Sleep-deprived Mice Research Articles

PL-1: DECIPHERING THE MYSTERY OF SLEEP: TOWARD THE MOLECULAR SUBSTRATE FOR SLEEPINESS

Although sleep is a ubiquitous behavior in animal species with central nervous systems, the neurobiology of sleep remain mysterious. Our discovery of orexin, a hypothalamic neuropeptide involved in the maintenance of wakefulness, has helped reveal neural pathways in the regulation of sleep/wakefulness. Orexin receptor antagonists, which specifically block the endogenous waking system, have been approved as a new drug to treat insomnia. Also, since the sleep disorder narcolepsy-cataplexy is caused by orexin deficiency, orexin receptor agonists are expected to provide mechanistic therapy for narcolepsy; they will likely be also useful for treating excessive sleepiness due to other etiologies. Despite the fact that the executive neurocircuitry and neurochemistry for sleep/wake switching has been increasingly revealed in recent years, the mechanism for homeostatic regulation of sleep, as well as the neural substrate for “sleepiness” (sleep need), remains unknown. To crack open this black box, we have initiated a large-scale forward genetic screen of sleep/wake phenotype in mice based on true somnographic (EEG/EMG) measurements. We have so far screened > 10,000 heterozygous ENU-mutagenized founders and established a number of pedigrees exhibiting heritable and specific sleep/wake abnormalities. By combining linkage analysis and the next-generation whole exome sequencing, we have molecularly identified and verified the causal mutations in several of these pedigrees. Biochemical and neurophysiological analyses of these mutations are underway. Indeed, through a systematic cross-comparison of the Sleepy mutants (with a gain-of-function change in a serine/threonine kinase pathway) and sleep-deprived mice, we have found that the cumulative phosphorylation state of a specific set of mostly synaptic proteins may be the molecular substrate of sleep need.

NLRP3 upregulation related to sleep deprivation-induced memory and emotional behavior changes in TRPV1-/- mice

Sleep deprivation, which is a common problem in modern society, impairs memory function and emotional behavior. TRPV1, a subfamily of transient receptor potential cation channels, is abundantly expressed in the central nervous system and is associated with animal behavior. In this article, we report that TRPV1 deficiency in mice alleviates sleep deprivation-induced abnormal behaviors. We found that in the sleep-deprived mice, TRPV1 knockout increased the duration and visits in the central area in the open field task and increased visits to the open arms in the elevated plus maze. The TRPV1-/- mice performed better during the test stage in the Morris water maze phase after sleep deprivation. In the mPFC and hippocampus regions, western blotting results showed that TRPV1-/- attenuated sleep deprivation-induced increases in GFAP, NLRP3, and ASC and increased the expression of the mitochondrial marker Tom20. Immunofluorescence results showed that the action of TRPV1 knockout on NLRP3 was negatively correlated with Tom20 after sleep deprivation. Our results confirm that TRPV1 knockout attenuates sleep deprivation-induced behavioral disorders. The effect of TRPV1 on the behavior of sleep-deprived mice may be related to the neuroinflammation associated with mitochondria in the mPFC and hippocampus.

Butyrate Ameliorates Insufficient Sleep-Induced Intestinal Mucosal Damage in Humans and Mice.

