State Key Laboratory of Reproductive Medicine, Department of Ultrasound, Nanjing Maternal and Child Health Hospital, Nanjing Medical University, Nanjing 210029, PR China.
Int J Mol Med. 2012 Nov;30(5):1095-104. doi: 10.3892/ijmm.2012.1092. Epub 2012 Aug 9.
microRNAs (miRNAs) play an important role in regulating normal organ physiology and development. Many miRNAs show spatially and temporally restricted expression patterns during embryogenesis and organogenesis. This study aimed to characterize the miRNA profile of the fetal mouse heart at 4 key time-points [embryonic day (E)12.5, E14.5, E16.5 and E18.5] in its development, by performing a sequencing by oligonucleotide ligation and detection (SOLiD) miRNA screen. The 4 time-points were designated as groups M1 (E18.5), M2 (E16.5), M3 (E14.5) and M4 (E12.5). miRNAs found to have consistent fold-changes of >2.0) between the 4 time-points were selected for further analysis. Ten miRNAs (mmu-miR-23b, mmu-miR-24, mmu-miR-23a, mmu-miR-375, mmu-miR-29a, mmu-miR-93, mmu-miR-21, mmu-miR-25, mmu-let-7b and mmu-miR-27b) that were the most highly expressed in the 4 groups, including the percentage >1% of total read counts, were identified. No miRNA was consistently downregulated or upregulated. There were 16 differentially expressed miRNAs between the later development group (M1+M2) and the early development group (M3+M4), which were validated by quantitative real-time PCR. Several members of the let-7 miRNA cluster (mmu-let-7a/7d/7e/7f) were upregulated in the later development group compared with the early development group. A network analysis of the predicted targets of mmu-let-7a/7d/7e/7f identified 5 target genes (FOXP1, TBX5, HAND1, AKT2 and PPARGC1A), known to be involved in cardiac development. Therefore, this study identified several miRNAs that are abundantly expressed in the developing heart, several of which are differentially expressed in the 4 time-points studied. Findings of this analysis may thus clarify the mechanisms of normal heart development and provide a physiological basis for future studies on congenital heart disease.
微小 RNA（miRNAs）在调节正常器官生理和发育中发挥重要作用。许多 miRNA 在胚胎发生和器官发生过程中表现出时空受限的表达模式。本研究旨在通过寡核苷酸连接和检测测序（SOLiD）miRNA 筛选，描述胚胎期（E）12.5、E14.5、E16.5 和 E18.5 等 4 个关键时间点胎儿心脏的 miRNA 谱特征。这 4 个时间点分别命名为 M1（E18.5）、M2（E16.5）、M3（E14.5）和 M4（E12.5）。选择在 4 个时间点之间具有一致倍数变化（>2.0）的 miRNA 进行进一步分析。鉴定出 10 个 miRNA（mmu-miR-23b、mmu-miR-24、mmu-miR-23a、mmu-miR-375、mmu-miR-29a、mmu-miR-93、mmu-miR-21、mmu-miR-25、mmu-let-7b 和 mmu-miR-27b），它们在 4 个组中表达最高，包括总读数百分比>1%。没有 miRNA 被一致地下调或上调。在晚期发育组（M1+M2）和早期发育组（M3+M4）之间有 16 个差异表达的 miRNA，通过定量实时 PCR 进行了验证。在晚期发育组中，let-7 miRNA 簇（mmu-let-7a/7d/7e/7f）的几个成员上调。对 mmu-let-7a/7d/7e/7f 的预测靶基因的网络分析表明，有 5 个靶基因（FOXP1、TBX5、HAND1、AKT2 和 PPARGC1A）参与心脏发育。因此，本研究鉴定了一些在发育心脏中大量表达的 miRNA，其中一些在研究的 4 个时间点上表达差异。该分析的结果可能阐明正常心脏发育的机制，并为未来先天性心脏病的研究提供生理基础。
