Kainate Receptors as a Target for the Anticonvulsant Perampanel

红藻氨酸受体作为抗惊厥药吡仑帕奈的靶点

• 批准号: 10452382
• 负责人: GEOFFREY T SWANSON
• 金额: $ 23.07万
• 依托单位: NORTHWESTERN UNIVERSITY AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10452382
• 关键词: AMPA Receptors; Adverse effects; Amino Acids; Analgesics; Animal Model; Animals; Anticonvulsants; Anxiety; Behavioral Assay; Binding; Binding Sites; Brain; Brain region; Chronic; Clinical; Complex; Data; Dose; Elements; Epilepsy; Equilibrium; Exploratory/Developmental Grant; Family; Functional disorder; Generations; Glutamate Receptor; Hippocampal Mossy Fibers; Hippocampus (Brain); Kainic Acid Receptors; Knockout Mice; Lead; Mediator of activation protein; Modeling; Molecular; Mus; Neurons; Outcome; Pharmaceutical Preparations; Pharmacology; Play; Population; Proteins; Receptor Activation; Receptor Inhibition; Receptor Signaling; Recombinants; Recurrence; Refractory; Resolution; Role; Seizures; Spinal Ganglia; Synapses; Testing; Therapeutic; Therapeutic Effect; Therapeutic Index; Treatment Efficacy; antagonist; cell type; experimental study; high risk; hippocampal pyramidal neuron; inhibitor; innovation; mossy fiber; neurotransmission; pain behavior; pain model; patch clamp; postsynaptic; pre-clinical; receptor; receptor sensitivity; side effect

SUMMARY Perampanel (PMP) is a third-generation anticonvulsant that acts as a noncompetitive allosteric modulator (NAM) of AMPA receptors, the ionotropic glutamate receptors (iGluRs) that serve as principle mediators of excitatory neurotransmission in the CNS. Its anticonvulsant activity is thought to result from dampening hyperexcitability in an epileptic brain through AMPA receptor inhibition. The recent structural resolution of the binding site for PMP on the GluA2 AMPA receptor subunit revealed fine details into determinants of its NAM activity but also underscored the conservation of critical binding residues in AMPA and kainate receptor (KAR) subunits, a distinct but related family of iGluRs. KARs serve a variety of functions in the CNS that are generally characterized as modulating a balance between excitation and inhibition tone. We hypothesize that PMP acts as a NAM on KARs and that this activity in part contributes to its therapeutic efficacy. Our preliminary results provide initial tentative support for this hypothesis and additionally reveal that PMP inhibition depends on the incorporation of a specific KAR subunit, GluK5, into the receptor complex. In this project, we propose to explore this observation further in three related aims. In Specific Aim 1, we will test the hypothesis that PMP is a subunit-selective noncompetitive antagonist of KARs and explore the importance of key amino acid residues in the PMP binding domains that control sensitivity of KARs to the modulator. In Specific Aim 2, we will test if PMP inhibits neuronal KARs at hippocampal mossy fiber synapses on CA3 pyramidal neurons and in dorsal root ganglion neurons. Both of these types of neuronal receptors are known to contain the GluK5 subunit. We will compare relative inhibition of receptors in wildtype and GluK5-/- mice to test the hypothesis that GluK5 forms a key substrate for PMP inhibition in the CNS. In Specific Aim 3, we will discriminate between modulatory activity on AMPA vs. kainate receptors by comparing potency of PMP in wildtype and GluK5-/- knockout mice in animal seizure, anxiety, and pain models, indications in which PMP shows efficacy. These objectives are significant because they could change our understanding of the mechanism of action of the third-generation anticonvulsant perampanel. Optimization of inhibitors that effectively discriminate between AMPA and kainate receptors could lead to a new generation of drugs with larger therapeutic indices.

概括 Perampanel（PMP）是第三代抗惊厥药，充当非竞争性变构调节剂 （NAM）AMPA受体，离子型谷氨酸受体（iGlurs），它们用作主要介体的原理介体 中枢神经系统中的兴奋性神经传递。它的抗惊厥活性被认为是由于衰减而引起的 通过AMPA受体抑制作用在癫痫大脑中过度刺激。最近的结构分辨率 PMP在GLUA2 AMPA受体亚基上的结合位点显示了其NAM的决定因素的细节 活性但也强调了AMPA和海藻酸盐受体（KAR）中关键结合残基的保护 亚基，一个独特但相关的iglurs家族。 KARS在中枢神经系统中发挥了多种功能 特征是调节激发和抑制音之间的平衡。 我们假设PMP充当KARS的NAM，这项活动部分有助于其治疗 功效。我们的初步结果为这一假设提供了初步的初步支持，并揭示了 PMP抑制取决于将特定的KAR亚基Gluk5掺入受体复合物中。在 这个项目，我们建议在三个相关目标中进一步探讨这一观察结果。在特定目标1中，我们将测试 PMP是KARS的亚单位选择性拮抗剂的假设，并探讨了重要性 PMP结合结构域中关键氨基酸残基的控制，以控制KARS对调节剂的灵敏度。在 具体目标2，我们将测试PMP是否在CA3上的海马苔藓纤维突触中抑制神经元KAR 锥体神经元和背根神经神经元中。这两种类型的神经元受体都是已知的 包含GLUK5亚基。我们将比较野生型和gluk5 - / - 小鼠中受体的相对抑制作用与测试 GLUK5构成CNS中PMP抑制的关键底物的假设。在特定的目标3中，我们将 通过比较PMP中的效力，区分AMPA与Kainate受体的调节活动 野生型和gluk5 - / - 敲除小鼠动物癫痫发作，焦虑和疼痛模型，pMP的适应症 显示功效。 这些目标很重要，因为它们可以改变我们对行动机制的理解 第三代抗惊厥药Perampanel。优化有效区分的抑制剂 AMPA和海藻酸盐受体可能导致具有较大治疗指数的新一代药物。