哺乳類脳神経幹細胞の特性の経時変化を制御するエピゲノム修飾と細胞間シグナルの研究

控制哺乳动物神经干细胞特征时间变化的表观基因组修饰和细胞间信号研究

• 批准号: 15F15083
• 负责人: 松崎 文雄
• 金额: $ 1.47万
• 依托单位: Institute of Physical and Chemical Research
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for JSPS Fellows
• 财政年份: 2015
• 资助国家: 日本
• 起止时间: 2015-07-29 至 2017-03-31
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-15F15083/
• 关键词: 神経発生; 翻訳調節; Notchシグナル; RNA メチル基転移酵素; リボゾーム プロファイリング; 神経幹細胞; 対称分裂; 非対称分裂; エピジェネティクス; 単一遺伝子発現解析

In the last year, Wu continued to analyze the function of Fibrillarin in temporal fate change of neural stem cells (NSCs). As a result, Wu found that RNAi-mediated knockdown of Fibrillarin to ~50% at proliferative stage promoted premature neuronal differentiation of NSCs. Consistently, the activity of Notch signaling which is important for self-renewal of NSCs was strongly reduced after knockdown of Fibrillarin. In contrast, overexpression of Fibrillarin increased the population of NSCs. These results suggest that Fibrillarin is essential for proliferation of NSCs. Next, Wu tried to uncover the mechanism by which Fibrillarin affects the fate of NSCs. Because Fibrillarin is a methyltransferase of rRNA and methylation level of rRNA may affect translation, Wu asked that whether knockdown of Fibrillarin affects global protein translation or only impacts on specific targets. Using chemical probe to trace newly synthesized protein, Wu confirmed that RNAi-mediated knockdown of Fibrillarin to ~50% did not affect global protein translation. These results imply that Fibrillarin regulates cell fate through preferentially translating of target mRNAs. Then, to search the targets of Fibrillarin, Wu, cooperating with Dr. Iwasaki Shitano, performed ribosome profiling, a novel method to detect translating mRNAs based on deep-sequencing. Even this experiment is still ongoing, I think that results of this experiment will help us to better understand how NSC fate is precisely controlled. After finish of JSPS fellowship, Wu will continue to complete this project in my lab.

去年，吴继续分析Fibrillarin在神经干细胞（NSC）时间命运改变中的功能。结果，Wu 发现在增殖阶段 RNAi 介导的 Fibrillarin 敲低约 50% 可促进 NSC 的过早神经元分化。一致地，对 NSC 自我更新很重要的 Notch 信号传导活性在 Fibrillarin 敲除后显着降低。相反，Fibrillarin 的过度表达增加了 NSC 的数量。这些结果表明 Fibrillarin 对于 NSC 的增殖至关重要。接下来，吴试图揭示Fibrillarin影响NSCs命运的机制。由于Fibrillarin是rRNA的甲基转移酶，rRNA的甲基化水平可能会影响翻译，Wu询问Fibrillarin的敲低是否会影响整体蛋白质翻译，还是仅影响特定靶标。 Wu 使用化学探针追踪新合成的蛋白质，证实 RNAi 介导的 Fibrillarin 敲低约 50% 不会影响整体蛋白质翻译。这些结果表明 Fibrillarin 通过优先翻译目标 mRNA 来调节细胞命运。然后，为了寻找 Fibrillarin 的靶标，Wu 与 Iwasaki Shitano 博士合作进行了核糖体分析，这是一种基于深度测序检测翻译 mRNA 的新方法。即使这个实验仍在进行中，我认为这个实验的结果将帮助我们更好地理解 NSC 的命运是如何精确控制的。 JSPS 奖学金结束后，吴将继续在我的实验室完成这个项目。

项目成果

Fibrillarin-dependent rRNA methylation couples temporal fate transition of embryonic neural stem cells

纤维蛋白依赖性 rRNA 甲基化耦合胚胎神经干细胞的时间命运转变

• 发表时间: 2017
• 作者: Wu Q;Fukuda K;Kato Y;Zhou Z;Deng CX;Saga Y;Quan Wu
• 通讯作者: Quan Wu

Study of Intrinsic clocks controlling temporal identity of neural stem cells

控制神经干细胞时间特性的内在时钟的研究

• 发表时间: 2017
• 作者: Wu Q;Fukuda K;Kato Y;Zhou Z;Deng CX;Saga Y;Quan Wu;Quan Wu
• 通讯作者: Quan Wu

Sexual Fate Change of XX Germ Cells Caused by the Deletion of SMAD4 and STRA8 Independent of Somatic Sex Reprogramming.

• DOI: 10.1371/journal.pbio.1002553
• 发表时间: 2016-09
• 期刊: PLoS biology
• 影响因子: 9.8
• 作者: Wu Q;Fukuda K;Kato Y;Zhou Z;Deng CX;Saga Y
• 通讯作者: Saga Y