Characterization of the genes that were regulated by feeding with CBM 588
ABSTRACT: In the present study, we investigated the effect of CBM 588 on lifespan and multiple-stress resistance using Caenorhabditis elegans as a model animal. When adult C. elegans were fed a standard diet of Escherichia coli OP50 or CBM 588, the lifespan of the animals fed CBM 588 was significantly longer than that of animals fed OP50. Moreover, the worms fed CBM 588 were more resistant to certain stressors, including infections with pathogenic bacteria, UV irradiation, and the metal stressor Cu2+. CBM 588 failed to extend the lifespan of the daf-2/IR, daf-16/FOXO and skn-1/Nrf2 mutants. Transcriptional profiling comparing CBM 588-fed and control-fed animals suggested that DAF-16-dependent class II genes were regulated by CBM 588. In conclusion, CBM 588 extends the lifespan of C. elegans probably through regulation of the insulin/IGF-1 signaling (IIS) pathway and the Nrf2 transcription factor, and CBM 588 improves resistance to several stressors in C. elegans. Overall design: Transcriptional profiling of eight-day-old worms that were fed OP50 or CBM 588 for five days, by deep sequencing, using Illumina HiSeq.
Project description:The germ lineage is considered to be immortal. In the quest to extend lifespan, a possible strategy is to drive germline traits in somatic cells, to try to confer some of the germ lineage’s immortality on the somatic body. Notably, a study in C. elegans suggested that expression of germline genes in the somatic cells of long-lived daf-2 mutants confers some of daf-2’s longevity. Specifically, mRNAs encoding components of C. elegans germ granules (P granules) were up-regulated in daf-2 mutant worms, and knock-down of individual P-granule and other germline genes in daf-2 young adults modestly reduced their lifespan. We investigated the contribution of a germline program to daf-2’s long lifespan, and also tested if other mutants known to express germline genes in their somatic cells are long-lived. Our key findings are: 1) We could not detect P-granule proteins in the somatic cells of daf-2 mutants by immunostaining or by expression of a P-granule transgene. 2) Whole-genome transcript profiling of animals lacking a germline revealed that germline transcripts are not up-regulated in the soma of daf-2 worms compared to the soma of control worms. 3) Simultaneous removal of multiple P-granule proteins or the entire germline program from daf-2 worms did not reduce their lifespan. 4) Several mutants that robustly express a broad spectrum of germline genes in their somatic cells are not long-lived. Taken together, our findings argue against the hypothesis that acquisition of a germ cell program in somatic cells increases lifespan and contributes to daf-2’s longevity. Overall design: Transcriptome profiles of 3 replicates of sterile daf-2; mes-1 double mutants (experimental) and 3 replicates of sterile mes-1 single mutants (control) grown at 24°C
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:Numerous studies have shown that resistance to oxidative stress is crucial to stay healthy and to reduce the adverse effects of aging. Accordingly, nutritional interventions using antioxidant food-grade compounds or food products are currently an interesting option to help improve health and quality of life in the elderly. Live lactic acid bacteria (LAB) administered in food, such as probiotics, may be good antioxidant candidates. Nevertheless, information about LAB-induced oxidative stress protection is scarce. To identify and characterize new potential antioxidant probiotic strains, we have developed a new functional screening method using the nematode Caenorhabditis elegans as host. C. elegans were fed on different LAB strains (78 in total) and nematode viability was assessed after oxidative stress (3mM and 5mM H2O2). One strain, identified as Lactobacillus rhamnosus CNCM I-3690, protected worms by increasing their viability by 30% and, also, increased average worm lifespan by 20%. We performed a transcriptomic analysis of C. elegans fed with this strain and showed that increased lifespan is correlated with differential expression of the DAF-16/insulin-like pathway, which is highly conserved in humans. Gene expression in C. elegans wild-type strain (N2) was analyzed in worm populations fed with E. coli OP50 (control condition) or the corresponding LAB (Lactobacillus rhamnosus CNCM I-3690 or Lactobacillus rhamnosus CNCM I-4317) . Three days and ten days feeding period was analyzed.
