Project description:The licensed drug rapamycin has potential to be repurposed for geroprotection. A key challenge is to avoid the adverse side-effects of clinical dosing regimes. Here we show a profound memory effect of brief rapamycin treatment. Brief, early adult treatment extended lifespan in Drosophila to the same degree as lifelong dosing. Lasting memory of earlier rapamycin treatment was mediated by elevated autophagy in enterocytes of the gut, accompanied by increased intestinal spermidine levels and improved structure and function of the ageing intestine. Brief elevation of autophagy itself induced a long-term increase in autophagy. In mice, short-term, 3-month treatment also induced a full memory effect, with enhanced autophagy in Paneth cells, improved Paneth cell architecture and gut barrier function at levels induced by chronic treatment, even 6 months after rapamycin was withdrawn. Past rapamycin treatment also enhanced the regenerative potential of aged intestine in intestinal organoids. Full geroprotective effects of chronic rapamycin treatment can thus be obtained with a brief pulse of the drug.
Project description:Transplant recipients require lifelong, multimodal immunosuppression to prevent rejection by reducing alloreactive immunity. Rapamycin, a mechanistic target of rapamycin (mTOR) inhibitor, is known to modulate adaptive and innate immunity, while the full spectrum of its immunosuppressive mechanisms remains incompletely understood. Given the broad expression of mTOR, we investigated the understudied effects of rapamycin on lymph node (LN) architecture, leukocyte trafficking, and the gut microbiome and metabolism after 3, 7, and 30 days of rapamycin treatment, to characterize the early, intermediate, and late changes. Rapamycin significantly reduced CD4+ T cells, CD8+ T cells, and regulatory T (Treg) cells in peripheral LNs, mesenteric LNs, and the spleen over time. Rapamycin induced early pro-inflammation transition to pro-tolerogenic status, by modulating the LN laminin α4:α5 expression ratios (La4:La5) through LN stromal cells laminin α5 expression and by adjusting Treg numbers and distribution. Additionally, rapamycin significantly altered gut microbiota composition and metabolic functions, shifting the Bacteroides to Firmicutes ratio and increasing amino acid bioavailability in the gut lumen. These effects were evident by 7 days and became most pronounced by 30 days in naïve mice, with notable changes as early as 3 days in allogeneic splenocyte-stimulated mice. These findings reveal a novel mechanism of rapamycin action through time-dependent modulation of LN architecture and gut microbiome, which orchestrates changes in immune cell trafficking, providing a new framework for understanding and optimizing immunosuppressive therapies.
Project description:Snt2 is a yeast chromatin-interacting protein whose function has not been well characterized, that was recently shown to associate with Ecm5 and the Rpd3 deacetylase. Using chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq), we show that in response to H2O2, Snt2 and Ecm5 colocalize to promoters of genes involved in various aspects of the environmental stress response. By integrating these ChIP-seq results with expression analysis, we identify a key set of target genes that require Snt2 for proper expression after H2O2 stress. Finally, by mapping Snt2 and Ecm5 localization before and after rapamycin treatment, we identify a subset of H2O2-specific Snt2 and Ecm5 target promoters that are also targeted in response to rapamycin. Our results establish a function for Snt2 in regulating transcriptional changes in response to oxidative stress, and suggest Snt2 may have a role in additional stress pathways. Crosslinking ChIP analysis to identify sites of Snt2 or Ecm5 genomic localization before, 0.5 hours after, or 4 hours after treatment with rapamycin (final concentration 5 nM) or with DMSO as a control. Snt2 and Ecm5 were genomically tagged with a 13Myc tag at their C termini. ChIPs were performed using a Myc antibody on either Snt2-Myc or Ecm5-Myc strains, or on untagged wildtype strain (BY4741) as a control. Inputs and ChIPs from untagged strain were sequenced as controls.
Project description:Dynamic mRNA gene expression from the wildtype YSBN6 during a rapamycin treatment (rapamycin-induced downshift). Rapamycin was added to yeast cells growing exponentially on glutamine as sole nitrogen source. A sample was taken at steady-state 10 minutes before , and then 3, 7, 10, 14, 24, 56 and 120 minutes after rapamycin treatment. Biological triplicate gene expression was measured for samples -10, 7 and 24 minutes after shift, for a total of 14 chips. Changes were generally evaluated relative to the steady-state point (-10 minutes). Biological variability can be assessed from the replicates time points. Other dynamic omics data are associated with this dataset. Consult the publication for more details.
