Project description:<p>Chronic sleep loss profoundly impacts metabolic health and shortens lifespan, but studies of the mechanisms involved have focused largely on acute sleep deprivation. To identify metabolic consequences of chronically reduced sleep, we conducted unbiased metabolomics on heads of three adult Drosophila short-sleeping mutants with very different mechanisms of sleep loss: fumin (fmn), redeye (rye), and sleepless (sss). Common features included elevated ornithine and polyamines, with lipid, acyl-carnitine, and TCA cycle changes suggesting mitochondrial dysfunction. Studies of excretion demonstrate inefficient nitrogen elimination in adult sleep mutants, likely contributing to their polyamine accumulation. Increasing levels of polyamines, particularly putrescine, promote sleep in control flies but poison sleep mutants. This parallels the broadly enhanced toxicity of high dietary nitrogen load from protein in chronically sleep-restricted Drosophila, including both sleep mutants and flies with hyper-activated wake-promoting neurons. Together, our results implicate nitrogen stress as a novel mechanism linking chronic sleep loss to adverse health outcomes-and perhaps for linking food and sleep homeostasis at the cellular level in healthy organisms.</p>
Project description:HPLC MS/MS confirmation of lipids found to be heterogeneously distributed between rested and sleep-deprived Drosophila melanogaster brain samples by MALDI MSI. Data belongs to publication "Kv Channels Integrate Sleep Pressure in a Voltage-Gated Lipid Peroxidation Memory"
Project description:Analysis of brain of Canton-S females deprived of sleep by perturbations during their normal sleep period. Perturbation effect also assessed during their active period to control for its effect during sleep deprivation. Results suggest processes altered during prolonged wakefulness and during sleep.
Project description:This SuperSeries is composed of the following subset Series:; GSE9441: The effect of sleep deprivation on gene expression in the brain and the liver of three inbred mouse strains; GSE9442: Molecular correlates of sleep deprivation in the brain of three inbred mouse strains in an around-the-clock experiment; GSE9443: Gene expression in brain Homer1a-expressing cells after sleep deprivation Experiment Overall Design: Refer to individual Series
Project description:Micro-RNAs (miRNAs) are key, post-transcriptional regulators of gene expression that have been implicated in a plethora of biological processes. Their role in sleep, however, has received little attention. We first investigated the effects of sleep deprivation on the brain miRNA transcriptome. Sleep deprivation affected 52 miRNAs in the whole brain, and particularly miR-709, an activity-dependent microRNA, enriched in the cerebral cortex.
Project description:To gain insight into the dynamic molecular processes that are altered during prolonged wakefulness and during sleep. We performed an RNA expression profiling study examining temporal changes in the brain of Drosophila in relationship to the duration of prior sleep or wakefulness. Our experimental design allowed us to determine whether genes identified as differentially regulated between sleep and wakefulness were up- or down-regulated in these states. Because stimulation of the experimental animal during the normal sleep period is used to prolong wakefulness in most experimental paradigms, the interpretation of the effects of prolonged wakefulness is confounded by the effect of the perturbation stimulus itself on the animal’s biology. We controlled for this effect in our experimental paradigm by examining gene expression changes in response to identical stimulation but during the animal’s normal wakefulness. The design of our study also allowed us to control for circadian variation in gene expression, since we compared sleeping and sleep deprived flies at the same diurnal time. Keywords: sleep deprivation, time course, stress response
Project description:Evidence suggests that impaired synaptic and firing homeostasis represents a driving force of early Alzheimer’s disease (AD) progression. Here, we examine synaptic and sleep homeostasis in a Drosophila model by overexpressing human amyloid precursor protein (APP), whose duplication and mutations cause familial early-onset AD. We find that APP overexpression induces synaptic hyperexcitability. RNA-seq data indicate exaggerated expression of Ca2+ related signaling genes in APP mutants, including genes encoding Dmca1D, calcineurin (CaN) complex, and IP3R, but not in hyperexcitable mutants caused by TrpA1 or Shal/Kv4. We further demonstrate that increased CaN activity triggers transcriptional activation of Itpr (IP3R) through activating nuclear factor of activated T cells (NFAT). Strikingly, APP overexpression causes defects in both synaptic downscaling and sleep deprivation induced sleep rebound, and both defects could be restored by inhibiting IP3R. Our findings uncover IP3R as a shared signaling molecular in synaptic downscaling and sleep homeostasis, and its dysregulation may lead to synaptic hyperexcitability and AD progression at early stage.
