Project description:Transcriptional profiling of adult C. elegans comparing daf-16(-); daf-2(-) animals with adult daf-2(-) animals. Two-condition experiment, daf-2 mutants treated with daf-16 RNAi vs. daf-2 mutants treated with empty vector RNAi. Biological replicates: 8 daf-2 mutants treated with daf-16 RNAi vs. daf-2 mutants treated with empty vector RNAi, independently grown and harvested. One replicate per array.
Project description:Many studies have addressed the effect of dietary glycemic index on obesity and diabetes, but little is known about its effect on lifespan itself. We found that adding a small amount of glucose to the medium (0.1-2%) shortened the lifespan of C. elegans. Glucose shortened lifespan by inhibiting the activities of lifespan-extending transcription factors that are also inhibited by insulin signaling: the FOXO family member DAF-16 and the heat shock factor HSF-1. This effect involved the down-regulation of an aquaporin glycerol channel, aqp-1. We show that changes in glycerol metabolism are likely to underlie the lifespan-shortening effect of glucose, and that aqp-1 may act cell non-autonomously as a feedback regulator in the insulin/IGF-1 signaling pathway. Insulin down-regulates similar glycerol channels in mammals, suggesting that this glucose-responsive pathway might be conserved evolutionarily. Together these findings raise the possibility that a low-sugar diet might have beneficial effects on lifespan in higher organisms. Refer to individual Series. This SuperSeries is composed of the following subset Series: GSE18561: Adult C. elegans: Control daf-2 mutants treated with daf-16 RNAi vs. daf-2 mutants treated with empty vector RNAi GSE18562: Adult C. elegans: Control OP50 culture vs. OP50 + 2% glucose culture
Project description:Dysfunction of the motor subunit of the TIM23 translocase, the PAM complex located on the matrix side of the mitochondrial inner membrane in Saccharomyces cerevisiae, was shown to cause a decrease in mitochondrial protein import and precursor accumulation in the cytosol. We used an analogous model to study the non-mitochondrial response to defective mitochondrial import machinery in Caenorhabditis elegans in which we depleted DNJ-21 as the functional homolog of yeast Pam18. To gain a broader insight in potential changes in Caenorhabditis elegans proteome upon DNJ-21 depletion we performed a quantitative, label-free proteomics analysis. We compared protein levels upon knockdown of dnj-21 (dnj-21 RNAi) with control conditions (Empty vector RNAi). Synchronized N2 wild type worms were grown on NGM plates seeded with E. coli HT115(DE3) transformed with a construct targeting dnj-21 gene or with empty vector L4440 as a control.
Project description:To identify DAF-16-dependent transcriptional alterations that occur in a long-lived C. elegans strain, we used cDNA microarrays and genomic analysis to identify putative direct and indirect DAF-16 transcriptional target genes. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Keywords: Logical Set
Project description:DAF-16/FoxO and EGL-27/GATA promote developmental growth in response to persistent somatic DNA damage [N2, daf-2, daf-16, daf-2 daf-16]
Project description:Epigenetic modifications are thought to be important for gene expression changes during development and aging. However, besides the Sir2 histone deacetylase in somatic tissues and H3K4 trimethylation in germlines, there is scant evidence implicating epigenetic regulations in aging. The insulin/IGF-1 signaling (IIS) pathway is a major lifespan regulatory pathway. Here we show that progressive increases in gene expression and loss of H3K27me3 on IIS components are due, at least in part, to increased activity of the H3K27 demethylase UTX-1 during aging. RNAi of the utx-1 gene extended the mean lifespan of C. elegans by ~30%, dependent on DAF-16 activity and not additive in daf-2 mutants. The loss of utx-1 increased H3K27me3 on the Igf1r/daf-2 gene and decreased IIS activity leading to a more "naive" epigenetic state. Like stem cell reprogramming, our results suggest that reestablishing epigenetic marks lost during aging might help "reset" the developmental age of animal cells.