CTBI: Tauopathy in Mice and Human: Effects of Open-Field Low-Intensity Blast on Brain Ultrastructure and Outcomes in Mild Traumatic Brain Injury

项目总结 总体研究策略：开放性爆炸或重复性轻度头部撞击造成的创伤性脑损伤（TBI）， 人tau转基因小鼠将诱导阿尔茨海默病相关的tau依赖性病理学， 抑制tau表达或tau聚集抑制剂。爆炸诱导的tau蛋白相关的病理变化将 在退伍军人和暴露于爆炸的小鼠的大脑中进行分析，以及TBI，慢性创伤性脑损伤， 将在小鼠中鉴定脑病（CTE）和阿尔茨海默病病理学，并在人中验证。TBI由以下原因引起： 爆炸性武器是军事人员受伤的最主要类型。超过82%的战斗- 相关的TBI被归类为轻度TBI（mTBI）-最近战争的“标志性损伤”。服务成员， mTBI，通常无法通过传统的脑成像技术检测到，没有意识到他们已经持续了这一点， 损伤这种“无形的伤害”可能导致终身残疾的发展，包括神经精神疾病 和/或神经退行性疾病，给患者、家庭和社会带来社会经济负担。去- 迄今为止，我们对旷场低强度冲击波（LIB）引起mTBI和亚TBI的机制的理解， 神经系统的缺陷仍然不足。因此，迫切需要对LIB-in- 使用可靠的和“真实的世界”动物模型诱导发病机制。在这里，我们组建了一个投资团队- 具有跨学科专业知识和独特的爆炸和体内成像研究设施的gigators可在 Harry S.杜鲁门退伍军人医院和附属密苏里州大学。我们开发了一个平台- 使用压力传感器仪器和高速摄像机复制和记录露天爆炸展览， 确保高爆炸速度的C4爆炸。我们的初步研究表明，LIB暴露的小鼠结果 运动/探索活动减少，但没有死亡或其他影响/加速度介导的身体 受伤透射电镜观察细胞线粒体损伤， 特定脑区的髓鞘有缺陷进一步的组学和生物化学分析表明， 功能和磷酸化tau蛋白水平的增加。我们建议测试的假设，LIB诱导的神经元， 人tau转基因小鼠中的病理学是由线粒体功能障碍引发的， 氧化应激反应和生物能量损伤，这反过来又会诱导超微结构损伤， 导致代谢和行为缺陷的年龄和tau相关病理学。这项研究将使用反式- 在我们的研究中，将表达可调节的人tau蛋白（rTg-hTau）的基因小鼠暴露于单一或重复的原始细胞， 良好建立的平台，并研究线粒体功能障碍相关的氧化应激的影响， 老鼠大脑中的海绵体具体而言，Aim-1将评估LIB诱导的mTBI对小鼠脑组织超微结构的影响。 随着时间的推移，特定的大脑区域，评估行为变化，并通过PET/SPECT确定代谢谱 使用rTg-hTau小鼠进行扫描; Aim-2将进一步表征超微结构的细胞类型参与 应用透射电镜结合免疫金染色技术和免疫组化技术， 化学; Aim-3将研究线粒体功能障碍对mTBI致病基因的潜在机制- sis和评估LIB暴露后rTg-hTau小鼠中冲击伤是否受到性别差异的影响 以深入了解它与tau蛋白病理学的关系。这项研究的结果将影响我们的理解- 研究tau介导的战斗冲击波所致mTBI发病机制，并为其预防和治疗提供机制， 治疗

Project Summery Overall Research Strategy: Traumatic brain injury (TBI) from open-field blast or repetitive mild head impact to human tau transgenic mice will induce Alzheimer-relevant, tau-dependent pathology, that can be rescued by suppression of tau expression or tau aggregation inhibitors. Blast-induced tau-related pathological changes will be analyzed in brains from veterans and mice exposed to blast, and biomarkers for TBI, chronic traumatic en- cephalopathy (CTE) and Alzheimer-pathology will be identified in mice and validated in humans. TBI caused by explosive weaponry is the most prominent type of injury that occurs in military personnel. Over 82% of combat- related TBIs are classified as mild TBIs (mTBI)—the “signature injury” of recent wars. Service members with mTBI, often undetectable by conventional brain imaging techniques, do not realize they have sustained this injury. This “invisible injury” can lead to the development of lifelong disabilities, including neuropsychiatric and/or neurodegenerative diseases, imposing socioeconomic burdens on patients, families, and society. To- date, our understanding of the mechanisms by which open-field low-intensity blast (LIB) causes mTBI and sub- sequent neurological deficits remains inadequate. Thus, there is an urgent need for investigation of LIB-in- duced pathogenesis using reliable and “real world” animal models. Here, we have assembled a team of investi- gators with cross-disciplinary expertise and unique blast and in vivo imaging research facilities available at the Harry S. Truman Veterans Hospital and the affiliated University of Missouri. We have developed a platform us- ing pressure sensor instrumentations and high-speed cameras to reproduce and record open-field blast expo- sures with high-explosive velocity C4 detonation. Our preliminary studies show that LIB-exposed mice results in reduced locomotor/exploratory activity, but with no mortality or other impact/acceleration-mediated bodily injuries. Using transmission electron microscopy (TEM), we observed mitochondrial damage in cell bodies and defected myelin in selected brain areas. Further omics and biochemistry analyses indicated mitochondrial dys- function and increase in phospho-tau protein levels. We propose to test the hypothesis that LIB-induced neu- ropathology in a human tau transgenic mice is initiated by mitochondrial dysfunction associated with oxidative stress responses and bioenergetic impairment, which in turn, induces ultrastructural dam- ages and tau-related pathology leading to metabolic and behavioral deficits. This study will use the trans- genic mice expressing regulatable human tau (rTg-hTau) exposed either to a single or repetitive blasts in our well established platform, and investigate effects of mitochondrial dysfunction associated oxidative stress re- sponses in the mouse brain. Specifically, Aim-1 will evaluate effects of LIB-induced mTBI on ultrastructure in specific brain areas over time, assess behavioral changes, and determine metabolic profiles by PET/SPECT scanning using the rTg-hTau mice; Aim-2 will further characterize cell type involvement of ultrastructural changes and subcellular injuries using TEM combined with immunogold staining technique and immunohisto- chemistry; and Aim-3 will investigate underlying mechanism of mitochondrial dysfunction on mTBI pathogene- sis and evaluate whether the blast injury is affected by sex difference in rTg-hTau mice following LIB exposure to gain insights into its relationship with tau pathology. The results of this research will impact our understand- ing of tau-mediated pathogenesis of mTBI due to combat blast and provide mechanism for its prevention and treatment.