Project description:The roles and regulatory mechanisms of transcriptome changes during aging are unclear. It has been proposed that the transcriptome suffers decay during aging owing to age-associated down-regulation of transcription factors. In this study, we characterized the role of a transcription factor DAF-16, which is a highly conserved lifespan regulator, in the normal aging process of Caenorhabditis elegans. We found that DAF-16 translocates into the nucleus in aged wild-type worms and activates the expression of hundreds of genes in response to age-associated cellular stress. Most of the age-dependent DAF-16 targets are different from the canonical DAF-16 targets downstream of insulin signaling. This and other evidence suggest that activation of DAF-16 during aging is distinct from activation of DAF-16 due to reduced signaling from DAF-2. Further analysis showed that it is due in part to a loss of proteostasis during aging, at least in part. We also found that without daf-16, dramatic gene expression changes occur as early as on adult day 2, indicating that DAF-16 acts to stabilize the transcriptome during normal aging. Our results thus reveal that normal aging is not simply a process in which the gene expression program descends into chaos due to loss of regulatory activities; rather, there is active transcriptional regulation during aging. Overall design: Transcriptome analyses of fer-15(b26ts) and daf-16(mu86);fer-15(b26ts) worms were carried out in three biological replicates. Worms were grown on High Growth (HG) plates supplemented with OP50 bacteria at 25 °C and harvested on adult day 1 through day 7.
Project description:Synchronized C. elegans cultures of three geontypes -- wildype N2, daf-2(e1370) and sma-6(wk7) -- were prepared using standard techniques (http://cmgm.stanford.edu/~kimlab/index_methods.html). Live young adult worms were split between NG plates pre-seeded with the non-pathogenic E. coli strain OP50 or the Pseudomonas aeruginosa clinical isolate PA14 and incubated at 25C for 4 or 24 hours before harvesting. This experiment was repeated at least three times on independent occasions. cDNA probes were prepared from experimental samples and from reference mRNA extracted from mixed stage wild type worms grown at 25C, and were labeled with Cy3 or Cy5, as indicated. A reference experiement design type is where all samples are compared to a common reference. Elapsed Time: Time Infection: Exposure to the non-pathogenic E. coli strain OP50 or to the pathogenic Pseudomonas aeruginosa strain PA14 Strain Name: C. elegans wildtype strain N2 or the immune pathway mutants daf-2(e1370) or sma-6(wk7) Keywords: reference_design Overall design: Computed
Project description:Synchronized C. elegans cultures of three geontypes -- wildype N2, daf-2(e1370) and sma-6(wk7) -- were prepared using standard techniques (http://cmgm.stanford.edu/~kimlab/index_methods.html). Live young adult worms were split between NG plates pre-seeded with the non-pathogenic E. coli strain OP50 or the Pseudomonas aeruginosa clinical isolate PA14 and incubated at 25C for 4 or 24 hours before harvesting. This experiment was repeated at least three times on independent occasions. cDNA probes were prepared from experimental samples and from reference mRNA extracted from mixed stage wild type worms grown at 25C, and were labeled with Cy3 or Cy5, as indicated. A reference experiement design type is where all samples are compared to a common reference. Elapsed Time: Time Infection: Exposure to the non-pathogenic E. coli strain OP50 or to the pathogenic Pseudomonas aeruginosa strain PA14 Strain Name: C. elegans wildtype strain N2 or the immune pathway mutants daf-2(e1370) or sma-6(wk7) Keywords: reference_design Computed
Project description:Profiling of DAF-16 binding by comparison of DNA methylation of a C. elegans control strain expressing the DNA adenine methyltransferase (DAM) and an experimental strain expressing a DAF-16::DAM. Both strains were fed daf-2 RNAi to identify DAF-16 binding associated with long lived worms.
