The Effect of Sleep Deprivation and Subsequent Recovery Period on the Synaptic Proteome of Rat Cerebral Cortex

Abstract

Sleep deprivation (SD) is commonplace in the modern way of life and has a substantial social, medical, and human cost. Sleep deprivation induces cognitive impairment such as loss of executive attention, working memory decline, poor emotion regulation, increased reaction times, and higher cognitive functions are particularly vulnerable to sleep loss. Furthermore, SD is associated with obesity, diabetes, cardiovascular diseases, cancer, and a vast majority of psychiatric and neurodegenerative disorders are accompanied by sleep disturbances. Despite the widespread scientific interest in the effect of sleep loss on synaptic function, there is a lack of investigation focusing on synaptic transmission on the proteome level. In the present study, we report the effects of SD and recovery period (RP) on the cortical synaptic proteome in rats. Synaptosomes were isolated after 8 h of SD performed by gentle handling and after 16 h of RP. The purity of synaptosome fraction was validated with western blot and electron microscopy, and the protein abundance alterations were analyzed by mass spectrometry. We observed that SD and RP have a wide impact on neurotransmitter-related proteins at both the presynaptic and postsynaptic membranes. The abundance of synaptic proteins has changed to a greater extent in consequence of SD than during RP: we identified 78 proteins with altered abundance after SD and 39 proteins after the course of RP. Levels of most of the altered proteins were upregulated during SD, while RP showed the opposite tendency, and three proteins (Gabbr1, Anks1b, and Decr1) showed abundance changes with opposite direction after SD and RP. The functional cluster analysis revealed that a majority of the altered proteins is related to signal transduction and regulation, synaptic transmission and synaptic assembly, protein and ion transport, and lipid and fatty acid metabolism, while the interaction network analysis revealed several connections between the significantly altered proteins and the molecular processes of synaptic plasticity or sleep. Our proteomic data implies suppression of SNARE-mediated synaptic vesicle exocytosis and impaired endocytic processes after sleep deprivation. Both SD and RP altered GABA neurotransmission and affected protein synthesis, several regulatory processes and signaling pathways, energy homeostatic processes, and metabolic pathways.

Increased interaction between endoplasmic reticulum and mitochondria following sleep deprivation

“…Furthermore, our EM analysis did not consider other neuronal compartments such as dendrites or synapses, whose changes in structure and molecular composition have been linked to sleep and wake. Although direct evidence showing morphological changes of ER and mitochondria following sleep loss at synapses is missing, several proteomic analyses carried out in biochemical preparations enriched in synapses (synaptosomes) of sleep-deprived rats revealed that key proteins involved in protein folding, regulation of calcium homeostasis, and mitochondrial respiratory chain increased their expression after SD [ 57 ]. These data are consistent with our transcriptomic findings in forebrain homogenates.…”

Sleep and memory: The impact of sleep deprivation on transcription, translational control, and protein synthesis in the brain

“…Five hours of sleep deprivation was found to decrease in vivo protein synthesis by approximately 50% in the hippocampus (Tudor et al, 2016). In 8 hour sleep deprivation experiments with subsequent analysis of synaptic proteins in the cerebral cortex of Wistar rats, the protein abundance of 78 proteins was altered after sleep deprivation (Gulyassy et al, 2022). In contrast to what has been shown for the hippocampus, almost 70% of cortical proteins were up‐regulated by sleep deprivation including up‐regulation of metabotropic GABA receptors.…”

“…In contrast to what has been shown for the hippocampus, almost 70% of cortical proteins were up‐regulated by sleep deprivation including up‐regulation of metabotropic GABA receptors. Interestingly, these proteomic data suggested suppression of vesicle exocytosis and impaired endocytosis (Gulyassy et al, 2022). In the mouse forebrain as a whole, 6 h of sleep deprivation altered the synaptic proteome and protein abundance (Bruning et al, 2019; Noya et al, 2019).…”

Unravelling the role of adenosine A1 receptors (A1R) in toll like receptor-4 mediated neuroinflammation during sleep deprivation and recovery sleep

“…Evidence on the amelioration of SD induced synaptic plasticity de cits by A1R antagonism Sleep deprivation leads to critical cognitive de cits and hinders memory consolidation cascades by dysregulating synaptic plasticity (55,56). An interesting study of synaptic proteome analysis has shown the upregulation and downregulation of proteins involved in synaptic transmission, synaptic assembly, and other neuronal processes in the cerebral cortex of rats (57). Regulation of synaptic plasticity by adenosine via its receptors is mainly through the modulation of excitatory glutamatergic synaptic transmission (58, 59).…”