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.

项目摘要 该提案代表了直接研究体内中介代谢物烟酰胺的机会 腺嘌呤二核苷酸（NAD+）由于局部有限而导致与年龄相关的病理的发作 可用性。 NAD+对于细胞代谢和长期健康至关重要。稳定降低 - 状态NAD+水平与人类病理有关，例如神经退行性，心血管疾病， 代谢综合征和癌症。然而，NAD+浓度高度分隔了细胞类型， 亚细胞定位以及蛋白质结合或游离分数。因此，缺乏直接监视自由的方法 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学习， 阈值浓度和NAD+可能会导致疾病发作的时间。这排除了我们 在NAD+级别水平不受调查之前识别治疗方法或方法的能力。 为了解决这一障碍，我们免费开发了一种可遗传编码的荧光生物传感器 nad+。将传感器靶向亚细胞隔室已显示细胞内的隔室化 NAD+在不同的细胞类型中差异协调。令人兴奋的是，数据还指出了 推定的哺乳动物线粒体NAD+转运蛋白。我们相信传感器可以解决关键问题 衰老的假设是线粒体NAD+的正调是晚发的主要根本原因 病理。该建议将使用传感器来识别线粒体维持其所需的蛋白质 NAD+的浓度升高，以及如何改变较老神经元的池。这很重要 了解细胞生物能学和线粒体健康的影响，并确定新的 对抗神经退行性的选项。了解本地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+调节是否表示可行很重要 治疗方法或与年龄相关疾病的干预措施。