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：开阔场地爆炸或反复轻微头部撞击造成的创伤性脑损伤(TBI) 人类tau转基因小鼠将导致阿尔茨海默病相关的tau依赖的病理，可以通过以下方法拯救 抑制tau表达或tau聚集抑制剂。冲击波诱导的tau相关病变将 在退伍军人和暴露在冲击波中的小鼠的大脑中进行分析，以及脑损伤、慢性创伤和创伤的生物标志物。 脑病(CTE)和阿尔茨海默病-病理学将在小鼠身上得到确认，并在人类身上得到验证。由以下原因引起的TBI 爆炸性武器是发生在军事人员身上的最突出的伤害类型。超过82%的战斗- 相关的颅脑损伤被归类为轻度颅脑损伤(MTBI)--最近战争中的“标志性损伤”。服役人员具有 MTBI通常是传统的脑成像技术无法检测到的，但他们没有意识到他们已经维持了这种情况 受伤。这种“看不见的伤害”会导致终身残疾，包括神经精神障碍。 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。至- 目前，我们对旷野低强度冲击波(LIB)引起mTBI和亚急性脑损伤的机制的了解 连续的神经缺陷仍然是不够的。因此，迫切需要对自由党进行调查。 使用可靠的、“真实世界”的动物模型推断发病机制。在这里，我们组建了一支投资团队- 鳄鱼具有跨学科的专业知识和独特的BLAST和活体成像研究设施，可在 哈里·S·杜鲁门退伍军人医院和密苏里附属大学。我们已经开发了一个平台-- ING压力传感器仪器和高速摄像机，用于再现和记录露天爆炸博览会- 高爆速C4爆炸硫磺。我们的初步研究表明，暴露于Lib的小鼠 运动/探索活动减少，但没有死亡或其他由身体碰撞/加速引起的症状 受伤。用透射电子显微镜观察了细胞体线粒体的损伤情况。 选定脑区的髓鞘有缺陷。进一步的组学和生化分析表明线粒体DYS 功能和磷酸化tau蛋白水平的增加。我们建议检验这样一个假设，即Lib诱导的神经元- 人类tau转基因小鼠的病理改变是由线粒体功能障碍引起的 氧化应激反应和生物能量损伤，进而导致超微结构损伤。 AGEs和tau相关的病理导致代谢和行为缺陷。这项研究将使用反式- 表达可调控人tau基因的小鼠(rtg-hTau)暴露在单次或重复爆炸中 建立了良好的平台，并研究了线粒体功能障碍对氧化应激反应的影响 小鼠大脑中的海绵。具体地说，AIM-1将评估Lib诱导的mTBI对大鼠心肌细胞超微结构的影响。 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确定新陈代谢情况 利用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 透射电子显微镜结合免疫金染色法和免疫组织化学技术观察大鼠肝细胞的变化及亚细胞损伤 Aim-3将研究线粒体功能障碍在mTBI致病基因上的潜在机制- 评价Lib致RTG-hTau小鼠冲击伤是否受性别差异的影响 以深入了解其与tau病理的关系。这项研究的结果将影响我们的理解-- Tau介导的抗冲击伤发病机制及其防治机制的研究 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.