Neuronal exosomes to identify biomarkers and pathology of deployment-related TBI

创伤性脑损伤（TBI）是OIF/OEF退伍军人的标志性损伤。超过36万人服役 成员在2000年至2016年的战斗和训练期间持续TBI。目前没有诊断 TBI的生物标志物，目前的诊断工具也不能识别出慢性TBI风险最大的个体。 脑外伤后神经系统和随后的功能障碍。神经源性外泌体（NDEs） 从外周血中获得的DNA可能是开发可获得的基于CNS的生物标志物的有力工具 与神经元功能障碍有关，特别是与长期脑损伤有关， 神经变性我们最近发表的工作表明，神经病理蛋白（如 β-淀粉样蛋白、β-淀粉样蛋白和tau蛋白）可以预测从轻度认知障碍到 阿尔茨海默病（AD），而血浆水平没有。对濒死体验的研究现在正被作为一种 AD临床试验中的生物标志物，以帮助降低筛选失败率和增加入组。我们最近 发现细胞骨架和突触蛋白在>3个月的展开相关TBI患者中也异常 在TBI之后具体来说，在参与者的血浆NDE中， 经历了与部署相关的创伤性脑损伤总之，我们的数据支持这样的假设，即血浆NDE 可能是一个强大的工具，以确定可访问的和CNS特异性的蛋白质生物标志物的TBI。濒死体验也是 富含短长度“微”RNA（miRNA）货物。每种miRNA都可以调节蛋白质表达， 数百个靶信使RNA，提供了一种有效的机制，发挥全基因组调控 并同时影响多个细胞通路。miRNA赋予组织特异性，最近 成为神经变性的潜在生物标志物和治疗靶点。因此， 与NDE相关的CNS特异性miRNA可能为慢性胰腺炎的致病过程提供了一个窗口。 TBI用于未来干预。我们假设NDE中与神经变性相关的蛋白质， 如ABIs，以及与NDE相关的miRNA有可能成为TBI的生物标志物， 相关症状。为了验证这一假设，我们将利用我们的前瞻性纵向研究， 超过1200名海军陆战队员受到战斗部署影响，其中176人经历了轻度/中度部署相关影响 创伤性脑损伤本研究收集了1个月的身心健康、神经认知表现和血液样本， 在阿富汗作战部署之前和之后的4-6个月。我们将使用150个TBI样本， 无TBI病史的匹配对照样本完成2个目标。目标1将研究 NDE中的细胞骨架和神经元蛋白，以识别TBI，以及脑震荡后持续性 症状和认知能力下降。候选神经退行性蛋白包括tau、A β、神经颗粒蛋白， 神经丝轻链和钙蛋白酶切割的α II-血影蛋白N-末端片段。研究还将利用 这些前瞻性样本，以检查NDE蛋白在损伤前后的变化是否反映了症状， 变化，提供潜在的因果关系推断这些蛋白质在TBI的致病过程。目标2将 使用无偏倚的发现方法来鉴定与TBI相关的新的miRNAs， 症状和神经认知能力下降。将对外来体RNA进行小RNA测序。 与TBI相关的miRNA将使用RT-qPCR进行验证，并在独立的样本集中进行复制。 顶级候选人将被检查受伤前后的变化，以了解这些变化的贡献。 损伤后致病过程的标志物。这项研究有很大的潜力， TBI和相关症状的定量生物标志物，以及确定潜在的功能靶点， 干预! !

Traumatic brain injury (TBI) is a signature injury of OIF/OEF Veterans. More than 360,000 armed service members sustained TBI during combat and training from 2000 to 2016. There is currently no diagnostic biological marker for TBI nor can current diagnostic tools identify individuals at greatest risk for chronic neurological and subsequent functional impairments after TBI. Neuronally-derived exosomes (NDEs) obtained from peripheral blood may be a powerful tool to develop accessible CNS-based biomarkers associated with neuronal dysfunction, particularly in relation to long-term brain injury and neurodegeneration. Our recently published work demonstrates that neuropathological proteins (e.g betaamyloid, Aß, and tau) within NDEs can predict conversion from mild cognitive impairment to Alzheimer's Disease (AD) while plasma levels do not. Studies of NDEs are now being tested as companion biomarkers in AD clinical trials to help reduce screen fail rates and increased enrollment. We have recently found that cytoskeletal and synaptic proteins are also abnormal in deployment-related TBI patients >3 mo after TBI. Specifically, both Aß and neurogranin are altered in plasma NDEs from participants who experienced a deployment-related TBI. Taken together, our data support the hypothesis that plasma NDEs may be a powerful tool to identify accessible and CNS-specific protein biomarkers for TBI. NDEs are also enriched for short length “micro” RNA (miRNA) cargo. Each miRNA can regulate protein expression from hundreds of target messenger RNAs, providing an efficient mechanism to exert genome-wide regulation and simultaneously affect several cellular pathways. miRNAs confer tissue specificity and have recently emerged as potential biomarkers and therapeutic targets for neurodegeneration. Hence, identification of CNS-specific miRNAs associated with NDEs may provide a window to the pathogenic processes in chronic TBI for future intervention. We hypothesize that proteins related to neurodegeneration within NDEs, such as Aß, as well as miRNAs associated with NDEs have the potential to be biomarkers of TBI and associated symptoms. To test this hypothesis we will leverage our prospective longitudinal study of combat deployment effects in >1200 Marines, of which 176 experienced mild/moderate deployment-related TBI. This study collected physical and mental health, neurocognitive performance and blood samples 1 mo before and 4-6 mo after a combat deployment to Afghanistan. We will use 150 TBI samples with 150 samples of matched controls with no TBI history to complete 2 aims. Aim 1 will examine utility of cytoskeletal and neuronal proteins in NDEs to identify TBI in addition to persistence of post-concussive symptoms and cognitive decline. Candidate neurodegenerative proteins include tau, Aß, neurogranin, neurofilament light chain and calpain-cleaved αII-spectrin N-terminal fragment. Studies will also leverage these prospective samples to examine if change in NDE proteins from pre-and post injury reflects symptom change, providing potential causal inferences for these proteins in the pathogenic process of TBI. Aim 2 will use an unbiased discovery approach to identify novel miRNAs associated with TBI and associated symptoms and neurocognitive decline. Small RNA sequencing will be conducted on exosomal RNA. miRNA associated with TBI will be validated using RT-qPCR and replicated in an independent sample set. Top candidates will be examined for changes pre and post injury to understand the contribution of these markers to the pathogenic process after injury. This study has strong potential to provide accessible, quantitative biomarkers for TBI and associated symptoms, as well as identify potential functional targets for intervention. ! !