Project description:Calorie restriction is a major intervention consistently demonstrated to retard aging and delay age-associated diseases. A novel micronutrient blend, a putative calorie restriction mimetic, was developed based on a screening tool we previously described. Whole transcriptomic analysis was examined in brain cortex, skeletal muscle and heart in three groups of mice: old controls (30 months), old + calorie restriction and old + novel micronutrient blend. The micronutrient blend elicited transcriptomic changes in a manner similar to those in the calorie-restricted group and unique from those in the control group. Subgroup analysis revealed that nuclear hormone receptor, proteasome complex and angiotensinogen genes, all of which are known to be directly related to the aging process, were the most affected by the micronutrient blend and by calorie restriction. Thus, these three genes may be considered master regulators of the favorable effects of calorie restriction and of the micronutrient blend. Based on the calorie restriction mimetic effects on transcriptomics, it was hypothesized that the micronutrient blend would promotes longevity and vitality. To test this hypothesis, a functional analysis in C. Elegans was used to examine the effects of the micronutrient blend on longevity and biomarkers of vitality. Results indicate that feeding C. Elegans the micronutrient blend increased longevity as well as vitality. Further studies are required to confirm that the calorie restriction mimicking benefits described here are elicited by the micronutrient blend in humans.
Project description:Background: Calorie restriction (CR) is the only intervention known to extend lifespan in a wide range of organisms, including mammals. However, the mechanisms by which it regulates mammalian aging remain largely unknown and the involvement of the TOR and Sirtuin pathways (which regulate aging in lower organisms) remain controversial. Femaleness is a second phenotype generally associated with longevity but the relationship between sex-biased and CR-induced gene expression remains undetermined. Methodology/Principal Findings: We generated microarray gene expression data from livers of male mice fed high calorie or CR diets, and we find that CR significantly changes the expression of over 3,000 genes, many between 10- and 50-fold. We compare our data to the GenAge database of known aging-related genes and to prior microarray expression data of genes expressed differently between male and female mice. CR generally feminizes gene expression and many of the most significantly changed individual genes are involved in aging, hormone signaling, and p53-associated regulation of the cell cycle and apoptosis. Among the genes showing the largest and most statistically significant CR-induced expression differences are Ddit4, a key regulator of the TOR pathway, and Nnmt, a regulator of lifespan linked to the Sirtuin pathway. Using Western analyses, we confirmed post-translational inhibition of the TOR pathway. Conclusions: Our data show that CR induces widespread gene expression changes and acts through highly evolutionarily conserved pathways, from microorganisms to mammals, and that its life-extension effects might arise partly from a shift toward a gene expression profile more typical of the longer-lived female sex. Keywords: Two-class gene expression comparison. Calorie restriction (CR) versus HIGH CALORIE feeding. Design of the experiment is a two-class paired design in which the two classes are HIGH CALORIE and CALORIE RESTRICTION (CR) dietary regimens fed to mice, resulting in 15 HIGH CALORIE microarrays and 8 CR microarrays; 23 total microarrays. Four HIGH CALORIE and 2 CR microarrays were produced using pools of 3 RNA samples for each microarray (6 pools of 3, plus 17 individual samples = 35 individual mouse liver samples, 23 microarrays). Total liver RNA was labeled directly. Reference RNA: Stratagene Universal Mouse Reference RNA.
Project description:Analysis of treatment at gene expression level in aged mice. Results provide important information of the response of drug modifying NAD metabolism which has been implicated in anti-aging effect of calorie restriction in aging process. Total RNA obtained from skeletal muscles and brain (cortex) subjected to calorie restriction or β-lapachone treatment compared to untreated control.
Project description:Dietary restriction (also known as caloric/calorie restriction; CR) extends the lifespan of species from all three eukaryotic kingdoms. The restriction of the diet interferes directly with the aging process by triggering a tightly controlled genetic program where specific sets of genes are either upregulated downreguled. We used microarray-technology to detail the global program of gene expression underlying the anti-aging effect of dietary restriction and identified distinct classes of up- and down-regulated genes.
Project description:As global life expectancy continues to climb, maintaining skeletal muscle function is increasingly essential to ensure a good life quality for aging populations. Calorie restriction (CR) is the most potent and reproducible intervention to extend health and lifespan, but is largely unachievable in humans. Therefore, identification of “CR mimetics” has received much attention. Since CR targets nutrient-sensing pathways centering on mTORC1, rapamycin, the allosteric inhibitor of mTORC1, has been proposed as a potential CR mimetic and counteracts age-related muscle loss. Therefore, we tested whether rapamycin acts via similar mechanisms as CR to slow muscle aging. Contrary to our prediction, long-term CR and rapamycin-treated geriatric mice display distinct skeletal muscle gene expression profiles despite both conferring benefits to aging skeletal muscle. Furthermore, CR improved muscle integrity in a mouse with nutrient-insensitive sustained muscle mTORC1 activity and rapamycin provided additive benefits to CR in aging mouse muscles. Therefore, RM and CR exert distinct, compounding effects in aging skeletal muscle, opening the possibility of parallel interventions to counteract muscle aging.
Project description:We performed a factorial experiment examining the effects of calorie restriction (CR) and exercise (EX) in mice. CR mice received 70% of calories but 100% of all other nutrients compared to AL mice. Food consumption, weight gain, and physical activity levels were recorded for 6 weeks. Diet and exercise treatments, both alone and in combination, had significant effects on body composition and levels of physical activity. Affymetrix oligo microarrays were used to determine global gene expression patterns in mammary gland total RNA. CR and EX had some overlapping but primarily unique effects on mammary gene expression, with CR affecting a much larger number of genes. The gene changes presented suggest that CR and EX influence mammary gland development and potentially carcinogenesis through distinct pathways. Keywords: 2 X 2 factorial mouse experiment; ad lib; calorie restriction; exercise; exercise + calorie restriction. Endpoints: body composition; bone density; gene expression in mammary gland
Project description:Dietary restriction (also known as caloric/calorie restriction; CR) extends the lifespan of species from all three eukaryotic kingdoms. The restriction of the diet interferes directly with the aging process by triggering a tightly controlled genetic program where specific sets of genes are either upregulated downreguled. We used microarray-technology to detail the global program of gene expression underlying the anti-aging effect of dietary restriction and identified distinct classes of up- and down-regulated genes. In order to apply dietary restriction in budding yeast we cultured cells on a reduced glucose medium (0.5% vs. 2.0%), which is known as moderate DR regimen. We then compared mRNA expression of yeast cells cultured under dietary restricted (0.5% glucose) and ad libitum (2.0% glucose) conditions.