Exploring the Role Dense Core Vesicle Release in Glial Immunity

探索致密核心囊泡释放在神经胶质免疫中的作用

基本信息

批准号：
10682425
负责人：
Mary Allison Logan
金额：
$ 36.19万
依托单位：
OREGON HEALTH & SCIENCE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-07-01 至 2025-06-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10682425
关键词：
Acute Adult Affect Astrocytes Axon Axotomy Biological Assay Biological Models Brain Calcium Calcium Oscillations Cells Chronic Communication Communities Coupled Cues Cytoskeleton Data Defect Degenerative Disorder Dense Core Vesicle Drosophila genus Drosophila melanogaster Ensure Event Excision Fluorescence Fluorescent in Situ Hybridization Gene Expression Gene Expression Profiling Genes Genetic Models Genetic Transcription Immune Immune response Immunity Immunologic Factors Infiltration Inflammation Injury Innate Immune Response Insulin Label Ligands Matrix Metalloproteinases Messenger RNA Methods Mission Modeling Molecular Monitor Nerve Nerve Degeneration Nervous System Neuroglia Neurologic Neurons Neuropeptides Olfactory Pathways Organism Peripheral Phagocytes Play Process Public Health Reaction Recovery Reporter Ribosomal Interaction Role Signal Pathway Signal Transduction Site Stress Synaptic plasticity System Techniques Transcript Translating Translations Trauma United States National Institutes of Health Up-Regulation Visualization Wallerian Degeneration Wing Work axon injury axonal degeneration brain health cell motility cohort confocal imaging fly genetic manipulation high resolution imaging imaging modality immunoreaction immunoregulation in vivo in vivo monitoring insight insulin-like signaling migration molecular subtypes nerve injury nervous system disorder neuroprotection neurotoxic neurotransmission novel programs receptor response single molecule therapy development transcriptome sequencing traumatic event vesicular release

项目摘要

SUMMARY Glial cells play an essential role in defending brain health and managing neuronal stress and damage. Neurodegeneration triggers robust glial immune responses, including changes in cytoskeletal dynamics, glial cell migration, and increased phagocytic activity. Timely removal and degradation of degenerating axons and neuronal debris by glia confers neuroprotection in the brain. Despite the importance of glial responses to axon injury, we still know surprisingly little about how damaged neurons invoke immune reactions in glial cells. What signals are released from degenerating neurons? What prompts the release of these injury cues? Finally, how are these signals translated by glia to carry out efficient immune responses to damage? We are using the fruit fly Drosophila melanogaster as a tractable model to investigate the immune communication relays that exist between neurons and glial cells in vivo. The fly nervous system contains distinct glial subtypes that are molecularly and functionally similar to vertebrate glia. Moreover, well-established axotomy assays in the adult olfactory system and the adult wing reveal that Drosophila axons undergo a classic Wallerian degeneration (WD) program, which includes increased intra-axonal calcium waves, axon fragmentation, and subsequent clearance by phagocytic glia. Notably, our lab has recently shown that axon degeneration triggers activation of the insulin-like signaling (ILS) pathway in reactive ensheathing glia, which, in turn, elicits essential glial immune responses, including transcriptional upregulation of immune genes (e.g. the engulfment receptor Draper) and phagocytic activity. We hypothesize that neuropeptide-containing dense core vesicles (DCVs) are broadly released from severed axons to trigger immune responses in local glial cells. Here, we propose to use static and live confocal imaging, transcriptional profiling, and newly developed in vivo reporters to investigate how neuropeptide signaling between neurons and glia informs glial immune responses to nerve injury. Specifically, we will 1) monitor DCV dynamics and release in adult severed nerves, 2) utilize novel single transcript labeling methods to visualize local translation of immune mRNA transcripts in glial extensions at sites of injury, and 3) determine how neuropeptide signaling between discrete glial subtypes ensures that glial responses to degenerating axons are properly carried out. Together, these findings will offer exciting molecular and cellular insight into how neuropeptide signaling between neurons and glia govern immune responses in both acute and chronic degenerative conditions.

概括神经胶质细胞在捍卫大脑健康和管理神经元应力和损害方面起着至关重要的作用。神经变性触发鲁棒的神经胶质免疫反应，包括细胞骨架动力学的变化，神经胶质细胞迁移和增加的吞噬活性。及时去除和退化轴突和降解神经胶质的神经元碎片赋予大脑中的神经保护。尽管对轴突有胶质反应的重要性受伤，我们仍然对受损神经元如何调用神经胶质细胞中的免疫反应几乎不知道。什么信号是从退化神经元中释放出来的吗？是什么促使这些伤害提示的释放？最后，怎么样这些信号是否由GLIA翻译成对损害的有效免疫反应？我们正在使用果蝇果蝇Melanogaster作为一种可拖动模型来研究免疫在体内神经元和神经胶质细胞之间存在的通信中继。苍蝇神经系统包含分子和功能上与脊椎动物胶质的不同神经胶质亚型。而且，建立的成人嗅觉系统和成年机翼中的轴突切除术显示果蝇轴突经历了经典沃勒利变性（WD）程序，其中包括增加轴内钙波，轴突碎裂和随后的吞噬细胞胶质化。值得注意的是，我们的实验室最近显示了轴突退化会触发反应性振兴胶质中胰岛素样信号传导（ILS）途径的激活，该胶质神经胶质的激活反过来，引起基本的神经胶质免疫反应，包括免疫基因的转录上调（例如吞噬受体draper）和吞噬活性。我们假设含神经肽的密集核囊泡（DCV）从切断的轴突广泛释放，以触发局部神经胶质细胞的免疫反应。在这里，我们建议使用静态和现场共焦成像，转录分析以及新开发的体内记者研究神经元和神经胶质之间的神经肽信号如何告知神经胶质免疫反应神经损伤。具体而言，我们将1）监视DCV动力学并在成年神经中释放，2）使用新颖的单成绩单标记方法可视化神经胶质中免疫mRNA转录本的局部翻译损伤部位的延伸，3）确定离散神经胶质亚型之间的神经肽信号传导如何确保正确执行对退化轴突的神经胶质反应。在一起，这些发现将提供令人兴奋的分子和细胞洞察神经元和神经胶质之间如何控制神经肽信号传导急性和慢性退化条件下的免疫反应。