Insufficient sleep is a key factor in the occurrence of intestinal diseases. This study was performed to clarify how sleep deficiency mediates the intestinal microbiota, metabolite butyrate disturbance induces intestinal mucosal damage, and butyrate ameliorates it. A questionnaire was launched for sleep and intestinal health issues. Twenty-two healthy volunteers were interviewed, and the influence of insufficient sleep on the gut microbiota and metabolite composition was explored. Moreover, a 72-h sleep deprivation (SD) mouse model with or without butyrate supplementation was used to reveal the effect of butyrate on ameliorating small intestines damage caused by SD. The questionnaire survey of 534 college students showed that among 85.39% of the students who slept less than 7 h, 41.76% were suffering from various bowel disorders. High-throughput 16S rRNA pyrosequencing demonstrated that SD and sleep restriction (SR) resulted in downregulation of Faecalibacterium and butyrate abundance in the feces of college students. Furthermore, we observed that butyrate supplementation markedly reversed sleep-deprivation-induced small intestinal mucosal injury in mice. Meanwhile, butyrate supplementation inverted the SD-caused inflammation response and oxidative stress and the decline of phospho-glycogen synthase kinase 3β (p-GSK-3β), β-catenin, Nrf2, and cyclin D1 and the increase in histone deacetylase 3 (HDAC3) and phospho-P65 (p-P65) proteins in the small intestines. Furthermore, in vitro, the ameliorative effects of butyrate were blocked by treatment with the HDAC3 agonist ITSA-1 and the Nrf2 antagonist ML385 and mimicked by treatment with the HDAC3 antagonist RGFP966 and p-P65 antagonist PDTC. Our study revealed that SD and SR downregulated butyrate production, further causing intestinal homeostasis dysfunction via the HDAC3-p-GSK-3β-β-catenin-Nrf2-NF-κB pathway. IMPORTANCE Radical inflammatory bowel disease (IBD) induced by sleep deficiency is a serious global public health threat. Butyrate, a member of the short-chain fatty acids, exerts multiple effects on it. However, existing research focuses on injury to the colon caused by insufficient sleep, while the changes in the small intestines are often overlooked. This study focused on revealing the influence of insufficient sleep on the intestinal microbiota and its metabolites and further revealed the ameliorative effect of butyrate on sleep deprivation (SD)-induced small intestinal mucosal damage in human and mice. Our studies suggest that butyrate can be used as a probiotic to restore SD-induced IBD and contribute to a better understanding of the mechanisms that govern the beneficial effects of butyrate.

Chinese traditional formula Kaixin San suppressed ferroptosis of hippocampal neurons and cardiomyocytes in mice with paradoxical sleep deprivation

Kaixin San (KXS) is one of the most famous traditional Chinese formulas prescribed by Sun Simiao in 652 Christian era. It is composed of Panax ginseng C.A.Mey, Polygala tenuifolia, Poria cocos and Acorus calamus var. angustatus Besser. KXS is widely used for the treatment of emotion-thought disease, such as settling fright, quieting the spirit and nourishing the heart. However, whether KXS benefits hippocampal neurons and myocardial cells of mice impaired by paradoxical sleep deprivation (PSD) and its mechanism remains unclear. This study was aimed to investigate the effect of KXS on hippocampal neuron and cardiac ferroptosis in rapid-eye-movement (REM) sleep deprived mice and clarify its potential mechanism. PSD was induced by a modified multi-platform method. Morris water maze (MWM) was used to detect the ability of learning and memory. Cardiac morphological changes were assessed by hematoxylin and eosin (HE) staining. Heart rate was detected by a PowerLab multichannel physiological recorder. Serum levels of atrial natriuretic peptide (ANP) and lactate dehydrogenase (LDH) were measured with biochemical kits. Transmission electron microscopy (TEM), immunofluorescent, and Western blotting analysis were used to observe the process and pathway of ferrotosis in hippocampus tissue and heart tissue of PSD mice. KXS administration improved the impaired learning and memory of PSD mice. It prevented the damage of mitochondria in the hippocampus and heart of PSD mice. KXS also alleviated the myocardial injury, such as morphological damage, abnormal heart rate, serum ANP, and serum LDH induced by PSD. Further study disclosed that KXS reversed the expressions of proteins involved in ferroptosis such as TFRC, SLC7A11/xCT, GPX-4, ACSL4, and FTH1 in hippocampus and heart tissues. KXS improved learning and memory of mice with REM sleep deprivation, which was closely associated with suppressed ferroptosis in hippocampal neurons and myocardiocytes.

8-O-acetyl shanzhiside methylester protects against sleep deprivation-induced cognitive deficits and anxiety-like behaviors by regulating NLRP3 and Nrf2 pathways in mice.

