Mechanisms Driving Fasting-Induced Protection from Genotoxic Injury in the Small Intestine
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE245477 | GEO | 2024/01/01
REPOSITORIES: GEO
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Project description:Mechanisms Driving Fasting-Induced Protection from Genotoxic Injury in the Small Intestine
| PRJNA1028562 | ENA
Project description:Background The gut is a major energy consumer, but a comprehensive overview of the adaptive response to fasting is lacking. Gene-expression profiling, pathway analysis, and immunohistochemistry were therefore carried out on mouse small intestine after 0, 12, 24, and 72 hours of fasting. Results Intestinal weight declined to 50% of control, but this loss of tissue mass was distributed proportionally among the gut’s structural components, so that the microarrays’ tissue base remained unaffected. Unsupervised hierarchical clustering of the microarrays revealed that the successive time points separated into distinct branches. Pathway analysis depicted a pronounced, but transient early response that peaked at 12 hours, and a late response that became progressively more pronounced with continued fasting. Early changes in gene expression were compatible with a cellular deficiency in glutamine and metabolic adaptations directed at glutamine conservation, inhibition of pyruvate oxidation, stimulation of glutamate catabolism via aspartate and phosphoenolpyruvate to lactate, and enhanced fatty-acid oxidation and ketone-body synthesis. In addition, the expression of key genes involved in cell cycling and apoptosis was suppressed. At 24 hours of fasting, many of the early adaptive changes abated. Major changes upon continued fasting implied the production of glucose rather than lactate from carbohydrate backbones, a downregulation of fatty-acid oxidation and a very strong downregulation of the electron-transport chain. Cell cycling and apoptosis remained suppressed. Conclusion The changes in gene expression indicate that the small intestine rapidly looses mass during fasting to generate lactate or glucose and ketone bodies. Meanwhile, intestinal architecture is maintained by downregulation of cell turnover. Keywords: fasting response, time course
2007-11-12 | GSE8019 | GEO
Project description:The mechanistic target of rapamycin complex 1 (mTORC1) integrates cellular nutrient signaling and hormonal cues to control metabolism. We have previously shown that constitutive nutrient signaling to mTORC1 by means of genetic activation of RagA (RagAGTP) in mice resulted in a fatal energetic crisis at birth. Herein, we have rescued neonatal lethality in RagAGTP mice and found morphometric and metabolic alterations that span glucose, lipid, ketone, bile acid and amino acid homeostasis in adults, and a median lifespan of nine months. Proteomic and metabolomic analyses of livers from RagAGTP mice revealed a failed metabolic adaptation to fasting due to a global impairment in PPARα transcriptional program. These metabolic defects were partially recapitulated by restricting activation of RagA to hepatocytes, and reverted by pharmacological inhibition of mTORC1. Constitutive hepatic nutrient signaling did not cause hepatocellular damage and carcinomas, unlike genetic activation of growth factor signaling upstream of mTORC1. In summary, RagA signaling dictates dynamic responses to feeding-fasting cycles to tune metabolism so as to match the nutritional state.
2021-05-11 | MTBLS2397 | MetaboLights
Project description:Caloric restriction and acute fasting are known to reduce seizures but through unclear mechanisms. In this study, we demonstrate that mTORC1 signaling is reduced after acute fasting of mice. In neurons, mTORC1 is most sensitive to withdrawal of leucine, arginine, and glutamine, which is dependent on DEPDC5. We performed metabolomic analysis of brain cortex from neuronal specific Depdc5 knockout in fed and fasting state. The Depdc5 neuronal specific knockout mice are resistant to sensing significant fluctuations in brain amino acid levels after fasting. These results establish that acute fasting reduces seizure susceptibility in a DEPDC5-dependent manner.
2022-07-27 | ST002237 | MetabolomicsWorkbench
Project description:Background; The gut is a major energy consumer, but a comprehensive overview of the adaptive response to fasting is lacking. Gene-expression profiling, pathway analysis, and immunohistochemistry were therefore carried out on mouse small intestine after 0, 12, 24, and 72 hours of fasting. Results; Intestinal weight declined to 50% of control, but this loss of tissue mass was distributed proportionally among the gutâs structural components, so that the microarraysâ tissue base remained unaffected. Unsupervised hierarchical clustering of the microarrays revealed that the successive time points separated into distinct branches. Pathway analysis depicted a pronounced, but transient early response that peaked at 12 hours, and a late response that became progressively more pronounced with continued fasting. Early changes in gene expression were compatible with a cellular deficiency in glutamine and metabolic adaptations directed at glutamine conservation, inhibition of pyruvate oxidation, stimulation of glutamate catabolism via aspartate and phosphoenolpyruvate to lactate, and enhanced fatty-acid oxidation and ketone-body synthesis. In addition, the expression of key genes involved in cell cycling and apoptosis was suppressed. At 24 hours of fasting, many of the early adaptive changes abated. Major changes upon continued fasting implied the production of glucose rather than lactate from carbohydrate backbones, a downregulation of fatty-acid oxidation and a very strong downregulation of the electron-transport chain. Cell cycling and apoptosis remained suppressed. Conclusion; The changes in gene expression indicate that the small intestine rapidly looses mass during fasting to generate lactate or glucose and ketone bodies. Meanwhile, intestinal architecture is maintained by downregulation