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: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
Project description:Acne vulgaris is a chronic inflammatory dermatosis where conventional therapies of-ten face limitations in efficacy and safety, necessitating the development of microbi-ome-targeted interventions. This study investigated the immunomodulatory potential of microbiome-derived tryptophan metabolites as a novel therapeutic strategy for Cutibacterium acnes-induced inflammation, focusing on the aryl hydrocarbon receptor (AHR) pathway. We evaluated indole-3-lactic acid (ILA), indole-3-acrylic acid (IAA), and indole-3-propionic acid (IPA) in comparison to tapinarof, utilizing C. ac-nes-stimulated human epidermal keratinocytes and a C. acnes-induced acne mouse model. In vitro, ILA and IPA significantly suppressed C. acnes-driven inflammatory mediators, including TNF-α, IL-1β, and COX2, whereas IAA demonstrated limited ef-ficacy. In vivo, ILA treatment exhibited superior therapeutic activity, markedly reduc-ing inflammatory cell infiltration, epidermal hyperplasia, and IL-1β expression. Tran-scriptomic analysis confirmed that ILA attenuates inflammatory signaling (e.g., IL-17 and TNF pathways) while upregulating AHR-responsive genes such as CYP1A1 and CYP1B1. Collectively, these findings establish ILA as a potent postbiotic that mitigates cutaneous inflammation through selective activation of the AHR. Future studies should prioritize the clinical translation of ILA-based topical fomulations, with rigorous evaluation of their efficacy and safety in well-designed human trials, to support their development as a non-antibiotic therapeutic alternative for acne management.
Project description:Lactobacillus intestinalis-derived indole-3-propionic acid mediates benefits of maternal tryptophan metabolism on offspring intestinal health
| PRJNA721108 | ENA
Project description:Clostridium sporogenes and its tryptophan metabolite indole-3-propionic acid repair antibiotic-induced muscle atrophy in mice
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:Sensing of microbial tryptophan catabolites by the aryl hydrocarbon receptor (AhR) plays a pivotal role in host-microbiome homeostasis by modulating the host immune response. Thereby the involved cellular processes triggered by the metabolites are largely unknown. We analyzed proteomic changes in macrophages trough 24h after treatment with the tryptophan metabolites indole-3-acetic acid (I3AA) or indole-3-aldehyde (IAld), as well as the prototypic AhR-ligand Benzo(a)pyrene (BaP) in the absence and presence of LPS to identify affected processes and pathways.