Sleep deprivation (SD) is prevalent throughout the world, which has negative effects on cognitive abilities, and causing mood alterations. 8-O-acetyl shanzhiside methylester (8-OaS), a chief component in Lamiophlomis rotata (L. rotata) Kudo, possesses potent neuroprotective properties and analgesic effects. Here, we evaluated the alleviative effects of 8-OaS on memory impairment and anxiety in mice subjected to SD (for 72-h). Our results demonstrated that 8-OaS (0.2, 2, 20mg/kg) administration dose-dependently ameliorated behavioral abnormalities in SD mice, accompanied with restored synaptic plasticity and reduced shrinkage and loss of hippocampal neurons. 8-OaS reduced the inflammatory response and oxidative stress injury in hippocampus caused by SD, which may be related to inhibition of NLRP3 inflammasome-mediated inflammatory process and activation of the Nrf2/HO-1 pathway. SD also led to increases in the expressions of TLR-4/MyD88, active NF-κB, pro-IL-1β, TNFα and MDA, as well as a decrease in the level of SOD in mice hippocampus, which were reversed by 8-OaS administration. Moreover, our molecular docking analyses showed that 8-OaS also has good affinity for NLRP3 and Nrf2 signaling pathways. These results suggested that 8-OaS could be used as a novel herbal medicine for the treatment of sleep loss and for use as a structural base for developing new drugs.

Caffeine combined with taurine improves cognitive function and locomotor performance in sleep-deprived mice

• Caffeine and taurine (C&T) synergistically relieve sleep-deprived (SD) fatigue. • C&T improve SD-induced cognition deficits and locomotor imbalance. • C&T act as multiple roles in the actions against both central and physical fatigue. • Anti-fatigue effect of C&T is closely related to oxidative stress, inflammatory factors. Sleep deprivation negatively influences cognitive function and locomotor performance. In this study, a sleep-deprived mice model was used to evaluate the protective effects of caffeine combined with taurine (C&T, 4.35, 8.70, 13.05 g/kg) on fatigue and the underlying mechanisms, showing that a high concentration of combined caffeine and taurine significantly increased the movement speed in the open field by 47 % (3.69 vs 5.42 cm/s, P < 0.05) and in the Y maze (3.31 vs 6.40 cm/s, P < 0.01). Combined caffeine and taurine improved the cognitive deficits and locomotor imbalance caused by sleep deprivation. Additionally, after weight-loaded swimming test, the caffeine and taurine-treated mice had increased glycogen content and antioxidant enzyme activity and significantly reduced serum inflammatory factors indicating that the mechanism may involve reducing oxidative stress and inflammation. In conclusion, combined caffeine and taurine may be a potential treatment for preventing and improving fatigue.

A strategy for screening and identification of new amino acid-conjugated bile acids with high coverage by liquid chromatography-mass spectrometry

Bile acids (BAs) are a class of vital gut microbiota-host cometabolites, and they play an important role in maintaining gut microbiota-host metabolic homeostasis. Very recently, a new mechanism of BA anabolic metabolism mediated by gut microbiota (BA-amino acid conjugation) has been revealed, which provides a perspective for the research on BA metabolism and gut metabolome. In this study, we established a polarity-switching multiple reaction monitoring mass spectrometry-based screening method to mine amino acid-conjugated bile acids (AA-BAs) derived from host-gut microbiota co-metabolism. In addition, a retention time-based annotation strategy was further proposed to identify the AA-BA isomers and epimers. Using the developed methods, we successfully screened 118 AA-BA conjugates from mouse and human feces, 28 of them were confirmed by standards, and 62 putatively identified based on their predicted retention times. Moreover, we observed that the levels of most AA-BAs were significantly downregulated in the feces of chronic sleep deprivation mice, suggesting that the AA-BA metabolism was closely related to the physiological state of the host.

