Ageing, metabolism and the intestine.
Ontology highlight
ABSTRACT:
SUBMITTER: Funk MC
PROVIDER: S-EPMC7332987 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Glucose transport and metabolism by rat small intestine was investigated by using a preparation for the combined perfusion of the lumen and the vascular bed. 2. When 5 mM-glucose was present in the lumen, only 29% was transported unchanged to the vascular side. Lactate output into the vascular and luminal fluids accounted for a further 53% and 4% respectively of the glucose taken up from the lumen. 3. Glucose was readily taken up when added at 5 mM to the vascular compartment only. Vascular lactate output accounted for approx. 33% of the glucose uptake, and luminal lactate for 6%. 4. When 2 mM-glucose was added to the lumen with 5 mM-glucose in the vascular perfusate, there was no detectable net transport of glucose to the vascular side. However, of the glucose taken up from the lumen, 31% and 2% could be accounted for by increases in vascular and luminal lactate respectively. 5. When 10 mM-glucose was added to the lumen, with 5 mM-glucose in the vascular perfusate, 33% of the glucose disappearing from the lumen was transported to the vascular side. Extra lactate output to the vascular and lumen perfusates accounted for 50% and 9% respectively of the glucose uptake from the lumen. 6. These studies indicate that at low luminal glucose concentrations no sugar is transferred to the blood unchanged, and at sugar concentrations of 5--10 mM only 25--50% of the glucose leaving the lumen reaches the serosal side intact. Furthermore, the small intestine has a greater propensity to form lactate from luminal glucose than from vascular glucose.
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Project description:Genetically modified mouse models of ageing are the living proof that lifespan and healthspan can be lengthened or shortened, and provide a powerful context in which to unravel the molecular mechanisms at work. In this study, we analysed and compared gene expression data from 10 long-lived and 8 short-lived mouse models of ageing. Transcriptome-wide correlation analysis revealed that mutations with equivalent effects on lifespan induce more similar transcriptomic changes, especially if they target the same pathway. Using functional enrichment analysis, we identified 58 gene sets with consistent changes in long- and short-lived mice, 55 of which were up-regulated in long-lived mice and down-regulated in short-lived mice. Half of these sets represented genes involved in energy and lipid metabolism, among which Ppargc1a, Mif, Aldh5a1 and Idh1 were frequently observed. Based on the gene sets with consistent changes, and also the whole transcriptome, the gene expression changes during normal ageing resembled the transcriptome of short-lived models, suggesting that accelerated ageing models reproduce partially the molecular changes of ageing. Finally, we identified new genetic interventions that may ameliorate ageing, by comparing the transcriptomes of 51 mouse mutants not previously associated with ageing to expression signatures of long- and short-lived mice and ageing-related changes.
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