of cell turnover. Experiment Overall Design: Male FVB mice (Charles River, Maastricht, The Netherlands) were housed at 20-22°C, 50-60% humidity, a 12 hours light/dark cycle, and food and water ad libitum. At 6 weeks of age, mice were fasted by removing chow for up to 72 hours before sacrifice (n = 6 per group). The animals were kept in metabolic cages to prevent the consumption of beddings and were kept warm with an infrared lamp starting at 24h. Experiment Overall Design: All animals were sacrificed between 9:00 and 10:00 a.m. by cervical dislocation. The small intestine was removed quickly in such a way that adherent tissue remained behind. It was opened longitudinally, rinsed in phosphate-buffered saline, blotted, weighed, snap-frozen in liquid N2, and stored at -80°C. We opted to use extracts of full-thickness intestine for gene-expression profiling, because the epithelial component of the murine small intestine comprises over 70% of its volume The suitability of this strategy is underscored by a recent microarray study of transporters in the mouse intestine [Anderle P et al., BMC Genomics 2005, 6: 69.]. In addition, isolation of enterocytes is time-consuming and, hence, entails a risk of mRNA degradation, while mucosal scraping harvests villi more efficiently than crypts , whereas many mRNAs are most abundant in the crypts. Experiment Overall Design: Total intestinal RNA was extracted from frozen tissue with guanidiniumthiocyanate [Chomczynski P, Sacchi N: Analytical Biochemistry 1987, 162: 156-159.], followed by cesium-chloride centrifugation [Glisin V, Crkvenjakov R BC: Biochemistry 1974, 13: 2633-2637.] to avoid contamination with mucus. The quality of RNA was assessed with the RNA 6000 Nano LabChip® Kit in an Agilent 2100 bioanalyzer (Agilent Technologies, Palo Alto, USA). Microarray-based quantification of 8 mRNAs with a 1.3-9.2-fold change in expression was validated by qPCR, as described [58]. mRNA concentration was calculated using the LinReg program [59]. In the absence of reverse transcriptase, the signal was < 0.1% of that in its presence for each primer pair (not shown). Experiment Overall Design: Microarrays. The 60-mer Mouse Development (22K) Oligo Microarray G4120A (Agilent) was used. Three arrays per experimental condition were used. Per microarray, 20 μg mRNA, pooled from 2 intestines, was reverse transcribed with Cy3-labelled dCTP (Perkin Elmer, Boston, USA), using the Agilent Fluorescent Direct Label Kit. Cy5-labeled cDNA produced from RNA pooled from 6 fed animals served as the common reference across all arrays (Figure 1A). Hybridized cDNAs were detected with Agilentâs dual-laser microarray slide scanner. The data were retrieved with Agilentâs Feature Extraction software 6.1.1.
2009-05-13 | E-GEOD-8019 | biostudies-arrayexpress
Project description:To study the protective effects of preoperative fasting against renal ischemia-reperfusion injury, young-lean as well as aged overweight mice were subjected to three days of fasting or ad libitum food consumption, and gene expressions in kidneys of male mice were analyzed
2014-06-03 | GSE52982 | GEO
Project description:We used mircoarray to identify the potential regulation on the gene level between DDIT4+/+ and DDIT4−/− cells treated with 5-FU at 24h. Genes related to protein secretion, androgen response, mitotic spindle, hypoxia, TNFa signaling via NFKB, apoptosis, glycolysis, mTORC1 signaling, G2M checkpoint, KRAS signaling up are enriched in the DDIT4KO gastric cancer cell treated with 5-FU.
2023-08-27 | GSE156955 | GEO
Project description:To study the protective effects of preoperative fasting against renal ischemia-reperfusion injury, young-lean as well as aged overweight mice were subjected to three days of fasting or ad libitum food consumption, and gene expressions in kidneys of male mice were analyzed 19 samples (5 young control, 4 young fasted, 5 aged control, 5 aged fasted), each from individual mice
2014-06-03 | E-GEOD-52982 | biostudies-arrayexpress
Project description:Gene expression regulation of transporters and phase I/II metabolic enzymes in murine small intestine during fasting Keywords: metabolic state analysis
2007-07-04 | GSE6864 | GEO
Project description:The sensation of hunger after a period of fasting and the sensation of satiety after eating is crucial to behavioral regulation of food intake, but the biological mechanisms regulating these sensations are incompletely understood. We studied the behavioral and physiological adaptation to fasting in the vinegar fly (Drosophila melanogaster). Here we show that flies demonstrated increased behavioral attraction to food odor when food-deprived with no corresponding increase in sensitivity in the peripheral olfactory system. Flies increased their food intake transiently in the post-fasted state, but returned to a stable baseline feeding level within 24 hr after return to food. This modulation in feeding was accompanied by a significant increase in the size of the crop organ of the digestive system, suggesting that fasted flies responded both by increasing their food intake and storing reserve food in their crop. The post-fasting feeding response was observed in both male and female flies of diverse genetic backgrounds. Expression profiling of head, body, and chemosensory tissues by microarray analysis revealed several hundred genes that are regulated by feeding state, including 247 genes in the fly head. We performed RNA interference-mediated knockdown of, takeout, one of the genes strongly downregulated by fasting in multiple tissues. When takeout was knocked down in all neurons the post-fasting feeding response was abolished. These observations suggest that a coordinated transcriptional response to internal physiological state may regulate both ingestive behaviors and chemosensory perception of food 6 Pool of flies were used for this experiment. For each pool, samples were taken at 0,24 and 48h and separated in each body part. 56 samples were used for the analysis.
2011-09-23 | E-GEOD-27927 | biostudies-arrayexpress