Circadian Timekeeping, Oxidative Stress and Metabolism in ALS Models

这项提案的目标是确定昼夜节律计时的中断是否在 在肌萎缩侧索硬化症（ALS）中观察到的代谢和氧化应激改变。昼夜节律 协调新陈代谢和行为，以重复的日常环境变化，如光/暗周期和食物 空房的几乎在每个细胞上都发现了分子钟，它们创造了细胞自主的昼夜节律。一群 位于视交叉上核（SCN）的神经元将这些振荡器分布在整个大脑中 区域和整个身体。昼夜节律时间保持的丧失与细胞和系统范围的 代谢、氧化还原稳态和炎症的改变。ALS或Lou Gehrig病的特征是 脊髓、脑干和运动皮层中运动神经元的进行性退化。超出 进行性运动损伤，ALS患者遭受能量代谢的主要缺陷。此外，委员会认为， 线粒体功能障碍和增加的氧化应激已经在散发性和家族性ALS中被记录， 以及ALS动物模型。ALS-星形胶质细胞在共培养模型中诱导运动神经元死亡， 确定hSOD 1-连锁ALS-小鼠中的疾病进展。由于星形胶质细胞在控制 代谢和抗氧化防御中枢神经系统，改变昼夜调节这些 这些过程可能对神经元健康产生重大影响。我们的初步数据显示改变的生物钟基因 在两个hSOD 1连锁ALS小鼠模型中的表达以及在原发性ALS小鼠中改变时钟基因的同步性。 ALS-星形胶质细胞。昼夜节律赋予的健身优势依赖于自我自主的能力 在不同的细胞中发现的振荡器，以适当地响应相位设置线索。因此，ALS-星形胶质细胞的失败 对这些线索做出适当的反应可能会对神经元的功能和活力产生负面影响。尽管有众多 支持氧化还原代谢和昼夜节律之间强联系的例子，仍然很少 将这两个过程与神经变性相结合的直接体内实验证据。在这个探索性的 我们将把重点放在以下具体目标上：目标1。为了确定昼夜节律改变 ALS-星形胶质细胞中氧化还原稳态和抗氧化防御的计时。目标2。确定的作用 ALS小鼠模型外周同步化和昼夜节律行为中改变的时钟基因表达。 这些结果将为星形胶质细胞昼夜节律时间保持的改变提供直接的实验证据。 介导的神经毒性。此外，获得的数据将突出昼夜节律计时之间的新联系， 和运动神经元变性的关系由于昼夜节律不同步可以被挽救， 可能有助于为改变疾病的干预措施奠定基础。

The goal of this proposal is to establish whether disruption of the circadian timekeeping plays a role in the altered metabolism and oxidative stress observed in amyotrophic lateral sclerosis (ALS). The circadian rhythm coordinates metabolism and behavior to recurring daily environmental changes like light/dark cycles and food availability. Molecular clocks found on almost every cell create cell-autonomous circadian rhythms. A group of neurons located in the suprachiasmatic nucleus (SCN) synchronizes this multitude of oscillators across brain regions and the entire body. Loss of circadian timekeeping has been associated with cellular and system-wide alterations in metabolism, redox homeostasis and inflammation. ALS or Lou Gehrig's disease is characterized by the progressive degeneration of motor neurons in the spinal cord, brain stem, and motor cortex. Beyond progressive motor impairment, ALS patients suffer from major defects in energy metabolism. Moreover, mitochondrial dysfunction and increased oxidative stress have been documented in sporadic and familial ALS, as well as in ALS-animal models. ALS-astrocytes induce motor neuron death in co-culture models and actively determine disease progression in hSOD1-linked ALS-mice. Since astrocytes play a major role in the control of metabolism and antioxidant defenses in the central nervous system, altered circadian regulation of these processes could have major consequences for neuronal health. Our preliminary data show altered clock genes expression in two hSOD1-linked ALS-mouse models and altered synchronization of clock genes in primary ALS-astrocytes. The fitness advantage that circadian rhythm confers relies in the ability of the self-autonomous oscillators found in different cells to properly respond to phase-setting cues. Thus, the failure of ALS-astrocytes to properly respond to these cues can negatively impact neuronal function and viability. Despite the numerous examples in support of the strong link between redox metabolism and circadian rhythmicity, there is still sparse direct in vivo experimental evidence coupling the two processes to neurodegeneration. In this exploratory proposal we will focus on the following specific aims: Aim1. To determine the role of altered circadian timekeeping in redox homeostasis and antioxidant defenses in ALS-astrocytes. Aim2. To determine the role of altered clock genes expression in peripheral synchronization and circadian behavior in ALS-mouse models. The results will provide direct experimental evidence for a role of altered circadian timekeeping in astrocyte- mediated neurotoxicity. Moreover the data obtained will highlight a novel link between circadian timekeeping and motor neuron degeneration in ALS. Since circadian dyssynchrony can be rescued, the results obtained may contribute to lay the groundwork for disease-modifying interventions.