Mechanisms of 2DGs Antiepileptic Effects

2DGs 抗癫痫作用的机制

• 批准号: 8735457
• 负责人: Paul A Rutecki
• 金额: --
• 依托单位: WM S. MIDDLETON MEMORIAL VETERANS HOSP
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2018-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8735457
• 关键词: Action Potentials; Acute; Address; Adenosine Triphosphate; Adverse drug effect; Adverse effects; Affect; Alternative Therapies; Anticonvulsants; Antiepileptic Agents; Brain; Calcium; Cells; Characteristics; Childhood; Chronic; Data; Deoxyglucose; Development; Diet; Disease; Electrodes; Epilepsy; Epileptogenesis; Fatty acid glycerol esters; Gene Expression; Generations; Glucose; Glycolysis; Glycolysis Inhibition; Health; Hippocampus (Brain); Intractable Epilepsy; Investigational Drugs; Kindling (Neurology); Long-Term Depression; Mediating; Medical; Membrane; Metabolic; Metabotropic Glutamate Receptors; Modeling; Monitor; Na(+)-K(+)-Exchanging ATPase; Neurons; Pathway interactions; Patients; Pharmaceutical Preparations; Physiologic pulse; Population; Potassium; Potassium Channel; Probability; Property; Protein Tyrosine Kinase; Proteins; Pump; Receptor Activation; Recurrence; Refractory; Seizures; Slice; Sodium; Sodium-Calcium Exchanger; Synapses; Synaptic Transmission; Testing; Transcriptional Regulation; United States National Institutes of Health; Veterans; Work; alternative treatment; analog; drug development; glucose analog; hippocampal pyramidal neuron; improved; insight; ketogenic diet; ketogentic; neuronal excitability; new therapeutic target; novel; novel strategies; postsynaptic; presynaptic; public health relevance; research study; sugar; synaptic function; voltage; voltage clamp

DESCRIPTION (provided by applicant): Epilepsy occurs in about 1% of Veteran patients and is not controlled by current anti-epileptic drugs (AEDs) in approximately one third of patients. For the third who do not have their seizures controlled and for those who find AEDs to have unacceptable side effects, new treatment approaches are needed. An alternative treatment can be metabolic and a protein and high fat diet without glucose, the ketogenic diet, can improve seizure control in those patients who do not respond to conventional AEDs. The ketogenic diet inhibits glycolysis, the breakdown of sugar, and seizure control is lost when glucose ingested. A novel alternative to the diet is to inhibit glycolysis using 2-deoxy-D-glucose (2DG), a glucose analog that interferes with the initial isomerization step in the glycolytic pathway. 2DG is being evaluated as investigational new drug and offers a new therapy option. 2DG has been shown to decrease the development of epilepsy in the kindling model as well as having acute antiepileptic effects in the 6 Hz and audiogenic stimulation models, and against chemoconvulsants in hippocampal slices. We will try to determine what effects 2DG has on neuronal excitability at a single neuron level and at the neuronal network level. By defining mechanisms of 2DG's antiepileptic properties, we expect new approaches to therapy of epilepsy will follow. 2DG also appears to have disease-modifying actions, and this proposal will study the use-dependent action of 2DG's effects. Our underlying hypothesis is that inhibition of glycolysis by 2DG results in antiepileptic effects, and we will address possible mechanisms as they relate to neuronal membrane excitability and changes in synaptic transmission. We will assess the following 2 specific aims: Aim 1: To identify changes in membrane excitability produced by 2DG treatment. We will evaluate a number of possible mechanisms of action as they relate to inhibition of glycolysis and a change in energy substrate near the membrane. This will include analysis of action potential generation which may be changed by a decrease in sodium-potassium pump, enhancement in the adenosine triphosphate (ATP) sensitive potassium channel that is activated with a decrease in ATP levels, and changes in the afterhyperpolarization that follows action potential generation. Aim 2: To assess 2DG's effect on synaptic transmission mediated by presynaptic mechanisms that alter the network excitability of the CA3 region of the hippocampus. Specifically we will see how 2DG alters the abnormal synaptic activity that occurs after prolonged activation of group I metabotropic glutamate receptor activation and produces CA3 epileptiform synchronization. We will also define changes in synaptic transmission using minimal stimulation and analysis of miniature post synaptic currents. All studies will use the CA3 region of the hippocampus which is vulnerable to epileptiform synchronization, in part related to the properties of the CA3 neurons and their recurrent excitatory synaptic network. We will assess CA3 neuron firing characteristics using sharp intracellular electrode recordings and how they change after 2DG. We will also use patch and whole-cell voltage clamp recordings to study intrinsic and postsynaptic currents. Our approach will test for specific changes in single neuron and network synaptic function that are modified by 2DG and will elucidate potential mechanisms of action for the antiepileptic effects of glycolytic inhibition. In the proposed study, we will be performing experiments that will increase neuronal activity to load neurons with DG and monitor for use-dependent effects that may explain any disease modifying features of 2DG treatment. Defining these actions will give new therapeutic targets for antiepileptic drug development as well as understanding the mechanism of 2DG's acute antiepileptic action.

