The Translational Regulatory Mechanisms of Neural Precursor Cell Maintenance and Differentiation

神经前体细胞维持和分化的翻译调控机制

• 批准号: RGPIN-2018-04246
• 负责人: Yang, Guang
• 金额: $ 2.99万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=669168
• 关键词: Translational; Regulatory; Mechanisms; Neural; Precursor

In mammals, neural stem/precursor cells (NPCs) give rise to billions of neurons to build the brain. To ensure the appropriate neurogenesis the balance between NPC maintenance and differentiation is tightly controlled. The long-term objective of my research program is to understand gene regulatory mechanisms that underlie NPC maintenance and differentiation. In the past few decades, considerable efforts have been directed towards understanding transcriptional mechanisms that regulate NPCs. Nevertheless, how other layers of gene regulation control NPCs remains largely unexplored. Using the developing mouse cortex as our model system, we have recently found that many genes that promote differentiation are transcribed ubiquitously in cortical NPCs, but those transcripts are not translated. Thus, translational regulation plays a critical role in NPC maintenance and differentiation, though the specific mechanisms are poorly understood. Therefore, my short-term objective is focused on understanding translational control mechanisms. ******We identified a group of translational repression complexes that contain the core repressor protein 4E-T. The complexes play a key role in maintaining the stem cell state of cortical NPCs. In searching the other components of the 4E-T complexes, we identified many target-specific RNA-binding proteins that interact with 4E-T in NPCs, such as the cytoplasmic polyadenylation element binding protein 4 (CPEB4). We hypothesize that by forming complexes with distinct target-specific RNA-binding proteins, 4E-T controls different subsets of mRNAs to regulate NPC maintenance and differentiation. In this proposal, we will use CPEB4 as an example to illustrate how in the long term we will dissect the role of various RNA-binding proteins in NPC homeostasis. In three specific aims, we will: 1) Determine the roles of RNA-binding proteins in NPC maintenance and differentiation both in vitro and in vivo, by applying loss- and gain-of-function approaches; 2) Identify target mRNAs for the RNA-binding proteins, using both genome-wide and candidate-gene approaches; and 3) Characterize the interactions between 4E-T and RNA-binding proteins to assess how the different complexes regulate NPC homeostasis. ******The proposed studies will elucidate translational control mechanisms of NPC homeostasis and serve as a foundation for my long-term research goal to fully reveal the gene regulatory landscape in NPCs. By advancing our understanding of how gene expression is controlled at multiple levels to coordinate stem cell homeostasis, my research will spark new technologies for stem cell manufacturing and tissue engineering applications. Importantly, by learning state-of-the-art techniques for high-resolution imaging, gene regulation, and stem cell biology, HQP in my research program will develop professional skills for a career within or outside academia.

在哺乳动物中，神经干/前体细胞 (NPC) 产生数十亿个神经元来构建大脑。为了确保适当的神经发生，NPC 维持和分化之间的平衡受到严格控制。我的研究计划的长期目标是了解 NPC 维持和分化的基因调控机制。在过去的几十年里，人们付出了大量的努力来了解调节 NPC 的转录机制。然而，基因调控的其他层面如何控制 NPC 仍然很大程度上尚未被探索。使用发育中的小鼠皮层作为我们的模型系统，我们最近发现许多促进分化的基因在皮层 NPC 中普遍转录，但这些转录物不被翻译。因此，翻译调控在 NPC 维持和分化中起着至关重要的作用，尽管具体机制尚不清楚。因此，我的短期目标集中在理解翻译控制机制。 ******我们鉴定了一组包含核心阻遏蛋白 4E-T 的翻译阻抑复合物。这些复合物在维持皮质 NPC 的干细胞状态中发挥着关键作用。在寻找 4E-T 复合物的其他成分时，我们鉴定了许多与 NPC 中的 4E-T 相互作用的靶标特异性 RNA 结合蛋白，例如细胞质多腺苷酸化元件结合蛋白 4 (CPEB4)。我们假设，4E-T 通过与不同的靶标特异性 RNA 结合蛋白形成复合物，控制不同的 mRNA 子集来调节 NPC 的维持和分化。在本提案中，我们将以 CPEB4 为例来说明从长远来看我们将如何剖析各种 RNA 结合蛋白在 NPC 稳态中的作用。为了实现三个具体目标，我们将： 1) 通过应用功能丧失和获得功能的方法，确定 RNA 结合蛋白在体外和体内 NPC 维持和分化中的作用； 2) 使用全基因组和候选基因方法鉴定 RNA 结合蛋白的靶 mRNA； 3) 表征 4E-T 和 RNA 结合蛋白之间的相互作用，以评估不同复合物如何调节 NPC 稳态。 ******拟议的研究将阐明鼻咽癌稳态的翻译控制机制，并为我全面揭示鼻咽癌基因调控景观的长期研究目标奠定基础。通过加深我们对如何在多个水平上控制基因表达以协调干细胞稳态的理解，我的研究将激发干细胞制造和组织工程应用的新技术。重要的是，通过学习高分辨率成像、基因调控和干细胞生物学的最先进技术，我的研究项目中的 HQP 将为学术界内外的职业发展专业技能。