Arachidonic acid/Alox15 alleviates the progression of ulcerative colitis by modulating ferroptosis levels

Ulcerative colitis (UC) is a long-lasting, nonspecific inflammatory bowel disease involving continuous, diffuse intestinal mucosal injury. The pathogenesis of UC involves genetic polymorphism, oxidative stress, immune response, and microbial infection. Ferroptosis participates in UC progression as a novel non-apoptotic cell death, and its specific mechanism in UC progression deserves further investigation.

In this study, mouse colonic crypts were isolated for 3D cell culture to establish colonic organoid models, and then inflammation was induced by dextran sulfate sodium salt (DSS). Subsequently, the successful establishment of mouse UC organoid models was confirmed by transmission electron microscope (TEM), enzyme-linked immunosorbent assay (ELISA), immunofluorescence (IF), and other assays. Further, the identified UC organoids were analyzed by transcriptome sequencing (RNA-seq) and metabolome assay. The key gene and signaling pathways affecting UC progression were screened by differential expression analysis, enrichment analysis, gene set enrichment analysis (GSEA), and joint analysis. Next, UC mouse models were constructed and the levels of the hub gene were knocked down. The changes in UC progression were observed via hematoxylin and eosin (H&E) staining and ELISA. Finally, UC mice were treated with ferroptosis inhibitors or knockdown molecular, and the specific regulatory mechanism of ferroptosis in UC was verified by ferroptosis marker detection.

After DSS induction, the crypt structure of colonic organoids was incomplete, cell viability was decreased, levels of inflammatory factors were elevated, and levels of epithelial tight junction proteins were reduced, demonstrating the successful establishment of UC organoid models. After joint transcriptome and metabolome analysis of the identified UC organoid models, it was revealed that arachidonic acid/arachidonic acid 15-lipoxygenase (Alox15) was the key pathway and gene affecting UC progression. Further, subsequent assays found that knocking down Alox15 levels did improve UC progression. Finally, UC mice were subjected to ferroptosis inhibition and molecular knockdown treatment. It was found that Alox15 alleviated UC progression by modulating ferroptosis levels.

Alox15 alleviates UC progression by modulating ferroptosis levels.