ROLE OF GLYCERALDEHYDE-3-PHOSPHATE DEHYDROGENASE IN DEPRESSION & ALCOHOLISM

3-磷酸甘油醛脱氢酶在抑郁症中的作用

基本信息

批准号：
7720508
负责人：
Xiao-Ming Ou
金额：
$ 2.97万
依托单位：
UNIVERSITY OF MISSISSIPPI MED CTR
依托单位国家：
美国
项目类别：
财政年份：
2008
资助国家：
美国
起止时间：
2008-07-01 至 2009-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7720508
关键词：
Affect Alcohol dependence Alcoholism Apoptosis Apoptotic Autopsy Binding Brain Cell Death Cell Line Cell Nucleus Cells Cessation of life Complex Computer Retrieval of Information on Scientific Projects Database DNA Data Depressed mood Disease Enzymes Ethanol Functional disorder Funding Genes Genetic Glutamates Glyceraldehyde-3-Phosphate Dehydrogenases Grant Growth Hydrogen Peroxide Institution Lead Major Depressive Disorder Measures Mediating Mental Depression Molecular Monoamine Oxidase B Neuroglia Neurons Neurotransmitters Nuclear Translocation Numbers Oxygen Pathogenesis Pathway interactions Prefrontal Cortex Rattus Regulation Reporting Research Research Personnel Resources Role Serotonin Serotonin Degradation Signal Transduction Small Interfering RNA Source Stress System Testing United States National Institutes of Health brain cell brain tissue insight neuron loss novel novel therapeutics problem drinker response stressor

项目摘要

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Depression and alcoholism are increasingly understood as debilitating and oftentimes fatal disorders, and co-occur more commonly than expected by chance. The molecular mechanisms contributing to observed neuronal and glial cell loss in both major depressive disorder and alcoholism remain unclear. Recent studies have focused on the apoptotic role of glyceraldehyde-3-phosphate dehydrogenase (GAPDH), a traditional glycolytic enzyme. Several groups have reported that GAPDH translocates into the cell nucleus when cells are stressed. Our preliminary data show that cell stressors or ethanol increase the expression of GAPDH in brain-derived cell lines and also increase the binding of GAPDH with early growth response-1 (Egr-1), resulting in nuclear translocation of the GAPDH/Egr-1 complex. Treatment of brain-derived cell lines with both cell stressors and ethanol increases GAPDH expression and the interaction of GAPDH/Egr-1 more than that of treatment with cell stressors or ethanol alone. Our pilot data also demonstrate that when compared to normal control subjects, GAPDH levels are more elevated in the prefrontal cortex of subjects with co-morbid depression plus alcoholism than in subjects with either depression or alcoholism alone. In the current application, we propose a novel GAPDHmediated neuronal stress pathway that may involve GAPDH binding to Egr-1. Once inside the nucleus, the GAPDHEgr-1 complex separates, Egr-1 targets the monoamine oxidase B (MAO B) gene, thus increasing the expression of MAO B. MAO B then enzymatically degrades a number of neurotransmitters, producing toxic reactive oxygen (H2O2) and resulting in neuronal cell stress which promotes cell death or apoptosis. We hypothesize that the GAPDH-Egr-1-MAO-B-mediated neuronal stress pathway contributes to the pathogenesis of depression and alcoholism and is more evident in co-morbid depression and alcoholism than in either depression or alcoholism alone. We further hypothesize that the inhibition of the GAPDH-Egr-1-MAO-Bmediated neuronal stress pathway will protect brain cells from harmful stress- and ethanol-induced effects. Our Specific Aims are: (1) to characterize the components active in the GAPDH-Egr-1-MAO-B -mediated neuronal stress pathway by measuring the apoptotic marker (fragmented DNA) and the levels of Egr-1 and MAO B (the downstream targets of GAPDH) in the prefrontal cortex from stressed or ethanol-treated rats as compared to untreated controls; (2) to examine the expression of apoptotic markers (fragmented DNA), GAPDH and its downstream targets in postmortem brain tissue from depressed alcoholic subjects as compared to depressed subjects, alcohol-dependent subjects and normal control subjects; and (3) to disrupt the GAPDH-Egr-1-MAO-B -mediated neuronal stress pathway (using the siRNA) to test the hypothesis that inhibition of GAPDH will reduce the harmful effects of cell stressors and ethanol. These studies are relevant to other CPN projects, because excessive glutamate signaling (Subproject 2) has been reported to trigger the GAPDH-mediated neuronal cell death cascade. The GAPDH-Egr-1-MAO-B pathway may contribute to this death cascade which causes brain cell loss in major depression (Subproject 1). Furthermore, GAPDH affects the genetic regulation of MAO, a key enzyme in degradation of serotonin. Thus, elucidating the GAPDH-Egr- 1-MAO-B -mediated neuronal stress/cell death pathway may provide new insights into serotonin system dysfunction (Subprojects 3 and 4), and might lead to novel therapeutic strategies for co-morbid depression and alcoholism.

