Project description:This study explored the role of the growth hormone (GH) / insulin-like growth factor 1 (IGF-1) axis on the life-long caloric restriction (CR)-associated remodeling of white adipose tissue (WAT). Adipocyte size and gene expression profiles, using high-density oligonucleotide microarrays, were analyzed in WAT of six- to seven-month old wild Wistar rats fed ad libitum (AL) or subjected to a 30% caloric restriction (CR), and heterozygous transgenic dwarf rats bearing an anti-sense GH transgene fed ad libitum (Tg). While not significant in Tg rats, adipocyte size was significantly reduced in CR rats compared with AL rats. The microarray data based on the principal component analysis demonstrated that the gene expression profile of CR rats markedly differed from the AL rats, while Tg hardly differed, suggesting that CR-associated WAT remodeling was predominantly regulated in a GH/IGF-1-independent manner. The gene cluster with the largest change induced by CR included several genes involved in lipid biosynthesis and inflammation. Moreover, many of the genes transcriptionally regulated by sterol regulatory element binding proteins (SREBPs) were found in the cluster related to lipid biosynthesis. Real-time reverse transcription polymerase chain reaction analysis confirmed that the expression of SREBP-1 and its down-stream targets was particularly up-regulated in CR rats compared with SREBP-2 and its down-stream targets. Our findings suggest that SREBP-1 is a major transcription factor in CR-associated remodeling of WAT, and might be one of the key regulators of the anti-aging and pro-longevity effects of CR. The three groups: GH antisense, caloric restriction, and the control were compared by using PCA.
Project description:Aging causes a functional decline in tissues throughout the body that may be delayed by caloric restriction (CR). However, the cellular profiles and signatures of aging, as well as those ameliorated by CR, remain unclear. Here, we built comprehensive single-cell and single-nucleus transcriptomic atlases across various rat tissues undergoing aging and CR. CR attenuated aging-related changes in cell type composition, gene expression, and core transcriptional regulatory networks. Immune cells were increased during aging, and CR favorably reversed the aging-disturbed immune ecosystem. Computational prediction revealed that the abnormal cell-cell communication patterns observed during aging, including the excessive proinflammatory ligand-receptor interplay, were reversed by CR. Our work provides multi-tissue single-cell transcriptional landscapes associated with aging and CR in a mammal, enhances our understanding of the robustness of CR as a geroprotective intervention, and uncovers how metabolic intervention can act upon the immune system to modify the process of aging.
Project description:SIRT1 is a NAD+-dependent protein deacetylase. SIRT1 plays key roles in metabolic regulation and adaptation. In this study, we wanted to compare gene expression profile in SIRT1 overexpressing mice to WT mice submitted to different intervention (caloric restriction and exercise training) in different tissues (liver, skeletal muscle, brown and white adipose tissues). SIRT1 transgenic model has already been described (Pfluger et al., 2008). Here we used homozygote transgenic mice which had been backcrossed to C57Bl/6N background. 3 months old WT and SIRT1tg mice were fed with a low fat diet. After sacrifice, total mRNA obtained from brown adipose were used for microarray. Caloric restriction (CR) : everyother day feeding during 3 months Exercise training (EX) : mice were housed in running wheel cages during 10 weeks
Project description:Aging-associated inflammatory and oxidative changes in the rat urinary bladder and dorsal root ganglia - preventive effect of caloric restriction [bladder]
Project description:This study explored the role of the growth hormone (GH) / insulin-like growth factor 1 (IGF-1) axis on the life-long caloric restriction (CR)-associated remodeling of white adipose tissue (WAT). Adipocyte size and gene expression profiles, using high-density oligonucleotide microarrays, were analyzed in WAT of six- to seven-month old wild Wistar rats fed ad libitum (AL) or subjected to a 30% caloric restriction (CR), and heterozygous transgenic dwarf rats bearing an anti-sense GH transgene fed ad libitum (Tg). While not significant in Tg rats, adipocyte size was significantly reduced in CR rats compared with AL rats. The microarray data based on the principal component analysis demonstrated that the gene expression profile of CR rats markedly differed from the AL rats, while Tg hardly differed, suggesting that CR-associated WAT remodeling was predominantly regulated in a GH/IGF-1-independent manner. The gene cluster with the largest change induced by CR included several genes involved in lipid biosynthesis and inflammation. Moreover, many of the genes transcriptionally regulated by sterol regulatory element binding proteins (SREBPs) were found in the cluster related to lipid biosynthesis. Real-time reverse transcription polymerase chain reaction analysis confirmed that the expression of SREBP-1 and its down-stream targets was particularly up-regulated in CR rats compared with SREBP-2 and its down-stream targets. Our findings suggest that SREBP-1 is a major transcription factor in CR-associated remodeling of WAT, and might be one of the key regulators of the anti-aging and pro-longevity effects of CR.