Project description:Besides promoting inflammation by mobilizing lipid mediators, secreted phospholipase A2 group IIA (sPLA2-IIA) prevents bacterial infection by degrading bacterial membranes. Here we show that despite the restricted intestinal expression of sPLA2-IIA in BALB/c mice, its genetic deletion leads to amelioration of cancer and exacerbation of psoriasis in distal skin. Intestinal expression of sPLA2-IIA is reduced after antibiotics treatment or under germ-free conditions, suggesting its upregulation by gut microbiota. Metagenome, transcriptome and metabolome analyses have revealed that sPLA2-IIA deficiency alters the gut microbiota, accompanied by notable changes in the intestinal expression of genes related to immunity and metabolism as well as the levels of various blood metabolites and fecal bacterial lipids, suggesting that sPLA2-IIA contributes to shaping of the gut microbiota. The skin phenotypes in Pla2g2a–/– mice are lost when they are co-housed with littermate wild-type mice, resulting in mixing of the microbiota between the genotypes, or when they are housed in a more stringent pathogen-free facility, where Pla2g2a expression in wild-type mice is low and the gut microbial compositions in both genotypes are nearly identical. Thus, our results highlight a new aspect of sPLA2-IIA as a modulator of gut microbiota, perturbation of which affects distal skin responses.
Project description:On going efforts are directed at understanding the mutualism between the gut microbiota and the host in breast-fed versus formula-fed infants. Due to the lack of tissue biopsies, no investigators have performed a global transcriptional (gene expression) analysis of the developing human intestine in healthy infants. As a result, the crosstalk between the microbiome and the host transcriptome in the developing mucosal-commensal environment has not been determined. In this study, we examined the host intestinal mRNA gene expression and microbial DNA profiles in full term 3 month-old infants exclusively formula fed (FF) (n=6) or breast fed (BF) (n=6) from birth to 3 months. Host mRNA microarray measurements were performed using isolated intact sloughed epithelial cells in stool samples collected at 3 months. Microbial composition from the same stool samples was assessed by metagenomic pyrosequencing. Both the host mRNA expression and bacterial microbiome phylogenetic profiles provided strong feature sets that clearly classified the two groups of babies (FF and BF). To determine the relationship between host epithelial cell gene expression and the bacterial colony profiles, the host transcriptome and functionally profiled microbiome data were analyzed in a multivariate manner. From a functional perspective, analysis of the gut microbiota's metagenome revealed that characteristics associated with virulence differed between the FF and BF babies. Using canonical correlation analysis, evidence of multivariate structure relating eleven host immunity / mucosal defense-related genes and microbiome virulence characteristics was observed. These results, for the first time, provide insight into the integrated responses of the host and microbiome to dietary substrates in the early neonatal period. Our data suggest that systems biology and computational modeling approaches that integrate “-omic” information from the host and the microbiome can identify important mechanistic pathways of intestinal development affecting the gut microbiome in the first few months of life. KEYWORDS: infant, breast-feeding, infant formula, exfoliated cells, transcriptome, metagenome, multivariate analysis, canonical correlation analysis 12 samples, 2 groups
Project description:Snt2 is a yeast chromatin-interacting protein whose function has not been well characterized, that was recently shown to associate with Ecm5 and the Rpd3 deacetylase. Using chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq), we show that in response to H2O2, Snt2 and Ecm5 colocalize to promoters of genes involved in various aspects of the environmental stress response. By integrating these ChIP-seq results with expression analysis, we identify a key set of target genes that require Snt2 for proper expression after H2O2 stress. Finally, by mapping Snt2 and Ecm5 localization before and after rapamycin treatment, we identify a subset of H2O2-specific Snt2 and Ecm5 target promoters that are also targeted in response to rapamycin. Our results establish a function for Snt2 in regulating transcriptional changes in response to oxidative stress, and suggest Snt2 may have a role in additional stress pathways. Crosslinking ChIP analysis to identify sites of Snt2 or Ecm5 genomic localization before, 0.5 hours after, or 4 hours after treatment with H2O2 (final concentration 0.4 mM). Snt2 and Ecm5 were genomically tagged with a 13Myc tag at their C termini. ChIPs were performed using a Myc antibody on either Snt2-Myc or Ecm5-Myc strains, or on an untagged wildtype strain (BY4741) as a control. Inputs and ChIPs from untagged strain were sequenced as controls.