Project description:To assess the effect of sleep deprivation on glucose metabolism and elucidate the mechanism, we established the mouse model wth C57BL/6J that is useful for the intervention on sleep deprivation associated diabetes and evaluate the liver metabolism and gene expression. Single six hours sleep deprivation induced increased hepatic glucose production assessed by pyruvate tolerance test and the hepatic triglyceride content was significantly higher in the sleep deprivation group than freely sleeping control group. Liver metabolites such as ketone bodies were increased in sleep deprivation group. Some gene expressions which associated with lipogenesis were increased.
Project description:We demonstrate that the ketogenic diet a low carbohydrate diet can induce fibrosis and NASH regardless of body weight loss compared to high-fat diet (HFD) fed mice. KD-fed mice develop severe hepatic injury, inflammation, and steatosis. In addition, KD increases IL-6-JNK signaling and aggravates diet induced-glucose intolerance and hepatic insulin resistance compared to HFD. Notably, pharmacological inhibition of IL-6 and JNK reverses KD‐induced glucose intolerance and restores insulin sensitivity.
Project description:Protein malnutrition promotes hepatic steatosis, decreases insulin-like growth factor (IGF)-I production, and retards growth. In order to identify new molecules involved in such changes, we conducted DNA microarray analysis for liver samples of rats fed isoenergetic low protein diet for 8 hours, and identified fibroblast growth factor 21 (Fgf21) as one of the most strongly up-regulated genes under conditions of acute protein malnutrition (P<0.05, FDR<0.001). In addition, amino acid deprivation from the culture media increased Fgf21 mRNA levels in rat liver-derived RL-34 cells (P<0.01). Thus, it was suggested that amino acid limitation directly increases Fgf21 expression. FGF21 is a polypeptide hormone that regulates glucose and lipid metabolism. Using transgenic mice, FGF21 has also been shown to promote a growth hormone-resistant state and suppress IGF-I. Therefore, to further determine whether the up-regulation of Fgf21 under protein malnutrition causes hepatic steatosis and growth retardation following decrease in IGF-I, we fed isoenergetic low protein diet to Fgf21-knockout (KO) mice. Fgf21-KO did not rescue growth retardation and reduced plasma IGF-I concentration of mice fed the low-protein diet. Meanwhile, Fgf21-KO mice showed greater epididymal white adipose tissue weight as well as hepatic triglyceride and cholesterol levels under protein malnutrition (P<0.05). Taken together, we showed that protein deprivation directly increases Fgf21 expression. However, growth retardation and decreased IGF-I were not mediated by increased FGF21 expression under protein malnutrition. Furthermore, up-regulated FGF21 rather appears to have a protective effect against obesity and hepatic steatosis in protein malnourished animals. Livers of rats from 2 groups (control (15P) or low-protain (5P) diet fed groups), total of 6 samples (3 replicates for each group) were analyzed.
Project description:The liver is critical for maintaining systemic energy balance during starvation. To understand the role of hepatic fatty acid β-oxidation on this process, we generated mice with a liver-specific knockout of carnitine palmitoyltransferase 2 (Cpt2L-/-), an obligate step in mitochondrial long-chain fatty acid β-oxidation. Surprisingly, Cpt2L-/- mice survived the perinatal period and a 24hr fast with sufficient blood glucose. The loss of hepatic fatty acid oxidation resulted in a significant loss in circulating ketones that remained unaltered by fasting. Fasting induced serum dyslipidemia, hepatic steatosis and adaptations in hepatic and systemic oxidative gene expression in Cpt2L-/- mice to maintain systemic energy homeostasis. Alternatively, feeding a ketogenic diet resulted in severe hepatomegaly, liver damage and death within one week with a complete absence of adipose triglyceride stores. These data show that hepatic fatty acid oxidation is not required for survival during acute food deprivation but essential for constraining adipocyte lipolysis and regulating systemic catabolism when glucose is limiting. In this dataset, we include the expression data obtained from dissected mouse liver from mice fasted for 24 hours with and without the deletion of carnitine palmitoyltransferase 2 (i.e. hepatocytes unable to beta-oxidize long chain fatty acids in mitochondria). WildType and KnockOut mice were fasted for 24 hours. Three biologic replicates were compared per class, thus six mice.
Project description:Purpose: To comprehensively identify the gene expression changes that occur after acute sleep deprivation. Method: We performed total RNA sequencing after 5hours of sleep deprivation. Results: Using total RNA-sequencing, we show that acute sleep deprivation causes dramatic gene expression changes in the mouse hippocampus. Conclusion: This study provides insight into the biological impact of acute sleep deprivation.
Project description:Protein malnutrition promotes hepatic steatosis, decreases insulin-like growth factor (IGF)-I production, and retards growth. In order to identify new molecules involved in such changes, we conducted DNA microarray analysis for liver samples of rats fed isoenergetic low protein diet for 8 hours, and identified fibroblast growth factor 21 (Fgf21) as one of the most strongly up-regulated genes under conditions of acute protein malnutrition (P<0.05, FDR<0.001). In addition, amino acid deprivation from the culture media increased Fgf21 mRNA levels in rat liver-derived RL-34 cells (P<0.01). Thus, it was suggested that amino acid limitation directly increases Fgf21 expression. FGF21 is a polypeptide hormone that regulates glucose and lipid metabolism. Using transgenic mice, FGF21 has also been shown to promote a growth hormone-resistant state and suppress IGF-I. Therefore, to further determine whether the up-regulation of Fgf21 under protein malnutrition causes hepatic steatosis and growth retardation following decrease in IGF-I, we fed isoenergetic low protein diet to Fgf21-knockout (KO) mice. Fgf21-KO did not rescue growth retardation and reduced plasma IGF-I concentration of mice fed the low-protein diet. Meanwhile, Fgf21-KO mice showed greater epididymal white adipose tissue weight as well as hepatic triglyceride and cholesterol levels under protein malnutrition (P<0.05). Taken together, we showed that protein deprivation directly increases Fgf21 expression. However, growth retardation and decreased IGF-I were not mediated by increased FGF21 expression under protein malnutrition. Furthermore, up-regulated FGF21 rather appears to have a protective effect against obesity and hepatic steatosis in protein malnourished animals.
