Department of Cardiology, First Affiliated Hospital, Chongqing Medical University, China.
Braz J Med Biol Res. 2012 Feb;45(2):131-8. doi: 10.1590/s0100-879x2012007500007. Epub 2012 Feb 9.
MicroRNAs (miRNAs) have gradually been recognized as regulators of embryonic development; however, relatively few miRNAs have been identified that regulate cardiac development. A series of recent papers have established an essential role for the miRNA-17-92 (miR-17-92) cluster of miRNAs in the development of the heart. Previous research has shown that the Friend of Gata-2 (FOG-2) is critical for cardiac development. To investigate the possibility that the miR-17-92 cluster regulates FOG-2 expression and inhibits proliferation in mouse embryonic cardiomyocytes we initially used bioinformatics to analyze 3' untranslated regions (3'UTR) of FOG-2 to predict the potential of miR-17-92 to target it. We used luciferase assays to demonstrate that miR-17-5p and miR-20a of miR-17-92 interact with the predicted target sites in the 3'UTR of FOG-2. Furthermore, RT-PCR and Western blot were used to demonstrate the post-transcriptional regulation of FOG-2 by miR-17-92 in embryonic cardiomyocytes from E12.5-day pregnant C57BL/6J mice. Finally, EdU cell assays together with the FOG-2 rescue strategy were employed to evaluate the effect of proliferation on embryonic cardiomyocytes. We first found that the miR-17-5p and miR-20a of miR-17-92 directly target the 3'UTR of FOG-2 and post-transcriptionally repress the expression of FOG-2. Moreover, our findings demonstrated that over-expression of miR-17-92 may inhibit cell proliferation via post-transcriptional repression of FOG-2 in embryonic cardiomyocytes. These results indicate that the miR-17-92 cluster regulates the expression of FOG-2 protein and suggest that the miR-17-92 cluster might play an important role in heart development.
微小 RNA（miRNAs）逐渐被认为是胚胎发育的调控因子；然而，被鉴定为调节心脏发育的 miRNAs 相对较少。一系列最近的论文已经确立了 miRNA-17-92（miR-17-92）簇在心脏发育中的重要作用。先前的研究表明，Gata-2 的朋友（FOG-2）对于心脏发育至关重要。为了研究 miR-17-92 簇是否调节 FOG-2 表达并抑制小鼠胚胎心肌细胞增殖的可能性，我们最初使用生物信息学方法分析了 FOG-2 的 3'非翻译区（3'UTR），以预测 miR-17-92 靶向它的潜力。我们使用荧光素酶测定法证明 miR-17-92 的 miR-17-5p 和 miR-20a 与 FOG-2 的 3'UTR 中的预测靶位点相互作用。此外，使用 RT-PCR 和 Western blot 证明 miR-17-92 在来自 C57BL/6J 孕鼠 E12.5 天的胚胎心肌细胞中对 FOG-2 进行转录后调节。最后，采用 EdU 细胞测定法结合 FOG-2 挽救策略来评估增殖对胚胎心肌细胞的影响。我们首先发现 miR-17-92 的 miR-17-5p 和 miR-20a 直接靶向 FOG-2 的 3'UTR，并转录后抑制 FOG-2 的表达。此外，我们的研究结果表明，miR-17-92 的过表达可能通过 FOG-2 的转录后抑制来抑制胚胎心肌细胞的增殖。这些结果表明，miR-17-92 簇调节 FOG-2 蛋白的表达，并表明 miR-17-92 簇可能在心脏发育中发挥重要作用。
