Project description:We assembled and annotated a de novo transcriptome using RNA-seq data consisting of regenerating and non-regenerating intestinal tissues from the sea cucumber Holothuria glaberrima. Analysis of differential expression revealed a large number of differentially expressed transcripts associated with transcription factors with diverse expression patterns. Activity involving developmental and cancer-related events found in the analysis could be related to the regenerative process. Our study demonstrates the broad and diversified gene expression profile during the early stages of the process using the mesentery as the focal point of intestinal regeneration. It also establishes the genes that are the most important candidates in the cellular processes that underlie regenerative responses.
Project description:Regenerating intestine tissues were compared with normal (non-regenerating tissues) to determine the gene expression profile at early stages of regeneration (3, 7 and 14 days post- evisceration (dpe)). Immuno activated tissues with LPS were compared with Normal (non-regenerating tissues) and regenerating tissues (3 and 7 dpe) to determine the gene expression of immune related genes in the sea cucumber and it's expression during early stages of regeneration.
Project description:Regenerating intestine tissues were compared with normal (non-regenerating tissues) to determine the gene expression profile at early stages of regeneration (3, 7 and 14 days post- evisceration (dpe)). Immuno activated tissues with LPS were compared with Normal (non-regenerating tissues) and regenerating tissues (3 and 7 dpe) to determine the gene expression of immune related genes in the sea cucumber and it's expression during early stages of regeneration. 16 Total arrays. 8 comparisons with 8 dye swap replicates. Normal Vs. (3, 7 and 14 days of regeneration), and Vs. (LPS) 2 microarray slides used. Each slide with 8 Arrays (8 x 15k). 15,744 probes printed per array. (all 16 arrays are identically printed). 7,209 ESTs from Normal, 3 dpe and 7 dpe tissues were used to design the probes. Two probes per EST from diferent regions of the sequence (as a technical replicate). 536 technical controls and more than 600 internal biological controls (from different species).
Project description:Invariant Natural Killer T (iNKT) cells are unconventional T cells that respond to microbe-derived glycolipid antigens. iNKT cells exert fast innate effector functions that regulate immune responses in a variety of contexts, including during infection, cancer, or inflammation. The roles these unconventional T cells play in intestinal inflammation remain poorly defined and vary based on the disease model and species. Our previous work suggested that the gut microbiota influenced iNKT cell functions during dextran sulfate sodium-induced colitis in mice. This study, shows that iNKT cell homeostasis and response following activation are altered in germ-free mice. Using prenatal fecal transplant in specific pathogen-free mice, we show that the transcriptional signatures of iNKT cells at steady state and following αGC-mediated activation in vivo are modulated by the microbiota. Our data suggest that iNKT cells sense the microbiota at homeostasis independently of their T cell receptors. Finally, iNKT cell transcriptional signatures are different in male and female mice. Collectively, our findings suggest that sex and the intestinal microbiota are important factors that regulate iNKT cell homeostasis and responses. A deeper understanding of microbiota-iNKT cell interactions and the impact of sex could improve the development of iNKT cell-based immunotherapies.
Project description:Inappropriate cross talk between mammals and their gut microbiota may trigger intestinal inflammation and drive extra-intestinal immune-mediated diseases. Studies with germ-free or gnotobiotic animals represent the gold standard for research on bacterial-host interaction but they are not readily accessible to the wide scientific community. We aimed at refining a protocol that in a robust manner would deplete murine intestinal microbiota and prove to have significant biologic validity. Previously published protocols for depleting mice of their intestinal microbiota by administering broad-spectrum antibiotics in drinking water were difficult to reproduce. We show that twice daily delivery of antibiotics by gavage depleted mice of their cultivable fecal microbiota and reduced the fecal bacterial DNA load by approximately 400 fold while ensuring the animals’ health. Mice subjected to the protocol for 17 days displayed enlarged ceca, reduced Peyer’s patches and small spleens. Antibiotic treatment significantly reduced the expression of antimicrobial factors and altered the expression of 517 genes in total in the colonic epithelium. Genes involved in cell cycle were significantly altered concomitant with reduced epithelial proliferative activity in situ assessed by Ki-67 expression, suggesting that commensal microbiota drives cellular proliferation in colonic epithelium. We present a robust protocol for depleting mice of their cultivatable intestinal microbiota with antibiotics by gavage and show that the biological effect of this depletion is phenotypic characteristics and epithelial gene expression profile similar to those of germ-free mice. Comparison of genome-wide gene expression of colon intestinal epithelial cells from mice subjected to microbiota depletion protocol against to control mice.