Project description:Every day, we sleep for a third of the day. Sleep is important for cognition, brain waste clearance, metabolism, and immune responses. Homeostatic regulation of sleep is maintained by progressively rising sleep need during wakefulness, which then dissipates during sleep. The molecular mechanisms governing sleep are largely unknown. Here, we used a combination of single-cell RNA sequencing and cell-type specific proteomics to interrogate the molecular and functional underpinnings of sleep. Different cell-types in the brain regions show similar transcriptional response to sleep need whereas sleep deprivation changes overall expression indicative of altered antigen processing, synaptic transmission and cellular metabolism in brainstem, cortex and hypothalamus, respectively. Increased sleep need enhances expression of transcription factor Sox2, Mafb, and Zic1 in brainstem; Hlf, Cebpb and Sox9 in cortex, and Atf3, Fosb and Mef2c in hypothalamus. Results from cell-type proteome analysis suggest that sleep deprivation changes abundance of proteins in cortical neurons indicative of altered synaptic vesicle cycles and glucose metabolism whereas in astrocytes it alters the abundance of proteins associated with fatty acid degradation. Similarly, phosphoproteomics of each cell type demonstrates large shifts in site-specific protein phosphorylation in neurons and astrocytes of sleep deprived mice. Our results indicate that sleep deprivation regulates transcriptional, translational and post-translational responses in a cell-specific manner and advances our understanding of the cellular and molecular mechanisms that govern sleep-wake homeostasis in mammals.
Project description:Sleep loss regulates gene expression throughout the brain and impacts learning and memory. However, the molecular consequences of sleep deprivation and the ability of subsequent sleep (recovery sleep) to restore baseline gene expression remain underexplored. Our goal here is to overview transcriptional changes at the gene level in the cortex of adult male wildtype mice in response to sleep loss and recovery sleep. This dataset constitutes an integration of novel data with two publicly available RNA-seq studies and contains 3, 5, and 6 hours of sleep deprivation and 2 and 6 hours of recovery sleep time points.
Project description:Purpose: To determine the specific effects of 6 hours sleep deprivation after a learning event on the transcriptomes of microglia. Sleep deprivation can generate inflammatory responses in the neuronal environment. In turn, this inflammation increases sleep drive, leading to a rebound in sleep duration. Microglia, a type of support cell found exclusively in the brain, have previously been found to release of inflammatory signals and exhibit altered characteristics in response to sleep deprivation. Together, this suggests microglia may be partially responsible for the brain’s response to sleep deprivation through their inflammatory activity. In this study, we fully and selectively ablated microglia from the mouse brain and assessed resulting sleep, circadian, and sleep deprivation phenotypes. We find microglia are dispensable for both homeostatic sleep and circadian function and the sleep rebound response to sleep deprivation. However, we uncover a phenomenon by which microglia appear to be essential for the protection of synapses and associated memories formed during a period of sleep deprivation, further expanding the list of known functions for microglia in synaptic modulation.
Project description:Abnormalities in hepatic lipid metabolism are believed to play a critical role in the etiology of nonalcoholic steatohepatitis (NASH). Monoacylglycerol acyltransferase (MGAT) enzymes convert monoacylglycerol to diacylglycerol, which is the penultimate step in one pathway for triacylglycerol (TAG) synthesis. Hepatic expression of Mogat1, which encodes an MGAT enzyme, is increased in the livers of mice with hepatic steatosis and knocking down Mogat1 improves insulin sensitivity, but whether increased MGAT activity plays a role in the etiology of NASH is unclear. To examine the effects of knocking down Mogat1 in the liver on the development of NASH, C57BL/6 mice were placed on a diet containing high levels of trans fatty acids, fructose, and cholesterol (HTF-C diet) or a low fat control diet for 4 weeks. Mice were then injected with antisense oligonucleotides (ASO) to knockdown Mogat1 or a scrambled ASO control for 12 weeks while remaining on diet. HTF-C diet caused glucose intolerance, hepatic steatosis, and induced hepatic gene expression markers of inflammation, macrophage infiltration, and stellate cell activation. Mogat1 ASO treatment, which suppressed Mogat1 expression in liver, attenuated weight gain, improved glucose tolerance, and decreased hepatic TAG content compared to control ASO-treated mice on HTF-C chow. However, Mogat1 ASO treatment did not reduce hepatic DAG, cholesterol, or free fatty acid content, improve histologic measures of liver injury, or reduce expression of markers of stellate cell activation, liver inflammation, and injury. In conclusion, inhibition of hepatic Mogat1 in HTF-C diet-fed mice improves glucose tolerance and hepatic TAG accumulation without attenuating liver inflammation and injury. Total RNA obtained from liver of 4 control vs. 4 Mogat1 ASO treated higf-fat diet (HFD) fed mice.