The influence of ApoE4 on signaling & poor outcome after traumatic brain injury

ApoE4 对信号传导的影响

• 批准号: 10266025
• 负责人: Naomi Ledene Sayre
• 金额: --
• 依托单位: SOUTH TEXAS VETERANS HEALTH CARE SYSTEM
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-01 至 2022-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10266025
• 关键词: Acute; Advisory Committees; Affect; Afghanistan; Aging; Alleles; Amyloid beta-Protein; Apolipoprotein E; Astrocytes; Attenuated; Behavior; Binding; Biology; Brain; Brain Injuries; Cell Culture Techniques; Cell Death; Cell Survival; Cell membrane; Cells; Chronic; Coculture Techniques; Critical Thinking; Cytokine Signaling; Cytosol; Data; Disease Progression; Edema; Endocytosis; Endosomes; Environment; Evaluation; Fostering; Funding; Future; GJB6 gene; Genetic Recombination; Goals; Headache; Health; Impairment; Incidence; Inflammation; Inflammatory; Injury; Intervention; Investigation; Iraq; Journals; K-Series Research Career Programs; Knock-out; LDL-Receptor Related Protein 1; LDL-Receptor Related Proteins; Lead; Learning; Link; Lipids; Lipoproteins; Manuscripts; Measurement; Measures; Mediating; Memory Loss; Mentors; Military Personnel; Modeling; Mus; Necrosis; Neurodegenerative Disorders; Neurologic; Neurologic Deficit; Neurological Models; Neurons; Neurosciences; Outcome; Pathologic; Pathology; Patients; Play; Post-Traumatic Stress Disorders; Proteins; Publishing; Recording of previous events; Recovery; Recycling; Research; Research Personnel; Risk; Role; Signal Transduction; Stress; Structure; Surface; System; TNF gene; TNFRSF1A gene; Testing; Time; Training; Traumatic Brain Injury; Veterans; War; Work; apolipoprotein E-3; apolipoprotein E-4; blood-brain barrier permeabilization; career; cell type; cytokine; design; effective therapy; improved; innovation; military veteran; mouse model; negative affect; nervous system disorder; neuropathology; novel; outcome prediction; prevent; protein expression; receptor; receptor mediated endocytosis; receptor recycling; response; response to injury; shear stress; symposium; training opportunity; tumor

This career development award proposal aims to define potential mechanisms that predict outcome after traumatic brain injury (TBI), while at the same time providing the applicant with training opportunities within the VA. TBI affects approximately 15% military population. Veterans were subjected to repeated TBI are at increased risk of developing long-term neurodegenerative disorders. Treatment options are limited, mainly because the pathology behind neurological deficits due to TBI is poorly understood. Apolipoprotein E (ApoE) has several alleles, and patients that express the E4 allele have worse outcomes, particularly in the long term after TBI. Despite a wide range of studies centered on the ApoE4 allele, none can be found that investigate the influence of a major ApoE receptor, low density lipoprotein related protein 1 (LRP1), on outcomes after TBI. Nevertheless, evidence suggests that LRP1 can play a role in modulating TBI outcome- -LRP1 removes a large variety of cellular proteins, both from the plasma membrane and in the cytosol, and plays an important role in determining protein expression at the plasma membrane. ApoE4 enters cells by binding to LRP1 and undergoing receptor mediated endocytosis. In contrast to other ApoE alleles (E2, E3), ApoE4 endocytosis and receptor recycling are impaired. In the case of LRP1, impaired recycling is postulated to greatly alter ability of LRP1 to act as a clearance receptor, therefore changing the milieu of proteins expressed on the plasma membrane and so altering cellular response to damage. For this proposal, I am focused on understanding the contribution of LRP1 to TBI pathology in a single cell type, astrocytes. Not only are astrocytes the primary producers of ApoE in the brain, they also play a tremendous role in determining outcome by limiting secondary spread of damage after TBI. My working hypothesis is that critical LRP1 function is disrupted by ApoE4 binding in astrocytes, thereby modulating normal cellular responses and sensitizing the brain to inflammation and cell death after TBI. My research strategy will test this hypothesis while also providing clear training objectives and career opportunities in order to develop independence. Aim 1 tests the hypothesis that loss of astrocyte LRP1 worsens outcome in TBI. Astrocyte-specific LRP1 mice have been generated, and mouse TBI models will test outcome in the acute and chronic outcome. Aim 2 will test the hypothesis that the impact of ApoE4 on TBI outcome depends on LRP1. TBI-like cell culture models will mechanistically test the influence of ApoE4 and LRP1 on cell survival. One new mouse line will be generated by crossing ApoE4 targeted replacement mice into the astrocyte-LRP1 knockout model, and then the effect on outcome after TBI will be tested similar to aim 1. Aim 3 tests the hypothesis that ApoE4 worsens outcome by increasing signaling through the inflammatory tumor necrosis alpha receptor 1 (TNFR1), elevating cytokine stimulated cell death. This aim will be tested mechanistically using cell culture models to test the influence of ApoE4 and LRP1 on TNFR1 plasma membrane expression, recycling, and TNFR1-mediated cell death. My career goal is to become a successful independent investigator within the VA system, eventually obtaining MERIT funding and contributing to better outcomes in Veterans with TBI. I have assembled a team that includes experts in the field of LRP1 biology, neuroscience, and most importantly, TBI. The scientific objectives will prepare me for a career studying the effects of TBI in mouse models, while the career objectives will improve scientific critical thinking and provide opportunities for networking and presentation of my results. These will be achieved via biannual evaluation by the advisory committee, attendance at national conferences, attending journal club, improving grantsmanship, and publishing manuscripts resulting from the proposed work. My co- mentors will also provide training related to proper direction of a successful independent research lab. Altogether, I expect that the activities detailed in this proposal will provide an exceptional environment from which to start an independent career.

