Ythdf2-mediated m6A mRNA clearance modulates neural development in mice. Ythdf2-mediated m6A mRNA clearance modulates neural development in mice

We found that the proliferation and differentiation capabilities of NSPCs decrease significantly in Ythdf2 null mutants.To explore the underlying molecular mechanism, we performed transcriptomics and well-established m6A-methylome analyses of NSPCs dervied from wild type and Ythdf2-/- embryo brains. RNA-seq data revealed that expressions of genes enriched in neural development pathways were significantly disturbed. The inhibitory genes, like Flrt2, Ptprd, et al. in regulation of JAK-STAT cascade, which contributes to the neuroprotection and neurite outgrowth, showed increased gene expressions and m6A enrichment by m6A-seq. We identified that without the recognizing and binding of Ythdf2, the degradation of neuron differentiation related m6A-modified mRNAs were delayed in Ythdf2-/-, thereby disturbing the proliferation and differentiation of NSPCs. In summary, our findings uncovered that Ythdf2 modulates neural developmental via regulating the clearance of mRNA targets. Overall design: Examination of gene expression levels and m6A levels in mRNAs in wild type and Ythdf2 deficient mouse E14.5 derived NSPCs

我们观察到，在Ythdf2基因缺失突变体中，神经干细胞/祖细胞（Neural Stem/Progenitor Cells，NSPCs）的增殖与分化能力显著降低。
为探究其潜在分子机制，我们对野生型及Ythdf2-/-小鼠胚胎脑组织来源的NSPCs开展了转录组学及经典的m6A甲基化组分析。
RNA测序（RNA-seq）数据显示，富集于神经发育通路的基因表达水平显著紊乱。
参与调控JAK-STAT信号通路的抑制性基因（如Flrt2、Ptprd等），其功能与神经保护及神经突起生长密切相关，经m6A测序（m6A-seq）分析发现，这些基因的表达水平及m6A修饰富集程度均显著上调。
我们证实，在缺乏Ythdf2的识别与结合作用时，Ythdf2-/-细胞中与神经元分化相关的m6A修饰mRNA的降解过程被延迟，进而扰乱了NSPCs的增殖与分化。
综上，本研究揭示Ythdf2可通过调控靶mRNA的清除过程，进而调节神经发育进程。
整体实验设计：检测野生型与Ythdf2基因缺陷型小鼠胚胎发育第14.5天（E14.5）来源的NSPCs中mRNA的基因表达水平与m6A修饰水平。