Involvement of astrocytic two-pore domain K+ channels in ischemic pathology

星形细胞双孔域 K 通道参与缺血病理学

• 批准号: 8670781
• 负责人: MIN ZHOU
• 金额: $ 32.37万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-01 至 2016-10-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8670781
• 关键词: Accounting; Acidosis; Affect; Antibodies; Apoptotic; Area; Astrocytes; Brain; Carotid Arteries; Cause of Death; Cell Death; Cell Proliferation; Cerebral Ischemia; Cerebrovascular Circulation; Chemosensitization; Electrophysiology (science); Event; Failure; Future; GLAST Protein; Genes; Glial Fibrillary Acidic Protein; Glucose; Gramicidin; Hippocampus (Brain); Hour; Hypoglycemia; Hypoxia; Immunohistochemistry; Individual; Infarction; Ischemia; Lead; Lesion; Light; Mediating; Membrane Potentials; Metabolic; Modeling; Monitor; Necrosis; Neuraxis; Neuronal Injury; Neurons; Neuroprotective Agents; Neurotransmitters; Outcome; Oxygen; Pathology; Peripheral; Pharmaceutical Preparations; Physiological; Potassium Channel; Predisposition; Proliferation Marker; Rattus; Riluzole; Role; Signal Transduction; Simulate; Slice; Staining method; Stains; Stimulus; Stroke; Testing; Therapeutic; Uncertainty; United States; Withdrawal; artery occlusion; base; brain cell; cell type; deprivation; disability; immunocytochemistry; insight; knock-down; member; neuronal survival; neurotransmitter release; novel; post stroke; potassium channel protein TREK-1; resilience; response; therapeutic target; voltage

DESCRIPTION (provided by applicant): Astrocytes are the most numerous cell types in the brain and are known to provide structural, metabolic and homeostatic support to the central nervous system (CNS). Although astrocytes can better survive than neurons in cerebral ischemia, the mechanisms accounting for such a different susceptibility among different brain cells are not clear. Predominant expression of a voltage-independent K+ channel conductance, or passive conductance, is a hallmark of mature astrocytes and essential for the homeostatic support of astrocytes to the CNS. Now we know that two members of the two-pore domain K+ channels (K2Ps) K+ channels, TWIK-1 and TREK-1, are among the long-sought for K+ channels accounting for astrocyte passive conductance. K2Ps can be dynamically modulated by a variety of physiochemical and pathological stimuli, including cerebral-ischemia-produced-neuronal-injury-factors (CIPNJFs), such as hypoxia, hypoglycemia, acidosis and pathological release of neurotransmitters. Pathological induction of K2P expression also contributes to the necrotic and apoptotic cell death and cell proliferation that are the two prominent pathological events occurring in the ischemic infarct and penumbra regions. To understand how the physiological expression of astrocyte K2Ps offers protection to astrocytes against early ischemic insults, and how the long-term ischemic conditions induce altered K2P expression in reactive astrocytes and its consequence on the post-stroke outcomes, we hypothesize that the activity of astrocytic K2Ps can be modulated by CIPNJFs in a manner protecting astrocytes against early ischemic insults, and the altered expression of K2P in reactive astrocytes contributes to the compromised homeostatic function in the peri- infarct penumbra region. Five specific aims are proposed to explore these completely unknown areas. 1) Modulation of astrocyte membrane potential and passive conductance by CIPNJFs. This will be done in rat hippocampal slices with gramicidin perforated patch recording to monitor K2Ps modulation without interfering with the CIPNJFs mediated intracellular energy failure and altered signal transduction; 2) Modulation of electrophysiological response of astrocytes to CIPNJFs by neuroprotectant and TREK-1 channel modulator riluzole and sipatrigine; 3) Identify specific K2P-CIPNJF interaction mechanisms by selective silencing of astrocytic K2Ps with siRNAs in organotypic hippocampal slice cultures; 4) Identify K2P expression in rat hippocampal reactive astrocytes in slices prepared from the penumbra region after reversible middle carotid artery occlusion (rMCAO) by confocal immunocytochemistry. 5) Identify functional K2P in reactive astrocytes in rat focal ischemia penumbra region using electrophysiology in acutely prepared hippocampal slices from the rat rMCAO penumbra region. The proposed studies should provide novel insights into the physiological roles and pathological involvement of astrocytic K2P in cerebral ischemia and whether these predominant astrocytic K+ channels could be potential targets for stroke therapeutic strategy.