该职业发展奖提案旨在定义预测结果之后结果的潜在机制 创伤性脑损伤（TBI），同时为申请人提供培训机会 VA。 TBI影响了大约15％的军人。将退伍军人重复进行TBI的重复 患有长期神经退行性疾病的风险。治疗选择是有限的，主要是因为 由于TBI引起的神经缺陷背后的病理学知之甚少。 载脂蛋白E（APOE）有几个等位基因，表达E4等位基因的患者的预后较差， 特别是在TBI之后的长期。尽管以APOE4等位基因为中心的广泛研究，但没有人可以 可以发现，研究主要的APOE受体低密度脂蛋白相关蛋白1（LRP1）的影响 关于TBI之后的结果。然而，有证据表明LRP1可以在调节TBI结果中发挥作用 - -lrp1从质膜和细胞质中去除各种细胞蛋白，并发挥作用 确定质膜上蛋白质表达的重要作用。 APOE4通过与LRP1结合并经历受体介导的内吞作用进入细胞。与其他 APOE等位基因（E2，E3），APOE4内吞作用和受体回收受损。对于LRP1，受损 据推测，回收是大大改变了LRP1充当清除受体的能力，因此改变了环境 在质膜上表达的蛋白质，从而改变了细胞对损伤的反应。对于这个建议， 我专注于了解LRP1对单细胞类型的星形胶质细胞中TBI病理的贡献。不是 仅星形胶质细胞是大脑中Apoe的主要生产商，它们在确定中也起着巨大的作用 通过限制TBI后损害的次要扩散来结果。我的工作假设是关键的LRP1 功能受到星形胶质细胞中APOE4结合的破坏，从而调节正常的细胞反应和 TBI后大脑对炎症和细胞死亡的敏感。我的研究策略将检验这一假设 同时还提供明确的培训目标和职业机会，以发展独立性。 AIM 1检验了以下假设：星形胶质细胞LRP1的丧失会使TBI的结果恶化。星形胶质细胞特异性LRP1 已经生成小鼠，小鼠TBI模型将在急性和慢性结局中测试结果。目标2 将检验以下假设：APOE4对TBI结果的影响取决于LRP1。 TBI样细胞培养模型 将机械地测试APOE4和LRP1对细胞存活的影响。将生成一条新的鼠标线 通过将靶向替换小鼠的靶向替换小鼠跨到星形胶质细胞LRP1敲除模型，然后对 TBI之后的结果将与AIM 1相似。AIM3检验APOE4会使结果恶化的假设。 通过炎症性肿瘤坏死α受体1（TNFR1）增加信号传导，升高细胞因子 刺激细胞死亡。该目标将使用细胞培养模型进行机理测试，以测试 TNFR1质膜表达，回收和TNFR1介导的细胞死亡上的APOE4和LRP1。 我的职业目标是成为VA系统中成功的独立调查员，最终获得 优点资金，并为与TBI的退伍军人提供更好的结果。我组建了一个团队，其中包括 LRP1生物学，神经科学，最重要的是TBI领域的专家。科学目标将 为我准备研究TBI在鼠标模型中的影响的职业，而职业目标将改善 科学的批判性思维，并为我的结果提供网络和呈现机会。这些将是 咨询委员会通过双年度评估，参加国家会议，参加 期刊俱乐部，改善了授予技巧和由拟议工作产生的出版手稿。我的共同 导师还将提供与成功独立研究实验室的正确方向相关的培训。共， 我希望该提案中详细介绍的活动将提供一个特殊的环境 独立职业。

项目成果

Spinal cord injury and the human microbiome: beyond the brain-gut axis.

• DOI: 10.3171/2018.12.focus18206
• 发表时间: 2019-03
• 期刊: Neurosurgical focus
• 影响因子: 4.1
• 作者: D. Wallace;Naomi L. Sayre;T. T. Patterson-T.;Susannah E. Nicholson;D. Hilton;Ramesh Grandhi;Ramesh Grandhi