The role of Infiltrating Macrophages in Seizure Generation Following CNS Infection

浸润巨噬细胞在中枢神经系统感染后癫痫发作中的作用

• 批准号: 10284661
• 负责人: Ana Beatriz de Paula e Silva
• 金额: $ 12.26万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-15 至 2023-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10284661
• 关键词: Acute; Address; Adult; Affect; Animal Model; Anti-Inflammatory Agents; Attention; Automobile Driving; Biological Assay; Biotinylation; Blood; Brain; Cells; Central Nervous System Infections; Central Nervous System Viral Diseases; Cephalic; Chronic; Data; Development; Disease; Down-Regulation; Encephalitis; Epilepsy; Flow Cytometry; GABA Receptor; Generations; Genetic; Grant; Hippocampus (Brain); Homeostasis; Infection; Infiltration; Inflammation; Inflammatory; Interleukin-10; Interleukin-6; Interleukins; Intervention; Knowledge; Laboratories; Lead; Learning; Measures; Mentors; MicroRNAs; Microglia; Modeling; Motor Seizures; Mus; Myeloid Cells; Neuraxis; Neurons; Pathogenesis; Pathologic; Pathway interactions; Patients; Pharmaceutical Preparations; Pharmacology; Phase; Phenotype; Play; Population; Positioning Attribute; Recombinant Proteins; Recurrence; Refractory; Research; Role; Seizures; Severities; Severity of illness; Signal Pathway; Signal Transduction; Source; Stimulus; TMEV; TNF gene; Techniques; Temporal Lobe Epilepsy; Testing; Time; Tissues; Training; Transforming Growth Factors; Viral; Viral Encephalitis; Virus; Virus Diseases; Work; acquired epilepsy; acute infection; astrogliosis; brain parenchyma; career; cytokine; experimental study; improved; macrophage; mouse model; nervous system disorder; neuroinflammation; neuron loss; new therapeutic target; novel; novel therapeutics; peripheral blood; prevent; receptor; receptor expression; response; skills; therapeutic target; tissue repair; trafficking; transcriptome sequencing

Abstract/Project Summary Temporal lobe epilepsy (TLE) is the most prevalent form of acquired epilepsy. 30% of the patients are refractory to therapy and new treatments are urgently needed. Viral infection of the central nervous system (CNS) is a significant cause of TLE, and, while encephalitis is an important contributor, the mechanisms of how inflammation leads to seizures is unclear. Using the first mouse model of viral-induced TLE, which was developed by our laboratory, we found that induction of acute seizures is associated with blood peripheral macrophage infiltration into the brain and secretion of pro-inflammatory cytokines, primarily IL-6. Through RNA sequencing (RNAseq) of infiltrating macrophages isolated from the brains of TMEV-infected mice at the peak of seizure activity, I found that a population of CNS-infiltrating macrophages expresses high levels of the triggering receptor expressed on myeloid cells-1 (TREM1). Activation of TREM1 leads to the secretion of pro-inflammatory cytokines. Increased TREM1 expression is associated with inflammatory conditions, and inhibition of TREM1 function ameliorates inflammation and disease severity in several animal models of inflammatory diseases. However, the involvement of TREM1 in the development of acute seizures is unknown. In Aim 1 I will determine the time course of TREM1 expression in brain-infiltrating macrophages, and address whether genetic and pharmacological inhibition of TREM1 decreases the development of acute seizures in TMEV-infected mice, via videoEEG. The pro-inflammatory cytokine IL-6, which is mainly produced by brain infiltrating macrophages during TMEV infection, plays a pivotal role in inducing seizures; however how IL-6 does it is unknown. In Aim 2, I will determine whether IL-6 induces downregulation of neuronal GABA receptors, via biotinylation assay, and address which IL-6 pathway (classical or trans-signaling) is involved in acute seizures. Since inflammatory macrophages in the brain are associated with generation of acute seizures in TMEV-infected mice, in Aim 3 I will determine whether skewing macrophages towards an anti-inflammatory phenotype will affect the development of acute seizures, via videoEEG. I will also identify microRNAs in brain-infiltrating macrophages that are driving inflammation during the course of acute seizure generation in TMEV-infected mice. VideoEEG and receptor biotinylation assay are critical techniques I will learn during my mentored phase (Aim1/Aim2a), that will be essential to carry out experiments in Phase II (Aim2b/Aim3). These new skills, combined to my previous training, will put me in a unique position to address crucial questions related to neuroinflammation and epilepsy in my own laboratory using cutting edge approaches, and will substantially impact my research and career. These aims will improve the knowledge of the relationship between inflammation and seizures, and has the great potential of revealing inflammatory macrophages as a novel therapeutic target of neuroinflammation, allowing for the development of novel intervention to prevent and treat the development of acquired epilepsy.

摘要/项目摘要 颞叶癫痫（TLE）是获得性癫痫最常见的形式。 30%的患者是 难以治疗，迫切需要新的治疗方法。中枢神经系统 (CNS) 病毒感染 是 TLE 的一个重要原因，虽然脑炎是一个重要的诱因，但其机制 炎症导致癫痫发作尚不清楚。使用第一个病毒诱导的 TLE 小鼠模型，该模型已开发 我们实验室发现急性癫痫发作的诱发与外周血巨噬细胞有关 浸润大脑并分泌促炎细胞因子，主要是 IL-6。 通过对从 TMEV 感染者的大脑中分离出的浸润巨噬细胞进行 RNA 测序 (RNAseq) 在癫痫发作活动高峰期的小鼠中，我发现一群中枢神经系统浸润的巨噬细胞表达高 骨髓细胞 1 (TREM1) 上表达的触发受体的水平。 TREM1 的激活导致 促炎细胞因子的分泌。 TREM1 表达增加与炎症相关 TREM1 功能的抑制可改善多种动物的炎症和疾病严重程度 炎症性疾病模型。然而，TREM1 参与急性癫痫发作的发生是 未知。在目标 1 中，我将确定脑浸润巨噬细胞中 TREM1 表达的时间过程，以及 解决 TREM1 的遗传和药理学抑制是否会减少急性癫痫发作的发展 在 TMEV 感染的小鼠中，通过视频脑电图。促炎细胞因子IL-6，主要由大脑产生 TMEV感染期间浸润的巨噬细胞在诱发癫痫发作中起着关键作用；然而 IL-6 是如何作用的 这是未知的。在目标 2 中，我将确定 IL-6 是否会诱导神经元 GABA 受体的下调，通过 生物素化测定，并确定哪种 IL-6 途径（经典或反式信号传导）参与急性癫痫发作。 由于大脑中的炎症巨噬细胞与 TMEV 感染者急性癫痫发作的发生有关 小鼠，在目标 3 中，我将确定巨噬细胞偏向抗炎表型是否会影响 通过视频脑电图观察急性癫痫发作的发展。我还将鉴定大脑浸润巨噬细胞中的 microRNA TMEV 感染小鼠在急性癫痫发作过程中会引发炎症。视频脑电图 和受体生物素化测定是我在指导阶段（Aim1/Aim2a）中将学习的关键技术， 对于进行第二阶段（Aim2b/Aim3）的实验至关重要。这些新技能与我以前的技能相结合 培训将使我处于一个独特的位置来解决与神经炎症和癫痫相关的关键问题 在我自己的实验室中使用尖端方法，将对我的研究和职业产生重大影响。 这些目标将提高对炎症和癫痫发作之间关系的认识，并具有 揭示炎症巨噬细胞作为神经炎症新治疗靶点的巨大潜力， 允许开发新的干预措施来预防和治疗获得性癫痫的发展。