Institute of Pediatrics, Nanjing Medical University, Nanjing 210029, P.R. China.
Int J Mol Med. 2012 Mar;29(3):393-402. doi: 10.3892/ijmm.2011.855. Epub 2011 Dec 6.
As well-known regulators of gene expression, microRNAs (miRNAs) play an important role not only in cell proliferation and differentiation, but also in tumorigenesis and organ development. Furthermore, it is estimated that miRNAs may be responsible for regulating the expression of nearly one-third of the human genome. Simultaneously, in the clinic, with advances in neonatal care, a larger number of premature infants are being saved, and thus diseases of lung development, including bronchopulmonary dysplasia (BPD) have become more and more common. However, only a few miRNA studies have studied their connection with diseases of lung development. In our study, we used a miRNA microarray including more than 1891 capture probes to profile the expression of miRNAs at three time points of rat lung development [embryonic (E) Day 16 (E16), E19, E21]. miRNAs found to have consistent fold-changes (fold-change>2.0) during all three time points were selected and validated by real-time PCR. As a result, 167 differentially expressed miRNAs were found during rat lung organogenesis, including 81 upregulated and 86 downregulated miRNAs. Seven miRNAs were selected and characterized by having a consistent >2-fold changes between all three groups. Among these 7 miRNAs, except for let-7a, the other 6 miRNAs (miR-1949, miR-125b-5p, miR-296, miR-93, miR-146b, miR-3560) are all first reported for the first time in lung development. Finally, due to the fact that they demonstrated higher fold changes, from these 7 miRNAs we selected miR-125b-5p, miR-296, miR-93, miR-146b and miR-3560 for real-time PCR. We hypothesized that these newly identified miRNAs may play an important role in fetal lung development, and this experimental result could help us to further clarify the mechanism of normal lung development including the development of type II pneumocytes. This may provide a physiological basis for future research on diseases of lung development.
作为基因表达的已知调控因子，microRNAs（miRNAs）不仅在细胞增殖和分化中发挥重要作用，而且在肿瘤发生和器官发育中也发挥重要作用。此外，据估计，miRNAs 可能负责调节人类基因组近三分之一的基因表达。同时，在临床上，随着新生儿护理的进步，越来越多的早产儿被挽救，因此肺部发育疾病，包括支气管肺发育不良（BPD），变得越来越普遍。然而，只有少数 miRNA 研究探讨了它们与肺部发育疾病的关系。在我们的研究中，我们使用了一个 miRNA 微阵列，该微阵列包含超过 1891 个捕获探针，以分析大鼠肺发育的三个时间点（胚胎（E）天 16（E16）、E19、E21）的 miRNA 表达。选择在所有三个时间点均表现出一致倍数变化（倍数变化>2.0）的 miRNAs，并通过实时 PCR 进行验证。结果，在大鼠肺器官发生过程中发现了 167 个差异表达的 miRNAs，包括 81 个上调和 86 个下调的 miRNAs。选择了 7 个 miRNAs 进行特征描述，这些 miRNAs 在所有三个组之间都表现出一致的>2 倍变化。在这 7 个 miRNAs 中，除了 let-7a 之外，其他 6 个 miRNAs（miR-1949、miR-125b-5p、miR-296、miR-93、miR-146b、miR-3560）均首次在肺发育中报道。最后，由于这些 miRNA 的倍数变化更高，我们从这 7 个 miRNAs 中选择了 miR-125b-5p、miR-296、miR-93、miR-146b 和 miR-3560 进行实时 PCR。我们假设这些新发现的 miRNAs 可能在胎儿肺发育中发挥重要作用，这一实验结果有助于我们进一步阐明正常肺发育的机制，包括 II 型肺泡细胞的发育。这可能为未来肺部发育疾病的研究提供生理基础。