Intestinal dysbiosis mediates cognitive impairment via the intestine and brain NLRP3 inflammasome activation in chronic sleep deprivation

Growing evidence suggests the involvement of the microbiota-gut-brain axis in cognitive impairment induced by sleep deprivation (SD), however how the microbiota-gut-brain axis work remains elusive. Here, we discovered that chronic SD induced intestinal dysbiosis, activated NLRP3 inflammasome in the colon and brain, destructed intestinal/blood–brain barrier, and impaired cognitive function in mice. Transplantation of “SD microbiota” could almost mimic the pathological and behavioral changes caused by chronic SD. Furthermore, all the behavioral and pathological abnormalities were practically reversed in chronic sleep-deprived NLRP3-/- mice. Regional knockdown NLRP3 expression in the gut and hippocampus, respectively. We observed that down-regulation of NLRP3 in the hippocampus inhibited neuroinflammation, and ameliorated synaptic dysfunction and cognitive impairment induced by chronic SD. More intriguingly, the down-regulation of NLRP3 in the gut protected the intestinal barrier, attenuated the levels of peripheral inflammatory factors, down-regulated the expression of NLRP3 in the brain, and improved cognitive function in chronic SD mice. Our results identified gut microbiota as a driver in chronic SD and highlighted the NLRP3 inflammasome as a key regulator within the microbiota-gut-brain axis.

The Impact of Sleep Disturbance on Gut Microbiota, Atrial Substrate, and Atrial Fibrillation Inducibility in Mice: A Multi-Omics Analysis.

This study examined the effect of sleep disturbance on gut microbiota (GM), atrial substrate, and atrial fibrillation (AF) inducibility. C57BL/6 mice were subjected to six weeks of sleep deprivation (SD) using the method of modified multiple-platform. Transesophageal burst pacing was performed to evaluate AF inducibility. Feces, plasma, and an atrium were collected and analyzed by 16s rRNA sequencing, liquid chromatography-mass spectrometry (LC-MS)-based metabolome, histological studies, and transcriptome. Higher AF inducibility (2/30 of control vs. 15/30 of SD, p = 0.001) and longer AF duration (p &lt; 0.001), concomitant with aggravated fibrosis, collagen, and lipid accumulation, were seen in the SD mice compared to control mice. Meanwhile, elevated alpha diversity, higher abundance of Flavonifractor, Ruminococcus, and Alloprevotella, as well as imbalanced functional pathways, were observed in the gut of SD mice. Moreover, the global patterns for the plasma metabolome were altered, e.g., the decreased butanoate metabolism intermediates in SD mice. In addition, disrupted metabolic homeostasis in the SD atrium, such as fatty acid metabolism, was analyzed by the transcriptome. These results demonstrated that the crosstalk between GM and atrial metabolism might be a promising target for SD-mediated AF susceptibility.

Modulation effect of low-intensity transcranial ultrasound stimulation on REM and NREM sleep.

Previous studies have shown that modulating neural activity can affect rapid eye movement (REM) and non-rapid eye movement (NREM) sleep. Low-intensity transcranial ultrasound stimulation (TUS) can effectively modulate neural activity. However, the modulation effect of TUS on REM and NREM sleep is still unclear. In this study, we used ultrasound to stimulate motor cortex and hippocampus, respectively, and found the following: (i) In healthy mice, TUS increased the NREM sleep ratio and decreased the REM sleep ratio, and altered the relative power and sample entropy of the delta band and spindle in NREM sleep and that of the theta and gamma bands in REM sleep. (ii) In sleep-deprived mice, TUS decreased the ratio of REM sleep or the relative power of the theta band during REM sleep. (iii) In sleep-disordered Alzheimer's disease (AD) mice, TUS increased the total sleep time and the ratio of NREM sleep and modulated the relative power and the sample entropy of the delta and spindle bands during NREM and that of the theta band during REM sleep. These results demonstrated that TUS can effectively modulate REM and NREM sleep and that modulation effect depends on the sleep state of the samples, and can improve sleep in sleep-disordered AD mice.

