METTL1-mediated m7G methylation maintains pluripotency in human stem cells and limits mesoderm differentiation and vascular development
METTL1-mediated m7G methylation maintains pluripotency in human stem cells and limits mesoderm differentiation and vascular development
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DOI：
10.1186/s13287-020-01814-4
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发表时间：
2020-07-22
影响因子：
7.5
通讯作者：
Wang, Min
中科院分区：
文献类型：
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作者：
Deng, Yujie;Zhou, Zhongyang;Wang, Min
背景7-甲基鸟苷（7-Methylguanosine，m（7）G）是tRNA和rRNA中最保守的核苷修饰之一。它在mRNA输出、剪接和翻译的调节中起重要作用。最近的研究强调了胃L1介导的m（7）G tRNA甲基化组通过其调节mRNA翻译的能力在小鼠胚胎干细胞（mESC）自我更新中的重要性。然而，胃L1调节人诱导多能干细胞（hiPSC）的多能性和分化的确切机制仍然未知。在这项研究中，我们评估的功能和潜在的分子机制，在调节hiPSC在体内和体外的自我更新和分化的胃L1 knockdown（KD）hiPSCs，基因表达谱进行RNA测序，然后进行通路分析。抗m（7）G Northwestern试验用于鉴定tRNA和mRNA中的m（7）G修饰。多核糖体分析用于评估主要多能转录因子的翻译效率。结果胃L1基因沉默后，hiPSCs中m（7）G基因表达谱发生改变，干细胞标记基因的翻译效率降低。胃L1-KD hiPSC表现出降低的多能性和较慢的细胞周期。此外，胃L1沉默加速hiPSC分化为EB并促进中胚层相关基因的表达。同样，通过促进细胞增殖和血管生成，在裸鼠中敲除胃L1增强畸胎瘤形成和中胚层分化。ConclusionOur findings provided novel insight into the critical role of胃L1介导的m（7）G修饰在hiPSC多能性和分化的调节中的关键作用，以及其在血管发育和血管疾病的治疗中的潜在作用。
Background7-Methylguanosine (m(7)G) is one of the most conserved modifications in nucleosides within tRNAs and rRNAs. It plays essential roles in the regulation of mRNA export, splicing, and translation. Recent studies highlighted the importance of METTL1-mediated m(7)G tRNA methylome in the self-renewal of mouse embryonic stem cells (mESCs) through its ability to regulate mRNA translation. However, the exact mechanisms by which METTL1 regulates pluripotency and differentiation in human induced pluripotent stem cells (hiPSCs) remain unknown. In this study, we evaluated the functions and underlying molecular mechanisms of METTL1 in regulating hiPSC self-renewal and differentiation in vivo and in vitro.MethodsBy establishing METTL1 knockdown (KD) hiPSCs, gene expression profiling was performed by RNA sequencing followed by pathway analyses. Anti-m(7)G northwestern assay was used to identify m(7)G modifications in tRNAs and mRNAs. Polysome profiling was used to assess the translation efficiency of the major pluripotent transcription factors. Moreover, the in vitro and in vivo differentiation capacities of METTL1-KD hiPSCs were assessed in embryoid body (EB) formation and teratoma formation assays.ResultsMETTL1 silencing resulted in alterations in the global m(7)G profile in hiPSCs and reduced the translational efficiency of stem cell marker genes. METTL1-KD hiPSCs exhibited reduced pluripotency with slower cell cycling. Moreover, METTL1 silencing accelerates hiPSC differentiation into EBs and promotes the expression of mesoderm-related genes. Similarly, METTL1 knockdown enhances teratoma formation and mesoderm differentiation in vivo by promoting cell proliferation and angiogenesis in nude mice.ConclusionOur findings provided novel insight into the critical role of METTL1-mediated m(7)G modification in the regulation of hiPSC pluripotency and differentiation, as well as its potential roles in vascular development and the treatment of vascular diseases.