Time course analysis of the cardiac transcriptome in the neonatal period

Adult mammalian cardiomyocytes (CM) are differentiated post-mitotic cells that lack significant proliferative potential through their inability to reactivate the cell cycle postnatally. In the week after birth, the mammalian heart goes through distinct stages of cell cycle progression and differentiation that govern the development of the mature adult CM phenotype. By establishing the fundamental framework of the molecular signals governing these early events after birth, a potential treatment strategy that restores the heart's ability to proliferate, and in theory, undergo "repair" after injury could be developed. At 0 days (d), 1d, 3d, 5d, 7d, 10d, and 15d after birth, hearts from C57BL/6J wild-type mice were excised and processed for total RNA isolation. Samples were analyzed by genome-wide messenger RNA (mRNA) microarray profiling. All experiments were performed on age- and sex-matched mice, with equal ratio of male to female mice.成年哺乳动物心肌细胞（cardiomyocytes, CM）属于终末分化的有丝分裂后细胞，因无法在出生后重新激活细胞周期，故而丧失显著的增殖潜能。出生后一周内，哺乳动物心脏会经历一系列特征明确的细胞周期进程与分化阶段，这些过程调控成熟成年心肌细胞表型的形成。若能阐明出生后这些早期事件的分子调控基础框架，便有望开发出可恢复心脏增殖能力、理论上能实现损伤后“修复”的潜在治疗策略。分别在小鼠出生后0天（d）、1d、3d、5d、7d、10d及15d时，摘取C57BL/6J野生型小鼠的心脏并提取总RNA。通过全基因组信使RNA（messenger RNA, mRNA）微阵列分析对样本进行检测。所有实验均采用年龄与性别匹配的小鼠，雌雄比例均等。