Spinal cord injury, progressive hemorrhagic necrosis and the NC(Ca-ATP) channel

脊髓损伤、进行性出血性坏死和 NC(Ca-ATP) 通道

• 批准号: 8576592
• 负责人: J. Marc Simard
• 金额: $ 33.58万
• 依托单位: UNIVERSITY OF MARYLAND BALTIMORE
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-02-15 至 2019-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8576592
• 关键词: Accounting; Adhesions; Affect; Attenuated; Binding; Biological; COS-7 Cell; Cell Death; Cells; Contusions; Cytoplasmic Protein; Data; Endothelium; Exocytosis; Genes; Glyburide; Goals; Grant; Hour; Human; IL8 gene; IL8RB gene; In Situ Nick-End Labeling; Inflammation; Inflammatory Response; Injection of therapeutic agent; Injury; Invaded; Investigation; Knockout Mice; Lesion; Leukocytes; Ligands; Lymphocyte; Measures; Medicine; Microglia; Modeling; Molecular; Molecular Biology Techniques; Mus; Myelogenous; Necrosis; Nervous System Physiology; Neurologic Dysfunctions; Outcome; Phagocytes; Play; Prevention; Process; Proteins; Reactive Oxygen Species; Rehabilitation therapy; Replacement Therapy; Research; Rest; Role; S100A8 gene; S100A9 gene; Spinal Cord; Spinal cord injury; Time; Tissues; Trauma; Wild Type Mouse; Work; effective therapy; improved; macrophage; migration; monocyte; neuroinflammation; neutrophil; novel; protective effect; public health relevance; research study; response; trafficking

DESCRIPTION (provided by applicant): In spinal cord injury (SCI), an innate cellular inflammatory response is induced that includes the invasion of phagocytes such as neutrophils. Neutrophils can cause secondary bystander injury to normal resident cells, inadvertently worsening the primary injury. MRP8/14, which comprises ~40% of neutrophil cytoplasmic protein, is released following neutrophil/ endothelium adhesion, and plays a crucial role in altering (damaging) the endothelial barrier to facilitate transendothelial migration of neutrophils The biological importance of MRP8/14 is well known, but molecular mechanism of intracellular trafficking and release of MRP8/14 from neutrophils are poorly understood. We made the unexpected discovery that the Sur1 antagonist, glibenclamide, administered as late as 12 hr after spinal cord trauma, reduces the number of neutrophils invading in the penumbra, leading to the novel hypothesis that Sur1 has a crucial role in neutrophil transmigration. Using a model of inflammation in which the CXCR2 ligand and potent neutrophil attractant, CXCL8, is injected directly into the spinal cord, we found in wild-type mice a robust invasion of neutrophils that was marked by significant TUNEL-positive cell death and neurological dysfunction. When the same experiment was repeated in Abcc8-/- mice, which lack Sur1, cell death, neutrophil invasion and neurological dysfunction were essentially eliminated, pointing to a crucial role of Sur1 in the neuroinflammatory response after SCI. Subsequent molecular experiments suggested that Sur1 physically co-associates with MRP8/14, and plays a critical role in the trafficking and release of MRP8/14 from neutrophils. The purpose of this competitive renewal is to expand upon these novel preliminary data, and to establish the role of Sur1 in neuroinflammation. DESCRIPTION: In Specific Aim (SA) 1, we will use gene knockout mice to demonstrate the critical role of Sur1 and MRP8/14 in the cellular inflammatory response in the spinal cord following CXCL8 injection. In SA2, we will use WT mice administered vehicle or glibenclamide at late times after contusion SCI to demonstrate the protective affect of Sur1 inhibition as regards the cellular inflammatory response after SCI. In SA3 we will characterize the functional role of Sur1 in neutrophil secretion of MRP8/14, and we will characterize the molecular interaction between Sur1 and MRP8/14.

描述（由申请人提供）：在脊髓损伤（SCI）中，诱导先天性细胞炎症反应，包括吞噬细胞如嗜中性粒细胞的侵入。中性粒细胞可对正常驻留细胞造成继发性旁观者损伤，无意中使原发性损伤恶化。MRP 8/14包含约40%的嗜中性粒细胞胞质蛋白，在嗜中性粒细胞/内皮细胞粘附后释放，并且在改变（破坏）内皮屏障以促进嗜中性粒细胞的跨内皮迁移中起关键作用。MRP 8/14的生物学重要性是众所周知的，但是对细胞内运输和从嗜中性粒细胞释放MRP 8/14的分子机制知之甚少。我们意外地发现，在脊髓创伤后12小时给予Sur 1拮抗剂格列本脲，可减少侵入半影区的中性粒细胞数量，从而提出了新的假设，即Sur 1在中性粒细胞迁移中起着至关重要的作用。使用炎症模型，其中CXCR 2配体和有效的中性粒细胞引诱剂CXCL 8直接注射到脊髓中，我们发现野生型小鼠中中性粒细胞的强烈侵袭， 以显著的TUNEL阳性细胞死亡和神经功能障碍为标志。当在缺乏Sur 1的Abcc 8-/-小鼠中重复相同的实验时，细胞死亡，中性粒细胞侵袭和神经功能障碍基本上被消除，这表明Sur 1在SCI后的神经炎症反应中起着至关重要的作用。随后的分子实验表明，Sur 1与MRP 8/14物理结合，并在中性粒细胞运输和释放MRP 8/14中发挥关键作用。这种竞争性更新的目的是扩展这些新的初步数据，并建立Sur 1在神经炎症中的作用。产品说明：在Specific Aim（SA）1中，我们将使用基因敲除小鼠来证明Sur 1和MRP 8/14在CXCL 8注射后脊髓细胞炎症反应中的关键作用。在SA 2中，我们将使用WT小鼠在挫伤SCI后的后期给予溶剂或格列本脲，以证明Sur 1抑制对SCI后细胞炎症反应的保护作用。在SA 3中，我们将描述Sur 1在中性粒细胞分泌MRP 8/14中的功能作用，并描述Sur 1和MRP 8/14之间的分子相互作用。