The potassium channel Kv1.3 in perinatal brain injury

钾通道Kv1.3在围产期脑损伤中的作用

• 批准号: 9893936
• 负责人: LEE-WAY JIN
• 金额: $ 43.24万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-03-15 至 2024-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9893936
• 关键词: Address; Adult; Affect; Alzheimer' s Disease; Brain; Brain Hypoxia-Ischemia; Brain Injuries; Cations; Cell membrane; Cell physiology; Cell surface; Cells; Clinical Trials; Data; Dose; Drug Targeting; Electrophysiology (science); Goals; Hypoxic-Ischemic Brain Injury; Immune; Infection; Inflammation; Inflammatory; Injections; Intervention; Invaded; Knock-out; Leukocytes; Link; Lipopolysaccharides; Measures; Membrane Potentials; Metabolic; Metabolic Pathway; Microglia; Mitochondria; Modeling; Molecular Target; Mononuclear; Motor; Mus; Myeloid Cells; Neonatal; Neonatal Intensive Care Units; Neuroimmunomodulation; Neurologic; Neuronal Injury; Newborn Infant; Oral; Pathologic; Peptides; Perinatal Brain Injury; Perinatal Infection; Phagocytes; Pharmacology; Play; Potassium Channel; Premature Birth; Proteins; RNA; Role; Signal Transduction; Stroke; Survivors; Tamoxifen; Testing; Translations; Tumor Cell Line; Validation; Voltage-Gated Potassium Channel; brain cell; comparative efficacy; design; immune activation; inhibitor/antagonist; insight; interest; macrophage; mitochondrial membrane; monocyte; mouse model; neonatal brain; neuroimaging; neuroinflammation; neuroprotection; neurotoxic; novel; novel therapeutic intervention; novel therapeutics; patch clamp; stroke model; therapeutic target; tool; transcriptome sequencing

Project Summary/Abstract Many survivors of premature birth and perinatal brain injury suffer from long-term neurological sequelae. These newborns urgently need early effective and safe interventions for neuroprotection. Our group is interested in the pharmacology of a voltage-gated potassium channel called Kv1.3 (KCNA3), which plays an important role in immune cell activation by modulating membrane potential to influence intracellular mechanisms such as Ca2+ signaling. Our group previously found that Kv1.3 is required for the pro-inflammatory state of microglia, and has provided evidence to support Kv1.3 as a therapeutic target for Alzheimer's disease and adult stroke. Recently we extended our study to a mouse model of neonatal lipopolysaccharides- sensitized hypoxic-ischemic brain injury (LPS-HI), in which activation of mononuclear phagocytes (MPs, which include microglia, monocytes, and macrophages) plays a key pathological role. This model replicates a major form of perinatal brain injury in which perinatal infection/inflammation sensitizes the brain to subsequent HI insult and augments brain injury. We showed that Kv1.3 knockout or selective pharmacological inhibition of Kv1.3 mitigates the LPS-HI brain injury. Surprisingly, while Kv1.3 RNA and protein levels were increased in MPs isolated from LPS-HI brains, whole-cell patch-clamp failed to detect significant plasma membrane Kv1.3 (PM-Kv1.3) channel activity on the MP cell surface. A logical inference is that an intracellular pool of Kv1.3, such as Kv1.3 in mitochondria, described in some tumor cell lines, is activated instead. Indeed, our recent data show increased mitochondrial Kv1.3 (mito-Kv1.3) in MPs isolated from LPS-HI brains. This discovery marks an important difference in MP activation mechanisms between the neonatal LPS-HI model and the adult models of stroke, Alzheimer's, and LPS injection, as in the latter the PM-Kv1.3 activity is significantly upregulated. Our hypothesis, therefore, is that pro-inflammatory activation of MPs, critical for neurotoxic actions in LPS-HI, requires Kv1.3, with a major contribution from mito-Kv1.3. To test this hypothesis, we will address three Aims. In Aim 1 we will use a targeted deletion approach to distinguish the respective contributions of Kv1.3 in residential microglia and Kv1.3 in invading monocytes. Such a determination will help understand dynamic neuroimmune mechanisms involving monocyte-microglia interactions and neuronal injury, about which little is known in neonatal brains. In view of our novel findings regarding mito-Kv1.3, in Aim 2 we will validate mito- Kv1.3 as a potential therapeutic target for LPS-HI brain injury. Pharmacological tools that are able to selectively target PM-Kv1.3 and mito-Kv1.3 will be tested for their efficacy in mitigating brain injury in the LPS- HI model. In Aim 3, we will further test the hypothesis that mito-Kv1.3, via regulating mitochondrial membrane potential, facilitates reprogramming of mitochondrial metabolic state to drive functional polarization. Our goal is to uncover the mechanistic link between mito-Kv1.3 and MP activation state, and design promising new therapeutic approaches to mitigate perinatal brain injury.

