Argonaute-2-null embryonic stem cells are retarded in self-renewal and differentiation
Argonaute-2-null embryonic stem cells are retarded in self-renewal and differentiation
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DOI：
10.1007/s12038-011-9094-1
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发表时间：
2011-09
影响因子：
2.9
通讯作者：
P. C. Shekar;Adnan Naim;D. P. Sarathi;Satish Kumar
中科院分区：
文献类型：
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作者：
P. C. Shekar;Adnan Naim;D. P. Sarathi;Satish Kumar
RNA干扰（RNA interference，RNAi）途径调控胚胎干细胞（embryonic stem cell，ES）的自我更新和分化，Argonaute 2（Ago 2）是RNA诱导沉默复合物（RNA-induced silencing complex，RISC）的重要组成部分，也是唯一具有切割活性的Ago蛋白。Ago 2缺陷的ES细胞在小RNA介导的基因沉默方面存在缺陷，并且在成熟microRNA的生物合成方面受到显著影响。Ago 2缺陷ES细胞的自我更新率受到影响，这是由于在Ago 2缺失的情况下，Cdkn 1和ES细胞特异性microRNA（miRNA）的沉默失败。有趣的是，与Dicer和Dgcr 8缺陷的ES细胞不同，它们在体内和体外都能分化为所有三个胚层。然而，Ago 2缺陷型ES细胞的早期分化延迟2-4天，如在分化期间持续存在较高水平的自我更新/多能性标记所示。此外，形态学和分化标记的出现在分化期间也延迟。在这项研究中，我们表明Ago 2是正常的自我更新和分化所必需的。此外，我们的数据表明ES细胞的自我更新和分化受到siRNA和miRNA途径的调节。
RNA interference (RNAi) pathways regulate self-renewal and differentiation of embryonic stem (ES) cells.Argonaute 2(Ago2) is a vital component of RNA-induced silencing complex (RISC) and the only Ago protein with slicer activity. We generatedAgo2-deficient ES cells by conditional gene targeting.Ago2-deficient ES cells are defective in the small-RNA-mediated gene silencing and are significantly compromised in biogenesis of mature microRNA. The self-renewal rate ofAgo2-deficient ES cells is affected due to failure of silencing ofCdkn1aby ES-cell-specific microRNAs (miRNA) in the absence ofAgo2. Interestingly, unlikeDicer-andDgcr8-deficient ES cells, they differentiate to all three germ layers bothin vivoandin vitro. However, early differentiation ofAgo2-deficient ES cells is delayed by 2–4 days as indicated by persistence of higher levels of self-renewal/ pluripotency markers during differentiation. Further, appearance of morphological and differentiation markers is also delayed during the differentiation. In this study we show thatAgo2is essential for normal self-renewal and differentiation. Also, our data suggest that self-renewal and differentiation of ES cells are regulated by both siRNA and miRNA pathways.