Project description:We reported the effects of AOS10 on the intestinal microbiota, and found that this drug could benefit the pig's sperm quantity via improvement of intestinal microbiota.
Project description:This SuperSeries is composed of the SubSeries listed below. Acquisition of the intestinal microbiota begins at birth, and a stable microbial community develops from a succession of key organisms. Disruption of the microbiota during maturation by low-dose antibiotic exposure can alter host metabolism and adiposity. We now show that low-dose penicillin (LDP), delivered from birth, induces metabolic alterations and affects ileal expression of genes involved in immunity. LDP that is limited to early life transiently perturbs the microbiota, which is sufficient to induce sustained effects on body composition, indicating that microbiota interactions in infancy may be critical determinants of long-term host metabolic effects. In addition, LDP enhances the effect of high-fat diet induced obesity. The growth promotion phenotype is transferrable to germ-free hosts by LDP-selected microbiota, showing that the altered microbiota, not antibiotics per se, play a causal role. These studies characterize important variables in early-life microbe-host metabolic interaction and identify several taxa consistently linked with metabolic alterations. Refer to individual Series
Project description:The intestinal microbiota is a key regulator of mammalian lipid absorption, metabolism, and storage. Here we show that the microbiota reprograms intestinal lipid metabolism in mice by repressing the expression of long non-coding RNA (lncRNA) Snhg9 in small intestinal epithelial cells. Snhg9 suppressed the activity of the transcription factor peroxisome proliferator–activated receptor γ (PPARγ) – a central regulator of lipid metabolism – by dissociating the PPARγ inhibitor Sirtuin 1 from cell cycle and apoptosis protein 2 (CCAR2). Forced expression of Snhg9 in the intestinal epithelium of conventional mice lowered dietary lipid absorption, reduced body fat, and protected against diet-induced obesity. The microbiota repressed Snhg9 expression through an immune cell signaling relay encompassing myeloid cells and innate lymphoid cells. Our findings thus identify an unanticipated role for a lncRNA in microbial control of host metabolism.
Project description:The intestinal microbiota has been identified as an environmental factor that markedly impacts energy storage and body fat accumulation, yet the underlying mechanisms remain unclear. Here we show that the microbiota regulates body composition through the circadian transcription factor NFIL3. Nfil3 transcription oscillates diurnally in intestinal epithelial cells and the amplitude of the circadian oscillation is controlled by the microbiota through type 3 innate lymphoid cells (ILC3), STAT3, and the epithelial cell circadian clock. NFIL3 controls expression of a circadian lipid metabolic program and regulates lipid absorption and export in intestinal epithelial cells. These findings provide mechanistic insight into how the intestinal microbiota regulates body composition and establish NFIL3 as an essential molecular link among the microbiota, the circadian clock, and host metabolism.
Project description:We profiled transcriptome and accessible chromatin landscapes in intestinal epithelial cells (IECs) from mice reared in the presence or absence of microbiota. We show that regional differences in gene transcription along the intestinal tract were accompanied by major alterations in chromatin organization. Surprisingly, we discovered that microbiota modify host gene transcription in IECs without significantly impacting the accessible chromatin landscape. Instead, microbiota regulation of host gene transcription might be achieved by differential expression of specific TFs and enrichment of their binding sites in nucleosome depleted CRRs near target genes. Our results suggest that the chromatin landscape in IECs is pre-programmed by the host in a region-specific manner to permit responses to microbiota through binding of open CRRs by specific TFs. mRNA and accessible chromatin (DNase-seq) profiles from colonic and ileal IECs were compared between conventionally-raised (CR), germ-free (GF), and conventionalized (CV) C57BL/6 mice.