Synaptic Circuitry in Stroke

中风中的突触回路

• 批准号: 10405094
• 负责人: SERGEI A KIROV
• 金额: $ 33.69万
• 依托单位: AUGUSTA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-01 至 2024-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10405094
• 关键词: Acute; Acute Brain Injuries; Address; Affect; Algorithmic Analysis; Anions; Apoptosis; Asphyxia; Astrocytes; Brain; Brain Edema; Brain Injuries; Brain hemorrhage; Carrier Proteins; Cell Membrane Permeability; Cell membrane; Cessation of life; Chlorides; Clinical; Clinical Data; Computers; Coupled; Craniocerebral Trauma; Data; Dendrites; Development; Edema; Electron Microscopy; Electrophysiology (science); Event; Extracellular Space; Genetic; Grant; Heart Arrest; Hypoxia; Image; Injury; Ions; Ischemia; Ischemic Stroke; Laser Scanning Microscopy; Laser Speckle Imaging; Lead; Learning; Link; Mediating; Metabolic; Microinjections; Mitochondria; Modeling; Molecular; Monitor; Morphology; Motion; Movement; Mus; Neuroglia; Neurologic; Neurological emergencies; Neurons; Organelles; Pathogenicity; Pathologic; Pathway interactions; Patients; Permeability; Pharmaceutical Preparations; Pharmacology; Play; Pre-Clinical Model; Protons; Pump; Recovery; Role; Slice; Specificity; Stress; Stroke; Structure; Supervision; Swelling; Technology; Testing; Therapeutic Intervention; Thinness; Time; Tissues; Transmission Electron Microscopy; Trauma; Traumatic Brain Injury; Traumatic injury; Tubular formation; Uncertainty; Viral; Water; base; brain cell; chloride-cotransporter potassium; conditional knockout; cytokine; cytotoxic; experimental study; hemodynamics; hippocampal pyramidal neuron; imaging study; in vivo; insight; ischemic injury; mortality; mouse genetics; nervous system disorder; neural circuit; neuronal cell body; neuronal survival; neuroprotection; novel; real-time images; targeted treatment; therapy design; tool; treatment strategy; two photon microscopy; two-photon; water channel

Spreading depolarizations (SDs) that occur in stroke and traumatic brain injury patients exacerbate the neuronal damage in metabolically compromised tissue. SDs are waves of sustained neuronal and glial depolarization that actively propagate a breakdown of ion gradients through the injured brain. The ion fluxes during SD are followed by a rapid accumulation of water inside neurons and astrocytes causing cytotoxic edema. Pyramidal neurons lack functional aquaporins. This implies that passive osmotically obligated water entry after the ionic movements during SD is unlikely. Using pharmacological inhibition, we have identified several chloride-coupled cotransporters that mediate ion and water fluxes and can participate in neuronal swelling. Recently mice with conditional deletion of these transporter proteins were generated offering unique opportunity to identify the exact molecular conduits of water influx into neurons during SD, and this will be studied in Aim 1. Cytotoxic edema distorts intracellular organelles. Mitochondria play a variety of functional roles in neurons, from metabolic support and neuroprotection to the release of cytokines that trigger apoptosis. In dendrites, the mitochondrial structure is closely linked to their function, and fragmentation of the normally elongated mitochondria indicates loss of their function under pathological conditions. To date, fragmentation of mitochondria was studied either in dissociated cultured neurons or brain slices, but not in the intact living brain. Using real-time in vivo 2-photon microscopy, we quantified mitochondrial fragmentation during brain injury. We demonstrated that alterations in neuronal mitochondria morphology occurs within minutes of injury onset and can be reversible in traumatic and ischemic injuries. Impact of SD on mitochondrial structure could be one of the major factors affecting mitochondrial fragmentation and neuronal survival during noxious conditions, and it will be examined in aims 2 and 3. The specific aims are: 1) To identify neuronal chloride cotransporters that are involved in the onset of SD-induced neuronal swelling. 2) To test the hypothesis that SD is the triggering mechanism of rapid neuronal mitochondrial fragmentation. 3) To test possible mechanistic links between SD and mitochondrial fragmentation. The proposal integrates a variety of classic and state of the art technologies; viral expression, mouse genetics, in vivo 2-photon microscopy coupled with electrophysiology and laser speckle imaging, as well as ultrastructural analyses with serial section transmission electron microscopy. A novel automatic analysis algorithm, based on supervised statistical computer learning will be used to quantify the degree of dendritic mitochondrial fragmentation. Model of transient global ischemia (BCCAO) will be used to evoke SD. In a model of focal stroke (photothrombotic occlusion) and the healthy cortex, SD will be evoked by KCl microinjection. The results will bring new insight into the development of cytotoxic edema during the stroke injury. The experiments will also address how and under what conditions the mitochondrial organelles are affected by SD and reveal mechanistic links between SD and mitochondrial fragmentation.