描述（由申请人提供）： 大约 1% 的退伍军人患者患有癫痫，大约三分之一的患者无法通过当前的抗癫痫药物 (AED) 得到控制。对于癫痫发作未得到控制的第三者以及发现 AED 具有不可接受的副作用的人，需要新的治疗方法。另一种治疗方法可以是代谢疗法，以及不含葡萄糖的蛋白质和高脂肪饮食，即生酮饮食，可以改善对传统 AED 没有反应的患者的癫痫发作控制。生酮饮食会抑制糖酵解（糖的分解），并且当摄入葡萄糖时，癫痫发作就会失去控制。 饮食的一种新颖替代方案是使用 2-脱氧-D-葡萄糖 (2DG) 抑制糖酵解，这是一种葡萄糖类似物，可干扰初始糖酵解。 糖酵解途径中的异构化步骤。 2DG 正在被评估为研究性新药，并提供了一种新的治疗选择。 2DG 已被证明可以在点燃模型中减少癫痫的发展，并在 6 Hz 和听源刺激模型中具有急性抗癫痫作用，并在海马切片中对抗化学惊厥。我们将尝试确定 2DG 对单个神经元水平和神经元网络水平的神经元兴奋性有何影响。通过定义 2DG 抗癫痫特性的机制，我们预计将会出现新的癫痫治疗方法。 2DG 似乎也具有改善疾病的作用，该提案将研究 2DG 效果的依赖于使用的作用。我们的基本假设是，2DG 抑制糖酵解会导致抗癫痫作用，我们将探讨可能的机制，因为它们与神经元膜兴奋性和突触传递的变化有关。 我们将评估以下 2 个具体目标： 目标 1：确定 2DG 治疗产生的膜兴奋性变化。我们将评估许多可能的作用机制，因为它们与糖酵解的抑制和膜附近能量底物的变化有关。这将包括分析动作电位的产生（可能因钠钾泵的减少而改变）、三磷酸腺苷（ATP）敏感钾通道的增强（随着 ATP 水平的降低而激活）以及动作后超极化的变化潜在的一代。 目标 2：评估 2DG 对通过改变海马 CA3 区域网络兴奋性的突触前机制介导的突触传递的影响。具体来说，我们将看到 2DG 如何改变 I 类代谢型谷氨酸受体长期激活后发生的异常突触活动，并产生 CA3 癫痫样同步。我们还将使用最小的刺激和对微型突触后电流的分析来定义突触传递的变化。 所有研究都将使用海马的 CA3 区域，该区域容易受到癫痫样同步的影响，部分与 CA3 神经元的特性有关 及其循环兴奋性突触网络。我们将使用清晰的细胞内电极记录来评估 CA3 神经元放电特性以及它们在 2DG 后如何变化。我们还将使用贴片和全细胞电压钳记录来研究内在电流和突触后电流。 我们的方法将测试 2DG 修饰的单个神经元和网络突触功能的具体变化，并将阐明糖酵解抑制的抗癫痫作用的潜在作用机制。在拟议的研究中，我们将进行实验，增加神经元活性，用 DG 加载神经元，并监测使用依赖性效应，这可能解释 2DG 治疗的任何疾病改变特征。定义这些作用将为抗癫痫药物开发提供新的治疗靶点，并了解 2DG 急性抗癫痫作用的机制。