Key Laboratory of Regenerative Biology, South China Institute for Stem Cell Biology and Regenerative Medicine, Chinese Academy of Sciences, Guangzhou 510530, China.
J Biol Chem. 2011 May 13;286(19):17359-64. doi: 10.1074/jbc.C111.235960. Epub 2011 Mar 22.
MicroRNAs (miRNAs) are emerging critical regulators of cell function that frequently reside in clusters throughout the genome. They influence a myriad of cell functions, including the generation of induced pluripotent stem cells, also termed reprogramming. Here, we have successfully delivered entire miRNA clusters into reprogramming fibroblasts using retroviral vectors. This strategy avoids caveats associated with transient transfection of chemically synthesized miRNA mimics. Overexpression of 2 miRNA clusters, 106a-363 and in particular 302-367, allowed potent increases in induced pluripotent stem cell generation efficiency in mouse fibroblasts using 3 exogenous factors (Sox2, Klf4, and Oct4). Pathway analysis highlighted potential relevant effectors, including mesenchymal-to-epithelial transition, cell cycle, and epigenetic regulators. Further study showed that miRNA cluster 302-367 targeted TGFβ receptor 2, promoted increased E-cadherin expression, and accelerated mesenchymal-to-epithelial changes necessary for colony formation. Our work thus provides an interesting alternative for improving reprogramming using miRNAs and adds new evidence for the emerging relationship between pluripotency and the epithelial phenotype.
微小 RNA（miRNA）是细胞功能的新兴关键调节因子，它们经常存在于基因组的簇中。它们影响着许多细胞功能，包括诱导多能干细胞的产生，也称为重编程。在这里，我们使用逆转录病毒载体成功地将整个 miRNA 簇递送到重编程成纤维细胞中。这种策略避免了与化学合成 miRNA 模拟物瞬时转染相关的注意事项。过表达 2 个 miRNA 簇，特别是 106a-363 和 302-367，允许在外源因子（Sox2、Klf4 和 Oct4）的作用下，显著增加小鼠成纤维细胞中诱导多能干细胞的生成效率。通路分析突出了潜在的相关效应物，包括上皮-间充质转化、细胞周期和表观遗传调节剂。进一步的研究表明，miRNA 簇 302-367 靶向 TGFβ 受体 2，促进 E-钙黏蛋白表达增加，并加速形成集落所必需的间充质-上皮转化。我们的工作因此为使用 miRNA 来提高重编程提供了一个有趣的替代方案，并为多能性和上皮表型之间新兴的关系提供了新的证据。
