Microglial uptake and inactivation of epoxyeicosatrienoic acid in stroke injury

描述(申请人提供)：中风是美国第三大致死原因，也是导致长期残疾的主要原因。大多数急性中风疗法的临床试验都失败了，这突显了确定新的治疗靶点和开发有效疗法以减少脑损伤的必要性。我们在这项建议中的广泛目标是揭示控制神经炎症的有害影响的分子途径，特别是在中风损伤中的小胶质细胞。所获得的知识将有助于确定中风治疗的新药物靶点。中心假说是，小胶质细胞在缺血期间被激活，并有助于损伤的发展。探讨了这种小胶质细胞介导的损伤的两个方面：缺血时环氧二十碳三烯酸(EET)的耗竭，增加神经元的死亡；以及缺血后EET的失活，增加小胶质细胞的激活，进一步加重损伤。在特定的目标1中，我们将确定小胶质细胞是否通过CD36介导的摄取来消耗EET，以及EET缺乏是否导致缺血后神经元死亡。在目标2中，我们将在体内确定小胶质细胞耗尽EET是否与卒中损伤有关。在目标3中，我们将测试阻断小胶质细胞中的EET失活是否减少了小胶质细胞的激活和小胶质细胞介导的神经元死亡。最后，在目标4中，我们将研究抑制EET失活小胶质细胞中的可溶性环氧化物水解酶是否会在体内阻断卒中后小胶质细胞的激活，从而减轻卒中损伤。主要目标是开发和表征新的实验方法来解决卒中的临床问题，特别是了解小胶质细胞在卒中病理中的作用，以及利用对小胶质细胞/神经元相互作用和小胶质细胞介导的损伤的日益了解来确定急性卒中的新的治疗靶点和方法。这些实验将有助于表征环氧二十碳三烯酸在中风后小胶质细胞激活和小胶质细胞介导的损伤中的作用。候选人是一名麻醉师和神经强化师，有很强的研究缺血性脑损伤的研究背景。候选人所在的机构提供了一个支持和合作的环境，非常适合培养一名新的独立调查员在学术和科学上的持续成长。通过拟议的实验获得的额外专业知识将促进候选人作为独立研究人员的科学发展和成长。这些研究中收集的证据将为未来成功应用R01奠定基础。 公共卫生相关性：拟议的实验将调查脑内常驻免疫细胞小胶质细胞在中风后脑损伤中的作用。具体地说，这些实验的重点是小胶质细胞对一种特定脑部脂肪酸的吸收和代谢，这会导致中风后脑细胞的炎症和死亡。从这些实验中获得的损伤分子机制的知识将有助于开发新的和更具体的中风治疗方法。

DESCRIPTION (provided by applicant): Stroke is the third leading cause of death and a major cause of long-term disability in the United States. Most clinical trials of acute stroke therapy have failed, underscoring the need to identify new therapeutic targets and develop effective therapies to reduce brain damage. Our broad goal in this proposal is to unravel the molecular pathways governing the detrimental effect of neuroinflammation and specifically microglia in stroke injury. Knowledge gained will help identify new drug targets for stroke therapy. The central hypothesis is that microglia are activated during ischemia and contribute to the development of injury. Two aspects of this microglia-mediated injury are explored, the depletion of epoxyeicosatrienoic acid (EET) during ischemia, which increases neuronal death, as well as the inactivation of EET after ischemia, which increases microglial activation and further exacerbates injury. In Specific Aim 1, we will determine whether microglia deplete EET through CD36-mediated uptake and whether EET deficiency contributes to neuronal death after ischemia. In Aim 2, we will determine whether depletion of EET by microglia contributes to stroke injury in vivo. In Aim 3, we will test whether blocking EET inactivation in microglia reduces microglial activation and microglia-mediated neuronal death. Finally, in Aim 4, we will investigate whether inhibition of EET-inactivating soluble epoxide hydrolase in microglia blocks microglial activation after stroke in vivo and reduces stroke injury. The overarching goals are to develop and characterize new experimental approaches to the clinical problem of stroke, specifically to understand the contribution of microglia to stroke pathology as well as use the increasing understanding of microglia/neuronal interplay and microglia-mediated injury to define new therapeutic targets and approaches for acute stroke. The experiments will help characterize the role of epoxyeicosatrienoic acid in microglia activation and microglia-mediated injury after stroke. The candidate is an anesthesiologist and neurointensivist with a strong research background studying ischemic brain injury. The candidate's institution provides a supportive and collaborative environment that is ideally suited to fostering the continued academic and scientific growth of a newly independent investigator. The additional expertise acquired through the proposed experiments will foster the candidate's scientific development and growth as an independent researcher. Evidence gathered in these studies will provide the base for a successful future R01 application. PUBLIC HEALTH RELEVANCE: The proposed experiments will investigate the role of microglia, the brain resident immune cells, in brain injury after stroke. Specifically, the experiments focus on uptake and metabolism of a specific brain fatty acid by microglia, which contributes to inflammation and the death of brain cells after stroke. Knowledge of molecular mechanisms of injury that will be gained from these experiments will help develop novel and more specific therapeutic approaches for stroke.