New Inactivators of GABA Aminotransferase for Epilepsy and Neuropathic Pain

用于治疗癫痫和神经性疼痛的新型 GABA 转氨酶灭活剂

• 批准号: 10647271
• 负责人: RICHARD B SILVERMAN
• 金额: $ 9.5万
• 依托单位: NORTHWESTERN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-15 至 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10647271
• 关键词: 20 year old; 4-Aminobutyrate aminotransferase; Affect; American; Blood - brain barrier anatomy; Brain; Cancer Patient; Chemotherapy-induced peripheral neuropathy; Computer Models; Convulsions; Coupled; Crystallization; Crystallography; Disease; Effectiveness; Enzymes; Epilepsy; Glutamate Decarboxylase; Glutamates; Glutamic Acid; Grant; High Pressure Liquid Chromatography; In Vitro; Maintenance; Motor Seizures; Neurons; Neurotransmitters; Pain management; Policies; Population; Productivity; Pyridoxal Phosphate; Regulation; Sedation procedure; Seizures; Spinal; Structure; Testing; Time; Training; Vendor; abuse liability; alpha ketoglutarate; analog; base; chemotherapy; design; driving force; gamma-Aminobutyric Acid; in vivo; mass spectrometer; mental state; painful neuropathy; relating to nervous system; repaired; side effect; succinic semialdehyde

Project Summary The two principal neurotransmitters involved in the regulation of brain neuronal activity are γ-aminobutyric acid (GABA), one of the most widely distributed inhibitory neurotransmitters, and L-glutamic acid, an excitatory neurotransmitter. The concentration of GABA is regulated by two pyridoxal 5'-phosphate (PLP)-dependent enzymes, L-glutamic acid decarboxylase (GAD), which catalyzes the conversion of L-glutamate to GABA, and GABA aminotransferase (GABA-AT), which degrades GABA to succinic semialdehyde and converts α- ketoglutarate to L-glutamic acid. When the concentration of GABA diminishes below a threshold level, convulsions result; raising GABA levels terminates the seizure. When epilepsy is defined broadly as any disease characterized by recurring convulsive seizures, then over 1% of the entire world population (including >3 million Americans) can be classified as having epilepsy. One approach to raise GABA levels is with a molecule that crosses the blood-brain barrier (BBB) and inhibits/inactivates GABA-AT. This effectively dampens excessive neural activity without affecting basal neuronal firing. Neuropathic pain, including chemotherapy-induced peripheral neuropathy (a problem for more than 60% of cancer patients treated with chemotherapy), affects 3- 17% of the world population. Inadequate current treatments of pain are exacerbated by adverse side effects, such as abuse liability, sedation, and altered mental status, which limit treatment utility. Two features of neuropathic pain that have been identified are reduced GABA levels and spinal GABAergic inhibitory function. The objective of this proposal is to design and evaluate new mechanism-based inactivator analogs of our previously successful GABA-AT inactivators to enhance potency and elucidate inactivation mechanisms using computer modeling and crystallography (Dr. Dali Liu does our crystal structures) as the driving force for design. New inactivators are being designed for selective GABA-AT inactivation. The effectiveness of our new molecules will be tested by my collaborator, Dr. Andrea Hohmann, for their effect on various neuropathic pains, including chemotherapy-induced peripheral neuropathy. Specific Aims 1-3 in grant R01 NS123057 describes a multitude of molecules that were proposed to synthesize for testing as inactivators of GABA-AT. Our 20-year old HPLC/mass spectrometer has been repaired multiple times and now has not functioned in over 8 months. This dramatically diminishes our productivity to synthesize new molecules, making the time to analyze and identify intermediates and products very long. Consequently, the following aim is proposed: Specific Aim 1. Purchase and installation of a new mass spectrometer coupled with high-performance liquid chromatography. A routine training/maintenance policy will be established, assisted by the vendor.

项目摘要 参与调节脑神经元活动的两种主要神经递质是γ-氨基丁酸 谷氨酸（GABA），一种分布最广泛的抑制性神经递质，和L-谷氨酸，一种兴奋性 神经传递素GABA的浓度是由两个吡哆醛5 '-磷酸（PLP）依赖性 酶，L-谷氨酸脱羧酶（GAD），其催化L-谷氨酸转化为GABA，和 GABA氨基转移酶（GABA-AT），将GABA降解为琥珀酸半醛并将α- 酮戊二酸转化为L-谷氨酸。当GABA的浓度降低到阈值水平以下时， 抽搐的结果;提高GABA水平终止癫痫发作。当癫痫被广泛定义为任何疾病时， 特征为反复惊厥发作，然后超过1%的全世界人口（包括> 300万） 美国人）可以被归类为患有癫痫。提高GABA水平的一种方法是使用一种分子， 穿过血脑屏障（BBB）并抑制/灭活GABA-AT。这有效地抑制了过度的 神经活动而不影响基础神经元放电。神经性疼痛，包括化疗引起的 周围神经病变（超过60%的接受化疗的癌症患者的问题），影响3- 占世界人口的17%。不良副作用加剧了目前对疼痛的不充分治疗， 例如滥用倾向、镇静和改变精神状态，这限制了治疗效用。的两个特征 已经确定的神经性疼痛的主要原因是GABA水平降低和脊髓GABA能抑制功能。 该提案的目的是设计和评估我们的新的基于机制的灭活类似物。 先前成功的GABA-AT灭活剂，以增强效力并阐明灭活机制， 计算机建模和晶体学（刘大力博士负责我们的晶体结构）作为设计的驱动力。 正在设计新的灭活剂用于选择性GABA-AT灭活。我们的新分子的有效性 将由我的合作者Andrea Hohmann博士测试它们对各种神经性疼痛的影响，包括 化疗引起的周围神经病变。 在授权R 01 NS 123057中的特定目的1-3描述了许多分子，这些分子被提出用于 合成用于作为GABA-AT灭活剂测试。我们20年的HPLC/质谱仪已经修复 多次，现在已经8个多月没有功能了。这大大降低了我们的生产力， 合成新的分子，使得分析和鉴定中间体和产品的时间非常长。 因此，提出了以下目标： 具体目标1.购买和安装一台配有高性能液体的新质谱仪 层析将在供应商的协助下制定常规培训/维护政策。