Ethanol induced brain injury is decreased by inhibiting TIEG2 mediated cell death

通过抑制 TIEG2 介导的细胞死亡来减少乙醇引起的脑损伤

• 批准号: 8187193
• 负责人: Xiao-Ming Ou
• 金额: $ 31.89万
• 依托单位: UNIVERSITY OF MISSISSIPPI MED CTR
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-01 至 2015-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8187193
• 关键词: Adult; Affect; Alcohol consumption; Alcohol-Induced Disorders; Alcohol-Induced Neurotoxicity; Alcohols; Antioxidants; Apoptosis; B-Lymphocytes; Biochemical; Biological Assay; Brain; Brain Injuries; Cell Death; Cell Line; Cell Nucleus; Cell Proliferation; Cells; Cessation of life; Clinic; DNA; Data; Dose; Drug Delivery Systems; Elements; Enzymes; Ethanol; Ethanol toxicity; Gel; Generations; Genes; Genetic Polymorphism; Genetic Transcription; Genetic Variation; Hippocampus (Brain); Human; Hydrogen Peroxide; Indium; Injury; Luciferases; Mediating; Mediator of activation protein; Molecular; Monoamine Oxidase B; Movement; Nerve Degeneration; Neuroblastoma; Neurons; Neurotransmitters; Nuclear Translocation; Oxidative Stress; Pathway interactions; Predisposition; Prefrontal Cortex; Prevention; Production; Promoter Regions; Proteins; Public Health; Publishing; Rattus; Reactive Oxygen Species; Reporting; Reverse Transcriptase Polymerase Chain Reaction; Risk Factors; Role; Selegiline; Signal Transduction; TdT-Mediated dUTP Nick End Labeling Assay; Testing; Therapeutic; Time; Tissues; Toxic effect; Transcription Coactivator; Transforming Growth Factor beta; Transforming Growth Factors; United States; Up-Regulation; Variant; Western Blotting; Work; alcohol effect; alcohol sensitivity; biological adaptation to stress; brain cell; brain tissue; catalase; cell growth; cell injury; chromatin immunoprecipitation; cytotoxicity; dentate gyrus; deprenyl; drinking; effective therapy; entorhinal cortex; enzyme activity; expression vector; genetic risk factor; genetic variant; human SOD2 protein; inhibitor/antagonist; innovation; monoamine; neuroprotection; neuropsychological; neurotoxicity; novel; novel therapeutic intervention; oxidation; prevent; problem drinker; protective effect; rasagiline; transcription factor; translational study; vector

DESCRIPTION (provided by applicant): It is well known that ethanol (EtOH) exposure damages brain tissue; however, the underlying mechanisms are not fully understood. Building on our recent work that the newly discovered cell death- mediator, transforming growth factor-¿-inducible early gene 2 (TIEG2) protein, is significantly increased by alcohol in human brain cells and also in adult rat brains, the objective of this innovative proposal is to further characterize the role of TIEG2 in EtOH-induced brain damage. TIEG2 is a transcription factor that inhibits cell growth, induces apoptosis, and increases the expression of monoamine oxidase B (MAO B). The enzymatic activity of MAO B generates H2O2, a major cause of reactive oxygen species (ROS) toxicity. EtOH reportedly increases the activity of MAO B, and secondarily increases the production of H2O2. Our published data show that physiologically-relevant EtOH increases the expression of the TIEG2-MAO B pathway in a neuronal cell line. Over-expression of TIEG2 enhances, whereas inhibitors of MAO B reduce EtOH-induced neuronal death. Additionally, a frequent TIEG2 gene variant (Gln62Arg, a polymorphism of TIEG2) alters the activity of TIEG2 and renders cells more sensitive to oxidative stress than the TIEG2 wild type. Therefore, we hypothesize that ethanol induces the expression of TIEG2 and its variant (the MAO B transcriptional activators). Secondly, we hypothesize that inhibitors of MAO B may provide protection against ethanol-induced brain tissue injury by reducing the TIEG2-MAO B- produced reactive oxygen species (ROS). Our Specific Aims are (1) To identify the molecular signaling components involved in ethanol-induced up-regulation of TIEG2; (2) To determine whether the TIEG2 gene variant (Gln62Arg) sensitizes cells to ethanol toxicity more than the TIEG2 wild type; (3) To determine the protective effects of MAO B inhibitors on cellular survival against ethanol-induced toxicity; and (4) To examine the protective effects of MAO B inhibitors on ethanol-induced neurotoxicity in adult rat brain tissues. The levels of TIEG2, MAO B, and cell death markers will be determined by quantitative real-time RT- PCR, Western blot and TUNEL assays, respectively. The cell proliferation rate, the production of ROS, and the neurodegeneration will also be determined. A comparison will be made among different groups: untreated controls; ethanol-treated; MAO B inhibitor-treated; and ethanol-treated accompanied with MAO B inhibitors. Our proposal will examine the potential role of a novel pathway involving TIEG2 and MAO B in EtOH- induced neurotoxicity and identifies a genetic risk factor that may confer susceptibility to ethanol-induced brain cell damage. It will also serve as the translational study for developing new antioxidant therapeutics for ethanol-induced brain tissue injury. Therefore, this proposal has the potential to greatly impact public health. PUBLIC HEALTH RELEVANCE: Approximately 10 million alcoholics in the United States suffer from mild to severe neuropsychological difficulties as a result of brain damage caused by drinking; however, no effective treatments have been developed because the pathological mechanisms by which alcohol affects the brain are unknown. Recently, we discovered that the cell death-mediator, TIEG2 protein, is significantly increased by alcohol in human brain cells. Our proposed studies will investigate (1) how alcohol can increase the expression of TIEG2; (2) whether the TIEG2 genetic variant is a risk factor that contributes to the wide range of alcohol-related brain damage; and (3) whether TIEG2 is a potential drug target to treat or prevent alcohol-induced brain cell death.

