Interrogating a white matter degeneration-specific astrocyte reactivity state and its role in governing repair-associated microglia specification and function.

询问白质变性特异性星形胶质细胞反应状态及其在控制修复相关小胶质细胞规格和功能中的作用。

• 批准号: 10660874
• 负责人: Joshua Evan Burda
• 金额: $ 68.52万
• 依托单位: CEDARS-SINAI MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-04-01 至 2028-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10660874
• 关键词: ATAC-seq; Acute; Acute Disease; Astrocytes; Attenuated; Axon; Biological Assay; Biological Markers; CNS degeneration; Cell Nucleus; Cells; Central Nervous System; Characteristics; Chromatin; Chromatin Structure; Chronic; Chronic Disease; Communication; Cues; Data; Deterioration; Disease; Disease Progression; Epigenetic Process; Excision; Exhibits; Genetic; Genetic Transcription; Human; Immune; In Vitro; Inflammation; Inflammatory; Inflammatory Response; Innate Immune Response; Integrins; Ischemia; Knockout Mice; Lesion; Link; Macrophage; Mediating; Methods; Microglia; Modeling; Molecular; Molecular Profiling; Multiple Sclerosis; Mus; Myelin; Nervous System Trauma; Neurodegenerative Disorders; Nodule; Pathway interactions; Peripheral; Phagocytes; Phagocytosis; Phenotype; Production; Recovery; Recovery of Function; Regulation; Regulator Genes; Regulatory Pathway; Research; Resolution; Role; Shapes; Signal Pathway; Signal Transduction; Small Nuclear RNA; Specific qualifier value; System; Testing; Therapeutic; Time; Tissues; Transgenic Organisms; Transposase; Validation; Work; analysis pipeline; axonal degeneration; cell motility; cell type; central nervous system injury; experimental study; improved outcome; in vivo; induced pluripotent stem cell; intercellular communication; loss of function; mouse model; neuroinflammation; novel; novel therapeutics; prevent; programs; receptor; recruit; remyelination; repaired; response; restoration; single nucleus RNA-sequencing; therapy development; tissue repair; transcriptomics; tumor microenvironment; white matter; white matter damage; white matter injury

Project Summary Clearance of cellular debris from the degenerating central nervous system (CNS) white matter is inefficient. Debris accumulation, especially from myelin, precipitates maladaptive neuroinflammation which furthers disease progression and prevents repair. Chronic white matter degeneration that produces cellular debris and protracted innate immune inflammation is a hallmark of diverse disorders, including traumatic and ischemic CNS injury and Multiple Sclerosis (MS). The development of therapies aimed enhancing debris clearance to promote repair is thereby of broad translational relevance. Research aimed at uncovering central regulatory mechanisms underlying the inflammatory response that facilitates debris clearance after white matter insult is therefore prudent and necessary. The overarching objective of this research is to dissect molecular pathways of astrocyte- microglia interaction that govern pro-restorative CNS innate immune responses to white matter degeneration. The present research will investigate a newly identified mechanism of intercellular communication, through which a distinct subpopulation of white matter degeneration-reactive astrocytes regulate microglia specification and function required for the removal of inflammatory myelin debris and tissue repair. In Aim 1, we will use a transgenic, cell type-specific loss-of-function system, single-nucleus RNA-Sequencing (snRNA-Seq) and mouse models of acute and chronic white matter degeneration to assess the involvement of this unique astrocyte- mediated signaling pathway in regulating damage-responsive microglia specification required for myelin debris clearance and remyelination. In Aim 2, we will dissect the direct effects and receptor dependent mechanism of action for a novel astrocyte-derived molecular cue on microglia molecular profile, motility, and capacity for myelin debris phagocytosis using cultures of mouse primary and human iPSC-derived microglia. In Aim 3, we will determine cell-intrinsic regulatory pathways underlying molecularly and functionally distinct states of white matter astrocyte reactivity using cell-paired snRNA-Seq and single-nucleus Assay for Transposase-Accessible Chromatin using Sequencing (snATAC-Seq), over time, in a mouse model of chronic white matter degeneration. An integrative analysis pipeline will be used to generate gene regulatory programs of astrocyte reactivity, including dynamic changes in chromatin structure and context-specific combinations of transcriptional regulators (TR), which together govern genetic accessibility and distinct reactive changes in transcriptomic profile. Select TR of molecularly distinct states of white matter astrocyte reactivity will be functionally interrogated in vivo by loss-of-function studies. Together, this research will enhance the understanding of how astrocyte-microglia interactions shape CNS innate immune responses that enable white matter repair. These data may also inform new therapeutic avenues for harnessing restorative innate immune responses, involving astrocytes and microglia, to prevent or attenuate maladaptive white matter inflammation, as well as improve outcome and promote recovery after CNS injury and in disease.

项目概要 从退化的中枢神经系统（CNS）白质中清除细胞碎片的效率很低。 碎片堆积，尤其是髓磷脂的碎片堆积，会引发适应不良的神经炎症，从而加剧疾病 进展并阻止修复。慢性白质变性，产生细胞碎片并长期存在 先天性免疫炎症是多种疾病的标志，包括创伤性和缺血性中枢神经系统损伤和 多发性硬化症（MS）。旨在增强碎片清除以促进修复的疗法的开发是 从而具有广泛的翻译相关性。旨在揭示中央监管机制的研究 因此，在白质损伤后促进碎片清除的炎症反应是潜在的 审慎且必要。这项研究的总体目标是剖析星形胶质细胞的分子途径 小胶质细胞相互作用控制着中枢神经系统对白质变性的先天免疫反应。 本研究将调查一种新发现的细胞间通讯机制，通过该机制 白质变性反应性星形胶质细胞的独特亚群调节小胶质细胞的规范和 清除炎症髓鞘碎片和组织修复所需的功能。在目标 1 中，我们将使用 转基因、细胞类型特异性功能丧失系统、单核 RNA 测序 (snRNA-Seq) 和小鼠 急性和慢性白质变性模型来评估这种独特的星形胶质细胞的参与 介导的信号通路调节髓磷脂碎片所需的损伤反应性小胶质细胞规范 清除和髓鞘再生。在目标 2 中，我们将剖析直接作用和受体依赖性机制 一种新型星形胶质细胞衍生的分子线索对小胶质细胞分子谱、运动性和髓磷脂能力的作用 使用小鼠原代和人 iPSC 衍生的小胶质细胞培养物进行碎片吞噬作用。在目标 3 中，我们将 确定白质分子和功能不同状态下的细胞内在调节途径 使用细胞配对 snRNA-Seq 和转座酶可及的单核测定进行星形胶质细胞反应 随着时间的推移，在慢性白质变性的小鼠模型中使用染色质测序 (snATAC-Seq)。 综合分析管道将用于生成星形胶质细胞反应性的基因调控程序， 包括染色质结构的动态变化和转录调节因子的特定组合 （TR），它们共同控制遗传可及性和转录组谱中独特的反应性变化。选择 白质星形胶质细胞反应性的分子不同状态的TR将在体内通过以下方式进行功能性询问： 功能丧失研究。总之，这项研究将增强对星形胶质细胞-小胶质细胞如何 相互作用塑造中枢神经系统先天免疫反应，从而实现白质修复。这些数据还可以告知 利用恢复性先天免疫反应的新治疗途径，涉及星形胶质细胞和 小胶质细胞，以预防或减轻适应不良的白质炎症，以及改善结果和 促进中枢神经系统损伤后和疾病中的恢复。