Investigating novel mechanisms that underlie glial-mediated synapse elimination in development and aging

研究发育和衰老过程中神经胶质介导的突触消除的新机制

• 批准号: 10721645
• 负责人: Taylor Reagan Jay
• 金额: $ 11.24万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-15 至 2025-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10721645
• 关键词: Address; Age-associated memory impairment; Aging; Biological; CD36 gene; Cell Culture Techniques; Data; Development; Developmental Process; Disease; Drosophila genus; Enzyme-Linked Immunosorbent Assay; Epilepsy; Event; Exhibits; Functional disorder; Gene Expression Profiling; Genes; Genetic Screening; Genetic Transcription; Goals; Immune system; Immunologic Receptors; Impairment; Label; Life; Ligands; Longevity; Maintenance; Mammals; Maps; Mediating; Mediator; Modeling; Molecular; Nerve Degeneration; Nervous System; Nervous System Physiology; Neurodegenerative Disorders; Neurodevelopmental Disorder; Neuroglia; Neurons; Pathologic; Pathology; Pathway interactions; Play; Process; Proteins; Reagent; Regulation; Reporter; Research; Research Personnel; Role; Schizophrenia; Signal Pathway; Specific qualifier value; Specificity; Synapses; System; Technical Expertise; Validation; Visualization; Work; age related; age related neurodegeneration; autism spectrum disorder; brain health; candidate identification; cell type; differential expression; experimental study; insight; knock-down; mouse model; nervous system development; novel; postsynaptic; presynaptic; receptor; screening; synaptogenesis; tool; trafficking

Project Summary Formation and maintenance of synaptic connections between appropriate neuronal partners is essential for proper nervous system function. Indeed, impairments in either initial synapse formation or in subsequent developmental synapse elimination underlie many neurodevelopmental disorders. Synapse elimination that occurs outside of appropriate developmental contexts underlies synaptic loss associated with age-related cognitive decline and in neurodegenerative diseases. Thus, defining the mechanisms that underlie the regulation of synapse number will provide insight into how appropriate connections are formed during development, and these pathologies of synapse elimination. Despite its essential role in nervous system development and function throughout life, we still know little about the mechanisms underlying this process. We do know, however, that glia are required. In order to identify novel glial regulators of synapse development, I completed a forward genetic screen in Drosophila, and identified 91 molecules that, when knocked down in glia, alter synapse number. Among these molecules is the immune receptor Crq, which I found is required for glial elimination of synapses in development. This proposal will focus on understanding Crq’s role in synapse elimination, in order to gain insight into the larger questions of which synapses undergo developmental synapse elimination, the mechanisms underlying the specificity of this process, and whether these same mechanisms are re-used in pathological synapse loss associated with aging. Aim 1 will address the question of which synapses undergo developmental elimination across the nervous system and evaluate which of these are Crq-dependent. I have recently developed an inducible pre-synaptic label that makes this work possible, and will generate inducible postsynaptic labels as part of this aim. Aim 2 will use proximity labeling to identify the neuronal ligand(s) for Crq that act to specify which synapses undergo elimination, and will identify how expression and localization of these ligands are regulated. Aim 3 will define which synapses are lost with aging, and identify whether Crq acts as a common mediator of synaptic loss in development and aging. I will also perform a targeted screen based on a recent transcriptional profiling experiment I completed to identify additional glial regulators of age-related synaptic loss. Together, these studies will address the mechanisms by which synapses are targeted for elimination and how. This is a key question in achieving the larger goal of understanding how neurons and glia work together to create and maintain appropriate synaptic connections throughout life. Dissecting these mechanisms will also provide insight into the process of age-related synaptic loss that underlies age-related cognitive decline. In addition, performing this work will allow me to address existing gaps in my technical skills that will allow me to carry out my long-term research goals as an independent invesitigator.

项目概要 适当的神经元伙伴之间突触连接的形成和维持对于 适当的神经系统功能。事实上，初始突触形成或随后的突触形成的损伤 发育性突触消除是许多神经发育障碍的基础。突触消除 发生在适当的发育环境之外是与年龄相关的突触损失的基础 认知能力下降和神经退行性疾病。因此，定义监管的机制 突触数量将有助于深入了解在发育过程中如何形成适当的连接，以及 这些突触消除的病理学。 尽管它在神经系统发育和终生功能中发挥着重要作用，但我们对它仍然知之甚少。 这一过程背后的机制。然而，我们确实知道神经胶质细胞是必需的。为了识别小说 突触发育的神经胶质调节因子，我在果蝇中完成了正向遗传筛选，并鉴定了 91 当神经胶质细胞中被击倒时，会改变突触数量的分子。这些分子中包括免疫分子 受体 Crq，我发现它是神经胶质细胞消除发育中突触所必需的。该提案将重点 了解 Crq 在突触消除中的作用，以便深入了解其中的更大问题 突触经历发育性突触消除，其特异性背后的机制 过程，以及这些相同的机制是否在与衰老相关的病理性突触丧失中被重复使用。 目标 1 将解决哪些突触在神经系统中经历发育消除的问题 系统并评估其中哪些是 Crq 相关的。我最近开发了一种可诱导的突触前 使这项工作成为可能的标签，并将生成可诱导的突触后标签作为此目标的一部分。目标2将 使用邻近标记来识别 Crq 的神经元配体，其作用是指定哪些突触经历 消除，并将确定如何调节这些配体的表达和定位。目标 3 将定义 哪些突触会随着衰老而丢失，并确定 Crq 是否作为突触丢失的常见介质 发育和衰老。我还将根据最近的转录分析进行有针对性的筛选 我完成的实验是为了识别与年龄相关的突触损失的额外神经胶质调节因子。 这些研究将共同​​探讨突触被消除的机制以及如何消除。 这是实现理解神经元和神经胶质细胞如何协同工作的更大目标的关键问题。 在一生中建立并维持适当的突触连接。剖析这些机制也将 深入了解与年龄相关的突触丧失的过程，这是与年龄相关的认知衰退的基础。在 此外，执行这项工作将使我能够解决我的技术技能中现有的差距，这将使我能够 作为一名独立研究者实现我的长期研究目标。