Abstract：
Exploring the mechanism of self-renewal and pluripotency maintenance of human embryonic stem cells (hESCs) is of great significance in basic research and clinical applications, but it has not been fully elucidated. Long non-coding RNAs (lncRNAs) have been shown to play a key role in the self-renewal and pluripotency maintenance of hESCs. We previously reported that the lncRNA ESRG, which is highly expressed in undifferentiated hESCs, can maintain the self-renewal and pluripotency of hPSCs. RNA pull-down mass spectrometry showed that ESRG could bind to other proteins, among which heterogeneous nuclear ribonucleoprotein A1 (HNRNPA1) attracted our attention. In this study, we showed that HNRNPA1 can maintain self-renewal and pluripotency of hESCs. ESRG bound to and stabilized HNRNPA1 protein through the ubiquitin-proteasome pathway. In addition, knockdown of ESRG or HNRNPA1 resulted in alternative splicing of TCF3, which originally and primarily encoded E12, to mainly encode E47 and inhibit CDH1 expression. HNRNPA1 could rescue the biological function changes of hESCs caused by ESRG knockdown or overexpression. Our results suggest that ESRG regulates the alternative splicing of TCF3 to affect CDH1 expression and maintain hESCs self-renewal and pluripotency by binding and stabilizing HNRNPA1 protein. This study lays a good foundation for exploring the new molecular regulatory mechanism by which ESRG maintains hESCs self-renewal and pluripotency.
摘要：
探索人胚胎干细胞(hESCs)的自我更新和多能性维持机制,在基础研究和临床应用中具有重要意义。但还没有完全阐明。长链非编码RNA（lncRNA）已被证明在hESC的自我更新和多能性维持中起关键作用。我们以前报道过lncRNAESRG，在未分化的hESC中高度表达，可以保持hPSC的自我更新和多能性。RNA下拉质谱显示ESRG可以与其他蛋白质结合，其中异质核核糖核蛋白A1（HNRNPA1）引起了我们的注意。在这项研究中,我们发现HNRNPA1可以维持hESCs的自我更新和多能性。ESRG通过泛素-蛋白酶体途径结合并稳定HNRNPA1蛋白。此外,ESRG或HNRNPA1的敲减导致TCF3的选择性剪接，TCF3最初和主要编码E12，主要编码E47并抑制CDH1表达。HNRNPA1可以挽救ESRG敲低或过表达引起的hESCs生物学功能变化。我们的结果表明，ESRG通过结合和稳定HNRNPA1蛋白来调节TCF3的可变剪接以影响CDH1表达并维持hESCs的自我更新和多能性。本研究为探索ESRG维持hESCs自我更新和多能性的分子调控机制奠定了良好的基础。
