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: 10329972
• 负责人: LEE-WAY JIN
• 金额: $ 42.13万
• 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/10329972
• 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; 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.

项目概要/摘要 许多早产和围产期脑损伤的幸存者患有长期的神经系统后遗症。 这些新生儿迫切需要早期有效且安全的神经保护干预措施。我们组是 对称为 Kv1.3 (KCNA3) 的电压门控钾通道的药理学感兴趣，该通道在 通过调节膜电位影响细胞内，在免疫细胞激活中发挥重要作用 Ca2+信号传导等机制。我们小组之前发现Kv1.3是促炎细胞所必需的 小胶质细胞的状态，并提供了支持 Kv1.3 作为阿尔茨海默病治疗靶点的证据 和成人中风。最近，我们将研究扩展到新生儿脂多糖小鼠模型 - 致敏性缺氧缺血性脑损伤（LPS-HI），其中单核吞噬细胞（MPs， 包括小胶质细胞、单核细胞和巨噬细胞）起着关键的病理作用。这个模型复制了一个主要的 围产期脑损伤的一种形式，其中围产期感染/炎症使大脑对随后的 HI 敏感 侮辱并加剧脑损伤。我们证明 Kv1.3 敲除或选择性药理学抑制 Kv1.3 减轻 LPS-HI 脑损伤。令人惊讶的是，虽然 Kv1.3 RNA 和蛋白质水平在 从 LPS-HI 大脑中分离出的 MP，全细胞膜片钳未能检测到显着的质膜 Kv1.3 (PM-Kv1.3) MP 细胞表面的通道活性。一个逻辑推论是 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。事实上，我们最近的数据 显示从 LPS-HI 大脑中分离的 MP 中线粒体 Kv1.3 (mito-Kv1.3) 增加。这一发现标志着 新生儿LPS-HI模型与成人模型MP激活机制存在重要差异 中风、阿尔茨海默病和 LPS 注射，因为后者 PM-Kv1.3 活性显着上调。我们的 因此，假设 MP 的促炎激活对 LPS-HI 的神经毒性作用至关重要， 需要 Kv1.3，其中 mito-Kv1.3 做出了主要贡献。为了检验这个假设，我们将实现三个目标。 在目标 1 中，我们将使用定向删除方法来区分 Kv1.3 在 入侵单核细胞中的驻留小胶质细胞和 Kv1.3。这样的确定将有助于理解动态 涉及单核细胞-小胶质细胞相互作用和神经元损伤的神经免疫机制，但对此知之甚少 在新生儿大脑中已知。鉴于我们关于 mito-Kv1.3 的新发现，在目标 2 中，我们将验证 mito- Kv1.3 作为 LPS-HI 脑损伤的潜在治疗靶点。药理学工具能够 选择性靶向 PM-Kv1.3 和 mito-Kv1.3 将测试其在 LPS 中减轻脑损伤的功效 嗨模型。在目标 3 中，我们将进一步检验 mito-Kv1.3 通过调节线粒体膜的假设 潜力，促进线粒体代谢状态的重新编程以驱动功能极化。我们的目标是 揭示 mito-Kv1.3 和 MP 激活状态之间的机制联系，并设计有前途的新产品 减轻围产期脑损伤的治疗方法。