Peptide WCPFSRSF alleviates sleep deprivation-induced memory impairment by inhibiting neuroinflammation and modulating IL-6/JAK/STAT signaling pathway

Our previous study revealed that Trp-Cys-Pro-Phe-Ser-Arg-Ser-Phe (WCPFSRSF) exerted memory-improving ability in sleep-deprived mice; however, the underlying regulatory network was still unclear. The purpose of this study was to evaluate the effects of WCPFSRSF in sleep-deprived mice and to clarify the main regulatory networks. Our results showed that WCPFSRSF ameliorated the abnormal morphology of neurons and loss of neurons in hippocampus of sleep-deprived mice. Furthermore, WCPFSRSF inhibited oxidative stress via enhancing the activities of antioxidant enzymes, reducing MDA levels and activating the Nrf2 pathway. Transcriptome analysis showed that WCPFSRSF mainly regulated inflammation-related pathways, such as IL-17, TNF and JAK/STAT pathways. Further analysis showed that WCPFSRSF reduced the release of pro-inflammatory cytokines and the expression of microglia marker Iba-1 and astrocyte marker GFAP, thereby inhibiting neuroinflammation. Western Blotting analysis showed that WCPFSRSF regulated the IL-6/JAK/STAT pathway. In addition, WCPFSRSF and its in silico gastrointestinal digested fragments WCP and FSR were potential JAK2/STAT3 inhibitors. WCPFSRSF and WCP could reduce the NO levels in LPS-treated BV-2 cells. Collectively, our results indicated that WCPFSRSF improved memory impairment induced by sleep deprivation through inhibiting glial cell activation and neuroinflammation.

Quantitative and site-specific detection of inosine modification in RNA by acrylonitrile labeling-mediated elongation stalling

RNA molecules contain diverse modifications that play crucial roles in a wide variety of biological processes. Inosine is one of the most prevalent modifications in RNA and dysregulation of inosine is correlated with many human diseases. Herein, we established an acrylonitrile labeling-mediated elongation stalling (ALES) method for quantitative and site-specific detection of inosine in RNA from biological samples. In ALES method, inosine is selectively cyanoethylated with acrylonitrile to form N1-cyanoethylinosine (ce1I) through a Michael addition reaction. The N1-cyanoethyl group of ce1I compromises the hydrogen bond between ce1I and other nucleobases, leading to the stalling of reverse transcription at original inosine site. This specific property of stalling at inosine site could be evaluated by subsequent real-time quantitative PCR (qPCR). With the proposed ALES method, we found the significantly increased level of inosine at position Chr1:63117284 of Ino80dos RNA of multiple tissues from sleep-deprived mice compared to the control mice. This is the first report on the investigation of inosine modification in sleep-deprived mice, which may open up new direction for deciphering insomnia from RNA modifications. In addition, we found the decreased level of inosine at GluA2 Q/R site (Chr4:157336723) in glioma tissues, indicating the decreased level of inosine at GluA2 Q/R site may serve as potential indicator for the diagnosis of glioma. Taken together, the proposed ALES method is capable of quantitative and site-specific detection of inosine in RNA, which provides a valuable tool to uncover the functions of inosine in human diseases.

The effects of citalopram, SB-334867 and orexin-1, alone or in various combinations, on the anxiogenic-like effects of REM sleep deprivation in male mice.