Project description:Transcriptional profiling of whole day 1 adult C. elegans, comparing animals carrying the m79 mutation in the daf-10 gene and wild-type isogenic animals. Genes that act downstream of sensory neurons to influence longevity, dauer formation and pathogen responses in Caenorhabditis elegans Manuscript abstract: Two-condition experiments, daf-10 vs wt, 3 biological repeats of each grown in parallel, verified lifespan increase in daf-10 mutant animals
Project description:(Part 1) Gene expression profiles of C. elegans in response to P. aeruginosa. Synchronized larval stage 1 (L1) worms were raised on E. coli OP50 for 72 hours. These synchronized young adult (YA) animals were subsequently exposed to P. aeruginosa PA14 for 4 hours. 25dC. (Part 2) Gene expression profiles of C. elegans in response to Neomycin/Streptomycin-mediated recovery after a 4 hour exposure to P. aeruginosa. Synchronized larval stage 1 (L1) worms were raised on E. coli OP50 for 72 hours. These synchronized young adult (YA) animals were subsequently exposed to P. aeruginosa PA14 for 4 hours and then treated with Neomycin and shifted to E. coli OP50 plus Streptomycin plates for 6, 12, or 24 hours to resolve the infection. As a control for Neomycin/Streptomycin exposure, synchronized larval stage 1 (L1) worms were raised on E. coli OP50 for 72 hours and either shifted to fresh E. coli OP50 plates for 6 hours or treated with Neomycin and shifted to E. coli OP50 plus Streptomycin plates for 6 hours. 25dC. Overall design: Samples include 72 hours on OP50 (72hOP), 72 hours on OP50 plus 4 hours on PA14 (76hPA), 72 hours on OP50 plus 4 hours on PA14 plus 6 hours of Neomycin/Streptomycin-mediated recovery (82hR), 72 hours on OP50 plus 4 hours on PA14 plus 12 hours of Neomycin/Streptomycin-mediated recovery (88hR), 72 hours on OP50 plus 4 hours on PA14 plus 24 hours of Neomycin/Streptomycin-mediated recovery (100hR), 82 hours on OP50 (82hOP), and 72 hours on OP50 plus 6 hours of Neomycin/Streptomycin (82hOPC). Triplicate biological samples were included for each timepoint except for 82hOP (which utilized duplicates). 20 total samples. Agilent C. elegans expression microarrays (GPL11346).
Project description:Intermittent fasting (IF), a dietary restriction regimen, extends the lifespans of C. elegans and mammals by inducing gene expression changes. How fasting induces gene expression changes and longevity remains unclear. MicroRNAs (miRNAs) are small non-coding RNAs (approximately 22 nucleotides) that repress gene expression, and the expression of several miRNAs has been reported to be altered by fasting. In this study, we examined the role of the miRNA machinery in fasting-induced transcriptional changes and longevity in C. elegans. Our miRNA array analyses revealed that the expression levels of numerous miRNAs changed in adult worms after 48 hours of fasting. In addition to these changes, miRNA-mediated silencing complex (miRISC) components, including Argonaute proteins and GW182 proteins, and the miRNA-processing enzyme Drosha/DRSH-1, were up-regulated by fasting. Our lifespan measurements demonstrated that IF-induced longevity was suppressed by knockout or knockdown of miRISC components and was completely inhibited by drsh-1 ablation. Remarkably, drsh-1 ablation inhibited the fasting-induced changes in the expression of the target genes of DAF-16, the insulin/IGF-1 signaling effector. Fasting-induced transcriptome alterations were substantially and modestly suppressed in the drsh-1 null mutant and the null mutant of ain-1, a gene encoding GW182, respectively. These results indicate that components of the miRNA machinery, especially the miRNA-processing enzyme Drosha, play an important role in mediating IF-induced longevity via the regulation of fasting-induced gene expression changes. To validate the involvement of drsh-1, ain-1 and daf-16 in fasting-induced gene expression changes, we compared the induction rates of all genes in the mutants with the induction rates of all genes in WT worms Overall design: We synchronized wild type (WT), drsh-1, ain-1 and daf-16 mutants raised them under normal conditions. The 2 day adult animals were transferred to the new plate with (Fed) or without food (Fasting). After 2 days incubation, we collected the animals and extracted total RNA and subject them to microarray.