Gatekeepers of Mitochondrial NAD+

线粒体 NAD 的看门人

• 批准号: 9341803
• 负责人: Xiaolu Ang Cambronne
• 金额: $ 5.71万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-30 至 2018-01-15
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9341803
• 关键词: Address; Affect; Age; Age of Onset; Aging; Binding Proteins; Bioenergetics; Biosensor; Cardiovascular Diseases; Cells; Data; Development; Disease; Disease Progression; Elderly; Enzymes; Gatekeeping; Health; Human; Human Pathology; Intervention; Learning; Link; Malignant Neoplasms; Metabolic syndrome; Metabolism; Methods; Mitochondria; Monitor; Nerve Degeneration; Neurons; Nicotinamide adenine dinucleotide; Onset of illness; Pathology; Proteins; Regulation; Sirtuins; age related; cell type; combat; early onset; in vivo; sensor

Project summary This proposal represents an opportunity to directly study in vivo how the intermediary metabolite nicotinamide adenine dinucleotide (NAD+) contributes to the onset of age-related pathologies, due to its limited local availability. NAD+ is critical for cellular metabolism and for prolonging health in old age. Decreased steady- state NAD+ levels have been linked to human pathologies such as neurodegeneration, cardiovascular disease, metabolic syndrome, and cancer. However, NAD+ concentrations are highly compartmentalized by cell type, subcellular localization, and protein-bound or free fractions. Thus, a lack of methods to directly monitor free NAD+ in cells with spatial and temporal information has hindered our learning about the relevant pools, threshold concentrations, and timing that NAD+ may undergo leading to disease onset. This precludes our ability to identify treatments or approaches to intervene before NAD+ levels are misregulated. To address this roadblock, we have developed a genetically-encodable fluorescent biosensor for free NAD+. Targeting of the sensor to subcellular compartments has revealed compartmentalization of intracellular NAD+ that is differentially coordinated in different cell types. Excitingly, the data also pointed to the existence of a putative mammalian mitochondrial NAD+ transporter. We believe the sensor can address key problems in aging with the hypothesis that misregulation of mitochondrial NAD+ is a major underlying cause of late-onset pathologies. This proposal will use the sensor to identify the proteins required for mitochondria to sustain their elevated concentrations of NAD+ and how this pool may be altered in older neurons. This has important implications for understanding cellular bioenergetics and mitochondrial health, as well as identifying new options to combat neurodegeneration. Understanding how local NAD+ levels fluctuate and may limit the function of NAD+-dependent enzymes is important to evaluate whether NAD+ regulation represents a viable treatment approach or intervention for age-related diseases.

项目概要 该提案提供了一个直接研究体内中间代谢物烟酰胺如何代谢的机会 腺嘌呤二核苷酸（NAD+）由于其有限的局部作用而导致与年龄相关的病理的发生。 可用性。 NAD+ 对于细胞代谢和延长老年健康至关重要。稳定下降- 国家 NAD+ 水平与人类疾病有关，如神经退行性疾病、心血管疾病、 代谢综合征和癌症。然而，NAD+ 浓度根据细胞类型高度划分， 亚细胞定位以及蛋白质结合或游离部分。因此，缺乏直接监控免费的方法 具有空间和时间信息的细胞中的 NAD+ 阻碍了我们对相关池的了解， NAD+ 可能导致疾病发作的阈值浓度和时间。这排除了我们 在 NAD+ 水平被错误调节之前确定治疗或干预方法的能力。 为了解决这个障碍，我们免费开发了一种可基因编码的荧光生物传感器 辅酶A+。将传感器靶向亚细胞区室揭示了细胞内的区室化 NAD+ 在不同细胞类型中的协调存在差异。令人兴奋的是，数据还表明存在 一种假定的哺乳动物线粒体 NAD+ 转运蛋白。我们相信该传感器可以解决以下领域的关键问题： 假设线粒体 NAD+ 的失调是晚发性衰老的一个主要原因 病理学。该提案将使用传感器来识别线粒体维持其功能所需的蛋白质 NAD+ 浓度升高以及该池在老年神经元中如何发生变化。这有重要的 对于理解细胞生物能量学和线粒体健康以及识别新的 对抗神经退行性疾病的选择。了解当地 NAD+ 水平如何波动并可能限制 NAD+依赖性酶的功能对于评估NAD+调节是否代表一种可行的方法非常重要 与年龄相关的疾病的治疗方法或干预。