MicroRNAs control de novo DNA methylation through regulation of transcriptional repressors in mouse embryonic stem cells
MicroRNAs control de novo DNA methylation through regulation of transcriptional repressors in mouse embryonic stem cells
复制标题
DOI：
10.1038/nsmb.1391
复制
发表时间：
2008-03-01
影响因子：
16.8
通讯作者：
Filipowicz, Witold
中科院分区：
文献类型：
--
作者：
Sinkkonen, Lasse;Hugenschmidt, Tabea;Filipowicz, Witold
microRNA (miRNA) 通路成分的丢失会对胚胎干 (ES) 细胞的分化产生负面影响，但潜在的分子机制仍不清楚。在这里，我们描述了缺乏 Dicer (Dicer1) 的小鼠 ES 细胞的变化。 Dicer(-/-)细胞的转录组分析表明ES特异性miR-290簇在未分化的ES细胞中具有重要的调节功能。一致的是，Dicer 缺陷细胞中的许多缺陷可以通过转染 miR-290 家族 miRNA 来逆转。我们证明，在分化的 Dicer(-/-) ES 细胞中，Oct4（也称为 Pou5f1）沉默伴随着抑制性组蛋白标记的积累，而不是通过 DNA 甲基化，从而阻止了 Oct4 的稳定抑制。甲基化缺陷与 de novo DNA 甲基转移酶 (Dnmts) 的下调相关。这种下调是由 Rbl2 和可能的其他转录抑制因子介导的，它们是 miR-290 簇 miRNA 的潜在直接靶标。有缺陷的DNA甲基化可以通过de novo Dnmts的异位表达或通过转染miR-290簇miRNA来挽救，这表明ES细胞中的de novo DNA甲基化是由miRNA控制的。
Loss of microRNA (miRNA) pathway components negatively affects differentiation of embryonic stem (ES) cells, but the underlying molecular mechanisms remain poorly defined. Here we characterize changes in mouse ES cells lacking Dicer (Dicer1). Transcriptome analysis of Dicer(-/-) cells indicates that the ES-specific miR-290 cluster has an important regulatory function in undifferentiated ES cells. Consistently, many of the defects in Dicer-deficient cells can be reversed by transfection with miR-290 family miRNAs. We demonstrate that Oct4 (also known as Pou5f1) silencing in differentiating Dicer(-/-) ES cells is accompanied by accumulation of repressive histone marks but not by DNA methylation, which prevents the stable repression of Oct4. The methylation defect correlates with downregulation of de novo DNA methyltransferases (Dnmts). The downregulation is mediated by Rbl2 and possibly other transcriptional repressors, potential direct targets of miR-290 cluster miRNAs. The defective DNA methylation can be rescued by ectopic expression of de novo Dnmts or by transfection of the miR-290 cluster miRNAs, indicating that de novo DNA methylation in ES cells is controlled by miRNAs.