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: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:Extending lifespan from yeast to mammals, calorie restriction (CR) is the most conserved longevity intervention. Numerous conserved pathways regulating aging and mediating CR have been identified; however, the overall proteomic changes during these conditions remain largely unexplored. We compared proteomes between young and replicatively aged yeast cells under normal and CR conditions using SILAC quantitative proteomics and discovered distinct signatures in the aging proteome. We found remarkable similarities between aged and CR cells, including induction of stress response pathways, providing evidence that CR pathways are engaged in aged cells. These observations also uncovered aberrant changes in mitochondria membrane proteins as well as a proteolytic cellular state in old cells. These proteomics analyses also help identify potential genes and pathways that have causal effects on longevity.
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: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.
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:Studies of aging and longevity are revealing how diseases that shorten life can be controlled to improve the quality of life and lifespan itself. Two strategies under intense study to accomplish this goal are rapamycin treatment and calorie restriction. New strategies are being discovered including one that uses low-dose myriocin treatment. Myriocin inhibits the first enzyme in sphingolipid synthesis in all eukaryotes and we showed recently that low-dose myriocin treatment increases yeast lifespan at least in part by down-regulating the sphingolipid-controlled Pkh1/2-Sch9 (ortholog of mammalian S6 kinase) signaling pathway. Here we show that myriocin treatment has global influences and modulates the evolutionarily conserved Snf1/AMPK, PKA and TORC1 signaling pathways to enhance yeast lifespan. These extensive affects of myriocin rival those of rapamycin and calorie restriction. Our studies in yeast along with other studies in mammals reveal the potential of myriocin or related compounds to lower the incidence of age-related diseases in humans. No-myriocin-treated cells and myriocin-treated cells; three biological replicates in each treatment