Project description:Aryl hydrocarbon receptor (AHR) activation by tryptophan (Trp) catabolites enhances tumor malignancy and suppresses anti-tumor immunity. Hitherto, indoleamine-2,3-dioxygenase 1 (IDO1) or tryptophan- 2, 3-dioxygenase (TDO2) are recognized as the main Trp-catabolizing enzymes (TCEs) responsible for the generation of AHR agonists. Here, the ability of the aromatic L-amino acid oxidase, interleukin 4 induced 1 (IL4I1), to activate the AHR was investigated using IL4I1 knockout CAS-1 glioblastoma cells.
Project description:RNA-sequencing was performed on intestinal tissues from wild-type, Lao1 knockout, and Lao1/Il4i1 double knockout germ-free mice under normal and 24-hour DSS treatment conditions to identify regulators of intestinal stress response. Lao1 controls 80.1% of DSS-induced transcriptional differences, with Il4i1 adding 14.7%. Lao1 mainly regulates oxidative phosphorylation and cell migration pathways, while Il4i1 modulates lipid metabolism and ER stress responses. These findings establish Lao1 and Il4i1 as hierarchical regulators of intestinal stress responses.
Project description:The objective of this study was to analyze AHR activation through aromatic amino acid metabolism. To this end, glioblastoma cells were exposed to aromatic amino acid derived metabolites and their ability to activate AHR was analysed. In addition, AHR activation was evaluated in glioblastoma cells expressing IL4I1, an aromatic amino acid degrading enzyme, with or without shRNA mediated knockdown of AHR.
Project description:The objective of this study was to analyze AHR activation through aromatic amino acid metabolism. To this end, glioblastoma cells were exposed to aromatic amino acid derived metabolites and their ability to activate AHR was analysed. In addition, AHR activation was evaluated in glioblastoma cells expressing IL4I1, an aromatic amino acid degrading enzyme, with or without shRNA mediated knockdown of AHR.
Project description:The objective of this study was to analyze AHR activation through aromatic amino acid metabolism. To this end, glioblastoma cells were exposed to aromatic amino acid derived metabolites and their ability to activate AHR was analysed. In addition, AHR activation was evaluated in glioblastoma cells expressing IL4I1, an aromatic amino acid degrading enzyme, with or without shRNA mediated knockdown of AHR.
Project description:The objective of this study was to analyze AHR activation through aromatic amino acid metabolism. To this end, glioblastoma cells were exposed to aromatic amino acid derived metabolites and their ability to activate AHR was analysed. In addition, AHR activation was evaluated in glioblastoma cells expressing IL4I1, an aromatic amino acid degrading enzyme, with or without shRNA mediated knockdown of AHR.
Project description:The oxidoreductases interleukin 4-induced gene 1 (IL4I1) and L-Amino acid oxidase 1 (LAO) are known to catalyze L-amino acid metabolism, yet their physiological roles in intestinal homeostasis remain largely unexplored. In this study, we investigated the impact of IL4I1 and LAO1 deficiency on colonic inflammation by generating wild-type, single knockout (IL4I1 KO and LAO1 KO), and double knockout (DKO) mice. Notably, DKO mice exhibited spontaneous diarrhea and histologically confirmed colitis, which were absent or rare in the other genotypes. Transcriptomic profiling and qRT-PCR analyses revealed upregulated expression of pro-inflammatory cytokines (IL-6, IL-17, IFN-γ) and Th1/Th17 transcription factors, along with overexpression of indoleamine 2,3-dioxygenase 1 (IDO1) in the colon of DKO mice. Metabolomic analysis indicated elevated colonic kynurenine levels and impaired metabolism of L-phenylalanine, L-tyrosine, and L-tryptophan. These changes were associated with a significant reduction in hydrogen peroxide (H₂O₂) production. Furthermore, 16S rRNA gene sequencing revealed altered beta diversity and reduced abundance of Short-chain fatty acid-producing bacteria in DKO mice. Among short-chain fatty acids, pentanoate was significantly decreased in DKO cecal contents. Collectively, these findings suggest that IL4I1 and LAO1 are essential for maintaining intestinal immune and metabolic balance. Their combined deficiency disrupts L-amino acid metabolism and H₂O₂-mediated regulation of the IDO1–kynurenine pathway, ultimately promoting gut dysbiosis and inflammatory diarrhea. This study provides novel insights into the metabolic and microbial mechanisms underlying colonic inflammation and highlights IL4I1 and LAO1 as potential targets for therapeutic intervention in inflammatory bowel diseases. This study provides novel insights into the metabolic and microbial mechanisms underlying colonic inflammation and highlights IL4I1 and LAO1 as potential targets for therapeutic intervention in inflammatory bowel diseases.
Project description:To study the function of AMD-associated gene POLDIP2 in retinal pigment epithelial (RPE) cells, we used CRISPR/Cas to knockout POLDIP2 in the human RPE cell line ARPE19. We then performed RNA-seq to profile the transcriptome of wildtype ARPE19 and POLDIP2 knockout.