Sleep deprivation may induce anxiety. On the other hand, anxiety disorders elicit main changes in the quality of sleep. Moreover, orexin and citalopram play a role in the modulation of insomnia and mood diseases. Thus, we planned preclinical research to evaluate the effect of combinations of orexin agents and citalopram on anxiety behavior in rapid eye movement (REM) sleep-deprived mice. For drug intracerebroventricular (i.c.v.) infusion, the guide cannula was surgically implanted in the left lateral ventricle of mice. REM sleep deprivation was conducted via water tank apparatus for 24 h. The anxiety behavior of mice was evaluated using the elevated plus maze (EPM). Our results revealed that REM sleep deprivation reduced the percentage of open arm time (%OAT) and the percentage of the open arm entries (%OAE) but not closed arm entries (locomotor activity) in the EPM test, presenting an anxiogenic response ( P < 0.05). We found a sub-threshold dose of SB-334867, orexin-1 receptor antagonist, and orexin-1 which did not alter anxiety reaction in the REM sleep-deprived mice ( P > 0.05). Intraperitoneal (i.p.) injections of citalopram (5 and 10 mg/kg) increased both %OAT and %OAE ( P < 0.001) representing an anxiolytic effect, but not locomotor activity in the REM sleep-deprived mice. Interestingly, co-treatment of citalopram (1, 5 and 10 mg/kg; i.p.) and SB-334867 (0.1 µg/mouse; i.c.v.) potentiated the anxiolytic effect in the REM sleep-deprived mice. On the other hand, co-treatment of different dosages of citalopram along with a sub-threshold dose of orexin-1 did not alter %OAT, %OAE, and locomotor activity in the REM sleep-deprived mice. We found a synergistic anxiolytic effect of citalopram and SB-334867 in the REM sleep-deprived mice. These results suggested an interaction between citalopram and SB-334867 to prevent anxiogenic behavior in the REM sleep-deprived mice.

Activation of dopamine D2 receptors attenuates neuroinflammation and ameliorates the memory impairment induced by rapid eye movement sleep deprivation in a murine model.

The proinflammatory state, which may be induced by sleep deprivation, seems to be a determining factor in the development of neurodegenerative processes. Investigations of mechanisms that help to mitigate the inflammatory effects of sleep disorders are important. A new proposal involves the neurotransmitter dopamine, which may modulate the progression of the immune response by activating receptors expressed on immune cells. This study aimed to determine whether dopamine D2 receptor (D2DR) activation attenuates the proinflammatory response derived from rapid eye movement (REM) sleep deprivation in mice. REM sleep deprivation (RSD) was induced in 2-month-old male CD1 mice using the multiple platform model for three consecutive days; during this period, the D2DR receptor agonist quinpirole (QUIN) was administered (2 mg/kg/day i.p.). Proinflammatory cytokine levels were assessed in serum and homogenates of the brain cortex, hippocampus, and striatum using ELISAs. Long-term memory deficits were identified using the Morris water maze (MWM) and novel object recognition (NOR) tests. Animals were trained until learning criteria were achieved; then, they were subjected to RSD and treated with QUIN for 3 days. Memory evocation was determined afterward. Moreover, we found RSD induced anhedonia, as measured by the sucrose consumption test, which is commonly related to the dopaminergic system. Our data revealed increased levels of proinflammatory cytokines (TNFα and IL-1β) in both the hippocampus and serum from RSD mice. However, QUIN attenuated the increased levels of these cytokines. Furthermore, RSD caused a long-term memory evocation deficit in both the MWM and NOR tests. In contrast, QUIN coadministration during the RSD period significantly improved the performance of the animals. On the other hand, QUIN prevented the anhedonic condition induced by RSD. Based on our results, D2DR receptor activation protects against memory impairment induced by disturbed REM sleep by inhibiting neuroinflammation.

Melatonin protects against body weight gain induced by sleep deprivation in mice

Sleep deprivation is an epidemic phenomenon in modern society. Lack of sleep has been shown to result in metabolic and endocrine disorders that predispose to obesity and other chronic metabolic diseases. Melatonin is a sleep-related neurohormone and affected by the circadian rhythm and light/dark cycles. Melatonin has recently been used to ameliorate diet-induced or night light-induced energy metabolic imbalance. However, the effect of melatonin on sleep deprivation-induced obesity has been poorly characterized. This study focuses on the protective effects of melatonin on lipid metabolism and body weight homeostasis in sleep-deprived mice. Mice subjected to sleep deprivation had significantly decreased plasma melatonin content and increased food intake and body weight gain compared to that of control. Meanwhile, the transcription factor PPARγ protein in liver increased, but there were no significant changes in hepatic circadian proteins BMAL1 and REV-ERBα after 10 consecutive days of sleep deprivation. Moreover, melatonin supplementation increased liver AMPKα/PPARα signaling pathway activity, which leads to lipid catabolism and reduced fat accumulation. These findings suggested that melatonin may be a potential agent for protecting against sleep deprivation-induced obesity.

