Translational Study of Blast mTBI Effects on Locus Ceruleus-Cerebellar Network Structure and Function

母细胞 mTBI 对蓝斑-小脑网络结构和功能影响的转化研究

• 批准号: 10514609
• 负责人: James Stephan Meabon
• 金额: --
• 依托单位: VA PUGET SOUND HEALTHCARE SYSTEM
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-10-01 至 2024-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10514609
• 关键词: Ablation; Afghanistan; Aging; Alzheimer' s Disease; Anatomy; Animals; Arousal; Attention; Auditory; Autopsy; Back; Behavior; Behavioral; Bilateral; Brain; Brain Concussion; Brain Injuries; Canine Adenoviruses; Cellular Stress; Cerebellum; Cerebrospinal Fluid; Characteristics; Chronic Phase; Cognition; Cognitive; Color; Data; Dentate nucleus; Diffusion Magnetic Resonance Imaging; Diphtheria Toxin; Distress; Enzymes; Exhibits; Explosion; Fiber; Goals; Green Fluorescent Proteins; Headache; Hippocampus; Home; Human; Impairment; Injections; Injury; Iraq; Knock-out; Knowledge; Label; Length; Lesion; Lysophosphatidylcholines; Manufactured football; Mediating; Memory; Modeling; Mus; Myelin; Nature; Nerve Degeneration; Neurons; Norepinephrine; Performance; Phenotype; Post-Concussion Syndrome; Publishing; Reporter; Rodent Model; Scanning; Short-Term Memory; Signal Transduction; Sleep disturbances; Structure; Symptoms; Testing; Transgenic Organisms; Tyrosine 3-Monooxygenase; Up-Regulation; Veterans; Viral; War; brain tissue; case control; cognitive function; common symptom; comparison control; disability; disabling symptom; experience; flexibility; fluorodeoxyglucose positron emission tomography; glucose uptake; locus ceruleus structure; mild traumatic brain injury; military service; mouse model; noradrenergic; pressure; service member; single-cell RNA sequencing; transcriptomics; translational study; white matter; white matter injury

Mild traumatic brain injuries (mTBIs or concussions) caused by blast overpressure from exploding ordnance are the “signature injuries” of the wars in Iraq and Afghanistan. Postconcussive symptoms are common and often persist for years after Veterans have returned from deployment(s); however, the neuropathobiology underlying these symptoms is poorly understood. Our published and preliminary studies demonstrate in a battlefield-relevant mouse model of blast mTBI, in living Veterans with repetitive blast mTBIs, and in postmortem brain tissue from Veterans and Servicemembers with blast mTBIs that the cerebellum is particularly vulnerable. The cerebellum is increasingly implicated in cognitive/behavioral changes characteristic of persistent postconcussive symptoms. Our preliminary studies suggest that these neuropathobiologic changes extend to the noradrenergic locus coeruleus (LC) and its projections to the cerebellar dentate nucleus (CDN) via the superior cerebellar peduncles (SCP). To understand the nature and implications of mTBI damage to the LC-cerebellar dentate nucleus network, the following conceptually integrated translational Specific Aims are proposed: Specific Aim 1.1. To determine whether LC and cerebellar changes on initial DTI scan predict longitudinal impairments in: a) cerebellar regional glucose uptake by FDG-PET, b) working memory, and c) cognitive set-shifting in Iraq/Afghanistan Veterans with repetitive blast mTBI. Specific Aim 1.2. To determine in postmortem brain tissue from repetitive mTBI Veteran/Servicemember and control cases whether mTBI is specifically associated with LC-cerebellar fiber injury and/or loss as compared to LC-cortical and/or LC-hippocampal fibers injury and/or loss. Specific Aim 2. To determine, in our mouse blast model, whether LC-cerebellar projections are specifically vulnerable to degeneration following repetitive blast mTBI. Cerebellum-projecting LC neurons will be labeled using a canine adenovirus (CAV) red fluorescent reporter in mice expressing green fluorescent protein in LC fibers. Single cell RNA sequencing will test whether dual-labeled LC neurons projecting to the cerebellum exhibit a specific neurodegenerative and cell stress phenotype following repetitive blast mTBI. Specific Aim 3.1. To determine in non-blast mice whether working memory and cognitive set shifting deficits are caused by nonspecific SCP WM injury or by specific injury to LC fibers projecting to the cerebellum. SCP WM injury will be induced by bilateral injection of 1% lysolecithin. LC fiber injury will be induced using bilateral viral transduction with CAV-Cre AAV-DO diphtheria toxin. Specific Aim 3.2. To determine in non-blast mice if loss of NA signaling by LC neurons projecting to the posterior cerebellum is sufficient to cause working memory and cognitive set shifting deficits similar to blast mTBI. A viral transgenic approach will be used to knock out TH expression bilaterally in LC neurons passing through the SCP.

爆炸产生的冲击波超压造成的轻度创伤性脑损伤（mTBI或脑震荡） 军火是伊拉克和阿富汗战争的“标志性伤害”。脑震荡后的症状是 在退伍军人从部署中返回后，这种情况很常见，而且往往持续多年;然而， 这些症状背后的神经病理生物学知之甚少。我们已发表和初步研究 在战场相关的爆炸mTBI小鼠模型中，在具有重复爆炸的活着的退伍军人中， mTBIs，以及来自退伍军人和军人的死后脑组织中的爆炸mTBIs， 小脑尤其脆弱。小脑越来越多地参与认知/行为 持续性脑震荡后症状的特征性变化我们的初步研究表明， 神经病理生物学变化延伸到去甲肾上腺素能蓝斑（LC）及其向 经上级小脑脚（SCP）到达小脑齿状核（CDN）。了解自然， mTBI损伤对LC-小脑齿状核网络的影响，从概念上讲如下 提出了整合的翻译具体目标： 具体目标1.1.为了确定LC和小脑在初始DTI扫描上的变化是否预测 纵向损伤：a）FDG-PET显示的小脑区域葡萄糖摄取，B）工作记忆，和c） 重复性冲击波mTBI的伊拉克/阿富汗退伍军人的认知定势转换。 具体目标1.2.确定重复mTBI的死后脑组织 退伍军人/军人和对照病例mTBI是否与LC-小脑纤维特异性相关 与LC-皮质和/或LC-海马纤维损伤和/或损失相比，LC-皮质和/或LC-海马纤维损伤和/或损失。 具体目标2。为了确定，在我们的小鼠胚细胞模型中，LC-小脑投射是否 特别容易在重复性原始细胞mTBI后退化。投射小脑的LC神经元将 在表达绿色荧光的小鼠中使用犬腺病毒（CAV）红色荧光报告基因进行标记 LC纤维中的蛋白质。单细胞RNA测序将测试是否双标记LC神经元投射到 小脑在重复性胚细胞mTBI后表现出特定的神经变性和细胞应激表型。 具体目标3.1.为了确定非胚鼠的工作记忆和认知定势转换是否 缺陷是由非特异性SCP WM损伤或由投射到LC纤维的特异性损伤引起的。 小脑双侧注射1%溶血素可造成SCP WM损伤。LC纤维损伤将是 使用CAV-Cre AAV-DO白喉毒素双侧病毒转导诱导。 具体目标3.2.为了确定在非胚细胞小鼠中，LC神经元投射到 小脑后部足以导致工作记忆和认知设置转换缺陷， 冲击波mTBI将使用病毒转基因方法敲除LC神经元中双侧TH表达 穿过SCP。