该子项目是利用该技术的众多研究子项目之一资源由 NIH/NCRR 资助的中心拨款提供。子项目及研究者 (PI) 可能已从 NIH 的另一个来源获得主要资金，因此可以在其他 CRISP 条目中表示。列出的机构是中心，不一定是研究者的机构。抑郁症和酗酒越来越被认为是使人衰弱且常常致命的疾病，并且同时发生的几率比预期的偶然更大。在重度抑郁症和酗酒中观察到的神经元和神经胶质细胞损失的分子机制仍不清楚。最近的研究集中在甘油醛-3-磷酸脱氢酶（GAPDH）（一种传统的糖酵解酶）的细胞凋亡作用上。多个研究小组报告称，当细胞受到压力时，GAPDH 会易位到细胞核中。我们的初步数据表明，细胞应激源或乙醇会增加脑源性细胞系中的 GAPDH 还增加了 GAPDH 与早期生长反应 1 (Egr-1) 的结合，导致 GAPDH/Egr-1 复合物发生核转位。用细胞应激源和乙醇处理脑源性细胞系比单独用细胞应激源或乙醇处理更能增加 GAPDH 表达和 GAPDH/Egr-1 的相互作用。我们的试验数据还表明，与正常对照受试者相比，患有抑郁症和酗酒共病的受试者的前额叶皮层中的 GAPDH 水平比正常对照受试者更高。仅患有抑郁症或酗酒的受试者。在当前的应用中，我们提出了一种新的 GAPDH 介导的可能涉及 GAPDH 与 Egr-1 结合的神经元应激途径。一旦进入细胞核，GAPDHEgr-1 复合物就会分离，Egr-1 靶向单胺氧化酶 B (MAO B) 基因，从而增加 MAO B 的表达。然后 MAO B 酶促降解许多神经递质，产生有毒的活性氧 (H2O2) ）并导致神经元细胞应激，促进细胞死亡或凋亡。我们假设 GAPDH-Egr-1-MAO-B 介导的神经元应激途径有助于抑郁症和酗酒的发病机制，并且在共病抑郁症和酗酒中比单独的抑郁症或酗酒更为明显。我们进一步假设，抑制 GAPDH-Egr-1-MAO-B 介导的神经元应激途径将保护脑细胞免受应激和乙醇诱导的有害影响。我们的具体目标是：(1) 通过测量细胞凋亡标记物（片段化 DNA）以及 Egr-1 和 MAO B（与未处理的对照组相比，经应激或乙醇处理的大鼠的前额皮质中的 GAPDH 下游靶标； (2) 与抑郁受试者、酒精依赖受试者和正常对照受试者相比，检测抑郁酒精受试者死后脑组织中凋亡标志物（片段化DNA）、GAPDH及其下游靶标的表达； (3)破坏GAPDH-Egr-1-MAO-B介导的神经元应激途径（使用siRNA）以测试抑制GAPDH将减少细胞应激源和乙醇的有害影响的假设。这些研究与其他 CPN 项目相关，因为据报道过量的谷氨酸信号传导（子项目 2）会触发 GAPDH 介导的神经元细胞死亡级联。 GAPDH-Egr-1-MAO-B 通路可能会导致这种死亡级联反应，从而导致重度抑郁症中的脑细胞损失（子项目 1）。此外，GAPDH 影响 MAO 的基因调控，MAO 是血清素降解的关键酶。因此，阐明 GAPDH-Egr-1-MAO-B 介导的神经元应激/细胞死亡途径可能会为血清素系统功能障碍提供新的见解（子项目 3 和 4），并可能导致抑郁症和酗酒共病的新治疗策略。