Pretreatment of the ROS Inhibitor Phenyl-N-tert-butylnitrone Alleviates Sleep Deprivation-Induced Hyperalgesia by Suppressing Microglia Activation and NLRP3 Inflammasome Activity in the Spinal Dorsal Cord

Sleep deprivation, a common perioperative period health problem, causes ocular discomfort and affects postsurgical pain. However, the mechanism of sleep deprivation-induced increased pain sensitivity is elusive. This study aims to explore the role of ROS in sleep deprivation (SD)-induced hyperalgesia and the underlying mechanism. A 48-h continuous SD was performed prior to the hind paw incision pain modeling in mice. We measured ROS levels, microglial activation, DNA damage and protein levels of iNOS, NLRP3, p-P65 and P65 in mouse spinal dorsal cord. The involvement of ROS in SD-induced prolongation of postsurgical pain was further confirmed by intrathecal injection of ROS inhibitor, phenyl-N-tert-butylnitrone (PBN). Pretreatment of 48-h SD in mice significantly prolonged postsurgical pain recovery, manifesting as lowered paw withdrawal mechanical threshold and paw withdrawal thermal latency. It caused ROS increase and upregulation of iNOS on both Day 1 and 7 in mouse spinal dorsal cord. In addition, upregulation of NLRP3 and p-P65, microglial activation and DNA damage were observed in mice pretreated with 48-h SD prior to the incision. Notably, intrathecal injection of PBN significantly reversed the harmful effects of SD on postsurgical pain recovery, hyperalgesia, microglial activation and DNA damage via the NF-κB signaling pathway. Collectively, ROS increase is responsible for SD-induced hyperalgesia through activating microglial, triggering DNA damage and enhancing NLRP3 inflammasome activity in the spinal dorsal cord.

Exercise modifies lipid and glucose metabolism alterations induced by sleep deprivation in mice.

Insufficient sleep compromises lipid/glucose homeostasis. In opposition, exercise increases energy expenditure and has positive effects on glucose and fatty acid metabolism. Presently, it is hypothesized that exercise ameliorates metabolic dysfunction associated with sleep deprivation (SD). The effects of exercise (EX), SD and EX before SD. (EX+SD) on lipid and glucose metabolism were evaluated. Swiss mice were assigned to 4 groups (N=12, each) control, exercise (EX, 8 weeks, 1-hour of treadmill/9cm/s, 5x/week, from noon to 1:00 p.m.), SD (SD-72h, multiple platforms method), and exercise before SD (EX+SD). Exercise increased blood glucose, lactate and triglycerides (p<0.05). Both, SD and EX+SD reduced blood triglycerides (p<0.05). EX increased VLDL and reduced LDL; conversely, SD and EX+SD reduced VLDL and increased LDL. Hepatic triglycerides were markedly reduced by SD (p<0.05) and this was prevented by previous exercise (EX+SD). In summary, exercise improved essential cholesterol fractions and exercise before SD increased hepatic cholesterol and prevented hepatic triglycerides depletion.

Ketogenic diet prevents chronic sleep deprivation-induced Alzheimer's disease by inhibiting iron dyshomeostasis and promoting repair via Sirt1/Nrf2 pathway.

