Cell and Molecular Biology, Karolinska Institutet, SE-17177 Stockholm, Sweden; Department of Forensic Medicine, The National Board of Forensic Medicine, SE-17177 Stockholm, Sweden.
Cell and Molecular Biology, Karolinska Institutet, SE-17177 Stockholm, Sweden.
Cell. 2015 Nov 5;163(4):1026-36. doi: 10.1016/j.cell.2015.10.035.
The magnitude of cardiomyocyte generation in the adult heart has been heavily debated. A recent report suggests that during mouse preadolescence, cardiomyocyte proliferation leads to a 40% increase in the number of cardiomyocytes. Such an expansion would change our understanding of heart growth and have far-reaching implications for cardiac regeneration. Here, using design-based stereology, we found that cardiomyocyte proliferation accounted for 30% of postnatal DNA synthesis; however, we were unable to detect any changes in cardiomyocyte number after postnatal day 11. (15)N-thymidine and BrdU analyses provided no evidence for a proliferative peak in preadolescent mice. By contrast, cardiomyocyte multinucleation comprises 57% of postnatal DNA synthesis, followed by cardiomyocyte nuclear polyploidisation, contributing with 13% to DNA synthesis within the second and third postnatal weeks. We conclude that the majority of cardiomyocytes is set within the first postnatal week and that this event is followed by two waves of non-replicative DNA synthesis. This Matters Arising paper is in response to Naqvi et al. (2014), published in Cell. See also the associated Correspondence by Soonpaa et al. (2015), and the response by Naqvi et al. (2015), published in this issue.
成人心肌细胞生成的幅度一直存在激烈的争论。最近的一份报告表明，在小鼠青春期前，心肌细胞增殖导致心肌细胞数量增加 40%。这种扩张将改变我们对心脏生长的理解，并对心脏再生产生深远的影响。在这里，我们使用基于设计的体视学方法发现，心肌细胞增殖占出生后 DNA 合成的 30%；然而，我们无法在出生后第 11 天检测到心肌细胞数量的任何变化。(15)N-胸腺嘧啶和 BrdU 分析未提供青春期前小鼠存在增殖高峰的证据。相比之下，心肌细胞多核化占出生后 DNA 合成的 57%，随后是心肌细胞核多倍化，在第二和第三周的 DNA 合成中贡献了 13%。我们得出结论，大多数心肌细胞在出生后的第一周内形成，此后发生了两波非复制性 DNA 合成。本期的这篇观点文章是对 Naqvi 等人（2014）发表在《Cell》上的文章的回应。也请参见 Soonpaa 等人（2015）的相关通讯，以及 Naqvi 等人（2015）在本期杂志上发表的回应。
