NAD catabolism and mitochondrial dysfunction in acute neurodegenerative disease

急性神经退行性疾病中 NAD 分解代谢和线粒体功能障碍

• 批准号: 8696791
• 负责人: TIBOR KRISTIAN
• 金额: --
• 依托单位: BALTIMORE VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-04-01 至 2015-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8696791
• 关键词: ADP-ribosyl Cyclase; Acute; Acute Brain Injuries; Address; Age; Animals; Astrocytes; Bioenergetics; Blood; Body Temperature; Brain; Brain Injuries; Catabolism; Cause of Death; Cell Culture Techniques; Cell Death; Cerebrovascular Circulation; Chronic; Clinical; Cognitive; Data; Dose; Energy Metabolism; Enzyme Inhibition; Enzymes; Failure; Feeds; Fluorescence; Functional disorder; Genes; Glucose; Goals; Grant; Heart Arrest; High Prevalence; Hydrolysis; Impairment; Injury; Ischemia; Ischemic Brain Injury; Knockout Mice; Light; Long-Term Care; Mitochondria; Monitor; NAD+ Nucleosidase; NADP; Nerve Degeneration; Neurodegenerative Disorders; Neuroglia; Neurological outcome; Neurons; Nicotinamide Mononucleotide; Nicotine; Outcome; Oxygen; Pathologic; Pathology; Pathway interactions; Permeability; Play; Population; Process; Prosencephalon; Proteins; Reaction Time; Recovery; Relative (related person); Reperfusion Therapy; Research; Risk Factors; Role; Stroke; Stroke prevention; Study Subject; Survivors; TBI treatment; Techniques; Testing; Therapeutic; Time; Tissues; Transgenic Animals; Traumatic Brain Injury; Veterans; Work; acute stroke; brain tissue; cell type; clinical application; deprivation; design; disability; improved; in vivo; innovation; knockout animal; mitochondrial dysfunction; novel; novel therapeutic intervention; prevent; protective effect; pyridine nucleotide; respiratory; riboside; therapy development; translational approach

DESCRIPTION (provided by applicant): Impairments in mitochondrial functions have been frequently implicated in ischemic brain injury associated with stroke or cardiac arrest. However, the extent to which mitochondrial dysfunction in neurons and glia contribute to neurodegeneration is unknown and the mechanisms leading to mitochondrial failure are elusive. Mitochondrial impairment can result from activation of the permeability transition pore or excessive mitochondrial fission leading to loss of matrix pyridine nucleotides (NAD+, NADP+) and consequent detrimental NAD+ catabolism. We hypothesize that the major cellular NAD-regulating enzyme CD38 can significantly contributes to intracellular NAD+ hydrolysis following an ischemic insult and that inhibition of this enzyme will dramatically ameliorate the ischemic brain injury. This notion is strongly supported by our preliminary data that suggest promising protection against ischemic brain damage by nicotinamide mononucleotide (NMN), a naturally occurring compound that inhibits CD38 NAD+ glycohydrolase and also feeds into the NAD+ salvage pathway. The primary goal of this study is to determine whether pathologic morphological changes of neuronal or astrocytic mitochondria precedes brain tissue NAD+ depletion and, whether neuronal or astrocytic activity of CD38 is a major contributor to NAD+ hydrolysis following ischemia. To address these questions we propose to: 1. Utilize our unique transgenic animals that express fluorescent marker proteins specific either to neuronal or to astrocytic mitochondria. These animals will be used to quantify mitochondrial morphometric alterations specifically in neurons or astrocytes in brain. 2. To determine the specific role of CD38 in post-insult NAD+ catabolism we will utilize a CD38-null mice. The role of CD38 in cell death of astrocytes and neurons will be examined by exposing the pure neuronal and astrocytic cell culture to oxygen/glucose deprivation and by subjecting CD38 deficient animals to transient forebrain ischemia. 3. Examine the mechanisms of NMN protection against ischemic damage. We will perform both dose-dependent and time-effect studies with NMN administration following ischemic insult. After the designated recovery period, the histological and neurological outcome will be examined. The significance of this work is that it proposes both mechanistic and translational approaches to unravel the mechanisms of neuronal and astrocytic NAD+ catabolism and determine its role in acute brain injury. Furthermore, the identification of NMN protective mechanisms will significantly impact the clinical application of NAD+ precursors as therapeutic compounds for acute brain injury as stroke and TBI or chronic neurodegenerative disease.

描述（由申请人提供）： 线粒体功能的损伤经常与中风或心脏骤停相关的缺血性脑损伤有关。然而，神经元和神经胶质中的线粒体功能障碍在多大程度上导致神经变性的原因是未知的，导致线粒体衰竭的机制难以捉摸。线粒体损伤可能是由于渗透性过渡孔的激活或线粒体裂变过多而导致的，导致基质吡啶核苷酸（NAD+，NADP+）以及随之而来的有害NAD+分解代谢的损失。我们假设主要的细胞NAD调节酶CD38可以显着导致缺血性损伤后的细胞内NAD+水解，并且对这种酶的抑制作用将极大地改善缺血性脑损伤。我们的初步数据强烈支持了这一概念，这些数据表明烟酰胺单核苷酸（NMN）有望防止缺血性脑损伤，这是一种自然存在的化合物，抑制CD38 NAD+糖含量糖水酶，也抑制了NAD+ SALVAGE途径。这项研究的主要目的是确定神经元或星形细胞线粒体的病理形态变化比脑组织NAD+耗竭以及CD38的神经元或星形细胞活性是否是缺血后NAD+水解的主要因素。为了解决这些问题，我们提出：1。利用我们独特的转基因动物，这些动物表达针对神经元或星形细胞线粒体的荧光标记蛋白。这些动物将用于量化大脑中神经元或星形胶质细胞中的线粒体形态学改变。 2。为了确定CD38在后NAD+分解代谢中的特定作用，我们将使用CD38-NULL小鼠。 CD38在星形胶质细胞和神经元细胞死亡中的作用将通过将纯神经元和星形细胞培养物暴露于氧/葡萄糖剥夺中，并通过使CD38缺乏动物以短暂的前脑缺血来检查。 3。检查NMN保护免受缺血损伤的机制。在缺血性损伤之后，我们将通过NMN给药进行剂量依赖性和时间效应研究。在指定的恢复期之后，将检查组织学和神经系统结果。这项工作的意义在于，它提出了机械和翻译方法，以揭示神经元和星形胶质细胞NAD+分解代谢的机制，并确定其在急性脑损伤中的作用。此外，NMN保护机制的鉴定将显着影响NAD+前体作为急性脑损伤的治疗化合物作为中风和TBI或慢性神经退行性疾病的临床应用。