O-GlcNac Modulation of GABAergic Transmission

O-GlcNac 对 GABA 能传输的调节

基本信息

批准号：
10754746
负责人：
Shekinah Phillips
金额：
$ 4万
依托单位：
UNIVERSITY OF ALABAMA AT BIRMINGHAM
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-07-01 至 2025-06-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10754746
关键词：
Acute Address Affect Allopregnanolone Alzheimer&apos s Disease Anti-Anxiety Agents Anxiety Award Barbiturates Behavior Benzodiazepines Binding Biological Assay Biology Bipolar Disorder Brain Cells Chloride Channels Chronic Communication Cyclic AMP-Dependent Protein Kinases Data Depressed mood Diabetes Mellitus Diabetic mouse Disease Disease model Distant Electrophysiology (science)Endocytosis Endocytosis Induction Environment Epigenetic Process Epilepsy Equilibrium Exhibits Frequencies Functional disorder GABA Modulators Gene Expression Genes Genetic Polymorphism Genome Hippocampus Histone Code Impairment Individual Lead Ligands Link Location Long-Term Depression Major Depressive Disorder Mass Spectrum Analysis Mediating Mental Depression Metabolic Diseases Modeling Modification Mutation Neurodegenerative Disorders Neurons Phase Phosphorylation Post-Translational Protein Processing Postdoctoral Fellow Postpartum Depression Proteins Publishing Pyramidal Cells Regulation Reporting Research Research Project Grants Role Schizophrenia Serine Shapes Site Slice Steroids Synapses Syndrome Techniques Testing Therapeutic Threonine Training Transfection Transferase Western Blotting Work X-linked intellectual disability alcohol use disorder clinically relevant db/db mouse diabetic drug of abuse epigenetic regulation epigenome gamma-Aminobutyric Acid granule cell hypnotic in vivo induced pluripotent stem cell insight mouse model nervous system disorder neurodevelopment neuropsychiatric disorder neurosteroids novel patch clamp peptide O-linked N-acetylglucosamine-beta-N-acetylglucosaminidase pharmacologic positive allosteric modulator receptor receptor function restoration sedative synaptic function synaptic inhibition therapeutic development transcriptome transmission process

项目摘要

Changes in the strength of GABAergic transmission is heavily influenced by posttranslational modifications and allosteric modulators like benzodiazepines and neurosteroids. O-GlcNAcylation (O- GlcNAc) is a post- translational modification that is tightly regulated by O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), which add or remove the O-GlcNAc moiety of β–N-acetylglucosamine to Ser/Thr residues on proteins, respectively. Various neurodegenerative diseases like Alzheimer's disease (AD), and metabolic disorders like, diabetes exhibit dysregulated O-GlcNAc levels. Published reports from our lab have demonstrated that an acute increase in O-GlcNAcylation induces a long-term depression of evoked GABAAR mediated IPSCs (eIPSCs) and reduces the amplitude and frequency of spontaneous IPSC (sIPSC) in hippocampal principal cells, however the mechanism in which this occurs is unknown. Numerous studies have shown that serine phosphorylation of GABAAR can increase or decrease GABAAR currents depending on the neuron type and specific subunit. While O-GlcNAcylation modulates inhibitory GABA-gated currents, no studies have examined its interplay with serine phosphorylation on GABAergic transmission. Because the crosstalk between O-GlcNAcylation and phosphorylation affects the regulation of various proteins, the potential exists that O-OglcNAcylation and phosphorylation will interaction in the modulation of GABAAR function and the strength of inhibitory transmission. Furthermore, a potential interaction could impact how allosteric modulators effect GABAARs, since serine phosphorylation can either increase or decrease efficacy of these modulators. Studies proposed will investigate these hypotheses and will also test whether disease conditions where O- GlcNAc levels are chronically elevated lead to depressed GABAAR function that can be rescued via pharmacological inhibition of OGT. To determine O-GlcNAcylation's effect on GABAergic transmission in the presence of phosphorylation and allosteric modulators, I will use electrophysiological techniques, immunoblotting assays and mass spectrometry. Results will show whether the modulation of GABAAR function by PKA and allosteric modulators are shaped by the presence or absence of a co-occurring O- GlcNAc modification and if the restoration of O-GlcNAcylation levels in a disease models can restore the E/I balance.

GABA 能传递强度的变化很大程度上受到翻译后修饰和变构调节剂（如苯二氮卓类和神经类固醇）的影响。O-GlcNAc 修饰 (O-GlcNAc) 是一种受 O-GlcNAc 转移酶 (OGT) 和 O- 严格调节的翻译后修饰。 GlcNAcase (OGA)，添加或去除 β-N-乙酰氨基葡萄糖的 O-GlcNAc 部分各种神经退行性疾病（如阿尔茨海默氏病 (AD)）和代谢性疾病（如糖尿病）均表现出 O-GlcNAc 水平失调。我们实验室发表的报告表明，O-GlcNAc 酰化的急剧增加会导致长期抑制诱发的 GABAAR 介导的 IPSC（eIPSC）并降低海马主细胞中自发 IPSC（sIPSC）的幅度和频率，然而这种情况发生的机制大量研究表明，GABAAR 的丝氨酸磷酸化可以根据神经元类型和特定亚基增加或减少 GABAAR 电流，而 O-GlcNAc 酰化可调节抑制性 GABA 门控电流，但没有研究检验其与丝氨酸磷酸化对 GABA 能传递的相互作用。由于O-GlcNA酰化和磷酸化之间的串扰影响多种蛋白质的调节，因此O-OglcNA酰化存在潜在的可能性。此外，潜在的相互作用可能会影响变构调节剂如何影响 GABAAR，因为丝氨酸磷酸化可以增加或减少这些调节剂的功效。还将测试 O-GlcNAc 水平长期升高的疾病是否会导致 GABAAR 功能下降，并可通过 OGT 的药理学抑制来挽救。在磷酸化和变构调节剂存在的情况下，O-GlcNAc 酰化对 GABA 能传递的影响，我将使用电生理学技术、免疫印迹测定和质谱分析，结果将显示 PKA 和变构调节剂对 GABAAR 功能的调节是否取决于存在或不存在。共同发生的 O-GlcNAc 修饰以及疾病模型中 O-GlcNAc 修饰水平的恢复是否可以恢复 E/I平衡。