Project description:Purpose: Gut microbiota-derived metabolites play a pivotal role in the maintenance of local gut homeostasis and can even induce systemic effects via accumulation in the bloodstream. Here, we demonstrate that mono-colonization of germ-free (GF) mice with Clostridium sporogenes protects mice from inflamation and death induced by DSS colitis. Method: 8-12-week-old male mice (GF, SPF and GF colonized with C. sporogenes (CS)) were treated with 2.5% DSS in drinking water for 5 days and colon tissue was isolated on day 7. RNA was isolated from the colon tissue and RNA sequenzing was performed. Results: Mono-colonization of GF mice with Clostridium sporogenes protected the mice from DSS colitis induced death, while producing high amounts of indole-3-propionic acid (IPA), branched chain (BCFA) and short-chain (SCFA) fatty acids. In comparison to CS mice, SPF mice showed much higher levels of inflammatory related genes and a worse histological score. Conclusion: Histological stainings and the RNAseq both showed high levels of protection of C. sporogenes colonized mice in colitis, compared to SPF and GF animals. The data provide evidence for a therapeutic potential of C. sporogenes for IBD patients.
Project description:Recently, gut metabolites have been recognized to play significant roles in liver diseases via the gut-liver axis. In this study, we investigate the regulatory effects of the tryptophan metabolite, indole-3-propionic acid (IPA), on immune cells during liver fibrogenesis using single-cell RNA sequencing (scRNA-seq).
Project description:Genomic DNA of 61 strains of proteolytic Clostridium botulinum or Clostridium sporogenes was subjected to analysis by DNA microarray.
Project description:Indole-3-pyruvate (I3P), an endogenous metabolite derived from tryptophan by gut microbiota and IL4I1 enzyme in humans can potentially activate the transcriptional activity of the Aryl Hydrocarbon receptor. Here we test this by stimulating AHR proficient U-87MG cells with I3P alone or in combination with the AHR antagonist SR1.
Project description:Altered tryptophan catabolism has been identified in inflammatory diseases like rheumatoid arthritis (RA) and spondyloarthritis (SpA), but the causal mechanisms linking tryptophan metabolites to disease are unknown. Using the collagen-induced arthritis (CIA) model we identify alterations in tryptophan metabolism, and specifically indole, that correlate with disease. We demonstrate that both bacteria and dietary tryptophan are required for disease, and indole supplementation is sufficient to induce disease in their absence. When mice with CIA on a low-tryptophan diet were supplemented with indole, we observed significant increases in serum IL-6, TNF, and IL-1β; splenic RORγt+CD4+ T cells and ex vivo collagen-stimulated IL-17 production; and a pattern of anti-collagen antibody isotype switching and glycosylation that corresponded with increased complement fixation. IL-23 neutralization reduced disease severity in indole-induced CIA. Finally, exposure of human colon lymphocytes to indole increased expression of genes involved in IL-17 signaling and plasma cell activation. Altogether, we propose a mechanism by which intestinal dysbiosis during inflammatory arthritis results in altered tryptophan catabolism, leading to indole stimulation of arthritis development. Blockade of indole generation may present a novel therapeutic pathway for RA and SpA.
Project description:The members of the genus Clostridium, such as the other spore-forming anaerobic bacteria, have a complex and strictly regulated life-cycle but very little is known about genetic pathways involved at different stages. Clostridium sporogenes, Gram positive bacterium usually involved in food spoilage and frequently isolated from late blowed cheese is genetically indistinguishable from proteolytic Clostridium botulinum and is the non-neurotoxigenic counterpart often used as exemplar for the toxic subtypes. In this work we have performed a microscopy study combined with a custom array-based analysis of C. sporogenes cycle, from dormant spores to early stationary phase. We identified in spores a total of 211 transcripts validating the ipothesis that mRNAs are abundant and strikingly different from those present in growing cells. The spores transcripts included genes responsible of different life-sustaining functions, suggesting the theory of transcripts entrapment or of a basic poly-functional genes activation for future steps. In addition, after three hours from the beginning of the germination process, a 20% of the total up-regulated genes were temporally expressed in germinating spores. The vegetative condition appears to be the more active in terms of gene transcription and protein synthesis and also genes for germination and sporulation factors seem to be expressed at this point. These results suggest that spores are not silent entities and a wider knowledge about genetic pathways involved in Clostridium life cycle could be of help for a better understanding also of pathogenic clostridia types. RNA was isolated from spores, germinating spores (3h), outgrowth/transitional mid-log vegetative cells and early stationary cells of Clostridium sporogenes UC9000 previously isolated from milk. There were 3 biological replicates (independent cultures) for each condition. Probes corresponding to 3400 genomic CDSs of C. botulinum A ATCC 3502 were synthesized in three replicates randomly distributed on the chip.
Project description:The members of the genus Clostridium, such as the other spore-forming anaerobic bacteria, have a complex and strictly regulated life-cycle but very little is known about genetic pathways involved at different stages. Clostridium sporogenes, Gram positive bacterium usually involved in food spoilage and frequently isolated from late blowed cheese is genetically indistinguishable from proteolytic Clostridium botulinum and is the non-neurotoxigenic counterpart often used as exemplar for the toxic subtypes. In this work we have performed a microscopy study combined with a custom array-based analysis of C. sporogenes cycle, from dormant spores to early stationary phase. We identified in spores a total of 211 transcripts validating the ipothesis that mRNAs are abundant and strikingly different from those present in growing cells. The spores transcripts included genes responsible of different life-sustaining functions, suggesting the theory of transcripts entrapment or of a basic poly-functional genes activation for future steps. In addition, after three hours from the beginning of the germination process, a 20% of the total up-regulated genes were temporally expressed in germinating spores. The vegetative condition appears to be the more active in terms of gene transcription and protein synthesis and also genes for germination and sporulation factors seem to be expressed at this point. These results suggest that spores are not silent entities and a wider knowledge about genetic pathways involved in Clostridium life cycle could be of help for a better understanding also of pathogenic clostridia types.
Project description:Purpose: compare the response of DRG neurons to indole-3-propionic acid treatment before and after sciatic nerve injury Results: we found that IPA induced transcription changes before and after injury inside the DRG tissue. In particular expression of immune system related genes