Understanding the immune response after mild TBI: Do endothelial cells play a major role?

项目总结/摘要： 绝大多数（超过90%）创伤性脑损伤（TBI）被归类为轻度TBI（mTBI）。虽然大多数 mTBI患者恢复迅速，有mTBI经历的患者中有显著少数（10 - 15%） 持续的症状-没有FDA批准的治疗这些人。慢性神经炎症 并且TBI后的血管破裂产生了不利于恢复的环境。更广泛地说， 神经炎症和血管功能障碍也是其它CNS疾病的重要原因， 包括老年痴呆症我的初步结果表明，白细胞介素-1（IL-1）信号通过 白细胞介素-1受体1（IL-1R1）可能是慢性神经炎症和血管病变之间联系 作为一种治疗手段。IL-1是一种主要的促炎细胞因子，在所有TBI后均上调。 严重性IL-1的释放与血管系统的下游改变有关，包括 神经血管单位、血流改变、血管生成和细胞因子，趋化因子， 和生长因子。我们发现脑内皮细胞表达大量的IL-1R1受体。 此外，我们已经证明，缺乏IL-1R1的小鼠在以下情况下表现出减少的神经炎症： 实验性mTBI。我们假设，在mTBI后，脑内皮细胞，特别是通过IL- 1R1，作为神经免疫和血管反应的介质。为了验证这个假设，我们将使用 闭合性头部损伤模型（CHI）以在小鼠中建立mTBI模型。此外，我们将使用可诱导的 内皮细胞特异性IL-1R1敲除（eKO），一种全面敲除，其中IL-1R1仅在 内皮细胞（eRestore），以及其中蛋白质和mRNA被标记的IL-1R1报告小鼠。在 目的1：研究脑缺血后IL-1R1在脑组织中的表达变化 使用报告小鼠。通过这个目标，我将能够确定TBI如何随着时间的推移改变IL-1R1 作为IL-1R1与动脉，静脉和毛细血管的联系，同时也磨练了我在组织学技术方面的技能。 在目标2中，我们将描述CHI后内皮IL-1R1依赖性神经炎症反应， 野生型、eKO和eRestore小鼠。通过这个目标，我将获得动物手术和RNA的经验 分离和Nanostring基因表达分析。最后，在目标3中，我们将调查 内皮细胞IL-1R1在TBI后血管结构和血流变化中的作用。为此，我们将使用容器 绘画和散斑对比度扩散相关断层成像（scDCT）。如果我们的假设得到了支持， 我们将为开发用于治疗mTBI的IL-1疗法提供基础，以及 描述了可以应用于其他疾病的CNS的生理反应。总的来说，这个问题 该提案中概述的方法不仅推动了该领域的发展，而且还提供了重要的科学培训， 将使我成为博士后工作的有力候选人，并成为未来独立科学家的职业。

PROJECT SUMMARY/ABSTRACT: The vast majority (over 90%) of traumatic brain injuries (TBI) are classified as mild TBI (mTBI). While most individuals recover from mTBI quickly, a significant minority (10-15%) of patients with mTBI experience persistent symptoms – there are no FDA approved treatments for these individuals. Chronic neuroinflammation and vascular disruption following TBI create an unfavorable environment for recovery. More broadly, neuroinflammation and vascular dysfunction are significant contributors to other CNS diseases as well, including Alzheimer’s disease. My preliminary results demonstrate that interleukin-1 (IL-1) signaling through interleukin-1 receptor 1 (IL-1R1) may be as a link between chronic neuroinflammation and vascular pathology and serve as a therapeutic avenue. IL-1, a major pro-inflammatory cytokine, is upregulated following all TBI severities. IL-1 release has been linked with downstream alterations of the vasculature, including changes to the neurovascular unit, blood flow alteration, angiogenesis, and increased release of cytokines, chemokines, and growth factors. We have found that brain endothelial cells express a high number of IL-1R1 receptors. Further, we have demonstrated that mice lacking IL-1R1 show reduced neuroinflammation following experimental mTBI. We hypothesize that following mTBI, brain endothelial cells, specifically through IL- 1R1, act as a mediator of the neuroimmune and vascular responses. To test this hypothesis, we will use a closed head injury model (CHI) to model a mTBI in mice. Further, we will manipulate IL-1R1 using an inducible endothelial cell-specific IL-1R1 knockout (eKO), a global knockout in which IL-1R1 has been restored only in the endothelial cells (eRestore), and an IL-1R1 reporter mouse in which the protein and mRNA are labeled. In aim 1, we will determine the cellular and temporal expression changes of IL-1R1 in the brain following CHI using the reporter mice. Through this aim, I will be able to determine how TBI alters IL-1R1 across time as well as IL-1R1 association with arteries, veins, and capillaries, while also honing my skills in histology techniques. In aim 2, we will delineate endothelial IL-1R1-dependent neuroinflammatory responses following CHI in wildtype, eKO, and eRestore mice. Through this aim, I will get experience in animal surgeries as well as RNA isolation and Nanostring gene expression analysis. Finally, in aim 3, we will investigate the involvement of endothelial IL-1R1 in vascular structure and blood flow changes after TBI. To do this, we will use vessel painting and speckle contrast diffusion correlated tomography (scDCT). If we find support for our hypothesis, we will provide the groundwork for the development of IL-1 therapeutics for the treatment of mTBI, as well as describe a physiological response of the CNS that can be applied to other diseases. Overall, the question outlined in this proposal not only moves the field forward but also provides significant scientific training which will position me as a strong candidate for post-doctoral work and a future career as an independent scientist.