Project description:The gut-brain axis allows gut microbes to influence host social behavior, yet the specific role of microbial genetic variation in this process and its potential transgenerational effects remains poorly understood. Using C. elegans as a model, we identified 77 E. coli strains among 3,983 mutants that markedly enhanced C. elegans aggregation behavior. Our findings reveal that mutant bacteria modulate C. elegans social behavior through distinct neurobehavioral pathways, demonstrating a synergistic regulatory mechanism between microbial genetics and host heredity. Mechanistically, ycgJ mutant bacteria were found to impact C. elegans social behavior via the mitochondrial pathway. Additionally, even F2 offspring of parent C. elegans exposed to these mutant bacteria exhibited enhanced social behavior within their populations. These insights underscore the significance of investigating microbial genetic variation in relation to host behavior, particularly for the development of genetically engineered probiotics, aimed at promoting well-being across generations.
Project description:Analysis of gene expression in two long-lived daf-2 mutant (mutation in the insulin/IGF-1 receptor) and eat-2 mutant (caloric restriction model), comparison of gene expression profiles of two long-lived mutants provide novel insight into longevity Impaired insulin/IGF-1 signaling (IIS) pathway and caloric restriction (CR) are two well-established interventions to prolong lifespan in worm C. elegans. Although many studies using “-omics” approaches have gained informative knowledges on key longevity regulators in either IIS or CR models, few of those investigated the shared regulators between these two longevity interventions and integrated the messages from different –omics studies. In this study, we aimed to identify key pathways and metabolite fingerprints of longevity shared between the two interventions in worms using a multi-omics integration approach. We collected transcriptomics and metabolomics data from two long-lived mutant worm strains, i.e. daf-2 (impaired IIS pathway) and eat-2 (CR model) and compared with N2 strain. We detected many key pathways that were upregulated at the gene expression level in both long-lived mutants, such as defense response and lipid storage, while synthesis of macromolecules and developmental processes were downregulated at the transcript level. From our polar metabolite analysis, we discovered several shared metabolic features between the two long-lived mutants, including glycerol-3P, adenine, xanthine and AMP. In addition, we detected a lowered amino acid pool and two fatty acid species, C18:0 and C17:1, that behaved similarly in both long-lived mutants. After we integrated transcriptomics and metabolomics data based on the annotations in KEGG, our results highlighted a downregulation of pyrimidine metabolism and upregulation of purine metabolism in both long-lived mutants compared to N2 worms. Overall, our findings point towards the existence of shared metabolic pathways that are important for lifespan extension and provide novel insight of potential regulators and metabolic fingerprints for longevity.
Project description:The WDR-23 protein regulates the transcription factor SKN-1 directly. C. elegans wdr-23 mutants have highly active SKN-1 and are stress resistant, long-lived, small, and reproduce poorly. We used microarrays to measure global gene expression in wdr-23 mutants and to indentify genes regulated by SKN-1.
Project description:Long-lived genetic mutants from different pathways of lifespan extension were used to determine the extent to which there are common downstream mediators of longevity. We have previously obtained RNA-sequencing data from other long-lived mutants including sod-2, clk-1, isp-1, nuo-6 and daf-2. Gene expression will be compared between these nine long-lived mutants.
Project description:To understand how reduced insulin/IGF-1 signaling extends Drosophila lifespan through its downstream transcription factor dFOXO. We conducted ChIP analysis with a dFOXO antibody followed by Illumina high-throughput sequencing from chico heterozygous mutants, which are long-lived and normal sized, and from adult flies with ablated insulin producing cells (IPCs), which are also long-lived. dFOXO bound at promoters of 273 genes common among these genotypes, thus potentially enriching for shared factors in control of aging. Two replicates were sequenced from chico heterozygous mutants and IPC ablated flies.
Project description:HIV is known to severely affect the gastrointestinal immune system, in particular compartments of immunity that regulate gut microbial composition. Furthermore, recent studies in mice have shown that dysregulation of the gut microbiome can contribute to chronic inflammation, which is a hallmark of HIV and is thought to fuel disease progression. We sought to understand whether the gut microbial community differs in HIV-infected subjects, and whether such putative differences are associated with disease progression. We found that dysbiosis in the gut mucosally-adherent bacterial community associates with markers of chronic inflammation and disease progression in HIV-infected subjects, and this dysbiosis remains in many subjects undergiong antiretroviral therapy. We used G3 PhyloChip microarrays (commercially available from Second Genome, Inc.) to profile gut bacteria in rectosigmoid biopsies from 32 subjects: 6 HIV-infected viremic untreated (VU), 18 HIV-infected subjects on highly active antiretroviral therapy (HAART), 1 HIV-infected long-term non-progressor that is untreated (LTNP), and 9 HIV-uninfected subjects (HIV-).
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.
2016-01-20 | GSE76946 | GEO
Project description:Studies of the Gut Microbiota on the Long-Lived Elderly People partB