Characterization of RNA Binding Protein Regulation in Neural Stem Cell Quiescence Exit

项目摘要/摘要 神经发生，新生神经元的终生生成，发生在神经干细胞(NSC)的壁龛中 大脑。随着年龄的增长，神经发生能力下降，但也会导致疾病病理，如 痴呆症、焦虑症和抑郁症。这种减弱的神经发生在很大程度上是由于 NSC静止期退出，是NSC激活和细胞周期重入的过程。NSC在NSC之间动态转换 静止和激活的细胞状态；静止的神经干细胞(QNSCs)处于细胞周期的可逆G0状态 而激活的神经干细胞(ANSCs)分裂以自我更新或产生新的神经元。尽管静止的出口是 作为神经发生的限速步骤，其机制尚不清楚。 影响静止退出的一个关键内在机制是聚集的蛋白质通过 形成被中间丝波纹包围的侵袭体。在没有波形的情况下 蛋白质，在体内和体外都有qNSC活性降低，这表明波形蛋白在其中起着关键作用。 在调解静止退场方面。有趣的是，qNSCs独特地含有高Vimentin mRNA和低蛋白水平， 与aNSCs相比，提示qNSCs中Vimentin mRNA的翻译抑制迅速逆转 静息时退出，上调波形蛋白，促进侵袭体的形成。这表明 Vimentin的调节可能在细胞状态之间的转换中受到唯一的控制。因此， 确定在静止退出过程中这种转录后调控的潜在机制将揭示 可能以增加神经发生为目标的过程。 这项建议的目标是确定关键的翻译调节因子，特别是RNA结合 蛋白质(RBPs)，在NSC静止退出时控制Vimentin mRNA的翻译。我们将描述 在qNSCs中优先结合Vimentin mRNA的RBPs，并确定其对Vimentin mRNA的功能作用 翻译，最终目标是将转录后机制与生理关联联系起来 在体外和体内都能增强qNSC的激活。这一项目的完成将扩大对 研究了qNSC激活的分子机制，并提出了一种潜在的哺乳动物治疗方法 目标是增加神经发生，目标是随着年龄的增长改善认知功能。除了这一点， 威斯康星大学麦迪逊分校医学科学家培训计划和细胞和 分子生物学研究生课程将为我提供提高实验室技术技能的机会， 负责任地进行研究、专业发展和临床实践，这是成为 成功的独立内科医生科学家。

PROJECT SUMMARY/ABSTRACT Neurogenesis, the lifelong generation of newborn neurons, occurs in neural stem cell (NSC) niches in the brain. A decline in neurogenesis occurs with aging but also contributes to disease pathologies such as dementia, anxiety and depression. This attenuated neurogenesis is largely the result of the increased barrier to NSC quiescence exit, the process of NSC activation and cell cycle reentry. NSCs dynamically transition between quiescent and activated cell states; quiescent NSCs (qNSCs) are in a reversible G0 state of the cell cycle whereas activated NSCs (aNSCs) divide to self-renew or produce new neurons. Despite quiescence exit being the rate-limiting step in neurogenesis, its mechanisms are not well understood. One key intrinsic mechanism influencing quiescence exit is aggregated protein clearance through the formation of aggresomes which are surrounded by the intermediate filament vimentin. In the absence of vimentin protein, there is decreased qNSC activation both in vivo and in vitro, suggesting that vimentin plays a crucial role in mediating quiescence exit. Interestingly, qNSCs uniquely contain high vimentin mRNA and low protein levels, compared to aNSCs, suggesting that the translational repression of vimentin mRNA in qNSCs is rapidly reversed during quiescence exit to upregulate vimentin protein, facilitating the formation of aggresomes. This indicates that the regulation of vimentin may be uniquely controlled in the transition between cell states. Thus, the identification of the mechanisms underlying this post-transcriptional regulation during quiescence exit will reveal processes that may be targeted to increase neurogenesis. The objective of this proposal is to identify key translational regulators, specifically RNA binding proteins (RBPs), controlling vimentin mRNA translation during NSC quiescence exit. We will characterize RBPs that bind vimentin mRNA preferentially in qNSCs, and establish their functional roles on vimentin mRNA translation, with the eventual goal of correlating post transcriptional mechanisms with the physiologic relevance of enhanced qNSC activation both in vitro and in vivo. Completion of this project will broaden the understanding of the molecular mechanisms underlying qNSC activation and present a potential novel mammalian therapeutic target to increase neurogenesis, with the goals of improving cognitive function with age. In addition to this research, the University of Wisconsin-Madison Medical Scientist Training Program and the Cellular and Molecular Biology graduate program will provide opportunities for advancing my skills in laboratory techniques, responsible conduct of research, professional development, and clinical practice necessary to become a successful independent Physician Scientist.