Project description:This dataset comprises plasma proteomics data from 24 individuals measured at fasting and at 30, 60, 120, and 180 minutes following the intake of four distinct pure macronutrient loads (glucose, protein, butter, and olive oil).
Project description:Lipins are eukaryotic proteins with functions in lipid synthesis and the homeostatic control of energy balance. They execute these functions by acting as phosphatidate phosphatase enzymes in the cytoplasm and by changing gene expression after translocation into the cell nucleus, in particular under fasting conditions. Here, we asked how gene expression changes, under both fed and fasting conditions, when nuclear translocation of Lipin is impaired. To address this question, we created a Drosophila mutant expressing Lipin lacking a nuclear localization signal (LipinDNLS). Notably, adult LipinDNLS flies were not only viable but also exhibited improved life expectancy. In contrast, they were highly susceptible to starvation. To examine how these phenotypes correlate with changes in gene expression, we carried out an RNA-seq analysis with mRNA from female and male LipinDNLS and control flies that had been kept under fed or fasting conditions. We found that genes involved in metabolism, feeding behavior, and the immune response were mis-regulated in LipinDNLS flies. The changed expression of these genes supports hypotheses explaining improved life expectancy under fed and decreased life expectancy under fasting conditions. For instance, metabolic rate measurements confirmed the prediction based on the RNA-seq data that energy production by oxidative phosphorylation is reduced in fed LipinDNLS flies.
Project description:Short-term fasting is beneficial for the regeneration of multiple tissue types. However, the effects of fasting on muscle regeneration are largely unknown. Here we report that fasting slows muscle repair both immediately after the conclusion of fasting as well as after multiple days of refeeding. We show that ketosis, either endogenously produced during fasting or a ketogenic diet, or exogenously administered, promotes a deep quiescent state in MuSCs. Although deep quiescent MuSCs are less poised to activate, slowing muscle regeneration, they have markedly improved survival when facing sources of cellular stress. Further, we show that ketone bodies, specifically b- hydroxybutyrate, directly promote MuSC deep quiescence via a non‐metabolic mechanism. We show that b-hydroxybutyrate functions as an HDAC inhibitor within MuSCs leading to acetylation and activation of an HDAC1 target protein p53. Finally, we demonstrate that p53 activation contributes to the deep quiescence and enhanced resilience observed during fasting.
Project description:Calorie restriction (CR) improves health and longevity. CR induces a periodic fasting cycle in mammals; our study compares CR with unanticipated fasting (F), when the food is unexpectedly withheld. F induces hepatic steatosis, while CR reduces it; surprisingly, the difference is not due to hepatic β-oxidation. Liver transcriptome analysis identifies fatty acid transporters (Slc27a1 and Slc27a2), TAG synthesis (Gpat4), and lipid storage (Plin2 and Cidec) genes to be upregulated only in F in agreement with hepatic steatosis. The circadian clock and anticipated fasting contribute to preventing fasting-associate hepatic steatosis in CR. Mechanistically, Slc27a1, Plin2 and Cidec genes are upregulated, and liver TAGs accumulate in circadian clock mutant mice on CR or if wild type CR mice miss their anticipated meal. The results highlight similarities and differences between unanticipated fasting and CR, suggesting that circadian clock dependent gating of transcriptional response to fasting controls lipid homeostasis and prevents hepatic steatosis.
Project description:Oscillations between lipid anabolism and catabolism allow for long-term preservation of cellular health amid systemic metabolic fluctuations. As a conserved aging determinant, fasting can improve disease outcomes and extend lifespan. Yet, the relative importance of activating lipid catabolism versus its attenuation in fasting-induced longevity remains unclear. The robust adaptability of the soil-dwelling worms, C. elegans, to variable nutrient availability provides an excellent means to better understand how metabolic transitions alter aging trajectories. Here, we show that, rather than activation, the silencing of lipid catabolism upon nutrient replenishment is essential for lifespan extension through fasting. The fasting-responsive nuclear hormone receptor, NHR-49, is pivotal in activating lipid catabolism through β-oxidation. Unlike traditional ligand-regulated nuclear hormone receptors, NHR-49 employs a unique regulatory mechanism that bypasses ligand binding, instead relying on cofactors to mediate its transcriptional attenuation and turnover during times of nutrient stress. Here, we identify casein kinase 1 alpha 1 (KIN-19) as a central regulator of metabolic plasticity and fasting-induced longevity, which attenuates β-oxidation via primed phosphorylation of NHR-49. Overall, cooperative, ligand-independent silencing of this conserved nuclear hormone receptor promotes longevity associated with fasting.
Project description:First, lentivirus-mediated overexpression of FDFT1 and lentivirus-mediated knockdown of FDFT1 were performed in CT26 cells. Then control CT26 cells, FDFT1 overexpressing CT26 cells and FDFT1 knockdown CT26 cells were cultured under normal medium or fasting mimic medium. Fasting mimic medium was done by incubating cells in glucose-free DMEM (Gibco, USA) supplemented with 0.5g/L glucose and 1% FBS for 48h. So we have 6 groups: control CT26 cells, FDFT1 overexpressing CT26 cells, FDFT1 knockdown CT26 cells, control CT26 cells-under fasting mimic medium, FDFT1 overexpressing CT26 cells- under fasting mimic medium, FDFT1 knockdown CT26 cells- under fasting mimic medium.
Project description:Temporally restricted feeding has a profound effect on the hepatic circadian clock. While the circadian clock is largely unaffected by by extensive fasting, many transcripts are known to be affected by a fasting paradigm. This dataset shows the effect of extensive fasting on dynamic gene expression in the liver
Project description:Analysis of fasting-induced change of metabolites in mice confirmed that glucose level was reduced in the liver, but unaffected in the brain of fasted mice. To explore molecular mechanisms for the preferential glucose supply to the brain upon fasting, we compared gene expression profiles of the brain between fasted and fed mice. Gene ontology (GO) term analysis revealed the enrichment of one GO term, “active membrane transporters activity”. We also showed that fasting enhances the expression of a glucose transporter Slc2a1 (Glut1) gene.