描述（由申请人提供）：众所周知，乙醇（EtOH）暴露会损害脑组织；然而，其根本机制尚未完全了解。我们最近的研究表明，酒精会显着增加人脑细胞和成年大鼠大脑中的细胞死亡介导物转化生长因子诱导早期基因 2 (TIEG2) 蛋白，这一创新提案的目的是进一步表征 TIEG2 在乙醇诱导的脑损伤中的作用。 TIEG2 是一种转录因子，可抑制细胞生长、诱导细胞凋亡并增加单胺氧化酶 B (MAO B) 的表达。 MAO B 的酶活性会产生 H2O2，这是活性氧 (ROS) 毒性的主要原因。据报道，EtOH 会增加 MAO B 的活性，其次会增加 H2O2 的产生。我们发表的数据表明，生理相关的 EtOH 会增加神经元细胞系中 TIEG2-MAO B 通路的表达。 TIEG2 的过度表达会增强乙醇诱导的神经元死亡，而 MAO B 的抑制剂会减少乙醇诱导的神经元死亡。此外，常见的 TIEG2 基因变异（Gln62Arg，TIEG2 的多态性）会改变 TIEG2 的活性，并使细胞比 TIEG2 野生型对氧化应激更加敏感。因此，我们假设乙醇诱导 TIEG2 及其变体（MAO B 转录激活剂）的表达。其次，我们假设 MAO B 抑制剂可能通过减少 TIEG2-MAO B 产生的活性氧 (ROS) 来提供针对乙醇诱导的脑组织损伤的保护。我们的具体目标是 (1) 鉴定参与乙醇诱导的 TIEG2 上调的分子信号成分； (2) 确定TIEG2基因变异体（Gln62Arg）是否比TIEG2野生型更使细胞对乙醇毒性敏感； (3) 确定 MAO B 抑制剂对细胞存活免受乙醇诱导的毒性的保护作用； (4) 检测MAO B抑制剂对成年大鼠脑组织中乙醇诱导的神经毒性的保护作用。 TIEG2、MAO B 和细胞死亡标记物的水平将分别通过定量实时 RT-PCR、Western blot 和 TUNEL 测定来确定。细胞增殖率、ROS 的产生和神经变性也将被确定。将在不同组之间进行比较：未处理的对照组；乙醇处理； MAO B 抑制剂处理；以及用MAO B 抑制剂进行乙醇处理。 我们的提案将研究涉及 TIEG2 和 MAO B 的新途径在乙醇诱导的神经毒性中的潜在作用，并确定可能导致乙醇诱导的脑细胞损伤易感性的遗传风险因素。它还将作为开发新的抗氧化疗法治疗乙醇引起的脑组织损伤的转化研究。因此，该提案有可能对公众健康产生重大影响。 公共健康相关性：美国约有 1000 万酗酒者因饮酒造成脑损伤而遭受轻度至重度神经心理困难；然而，由于酒精影响大脑的病理机制尚不清楚，因此尚未开发出有效的治疗方法。最近，我们发现酒精会显着增加人脑细胞中的细胞死亡介质TIEG2蛋白。我们提出的研究将调查（1）酒精如何增加 TIEG2 的表达； (2) TIEG2基因变异是否是导致广泛的酒精相关脑损伤的危险因素； (3) TIEG2是否是治疗或预防酒精引起的脑细胞死亡的潜在药物靶点。