Sleep deprivation (SD) is one of the main risk factors for Alzheimer’s disease (AD), but the underlying mechanism is still unclear. Ketogenic diet (KD) has been shown widely neuroprotective effects but less known about its effect on SD-induced AD. In the present study, a continuous 21 days SD mouse model with or without KD was established. The changes of cognitive function, pathological hallmarks of AD, ferroptosis, and intracellular signal pathways in mice were detected by Morris water maze, ThS staining, diaminobenzidine (DAB)-enhanced Perls’ stain, antioxidant assay, immuno-histochemistry, and western blot. The results showed that KD can prevent the cognitive deficiency, amyloid deposition and hyperphosphorylated tau induced by chronic SD. Analysis of ferroptosis revealed that KD can inhibit iron dyshomeostasis by down-regulating the expression of TfR1 and DMT1 and up-regulating the expression of FTH1, FPN1. Meanwhile, KD alleviated oxidative stress with elevated xCT/GPX4 axis, FSP1 and reduced MDA. In addition, KD could promote neuronal repair by enhancing BDNF and DCX. Further studies demonstrated that KD activated Sirt1/Nrf2 signaling pathway in the hippocampus in SD-exposed mice. Our finding firstly suggested that KD could prevent chronic SD-induced AD by inhibiting ferroptosis and improving the neuronal repair ability via Sirt1/Nrf2 signaling pathway.

Isoquercetin alleviates sleep deprivation dependent hippocampal neurons damage by suppressing NLRP3-induced pyroptosis

Purpose: Sleep deprivation (SD) leads to memory and cognitive impairment due to damage to the hippocampus. Isoquercetin possesses neuron-protective properties. Our study aimed to investigate the effects of isoquercetin on SD-induced hippocampal neurons damage and the underlying mechanism. Materials and methods: Herein, the cognitive competence was evaluated by Morris water maze test after SD. The morphology of the hippocampus was observed after Nissl staining. Moreover, the level of NLRP3 was detected by Immunofluorescent staining and western blot. In vitro study, pyroptosis was tested by TUNEL assay and flow cytometry. The levels of pyroptosis-related factors were measured by western blot. Results: The results indicated that isoquercetin improved spatial memory and prevented change of hippocampal neurons of SD mice. Moreover, SD upregulated NLRP3 level, which was downregulated by isoquercetin. Additionally, isoquercetin rescued the increase of pyroptosis and the upregulation of NLRP3, caspase-1, ASC, IL-1β, IL-18, and GSDMD levels induced by LPS. Conclusions: In conclusion, isoquercetin improved learning and cognitive capability of SD mice via suppressing NLRP3-induced pyroptosis of hippocampal neurons cells, suggesting that isoquercetin might be an efficacious drug for memory disorders caused by SD.

Synergistic antidepressant effects of citalopram and SB-334867 in the REM sleep-deprived mice: Possible role of BDNF

This study was done to evaluate the effect of co-treatment of orexin agents along with citalopram on the modulation of depression-like behavior and the expression of BDNF in the prefrontal cortex (PFC) of sleep-deprived male mice. A sleep deprivation model was performed in which rapid eye movement (REM) sleep was completely prohibited, and non-REM sleep was intensely reduced for 24 h. For drug microinjection, the guide cannula was surgically fixed in the left lateral ventricle of mice. Furthermore, we used the open-field test (OFT), forced swim test (FST), tail suspension test (TST), and splash test for recording depression-like behavior as well as Real-Time PCR amplification for assessing the expression of BDNF in the PFC of REM sleep-deprived mice. Our results revealed that REM sleep deprivation did not change locomotor activity while increased depressive-like behavior in FST, TST, and splash tests. However, the expression of BDNF was decreased in the PFC. Intraperitoneally (i.p.) administration of citalopram induced antidepressant effect in the normal and REM sleep-deprived mice. Moreover, intracerebroventricular (i.c.v.) microinjection of a non-effective dose of SB-334867, an orexin antagonist, potentiated the antidepressant-like effect of citalopram.On the other hand, a non-significant dosage of orexin-1 reversed the antidepressant effect of citalopram in the normal and REM sleep-deprived animals. Furthermore, our results showed that injection of citalopram alone or with SB-334867 increased the mRNA expression level of BDNF in the PFC of REM sleep-deprived mice. These data suggest that REM sleep deprivation interferes with the neural systems underlying the depression-like process and supports a likely interaction of the orexin system with citalopram on the modulation of depression-like behavior in REM sleep-deprived mice.