MOLECULAR PATHOLOGY OF BINGE INDUCED BRAIN DAMAGE

暴食引起的脑损伤的分子病理学

• 批准号: 7552688
• 负责人: FULTON T CREWS
• 金额: $ 21.58万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7552688
• 关键词: NAD(P)H dehydrogenase; NMDA receptors; alcoholic beverage consumption; antioxidants; biological signal transduction; biomarker; brain injury; cytochrome P450; ethanol; genetically modified animals; immunocytochemistry; laboratory mouse; mitogen activated protein kinase; molecular pathology; neurons; neurotoxicology; nuclear factor kappa beta; oxidation; oxidative stress; phosphorylation; receptor expression; transcription factor; tumor necrosis factor alpha; western blottings

DESCRIPTION (provided by applicant): Alcoholics suffer from neuroticdeneration and loss of CNS function, which could occur due to hinge drinking. Studies in vivo using a 4-day animal binge model found neurodegeneration in corticolimbic areas, i.e. Binge-Induced Brain Damage (BIBD). BIBD is characterized by significant neuronal damage, long-lasting expression of markers of inflammation, and changes in behavior. Although in vitro studies have found glutamate-NMDA excitotoxicity following chronic ethanol treatment, BIBD is not blocked by glutamate-NMDA antagonists, hut BIBD is blocked by antioxidants. This proposal will investigate the role of oxidative stress in BIBD and how it alters signaling pathways involved in neuronal survival. We will also determine the contribution of multiple ethanol exposures and ethanol-induced plasma toxins to alcoholic neurodegeneration as both of these pathological states can lead to oxidative stress. Ethanol-induced plasma toxins may contribute to oxidative stress and multiple ethanol exposures may lead to cumulative stress prompting experiments to determine the contributions of these factors to alcoholic neurodegeneration. The following hypotheses will be tested. Aim 1. BIBD is related to oxidative stress. This hypothesis will be tested by measuring nitro-tyrosine, 4-hydroxynenenol and 8-hydroxyguanosine, indicators of protein, lipid and nucleic acid oxidation respectively. In addition, genes related to oxidative stress, e.g., NADPH oxidase, cytochrome P(450)2E1,TNFalpha and NFkappaB, will be studied as potential components of BIBD. Oxidative stress and TNFalpha can activate NFkappaB, which is known to induce COX-2, iNOS and MnSOD expression. We will also investigate prosurvival signaling molecules such as MAPK/ERK and CREB, which provide resistance to neurotoxic events such as oxidative stress. Preliminary studies comparing the P and NP rat strains indicate that ethanol increases MAPK/ERK activation, atrophic signaling pathway that causes prosurvival gene induction, likely as a protective response to ethanol-induced oxidative stress. MAPK/ERK activation is inversely related to BIBD, that is, P rats have greater BIBD and reduced MAPK/ERK activation compared to NP rats. Thus, a second component of this aim will be to investigate aspects of P-MAPK/ERK and P-CREB. The antioxidant butylated hydroxytoluene (BHT) pre-vents BIBD and these studies will be extended using other antioxidants. The effect of antioxidants on induction of oxidative stress markers, enzymes, and the signaling cascades mentioned above will also be determined using immunohistochemistry, EMSA, western and blot analyses. Experiments using transgenic mice strains including NFkappaB reporter gene mice, TNFalpha knockouts, CYP2E1 knockouts and PKC knockouts will test the role of these specific genes in B1BD. Aim 2. Peripheral tissue damage is involved in BIBD. Our 4-day binge elevates plasma ammonia and enzyme levels. Further, intragastric models of liver fibrosis induce CNS inflammation. Thus, models that are known to induce hepatotoxicity will be investigated for brain gene activation and neuropathology as described above. Aim 3. Repeated binge exposure will increase BIBD. Clinical studies have shown that multiple withdrawals lead to a higher incidence of seizures and correlates with memory and learning impairments. Thus, the effects of multiple episodes of alcohol exposure on BIBD, gene induction and oxidative stress will be determined. These in vivo studies will greatly increase our understanding of the factors that cause neurodegeneration in alcoholics.

描述（由申请人提供）：酗酒者会因酗酒而患有神经过敏和中枢神经系统功能丧失。使用 4 天动物暴饮暴食模型进行的体内研究发现皮质边缘区域出现神经退行性变，即暴饮暴食引起的脑损伤 (BIBD)。 BIBD 的特点是显着的神经元损伤、炎症标记物的长期表达以及行为的改变。尽管体外研究发现长期乙醇治疗后会出现谷氨酸-NMDA 兴奋性毒性，但 BIBD 不会被谷氨酸-NMDA 拮抗剂阻断，但 BIBD 会被抗氧化剂阻断。该提案将研究氧化应激在 BIBD 中的作用以及它如何改变涉及神经元存活的信号通路。我们还将确定多次乙醇暴露和乙醇诱导的血浆毒素对酒精性神经变性的影响，因为这两种病理状态都可能导致氧化应激。乙醇诱导的血浆毒素可能会导致氧化应激，多次接触乙醇可能会导致累积应激，从而促使实验确定这些因素对酒精性神经变性的影响。将检验以下假设。目标 1. BIBD 与氧化应激有关。这一假设将通过测量硝基酪氨酸、4-羟基烯醇和 8-羟基鸟苷（分别是蛋白质、脂质和核酸氧化的指标）来检验。此外，与氧化应激相关的基因，例如NADPH氧化酶、细胞色素P(450)2E1、TNFα和NFkappaB，将作为BIBD的潜在成分进行研究。氧化应激和 TNFα 可以激活 NFkappaB，已知它可以诱导 COX-2、iNOS 和 MnSOD 表达。 我们还将研究促生存信号分子，例如 MAPK/ERK 和 CREB，它们可以抵抗氧化应激等神经毒性事件。比较 P 和 NP 大鼠品系的初步研究表明，乙醇会增加 MAPK/ERK 的激活，这是导致促生存基因诱导的萎缩信号通路，可能是对乙醇诱导的氧化应激的保护性反应。 MAPK/ERK 激活与 BIBD 呈负相关，即与 NP 大鼠相比，P 大鼠的 BIBD 更大，而 MAPK/ERK 激活减少。因此，该目标的第二个组成部分是研究 P-MAPK/ERK 和 P-CREB ​​的各个方面。抗氧化剂丁基羟基甲苯 (BHT) 可预防 BIBD，这些研究将使用其他抗氧化剂进行扩展。抗氧化剂对诱导氧化应激标记物、酶和上述信号级联的影响也将通过免疫组织化学、EMSA、蛋白质印迹分析和印迹分析来确定。 使用转基因小鼠品系（包括 NFkappaB 报告基因小鼠、TNFα 敲除小鼠、CYP2E1 敲除小鼠和 PKC 敲除小鼠）进行的实验将测试这些特定基因在 B1BD 中的作用。 目标 2. BIBD 涉及周围组织损伤。我们四天的暴饮暴食会提高血浆氨和酶的水平。 此外，胃内肝纤维化模型会诱发中枢神经系统炎症。因此，如上所述，将研究已知诱导肝毒性的模型的脑基因激活和神经病理学。目标 3. 反复暴饮暴食会增加 BIBD。临床研究表明，多次戒断会导致癫痫发作的发生率更高，并与记忆和学习障碍相关。因此，将确定多次酒精暴露对 BIBD、基因诱导和氧化应激的影响。这些体内研究将极大地增加我们对导致酗酒者神经变性的因素的理解。