描述（由申请人提供）：星形胶质细胞是脑中数量最多的细胞类型，已知可为中枢神经系统（CNS）提供结构、代谢和稳态支持。虽然星形胶质细胞在脑缺血中比神经元更能存活，但不同脑细胞之间这种不同易感性的机制尚不清楚。电压非依赖性K+通道传导或被动传导的优势表达是成熟星形胶质细胞的标志，并且对于星形胶质细胞对CNS的稳态支持是必不可少的。现在我们知道，两个成员的双孔域K+通道（K2 Ps）的K+通道，TWIK-1和TREK-1，是长期寻找的K+通道占星形胶质细胞被动电导。K2 Ps可被多种生理化学和病理刺激动态调节，包括脑缺血产生的神经元损伤因子（CIPNJF），如缺氧、低血糖、酸中毒和神经递质的病理性释放。K2 P表达的病理诱导也有助于坏死性和凋亡性细胞死亡以及细胞增殖，这是发生在缺血性梗死和半影区的两个突出的病理事件。为了理解星形胶质细胞K2 P的生理表达如何保护星形胶质细胞免受早期缺血性损伤，以及长期缺血性条件如何诱导反应性星形胶质细胞中K2 P表达的改变及其对卒中后结果的影响，我们假设星形胶质细胞K2 P的活性可以通过CIPNJF以保护星形胶质细胞免受早期缺血性损伤的方式调节，并且K2 P在反应性星形胶质细胞中的表达改变有助于脑梗死半暗带区域内稳态功能的受损。我们提出了五个具体目标来探索这些完全未知的领域。1)CIPNJFs对星形胶质细胞膜电位和被动电导的调节。这将在大鼠海马切片中进行，用短杆菌肽穿孔膜片记录来监测K2 Ps调节，而不干扰CIPNJF介导的细胞内能量衰竭和改变的信号转导; 2）通过神经保护剂和TREK-1通道调节剂利鲁唑和西帕曲金调节星形胶质细胞对CIPNJF的电生理反应; 3）通过在器官型海马切片培养物中用siRNA选择性沉默星形胶质细胞K2 Ps来鉴定特异性K2 P-CIPNJF相互作用机制; 4）采用共聚焦免疫细胞化学技术检测大鼠颈总动脉阻断后海马半暗带区星形胶质细胞中K2 P的表达。5)采用电生理学方法鉴定大鼠局灶性缺血半暗带区反应性星形胶质细胞中的功能性K2 P。拟议的研究将提供新的见解星形胶质细胞K2 P在脑缺血的生理作用和病理参与，以及这些占主导地位的星形胶质细胞K+通道是否可能成为中风治疗策略的潜在目标。

项目成果

Spatial organization of NG2 glial cells and astrocytes in rat hippocampal CA1 region.

大鼠海马 CA1 区 NG2 胶质细胞和星形胶质细胞的空间组织

• DOI: 10.1002/hipo.22232
• 发表时间: 2014-04
• 期刊: HIPPOCAMPUS
• 影响因子: 3.5
• 作者: Xu, Guangjin;Wang, Wei;Zhou, Min
• 通讯作者: Zhou, Min

Electrophysiological behavior of neonatal astrocytes in hippocampal stratum radiatum.

• DOI: 10.1186/s13041-016-0213-7
• 发表时间: 2016-03-22
• 期刊: Molecular brain
• 影响因子: 3.6
• 作者: Zhong S;Du Y;Kiyoshi CM;Ma B;Alford CC;Wang Q;Yang Y;Liu X;Zhou M
• 通讯作者: Zhou M

Bicarbonate efflux via GABA(A) receptors depolarizes membrane potential and inhibits two-pore domain potassium channels of astrocytes in rat hippocampal slices.

• DOI: 10.1002/glia.22395
• 发表时间: 2012-11
• 期刊: GLIA
• 影响因子: 6.2
• 作者: Ma, Bao-Feng;Xie, Min-Jie;Zhou, Min
• 通讯作者: Zhou, Min

Genetic Deletion of TREK-1 or TWIK-1/TREK-1 Potassium Channels does not Alter the Basic Electrophysiological Properties of Mature Hippocampal Astrocytes In Situ.

TREK-1 或 TWIK-1/TREK-1 钾通道的基因删除不会原位改变成熟海马星形胶质细胞的基本电生理特性

• DOI: 10.3389/fncel.2016.00013
• 发表时间: 2016
• 期刊: Frontiers in cellular neuroscience
• 影响因子: 5.3
• 作者: Du Y;Kiyoshi CM;Wang Q;Wang W;Ma B;Alford CC;Zhong S;Wan Q;Chen H;Lloyd EE;Bryan RM Jr;Zhou M
• 通讯作者: Zhou M

Dual patch voltage clamp study of low membrane resistance astrocytes in situ.

• DOI: 10.1186/1756-6606-7-18
• 发表时间: 2014-03-17
• 期刊: Molecular brain
• 影响因子: 3.6
• 作者: Ma B;Xu G;Wang W;Enyeart JJ;Zhou M
• 通讯作者: Zhou M