Evolutionary Conserved Mechanisms that Control Central Nervous System Development Regeneration and Degeneration

控制中枢神经系统发育、再生和退化的进化保守机制

• 批准号: 10705614
• 负责人: Ayelet Voskoboynik
• 金额: $ 38.77万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-30 至 2027-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10705614
• 关键词: Adult; Affect; Age; Aging; Alzheimer' s Disease; Amyloid beta-Protein Precursor; Animals; Antisense RNA; Atlases; Behavioral; Biological Assay; Biological Metamorphosis; Biological Models; Brain; Candidate Disease Gene; Cell Aging; Cell Count; Cell Lineage; Cell Separation; Cell Transplantation; Cells; Central Nervous System; Chordata; Clinical Trials; Clonal Expansion; Clone Cells; Clustered Regularly Interspaced Short Palindromic Repeats; Collection; DNA; DNA Sequence Alteration; Dementia; Development; Disease; Early Onset Alzheimer Disease; Elements; Epigenetic Process; Exhibits; Failure; Frequencies; Gene Expression; Generations; Genes; Genetic Variation; Genome; Genotype; Homologous Gene; Human; Individual; Invertebrates; Larva; Life; Link; Longevity; Mediating; Molecular; Morphology; Mutation; Natural regeneration; Nerve Degeneration; Nervous System; Neurodegenerative Disorders; Neurons; Organ; Organism; Pathogenesis; Pathway interactions; Pattern; Phenotype; Population; Process; Publishing; Regenerative Medicine; Research; Role; Sampling; Secondary to; Senile dementia; Sexual Reproduction; Stimulus; Study models; Testing; Time; Tissues; Transplantation; Urochordata; Vertebrates; adult neurogenesis; age related; age related neurodegeneration; aged; aging brain; asexual; brain cell; circadian; circadian pacemaker; complement C2a; design; differential expression; fitness; germline stem cells; indexing; life history; model organism; nerve stem cell; nervous system development; neuron regeneration; preclinical trial; presenilin-1; progenitor; programs; prospective; reproductive; response; self organization; self renewing cell; self-renewal; sensory stimulus; single-cell RNA sequencing; stem cell aging; stem cell expansion; stem cell population; stem cell self renewal; stem cells; tissue regeneration; trait; transcriptome; transcriptomics

Gradual loss of brain function and neurodegeneration are common features of aging throughout diverse phyla. Senile dementias, including Alzheimer’s Disease (AD), likely involve failures of adult neural stem cell (NSC) number, viability, and/or functions. Our lab studies NSC’s role in central nervous system (CNS) development, adult regeneration, and in onset dementia such as AD. We are establishing a field of research in regenerative medicine and aging as the first lab to prospectively isolate human NSC and use them in published preclinical and clinical trial studies. In this proposal we seek to understand basic principles and evolutionarily conserved elements of NSC involvement in neuronal regeneration, degeneration, and aging in the colonial tunicate Botryllus schlosseri.  Botryllus has two reproductive modes: sexual reproduction which produces a primitive chordate with a simple CNS (the chordate brain), that will undergo metamorphosis into an asexually reproducing sessile invertebrate which propagates by budding. We have found that Botryllus buds contain self-renewing germline stem cells, and somatic stem cells which self-organize to form a colony composed of genetically identical individuals. This stage exhibits weekly assayable CNS tissue regeneration from candidate NSC and undergoes repeated neurodegeneration throughout its adult life, a process that resembles adult neurogenesis and neurodegeneration in vertebrates. Thus, Botryllus offers a unique opportunity to study the cellular and molecular mechanisms of CNS generation and degeneration through observing weekly regeneration cycles in young and old colonies (e.g. <3 months vs. >7 years). We aim to identify the mutations and/or epigenetic changes that accumulate in the NSC, and through self-renewal remain present throughout an organism's life. We have undertaken a systematic molecular (brain transcriptomic) analysis of CNS cells of old and young Botryllus colonies, paired with morphological and behavioral characterization of each of their CNS lineage cells. This analysis revealed 93 homologous genes that correlate with Alzheimer’s disease, including APP, GRN, PSEN1, GLUD2, and VPS35 that are differentially expressed between young and old colonies. Furthermore, the brains of old colonies contain a lower number of cells and have reduced neuron-mediated responses to sensory stimuli. Since stem cells are the only cells that self-renew and are maintained throughout the colony’s life, we hypothesize that genetic mutations or epigenetic changes that accumulate over time in NSC and their progenitors are the main cause of age-related neurodegenerative diseases. To test this hypothesis, we plan to characterize the molecular and cellular diversity of the Botryllus brain in chordate larvae and young and old colonies, isolate their NSCs at the single cell level, identify mutations that accumulate in NSC DNA, and test their effect on brain regeneration and function. Morpholino anti-sense RNAs will also be used to manipulate the activity of genes whose genetic variation predicts the onset of Alzheimer’s disease and test their effect on brain regeneration and degeneration capacity, and also attempt to introduce permanent alterations of their genomes by CRISPR.

脑功能和神经退行性的逐渐丧失是整个潜水员门的衰老的常见特征。老年痴呆症，包括阿尔茨海默氏病（AD），可能涉及成人神经元干细胞（NSC）数量，活力和/或功能的失败。我们的实验室研究NSC在中枢神经系统（CNS）发育，成人再生以及AD等发作痴呆症中的作用。我们正在建立一个在再生医学和衰老领域的研究领域，作为前瞻性隔离人类NSC的第一个实验室，并将其用于已发表的临床前和临床试验研究。在这项建议中，我们试图了解NSC参与神经元再生，退化和衰老的基本原理和进化保守的要素。 Botryllus具有两种生殖模式：有性繁殖产生具有简单的CNS（Chordate Brain）的原始弦酸，它将变质变质成一个无性繁殖的无脊椎动物无脊椎动物。我们发现，botryllus芽中包含自我更新的生殖干细胞，并且会自组织形成由遗传相同个体组成的菌落。该阶段每周都会从候选NSC中进行每周可测定的CNS组织再生，并在其成人的整个生活中经历重复的神经变性，这一过程类似于脊椎动物中成人神经发生和神经变性。因此，Botryllus提供了一个独特的机会，可以通过观察年轻和老年菌落的每周再生周期来研究中枢神经系统生成和变性的细胞和分子机制（例如，<3个月vs.> 7年）。我们旨在确定NSC中积累的突变和/或表观遗传变化，并通过自我更新在整个生物体的生活中仍然存在。我们已经对古老和年轻的botryllus菌落的中枢神经系统细胞进行了系统的分子（脑转录）分析，并与每个CNS谱系细胞的形态和行为表征配对。该分析揭示了与阿尔茨海默氏病相关的93个同源基因，包括APP，GRN，PSEN1，GLUD2和VPS35，它们在年轻人和老年殖民地之间表达不同。此外，旧菌落的大脑含有较少的细胞，并减少了神经介导的对感觉刺激的反应。由于干细胞是唯一在整个殖民地生命中自我更新和维持的细胞，因此我们假设随着时间的流逝，NSC及其祖细胞随着时间的推移而积累的基因突变或表观遗传变化是与年龄相关的神经退行性疾病的主要原因。为了检验这一假设，我们计划表征核菌幼虫和年轻和老菌落在单细胞水平上分离其NSC的分子和细胞多样性，鉴定其NSC在NSC DNA中积累的突变，并测试其对脑再生和功能的影响。 Morpholino抗敏感性RNA还将用于操纵基因的活性，其遗传变异预测阿尔茨海默氏病的发作，并测试其对脑再生和变性能力的影响，并试图通过CRISPR引入其基因组的永久变化。