Circadian control of neuroinflammation after spinal cord injury

项目摘要 脊髓损伤（SCI）每年新折磨18，000名美国人，对身体功能和 心理健康最初的脊髓创伤会引起延迟的级联损伤（“继发性损伤”）， 有害的炎症反应这种迟发性损伤是急性干预的窗口，但没有 有效的神经保护性SCI疗法。免疫激活在很大程度上受到昼夜节律系统的调节， 优化全天的生理活动。重要的是，关键的昼夜节律因子作为转录调节因子 控制着生物钟，但也控制着身体的关键过程，如免疫反应。那里 目前迫切需要阐明治疗SCI的新方法，如调节昼夜神经免疫功能， 轴，可以改善解剖和行为缺陷。一种有前途的昼夜节律蛋白REV-ERB是一种 转录抑制因子，抑制先天免疫细胞的反应性，包括中枢神经系统MI- croglia和外周巨噬细胞。本建议的总体目标是确定REV-ERB是否 一种可以靶向改善神经保护和神经功能的昼夜神经免疫抑制剂 SCI之后过去的研究表明，SCI扰乱了震中的昼夜节律，这可能会导致过度的炎症， mation。初步数据显示，激活REV-ERB可降低巨噬细胞的反应性， SCI后的康复因此，这项建议很重要，因为确定新的保护目标将有助于改善 SCI后的继发性损伤和缺陷。该提案的中心假设是，放大REV-ERB激活， 改善神经保护、运动功能、疼痛缓解和SCI后的情绪。理由是，重新- 在SCI后通过增强REV-ERB来压制有害的炎症转录程序， 这将对SCI治疗产生影响。本提案针对这些具体目标：1）揭示 是否需要小胶质细胞和/或巨噬细胞REV-ERB来限制神经毒性和神经系统损害 2）确定CNS巨噬细胞靶向REV-ERB过表达是否改善了组织保护 以及SCI后神经功能恢复;以及3）确定药理学REV-ERB激活是否有益于- 炎性细胞状态，以促进神经保护和SCI恢复。这是第一次，该提案结合了外地- 特定的SCI和昼夜神经免疫方法，包括震中的解剖学和分子分析; 运动，疼痛和情绪相关行为;细胞培养;和尖端的单细胞RNA测序。因此 建议的研究是创新的，因为它将SCI中的独特想法，专业知识和方法，昼夜节律， 神经炎症这一贡献将是显著的：它将揭示优化的广泛的、临床相关的作用。 神经免疫反应性，用于改善神经保护-以及用于促进运动恢复、疼痛缓解和 精神健康-SCI后。最终，这些知识可以为开发和实施新的 改善SCI患者的恢复和生活质量的治疗。

PROJECT SUMMARY Spinal cord injury (SCI) newly afflicts 18,000 Americans/year and has devastating effects on body function and mental health. Initial spinal cord trauma elicits a delayed cascade of damage (“secondary damage”) that is driven by a harmful inflammatory response. This delayed damage is a window for acute intervention, yet there are no effective neuroprotective SCI therapies. Immune activation is broadly regulated by the circadian system, which optimizes across-day physiologic activities. Importantly, pivotal circadian factors act as transcriptional regulators that govern the circadian clock – but also control crucial processes in the body, such as immune reactivity. There is a critical need to illuminate novel approaches for treating SCI, such as modulating the circadian-neuroimmune axis, that could ameliorate anatomical and behavioral deficits. One promising circadian protein, REV-ERB, is a transcriptional repressor that dampens reactivity of innate immune cells, including central nervous system mi- croglia and peripheral macrophages. The overall objective of this proposal is to establish whether REV-ERB is a circadian-neuroimmune repressor that can be targeted to improve neuroprotection and neurologic function after SCI. Past studies show that SCI perturbs epicenter circadian rhythms, which likely enables excess inflam- mation. Preliminary data reveal that activating REV-ERB reduces macrophage reactivity and boosts locomotor recovery after SCI. Therefore, this proposal is important, as identifying new protective targets will help ameliorate secondary damage and deficits after SCI. This proposal’s central hypothesis is that amplifying REV-ERB activa- tion will improve neuroprotection, locomotor function, pain relief, and mood after SCI. The rationale is that re- pressing harmful inflammatory transcriptional programs after SCI by boosting REV-ERBs will lead to neuropro- tection, which would have implications for SCI therapies. This proposal addresses these Specific Aims: 1) Reveal whether microglial and/or macrophage REV-ERBs are required to limit neurotoxic and neurologic detriments after SCI; 2) Establish whether CNS macrophage-targeted REV-ERB overexpression improves tissue sparing and neurologic recovery after SCI; and 3) Determine whether pharmacologic REV-ERB activation benefits in- flammatory cell state to boost neuroprotection and SCI recovery. For the first time, this proposal combines field- specific SCI and circadian-neuroimmune methods, including anatomical and molecular analysis of epicenter; motor, pain, and mood-related behaviors; cell culture; and cutting-edge single-cell RNA-sequencing. Thus, the proposed research is innovative, as it links unique ideas, expertise, and methods in SCI, circadian rhythms, and neuroinflammation. This contribution will be significant: it will reveal the broad, clinically relevant role of optimizing neuroimmune reactivity for improving neuroprotection – and for promoting locomotor recovery, pain relief, and mental health – after SCI. Ultimately, this knowledge could inform development and implementation of novel therapies for improving recovery and quality of life for those with SCI.