项目摘要/摘要 许多早产和围产期脑损伤的幸存者患有长期神经后遗症。 这些新生儿迫切需要早期有效，安全的干预措施才能进行神经保护。我们的小组是 对称为KV1.3（KCNA3）的电压门控钾通道的药理学感兴趣，该通道播放 通过调节膜潜能影响细胞内的重要作用 诸如CA2+信号传导之类的机制。我们的小组以前发现，促炎症需要KV1.3 小胶质细胞状态，并提供了支持KV1.3作为阿尔茨海默氏病的治疗靶点的证据 和成人中风。最近，我们将研究扩展到了新生儿脂多糖的小鼠模型 - 敏化的低氧缺血性脑损伤（LPS-HI），其中一核吞噬细胞的激活（MPS） 包括小胶质细胞，单核细胞和巨噬细胞）起关键的病理作用。该模型复制了一个专业 围产期脑损伤的形式，其中围产期感染/炎症使大脑对随后的HI敏感 侮辱和增加脑损伤。我们表明KV1.3基因敲除或选择性药理抑制 KV1.3减轻LPS-HI脑损伤。令人惊讶的是，虽然KV1.3 RNA和蛋白质水平升高 从LPS-HI大脑中分离出的MPS，全细胞斑块钳未能检测到明显的质膜KV1.3 （PM-KV1.3）在MP细胞表面上通道活性。逻辑推断是一个kv1.3的细胞内池 例如，在某些肿瘤细胞系中描述的线粒体中的KV1.3被激活。确实，我们最近的数据 显示从LPS-HI大脑分离的MPS中的线粒体KV1.3（Mito-Kv1.3）增加。这个发现标志着 新生儿LPS-HI模型与成人模型之间的MP激活机制的重要差异 中风，阿尔茨海默氏症和LPS注射，如后者，PM-KV1.3活性显着上调。我们的 因此，假设是MPS的促炎激活，对于LPS-HI中的神经毒性作用至关重要， 需要KV1.3，并从MITO-KV1.3做出重大贡献。为了检验这一假设，我们将解决三个目标。 在AIM 1中，我们将使用目标删除方法来区分KV1.3的各自贡献 入侵单核细胞中的住宅小胶质细胞和KV1.3。这样的决心将有助于理解动态 神经免疫机制涉及单核细胞 - 神细胞相互作用和神经元损伤，几乎没有 在新生儿大脑中已知。鉴于我们有关MITO-KV1.3的新发现，在AIM 2中，我们将验证Mito- KV1.3是LPS-HI脑损伤的潜在治疗靶标。能够 有选择地靶向PM-KV1.3和MITO-KV1.3，将测试它们在减轻LPS-的脑损伤方面的功效 嗨，型号。在AIM 3中，我们将进一步检验通过调节线粒体膜的Mito-Kv1.3的假设 潜力，促进线粒体代谢状态的重编程以驱动功能极化。我们的目标是 揭示Mito-Kv1.3和MP激活状态之间的机械联系，并设计有希望的新 减轻围产期脑损伤的治疗方法。