Characterization of Neural Stem Cells in the Adult Brain

成人大脑中神经干细胞的表征

• 批准号: 8281560
• 负责人: Arturo Alvarez-Buylla
• 金额: $ 54.74万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-04-01 至 2014-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8281560
• 关键词: Abbreviations; Address; Adenoviruses; Adult; Age; Animal Model; Anterior; Antimitotic Agents; Apical; Architecture; Aspartate; Astrocytes; B Cell Proliferation; B-Lymphocytes; Birth; Brain; Bromodeoxyuridine; Cell Cycle; Cell Proliferation; Cell division; Cell physiology; Cells; Chain Migrations; Cilia; Clinic; Cytosine; Data; Detection; Development; Electron Microscope; Embryo; Ependymal Cell; Epithelial; Erinaceidae; Figs - dietary; Fluorescence-Activated Cell Sorting; Funding; GLAST Protein; Galactosylceramides; Generations; Genetic; Glial Fibrillary Acidic Protein; Glutamates; Growth Factor Receptors; Health; Hippocampus (Brain); Horns; Human; Human Development; Human Resources; Immunohistochemistry; In Situ Hybridization; In Vitro; Interneurons; Knowledge; Label; Laboratories; Lateral; Lead; Length; Life; Liquid substance; Location; Maintenance; Medial; Methods; Mus; Myelin Basic Proteins; Natural regeneration; Neonatal; Neural Cell Adhesion Molecules; Neuroglia; Neurons; Nuclear Antigens; Nuclear Pore Complex; Oligodendroglia; Organelles; Pathway interactions; Pattern; Phenotype; Physiologic pulse; Platelet-Derived Growth Factor; Play; Polymerase Chain Reaction; Progress Reports; Property; Proteins; Radial; Reagent; Receptor Signaling; Regulation; Reporting; Research; Research Design; Research Methodology; Rodent; Role; Route; Signal Transduction; Signaling Molecule; Sonic hedgehog protein; Source; Staging; Stem cells; Steroids; Stream; Structure; Structure of thyroid parafollicular cell; Subependymal; Therapeutic; Therapeutic Uses; Time; Translating; Translations; Tubulin; Tyrosine 3-Monooxygenase; Ventricular; Work; adult neurogenesis; age related; base; brain repair; calbindin; calretinin; cell type; galactocerebroside; granule cell; human SMO protein; immunocytochemistry; in vivo; lateral ventricle; migration; nerve stem cell; nestin protein; neuroblast; neurogenesis; neuronal cell body; novel strategies; nucleoside analog; olfactory bulb; polysialyl neural cell adhesion molecule; postnatal; postnatal human; progenitor; promoter; research study; self-renewal; subventricular zone; transcription factor; tumor

DESCRIPTION (provided by applicant): Neurogenesis continues in the adult brain within an extensive germinal zone on the walls of the lateral ventricles called the Subventricular Zone (SVZ). SVZ astrocytes (B cells) function as adult neural stem cells (NSCs), generating transit amplifying C cells which give rise to neurons (Type A cells). New SVZ neurons migrate through the rostral migratory stream (RMS) to the olfactory bulb (OB) where they differentiate into multiple types of local interneurons. It remains unknown if B cells self-renew in vivo, how many times C cells divide before they generate new neurons, and whether generation of different neuronal lineages involves different patterns of proliferation for B and C cells. Aim 1 will address these important gaps in our understanding of the SVZ. A recent study has redefined the architecture for the SVZ, revealing a pinwheel arrangement of B and ependymal cells and the apical-basal organization of B cells. The core of these pinwheels contains the apical compartments of B cells with primary cilia contacting the ventricle. Primary cilia concentrate essential components for Shh signal transduction and other pathways known to regulate B cell proliferation. Aim 2 will explore the role of primary cilia in adult SVZ NSCs. SVZ astrocytes with NSC properties in vitro have also been identified in adult human brain, suggesting that SVZ adult NSCs could be used for therapeutic neuronal and glial replacement. However, the structure of the human SVZ is different from that in rodents. In addition, the extent of SVZ NSC proliferation in vivo and the ability of these cells to generate neurons that migrate long distances into the OB in adult humans remains highly controversial. This controversy is addressed by work proposed in Aim 3. Experiments in Aim 1 will investigate the cell cycle times of different SVZ progenitors, determine whether B cells self-renew in vivo and the number of times C cells divide before generation of different types of neurons in the rodent SVZ. Aim 2 uses genetic methods to remove the primary cilia in adult rodent NSCs to investigate the role of this apical organelle in the proliferation of adult NSCs. Aim 3 will determine the developmental origins of the unique organization of the adult human SVZ and will investigate age dependent changes in the levels of SVZ proliferation and possible fates of young neurons derived from the SVZ. We also intend to clarify whether an RMS exists in adult human brain and how this structure changes through development. Preliminary results suggest that: 1) B cells are consumed with age and their proliferation may be regionally regulated; 2) primary cilia play a key role in the proliferation of adult NSCs; 3) young neurons are present in the developing human SVZ, but interestingly very scarce along the olfactory track; 4) a possible medial extension of the human RMS may exist. The above experiments will provide basic information on the most extensive germinal niche in the postnatal brain. PUBLIC HEALTH RELEVANCE: Neural Stem Cells (NSCs) that continually generate new neurons exist in the walls of the liquid filled cavities (ventricles) in the adult brain. This germinal region, called the subventricular zone (SVZ), is the largest single source of NSCs in the adult brain. In rodents, new neurons born in the SVZ migrate to the olfactory bulb, where they continually replace older neurons. The progenitor cells involved in adult neurogenesis in rodents have been identified, but we do not know how frequently they divide or the precise pattern of cell divisions and cell cycle length that leads to the generation of different types of neurons. Experiments proposed here will specifically determine the cell cycle time for adult SVZ progenitors and determine if cell cycle dynamics vary for different regions of the SVZ. The regulation of SVZ NSCs proliferation remains poorly understood. Recent work indicates that the NSCs contact the ventricle directly with a specialized extension called the primary cilium. Primary cilia are like cellular antennas that are receptive to external signals and multiple important growth factor receptors and signaling molecules are thought to be concentrated in primary cilia. We propose experiments to remove the primary cilium in adult NSCs and study the effects on the proliferation of adult NSCs. It remains controversial whether neurogenesis and long-range migration to the olfactory bulb, like those observed in adult rodents, occurs in adult humans. We propose to study how the SVZ develops in humans and to identify migratory routes and levels of proliferation at different ages. This information is essential to translate some of our observations in animal models to the clinic. This work will help in the development of novel strategies for brain repair and suggest how derailed proliferation of endogenous precursors might lead to tumor formation.

