钙蛋白 T 和 I 核定位的人心肌细胞。最近 Kajstura 等人的一份报告表明，c 肌钙蛋白 I 仅在心肌细胞衰老亚群中定位于核内，这意味着 c 肌钙蛋白 T 和 I 阳性细胞群体的¹⁴C 标记低估了人类心肌细胞的更新。我们在这里表明，通过针对心脏肌钙蛋白 T 和 I 以及中心粒周围物质 1（PCM-1）的抗体对心脏细胞进行流式细胞术分离细胞核，可以根据倍性和标志物表达分离接近所有的心肌细胞核。我们还重新评估了心肌细胞的倍性，这对细胞周转和碘脱氧尿苷（IdU）掺入数据的分析有重要意义。这些数据为可靠分析人类心肌细胞更新提供了基础。