中风和创伤性脑损伤患者中发生的扩散去极化（SD）加剧了神经元 代谢损害的组织损害。 SD是持续神经元和神经胶质去极化的波 通过受伤的大脑积极地传播离子梯度的分解。遵循SD期间的离子通量 通过在神经元和星形胶质细胞内的水迅速积聚，导致细胞毒性水肿。金字塔神经元 缺乏功能性水通道蛋白。这意味着离子运动后被动渗透义务进入 在SD期间不太可能。使用药理抑制，我们已经确定了几个氯化物偶联 介导离子和水通量并可以参与神经元肿胀的共转运蛋白。最近有老鼠 这些转运蛋白的有条件缺失是生成的，提供了独特的机会来确定确切的 在SD期间，水流入神经元中的分子导管将在AIM 1中进行研究。细胞毒性水肿 扭曲细胞内细胞器。线粒体在神经元中起各种功能作用，来自代谢支持 和神经保护对引发凋亡的细胞因子的释放。在树突中，线粒体结构 与它们的功能紧密相关，正常拉长线粒体的分裂表明其丧失 病理条件下的功能。迄今为止，在解离的线粒体碎裂 培养的神经元或脑切片，但不在完整的活体大脑中。使用实时体内2光子显微镜， 我们在脑损伤过程中量化了线粒体碎片。我们证明了神经元的改变 线粒体形态发生在损伤发作后的几分钟内，并且在创伤性和缺血性中可能是可逆的 受伤。 SD对线粒体结构的影响可能是影响线粒体的主要因素之一 在有害条件下的碎裂和神经元存活，将在目标2和3中进行检查。 具体目的是：1）鉴定与SD诱导的发作有关 神经元肿胀。 2）测试SD是快速神经元线粒体的触发机制的假设 分散。 3）测试SD和线粒体碎片之间可能的机械联系。提案 整合了各种经典和状态的艺术技术；病毒表达，小鼠遗传学，体内2-光子 显微镜与电生理学和激光斑点成像，以及与超微结构分析一起 串行部分透射电子显微镜。一种基于监督的新型自动分析算法 统计计算机学习将用于量化树突状线粒体碎片的程度。模型 瞬态全局缺血（BCCAO）将用于唤起SD。在局灶性中风的模型中 闭塞）和健康的皮质，SD将通过KCL微注射唤起。结果将带来新的见解 中风损伤期间细胞毒性水肿的发展。实验还将解决如何和下方 线粒体细胞器受SD的影响，并揭示了SD和SD之间的机械联系 线粒体碎片。

项目成果

Adrenergic activation attenuates astrocyte swelling induced by hypotonicity and neurotrauma.

• DOI: 10.1002/glia.22981
• 发表时间: 2016-06
• 期刊: Glia
• 影响因子: 6.2
• 作者: Vardjan N;Horvat A;Anderson JE;Yu D;Croom D;Zeng X;Lužnik Z;Kreft M;Teng YD;Kirov SA;Zorec R
• 通讯作者: Zorec R

Longitudinal two-photon imaging in somatosensory cortex of behaving mice reveals dendritic spine formation enhancement by subchronic administration of low-dose ketamine.

• DOI: 10.1038/s41598-018-24933-8
• 发表时间: 2018-04-24
• 期刊: Scientific reports
• 影响因子: 4.6
• 作者: Pryazhnikov E;Mugantseva E;Casarotto P;Kolikova J;Fred SM;Toptunov D;Afzalov R;Hotulainen P;Voikar V;Terry-Lorenzo R;Engel S;Kirov S;Castren E;Khiroug L
• 通讯作者: Khiroug L

Plasticity of perisynaptic astroglia during ischemia-induced spreading depolarization.

缺血诱导的扩散去极化过程中突触周围星形胶质细胞的可塑性。

• DOI: 10.1093/cercor/bhac434
• 发表时间: 2023
• 期刊: Cerebral cortex (New York, N.Y. : 1991)
• 作者: Fomitcheva,IouliaV;Sword,Jeremy;Shi,Yang;Kirov,SergeiA
• 通讯作者: Kirov,SergeiA

Novel mechanism of hypoxic neuronal injury mediated by non-excitatory amino acids and astroglial swelling.

• DOI: 10.1002/glia.24241
• 发表时间: 2022-11
• 期刊: GLIA
• 影响因子: 6.2
• 作者: Alvarez-Merz, Iris;Fomitcheva, Ioulia, V;Sword, Jeremy;Hernandez-Guijo, Jesus M.;Solis, Jose M.;Kirov, Sergei A.
• 通讯作者: Kirov, Sergei A.

Questioning Glutamate Excitotoxicity in Acute Brain Damage: The Importance of Spreading Depolarization.

• DOI: 10.1007/s12028-021-01429-4
• 发表时间: 2022-06
• 期刊: Neurocritical care
• 影响因子: 3.5