Asytrocytes, sleep and neuroinflammation

星形胶质细胞、睡眠和神经炎症

• 批准号: 8974165
• 负责人: MARK R OPP
• 金额: $ 23.18万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-05-01 至 2017-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8974165
• 关键词: Acetylcholine; Achievement; Affinity; Astrocytes; Attenuated; Award; Behavior; Binding; Bioavailable; Brain; Cell physiology; Circadian Rhythms; Clozapine; Communication; Coupled; Data; Designer Drugs; Development; Electroencephalography; Engineering; Excision; Fostering; Funding Mechanisms; G-Protein-Coupled Receptors; GTP-Binding Proteins; Glial Fibrillary Acidic Protein; Goals; Human Engineering; Immune; Immune system; Inflammatory; Interleukin-1; Interleukins; Knowledge; Learning; Ligands; Link; Lipopolysaccharides; Mediating; Mediator of activation protein; Memory; Mental Depression; Methods; Microglia; Mus; Muscarinics; Neuroglia; Neurons; Oxides; Paper; Participant; Pathology; Pattern; Process; Proteins; Publications; Rattus; Regulation; Relative (related person); Reporting; Research; Research Project Grants; Role; Signal Pathway; Signal Transduction; Sleep; Sleep Deprivation; Source; Stimulus; Substance abuse problem; System; Technology; Temperature; Testing; Time; Tumor Necrosis Factor-alpha; United States National Institutes of Health; Use of New Techniques; adeno-associated viral vector; cell type; cytokine; feeding; immune activation; immune function; in vivo; meetings; neuroinflammation; neuronal circuitry; non rapid eye movement; novel; public health relevance; receptor; research study; response; selective expression; sleep regulation; tool; vesicular release

 DESCRIPTION (provided by applicant): Sleep research has historically been neuron-centric; much effort has focused on determining neuronal circuits and/or actions of transmitter substances produced by neurons. Historically, glia were thought to be merely passive brain residents, yet new research demonstrates that glial cells, particularly astrocytes and microglia, are active participants in sleep regulation and in sleep-immune interactions. For example, recent studies demonstrate that inhibiting vesicular release from astrocytes reduces EEG slow wave activity and attenuates sleep deprivation-induced increases in non-rapid eye movement (NREM) sleep. However, much remains to be learned about the relative contribution of astrocytes to mechanisms underlying alterations in sleep during immune challenge. The cytokines interleukin-1β (IL-1) and tumor necrosis factor-α (TNF) are involved in the regulation of sleep and in the alterations in sleep that occur during immune challenge. Importantly, IL-1 and TNF are produced by neurons and glia, their receptors are present on neurons and glia, and they constitute an important mechanistic link in neuronal-glial communication. Our knowledge about astrocyte contributions to sleep-immune interactions will be advanced if actions of this cell type can be specifically, independently, and reversibly modulated in vivo. Thus, the overall objective of this R21 Exploratory / Developmental Research Grant Award is to selectively stimulate G protein-coupled signaling cascades in astrocytes to elucidate their contributions to the regulation of sleep during immune challenge. To accomplish this task we will use designer receptors exclusively activated by designer drugs (DREADDs). DREADDs are engineered human muscarinic G protein-coupled receptors that are unable to bind their endogenous ligand, acetylcholine. Instead, they bind a chemically inert synthetic ligand, clozapine-N-oxide (CNO), which then stimulates intracellular signaling. To date, DREADDs have almost exclusively been used to modulate activity of neurons. The central hypothesis to be tested by experiments proposed in this application is that stimulating G protein-coupled signaling cascades in astrocytes will attenuate changes in sleep that are induced by immune challenge. We will use the Cre-loxP system, commercially-available GFAP:Cre mice, and adeno-associated virus vectors to selectively express DREADDs on astrocytes. We will then test our overall hypothesis by conducting experiments within the context of two Aims. In Aim 1 we will stimulate Gq or Gi G protein-coupled signaling in the absence of immune challenge and quantify regional changes in mouse brain cytokine protein. In Aim 2 we will activate these same signaling cascades and determine the impact of this manipulation on lipopolysaccharide (LPS)-induced alterations in mouse sleep patterns and brain cytokine protein. Upon completing these studies we will not only possess a new toolkit, but we will have novel data that will contribute to our understanding of mechanisms and functions for sleep-immune interactions. These achievements will have a prolonged and sustained impact on the field by filling a gap in our knowledge of sleep and gliotransmission during immune challenge.

 描述（由申请人提供）：睡眠研究在历史上一直以神经元为中心;许多努力都集中在确定神经元回路和/或神经元产生的递质物质的作用。从历史上看，胶质细胞被认为只是被动的大脑居民，但新的研究表明，胶质细胞，特别是星形胶质细胞和小胶质细胞，是睡眠调节和睡眠免疫相互作用的积极参与者。例如，最近的研究表明，抑制从星形胶质细胞释放囊泡会降低EEG慢波活动，并减弱睡眠剥夺诱导的非快速眼动（NREM）睡眠增加。然而，关于星形胶质细胞对免疫激发期间睡眠改变的相关机制的贡献还有很多有待了解。细胞因子白细胞介素-1 β（IL-1）和肿瘤坏死因子-α（TNF）参与睡眠调节和免疫激发期间发生的睡眠改变。重要的是，IL-1和TNF由神经元和神经胶质产生，它们的受体存在于神经元和神经胶质上，并且它们构成神经元-神经胶质通讯中的重要机制环节。我们的知识星形胶质细胞的贡献睡眠免疫相互作用将先进的，如果这种细胞类型的行动可以具体，独立和可逆的调制在体内。因此，这项R21探索性/发展性研究资助奖的总体目标是选择性地刺激星形胶质细胞中的G蛋白偶联信号级联，以阐明它们对调节星形胶质细胞的作用。 免疫挑战期间的睡眠。为了完成这项任务，我们将使用设计师受体专门激活的设计师药物（DREADD）。DREADD是工程化的人毒蕈碱G蛋白偶联受体，其不能结合其内源性配体乙酰胆碱。相反，它们结合化学惰性的合成配体，氯氮平-N-氧化物（CNO），然后刺激细胞内信号传导。迄今为止，DREADD几乎完全用于调节神经元的活性。通过本申请中提出的实验进行测试的中心假设是，刺激星形胶质细胞中的G蛋白偶联信号级联将减弱由免疫激发诱导的睡眠变化。我们将使用Cre-loxP系统、市售GFAP：Cre小鼠和腺相关病毒载体在星形胶质细胞上选择性表达DREADD。然后，我们将通过在两个目标的背景下进行实验来测试我们的总体假设。在目标1中，我们将在没有免疫攻击的情况下刺激Gq或Gi G蛋白偶联信号传导，并定量小鼠脑细胞因子蛋白的区域变化。在目标2中，我们将激活这些相同的信号级联反应，并确定这种操作对脂多糖（LPS）诱导的小鼠睡眠模式和脑细胞因子蛋白改变的影响。完成这些研究后，我们不仅将拥有一个新的工具包，而且我们将获得新的数据，这些数据将有助于我们理解睡眠-免疫相互作用的机制和功能。这些成就将通过填补我们在免疫挑战期间对睡眠和胶质传递的知识空白，对该领域产生长期和持续的影响。