Molecular mechanisms underlying isoflurane conditioning-induced neurovascular protection in subarachnoid hemorrhage

摘要/项目摘要： UMeshkumar Athiraman博士是一名神经学家和神经麻醉师，他的长期目标是成为 独立研究人员专注于了解麻醉条件作用的潜在机制- 诱导神经血管保护，以麻醉条件为基础的动脉瘤治疗方法的发展 蛛网膜下腔出血(SAH)，以及后来将这些见解应用于其他形式的脑损伤。Dr。 阿蒂拉曼是圣华盛顿大学神经外科齐普费尔博士实验室的成员 路易。实验室、系和大学提供了一个特殊的培训环境。阿蒂拉曼医生会 在Zipfel实验室接受SAH动物模型、免疫组织化学、分子生物学技术方面的培训 以及SAH后短期和长期神经行为结果的评估。他还将接受培训， 合作者Adam Bauer博士的实验室中用于功能连通性评估的光学成像。其他内容 申请者所在的麻醉科将提供支持和指导。SAH是一种严重的 出血性中风类型，发病率和死亡率极高。除了最初的出血严重程度外， 迟发性脑缺血(DCI)引起的继发性脑损伤对患者的预后有重要影响 萨哈。虽然许多对抗DCI的策略已经在临床前研究中开发并在后期阶段进行了测试 临床试验，没有一项被证明对改善长期功能结果有效。这些问题的原因是什么？ 失败可能是多方面的，但包括只针对已被证明的一种因素的治疗 多因素脑损伤过程。这项拟议的项目考察了一种已知有 对SAH后DCI有强大的、多方面的保护作用，称为AS-条件化(麻醉剂)。初步 数据显示，异氟醚调节对SAH诱导的DCI提供了强有力的保护，这 保护可能是通过抑制两个关键分子--核因子-kB和诱导型一氧化氮合酶来实现的。计划中的实验 将通过有针对性的遗传和药物干预严格检验以下假设：1) 抑制核因子-kB是异氟烷调节DCI保护的基础；2)抑制iNOS(一个关键 核因子-kB的下游靶点)是异氟烷调节所提供的DCI保护作用的基础；以及3)药物 模拟异氟烷调节的分子效应(核因子-kB抑制剂，PDTC-吡咯烷二硫代氨基甲酸酯；以及 INOS抑制剂，1400W)提供对神经行为和功能连接缺陷的长期保护 在SAH之后。这些实验的结果将从根本上确立抑制NF-kB/iNOS通路为 异氟醚预适应诱导SAH中DCI保护的关键诱导物及其对NF-kB/iNOS的抑制作用 有望成为治疗SAH的新策略。拟议的计划将为阿蒂拉曼博士提供培训， 指导和经验，以及时过渡到独立，并获得R01资金。

Abstract/Project Summary: Dr. Umeshkumar Athiraman MD, is a neuroscientist and neuroanesthesiologist with the long-term goal to be an independent investigator focused on understanding the underlying mechanisms of anesthetic conditioning- induced neurovascular protection, development of anesthetic conditioning-based therapeutics for aneurysmal subarachnoid hemorrhage (SAH), and later application of these insights to other forms of brain injury. Dr. Athiraman is a member of Dr. Zipfel’s lab in the Department of Neurosurgery at Washington University in Saint Louis. The lab, department, and the university provide an exceptional training environment. Dr. Athiraman will receive training in the Zipfel lab in SAH animal models, immunohistochemistry, molecular biology techniques and assessment of short and long-term neurobehavioral outcomes after SAH. He will also receive training in optical imaging for functional connectivity assessment in the lab of collaborator, Dr. Adam Bauer. Additional support and mentorship will be provided by the applicant’s host department of anesthesiology. SAH is a severe type of hemorrhagic stroke with extremely high morbidity and mortality. Apart from the initial hemorrhage severity, secondary brain injury due to delayed cerebral ischemia (DCI) plays a significant role in patient outcomes after SAH. While many strategies to combat DCI have been developed in preclinical studies and tested in late phase clinical trials, none have proven efficacious for improving long-term functional outcome. The causes of these failures are likely multitude, but include use of therapies targeting only one element of what has proven to be multifactorial brain injury process. The proposed project examines the impact of a therapy known to have powerful, multifaceted protective effects on DCI after SAH called as – conditioning (anesthetic). Preliminary data shows that isoflurane conditioning provides robust protection against SAH-induced DCI and that this protection is likely mediated via inhibition of two critical molecules – NF-kB and iNOS. The planned experiments will rigorously test the following hypothesis through targeted genetic and pharmacological interventions: 1) Inhibition of NF-kB underlies the DCI protection afforded by isoflurane conditioning; 2) Inhibition of iNOS (a key downstream target of NF-kB) underlies the DCI protection afforded by isoflurane conditioning; and 3) Drugs that mimic the molecular effects of isoflurane conditioning (NF-kB inhibitor, PDTC-pyrrolidine dithiocarbamate; and iNOS inhibitor, 1400W) provide long-term protection against neurobehavioral and functional connectivity deficits after SAH. The results of these experiments will fundamentally establish NF-kB/iNOS pathway inhibition as the key inducer of isoflurane conditioning-induced DCI protection in SAH and identify NF-kB/iNOS inhibition as a promising new therapeutic strategy for SAH. The proposed plan will provide Dr. Athiraman with the training, mentorship and experience to transition to independence in a timely manner and obtain R01 funding.