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: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:Human DNA-methylation data have been used to develop highly accurate biomarkers of aging ("epigenetic clocks"). Recent studies demonstrate that similar epigenetic clocks for mice (Mus Musculus) can be slowed by gold standard anti-aging interventions such as calorie restriction and growth hormone receptor knock-outs. Using DNA methylation data from previous publications with data collected in house for a total 1189 samples spanning 193,651 CpG sites, we developed 4 novel epigenetic clocks by choosing different regression models (elastic net- versus ridge regression) and by considering different sets of CpGs (all CpGs vs highly conserved CpGs). We demonstrate that accurate age estimators can be built on the basis of highly conserved CpGs. However, the most accurate clock results from applying elastic net regression to all CpGs. While the anti-aging effect of calorie restriction could be detected with all types of epigenetic clocks, only ridge regression based clocks replicated the finding of slow epigenetic aging effects in dwarf mice. Overall, this study demonstrates that there are trade-offs when it comes to epigenetic clocks in mice. Highly accurate clocks might not be optimal for detecting the beneficial effects of anti-aging interventions.
Project description:Human DNA-methylation data have been used to develop highly accurate biomarkers of aging ("epigenetic clocks"). Recent studies demonstrate that similar epigenetic clocks for mice (Mus Musculus) can be slowed by gold standard anti-aging interventions such as calorie restriction and growth hormone receptor knock-outs. Using DNA methylation data from previous publications with data collected in house for a total 1189 samples spanning 193,651 CpG sites, we developed 4 novel epigenetic clocks by choosing different regression models (elastic net- versus ridge regression) and by considering different sets of CpGs (all CpGs vs highly conserved CpGs). We demonstrate that accurate age estimators can be built on the basis of highly conserved CpGs. However, the most accurate clock results from applying elastic net regression to all CpGs. While the anti-aging effect of calorie restriction could be detected with all types of epigenetic clocks, only ridge regression based clocks replicated the finding of slow epigenetic aging effects in dwarf mice. Overall, this study demonstrates that there are trade-offs when it comes to epigenetic clocks in mice. Highly accurate clocks might not be optimal for detecting the beneficial effects of anti-aging interventions.
Project description:Calorie restriction (CR) extends lifespan by modulating the mechanisms involved in aging. We quantified the hepatic proteome of male C57BL/6 mice exposed to graded levels of CR (0% to 40% CR) for three months, and evaluated which signaling pathways were most affected.
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.
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: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.