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（适用提供）：睡眠研究历史上以神经元为中心；许多努力集中在确定神经元产生的发射器物质的神经元回路和/或作用上。从历史上看，神经胶质被认为仅仅是被动脑居民，但是新的研究表明，神经胶质细胞，尤其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活跃参与者。例如，最近的研究表明，抑制囊泡释放的星形胶质细胞会减少脑电图的慢波活性，并减轻睡眠剥夺引起的非比型眼运动（NREM）睡眠的增加。然而，关于星形胶质细胞对免疫挑战期间睡眠改变的机制的相对贡献还有很多待了解。细胞因子白介素-1β（IL-1）和肿瘤坏死因子-α（TNF）参与睡眠的调节以及在免疫挑战期间发生的睡眠改变。重要的是，IL-1和TNF是由神经元和神经胶质产生的，它们的接收器存在于神经元和神经胶质上，它们构成了神经元通信中的重要机械联系。如果该细胞类型的作用可以独立，独立和可逆地调节体内，我们将提出对星形胶质细胞对睡眠免疫相互作用的贡献的了解。这就是R21探索 /发展研究补助金的总体目标是选择性刺激星形胶质细胞中的G蛋白偶联信号级联反应，以阐明其对调节的贡献 免疫挑战期间的睡眠。为了完成这项任务，我们将使用设计师药物（Dreadds）专门激活的设计师接收器。 Dreadds是设计的人类毒蕈碱G蛋白偶联受体，无法结合其内源配体乙酰胆碱。取而代之的是，它们结合了化学惰性合成配体氯氮平-N-氧化物（CNO），然后刺激细胞内信号传导。迄今为止，Dreadds几乎完全拥有Cre-loxp系统，商业上可用的GFAP：CRE小鼠和与腺相关的病毒载体在星形胶质细胞上有选择地表达恐怖。然后，我们将通过在两个目标的背景下进行实验来检验总体假设。在AIM 1中，我们将在没有免疫攻击并量化小鼠脑细胞因子蛋白的区域变化的情况下刺激GQ或GI G蛋白偶联的信号传导。在AIM 2中，我们将激活这些相同的信号级联反应，并确定这种操纵对小鼠睡眠模式和脑细胞因子蛋白的改变（LPS）诱导的改变的影响。完成这些研究后，我们不仅拥有一个新的工具包，而且还将拥有新的数据，这将有助于我们对睡眠免疫相互作用的机制和功能的理解。这些成就将通过在免疫挑战期间填补我们对睡眠和Gliotsmissiral的知识的空白，从而对该领域产生延长和持续的影响。