The role of SOCE in microglia and secondary degeneration after SCI

SOCE 在小胶质细胞和 SCI 后继发性变性中的作用

• 批准号: 10567211
• 负责人: David Paul Stirling
• 金额: $ 46.06万
• 依托单位: UNIVERSITY OF LOUISVILLE
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-02-01 至 2027-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10567211
• 关键词: Acute; Afferent Neurons; Anti-Inflammatory Agents; Area; Axon; Biological Process; Blood; Breeding; Calcium; Cell physiology; Chronic; Cicatrix; Data; Drug Targeting; Environment; Event; FDA approved; Growth; Growth Factor; Histology; Homeostasis; Human; Image; Imaging Techniques; Immune; Inflammation Mediators; Inflammatory; Injury; Knock-out; Knockout Mice; LoxP-flanked allele; Mediating; Mediator; Microglia; Molecular; Mouse Strains; Multiple Sclerosis; Mus; Myelogenous; Myeloid Cells; Nerve Degeneration; Nervous System; Neurodegenerative Disorders; Neurologic Deficit; Neurological outcome; Neuronal Injury; Neurons; Nitrogen; Outcome; Oxygen; Pain; Pathologic; Pathway interactions; Patients; Permeability; Pharmaceutical Preparations; Phenotype; Physiological; Play; Process; Production; Recovery; Recovery of Function; Reporter; Reporting; Research; Role; STIM1 gene; Secondary to; Signal Transduction; Site; Source; Spinal; Spinal Cord; Spinal cord injury; Stroke; Technology; Time; Tissue Preservation; Tissues; Vertebral column; Visualization; Wallerian Degeneration; axon injury; axonal degeneration; behavior test; cell type; cytokine; cytotoxic; drug repurposing; effective therapy; experimental study; functional improvement; functional outcomes; glial activation; gray matter; improved; in vivo; inhibitor; innovation; intravital imaging; intravital microscopy; nervous system disorder; neuroinflammation; neurological recovery; neuroprotection; new therapeutic target; novel; pharmacologic; preclinical study; prevent; recruit; response; therapeutic target; two-photon; white matter; white matter injury; wound healing

Abstract: Neurological outcome after spinal cord injury (SCI) is dependent on the extent of primary injury and the delayed secondary degeneration of spared white matter (WM) and grey matter. Although Ca2+ overload is established as a key mediator of secondary injury, therapeutically targeting external sources of Ca2+ to date have failed to improve neurological recovery in pre-clinical studies and following human SCI. This proposal will assess the role of store-operated Ca2+ entry (SOCE) directly in spinal cord neurons and microglia after SCI using cell type specific knockout of key SOCE mediators. Although, SOCE plays a vital role in maintaining Ca2+ homeostasis and is necessary to sustain intracellular Ca2+ at critical levels for immune cell function, we propose that aberrant and excessive SOCE causes secondary degeneration of WM. The role of SOCE in WM injury, microglial activation, and function remains poorly understood. Furthermore, the precise role of the essential SOCE components including stromal interaction molecule (stim 1 and -2), and Orai 1-3 (form the Ca2+ channel pore) in microglial function and neuronal injury remains unclear. Our preliminary data support an important role for SOCE in mediating secondary degeneration, microglial activation and proinflammatory cytokine release, and worsening neurological recovery. We hypothesize that dysregulation of SOCE mediates “bystander” secondary axonal degeneration following SCI by increasing Ca2+ permeability through Stim and/or Orai channels causing Ca2+ overload in axons. In addition, we hypothesize that SOCE regulates microglial activation and release of proinflammatory factors that negatively impacts neurological recovery after SCI. Our specific Aims are to, 1. Determine the role of SOCE in secondary degeneration and neurological recovery following SCI. 2. Determine the role of microglial SOCE in secondary degeneration, wound healing, and neurological recovery after SCI. To accomplish these aims, we will use two photon excitation intravital imaging to visualize the dynamic response of spinal cord axons and microglia after SCI in real time. We will use both pharmacological SOCE inhibitors and cell type specific knockout of key SOCE mediators directly in spinal neurons and microglia. The most efficacious approach will then be assessed using behavioral testing, amount of spared WM and grey matter, and wound healing. The technology and approach may help advance the field as live imaging of axons over time allows unequivocal determination of the fate of injured axons and whether they can be rescued in real-time with treatment. Furthermore, it allows direct visualization of microglia simultaneously with axons and their interactions as these events are unfolding in the injured spinal cord. This proposal is innovative and uses advanced imaging techniques to explore overlooked areas of SCI research. The approach taken may also unveil novel drug targets and repurpose FDA approved drugs found to inhibit SOCE (e.g., teriflunomide). The underlying mechanisms of WM injury may also be relevant to other neurological diseases of the nervous system such as multiple sclerosis, stroke, and TBI.

摘要：脊髓损伤(SCI)后的神经预后取决于原发损伤的程度和 备用白质和灰质延迟性继发性变性。虽然钙超载是 被确定为继发性损伤的关键介质，迄今以外部钙来源为治疗靶点 在临床前研究和人类脊髓损伤后未能改善神经恢复。这项提议将 脊髓损伤后脊髓神经元和小胶质细胞中直接钙离子通道的作用 使用特定细胞类型的关键SOCE介体的敲除。虽然，SOCE在维持钙离子方面起着至关重要的作用 动态平衡，是维持细胞内钙离子在免疫细胞功能的关键水平所必需的 提出异常和过度的SOCE导致WM的继发性退变。SOCE在工作流管理中的作用 损伤、小胶质细胞激活和功能仍然知之甚少。此外，该组织的确切作用 基本的SOCE成分，包括基质相互作用分子(STIM 1和-2)和Orai 1-3(形成 钙通道孔)在小胶质细胞功能和神经元损伤中的作用尚不清楚。我们的初步数据支持 SOCE在介导继发性变性、小胶质细胞活化和促炎中的重要作用 细胞因子的释放，以及神经恢复的恶化。我们假设SOCE的失调在 脊髓损伤后“旁观者”继发性轴突变性通过STIM和/或增加钙离子通透性 Orai通道导致轴突钙超载。此外，我们假设SOCE调节小胶质细胞 促炎症因子的激活和释放，对脊髓损伤后的神经恢复产生负面影响。我们的 具体目标是：1.确定SOCE在继发性退行性变和神经恢复中的作用 追随SCI。2.确定小胶质细胞SOCE在继发性退变、伤口愈合和 脊髓损伤后的神经功能恢复。为了实现这些目标，我们将使用双光子激发活体成像 实时观察脊髓损伤后脊髓轴突和小胶质细胞的动态反应。我们将使用这两种方法 药理学SOCE抑制剂和直接在脊髓中敲除关键SOCE介体的细胞类型特异性 神经元和小胶质细胞。然后将使用行为测试来评估最有效的方法，数量 剩余的白质和灰质，以及伤口愈合。这种技术和方法可能有助于推动该领域的发展 随着时间的推移，轴突的实时成像可以明确地确定受损轴突的命运以及 通过治疗，他们可以实时获救。此外，它还允许直接显示小胶质细胞。 与轴突及其相互作用同时发生，因为这些事件正在损伤的脊髓中展开。这 提案具有创新性，使用先进的成像技术来探索脊髓损伤研究中被忽视的领域。 所采取的方法还可能揭示新的药物靶点，并改变FDA批准的已发现抑制药物的用途 SOCE(如特氟米特)。WM损伤的潜在机制也可能与其他 神经系统疾病，如多发性硬化症、中风和脑外伤。