描述（由申请人提供）：神经发生在成人大脑中持续进行，位于侧脑室壁上的广泛生发区内，称为脑室下区（SVZ）。 SVZ 星形胶质细胞（B 细胞）的功能与成体神经干细胞（NSC）一样，产生转运放大 C 细胞，从而产生神经元（A 型细胞）。新的 SVZ 神经元通过头端迁移流 (RMS) 迁移到嗅球 (OB)，在那里它们分化成多种类型的局部中间神经元。目前尚不清楚 B 细胞是否在体内自我更新、C 细胞在产生新神经元之前分裂了多少次、以及不同神经元谱系的产生是否涉及 B 细胞和 C 细胞的不同增殖模式。目标 1 将解决我们对 SVZ 理解中的这些重要差距。最近的一项研究重新定义了 SVZ 的结构，揭示了 B 细胞和室管膜细胞的风车排列以及 B 细胞的顶端-基底组织。这些风车的核心包含 B 细胞的顶端室，初级纤毛与心室接触。初级纤毛集中了Shh信号转导和其他已知调节B细胞增殖途径的重要成分。目标 2 将探讨初级纤毛在成人 SVZ NSC 中的作用。体外具有 NSC 特性的 SVZ 星形胶质细胞也在成人大脑中被发现，这表明 SVZ 成人 NSC 可用于治疗性神经元和神经胶质替代。然而，人类 SVZ 的结构与啮齿类动物不同。此外，SVZ NSC 在体内增殖的程度以及这些细胞产生长距离迁移到成人 OB 的神经元的能力仍然存在很大争议。目标 3 中提出的工作解决了这一争议。目标 1 中的实验将研究不同 SVZ 祖细胞的细胞周期时间，确定 B 细胞是否在体内自我更新以及 C 细胞在生成不同类型神经元之前分裂的次数在啮齿动物 SVZ 中。目标 2 使用遗传方法去除成年啮齿动物 NSC 中的初级纤毛，以研究这种顶端细胞器在成年 NSC 增殖中的作用。目标 3 将确定成人 SVZ 独特组织的发育起源，并将研究 SVZ 增殖水平的年龄依赖性变化以及源自 SVZ 的年轻神经元的可能命运。我们还打算澄清成人大脑中是否存在 RMS 以及这种结构在发育过程中如何变化。初步结果表明：1）B细胞随着年龄的增长而消耗，其增殖可能受到区域性调节； 2）初级纤毛在成体NSC的增殖中发挥关键作用； 3) 发育中的人类 SVZ 中存在年轻神经元，但有趣的是，嗅觉轨道上的神经元非常稀少； 4) 人类 RMS 可能存在内侧延伸。上述实验将提供出生后大脑中最广泛的生发生态位的基本信息。 公共健康相关性：成人大脑中充满液体的空腔（心室）的壁中存在着不断产生新神经元的神经干细胞 (NSC)。这个生发区称为室下区 (SVZ)，是成人大脑中 NSC 的最大单一来源。在啮齿类动物中，SVZ 中产生的新神经元会迁移到嗅球，并在那里不断取代旧的神经元。参与啮齿动物成体神经发生的祖细胞已被鉴定，但我们不知道它们分裂的频率或导致不同类型神经元生成的细胞分裂的精确模式和细胞周期长度。这里提出的实验将专门确定成年 SVZ 祖细胞的细胞周期时间，并确定 SVZ 不同区域的细胞周期动态是否有所不同。 SVZ NSC 增殖的调控仍知之甚少。最近的研究表明，神经干细胞通过称为初级纤毛的特殊延伸直接与心室接触。初级纤毛就像接收外部信号的细胞天线，多种重要的生长因子受体和信号分子被认为集中在初级纤毛中。我们提出了去除成年神经干细胞中初级纤毛的实验，并研究其对成年神经干细胞增殖的影响。像在成年啮齿动物中观察到的那样，神经发生和向嗅球的远距离迁移是否发生在成年人身上仍然存在争议。我们建议研究人类 SVZ 如何发育，并确定不同年龄的迁移路线和增殖水平。这些信息对于将我们在动物模型中的一些观察结果转化为临床至关重要。这项工作将有助于开发新的脑修复策略，并表明内源性前体细胞的脱轨增殖如何可能导致肿瘤形成。