Project description:To gain insight into the molecular changes of sleep need, this study addresses gene expression changes in a subpopulation of neurons selectively activated by sleep deprivation. Whole brain expression analyses after 6h sleep deprivation clearly indicate that Homer1a is the best index of sleep need, consistently in all mouse strains analyzed. Transgenic mice expressing a FLAG-tagged poly(A)-binding protein (PABP) under the control of Homer1a promoter were generated. Because PABP binds the poly(A) tails of mRNA, affinity purification of FLAG-tagged PABP proteins from whole brain lysates, is expected to co-precipitate all mRNAs from neurons expressing Homer1a. Three other activity-induced genes (Ptgs2, Jph3, and Nptx2) were identified by this technique to be over-expressed after sleep loss. All four genes play a role in recovery from glutamate-induced neuronal hyperactivity. The consistent activation of Homer1a suggests a role for sleep in intracellular calcium homeostasis for protecting and recovering from the neuronal activation imposed by wakefulness. Experiment Overall Design: Experiments were performed on male mice, 12 weeks of age +/- 1 week. Animals were housed in polycarbonate cages (31x18x18cm) in an experimental room with an ambient temperature varying from 23° to 25°C under a 12:12 hrs light/dark cycle. Food and water were available ad libitum. At light onset mice were either sleep deprived by gentle handling (n=10) or left undisturbed (n=10) for 6 hrs. Animals were then randomly sacrificed by cervical dislocation. Total RNA from the whole brain was isolated for control (n=4) and sleep deprived (n=4) using a commercial RNA extraction kit (RNeasy Lipid Tissue Kit, Quiagen). Specific Homer1a-expressing cells polyA RNAs were immunoprecipitated following the total brain crosslinking (1% formaldehyde perfusion) for sleep deprived (n=6) and control (n=6) animals. The total RNA from the pull-down supernatants were also harvested (n=4). To test for transcriptional changes after sleep deprivation Homer1a-expressing cells, we proceeded in 2 steps: (1) identify probe sets enriched in the pull-down extracts, (2) among those probe sets compare sleep deprivation to control condition in both pull-down (6 vs. 6 chip comparison) and whole-brain (4 vs. 4 chip comparison) extracts. 4728 probe sets were significantly enriched at 5% FDR when pull-downs were compared to both supernatant and whole-brain extracts.
Project description:To gain insight into the molecular changes of sleep need, this study addresses gene expression changes in a subpopulation of neurons selectively activated by sleep deprivation. Whole brain expression analyses after 6h sleep deprivation clearly indicate that Homer1a is the best index of sleep need, consistently in all mouse strains analyzed. Transgenic mice expressing a FLAG-tagged poly(A)-binding protein (PABP) under the control of Homer1a promoter were generated. Because PABP binds the poly(A) tails of mRNA, affinity purification of FLAG-tagged PABP proteins from whole brain lysates, is expected to co-precipitate all mRNAs from neurons expressing Homer1a. Three other activity-induced genes (Ptgs2, Jph3, and Nptx2) were identified by this technique to be over-expressed after sleep loss. All four genes play a role in recovery from glutamate-induced neuronal hyperactivity. The consistent activation of Homer1a suggests a role for sleep in intracellular calcium homeostasis for protecting and recovering from the neuronal activation imposed by wakefulness. Keywords: sleep deprivation, neuronal subpopulation transcriptome