Bile acid metabolism Modulate intestinal immunity involved in ulcerative colitis progression

Abstract Background: Bile acid is an important participant in intestinal immunity and inflammation, which exert their immune regulatory effects by interacting with immune cells in the intestine，many immune cells are involved in the pathogenesis of ulcerative colitis (UC), but the underlying mechanisms between Bile acid and immunity are unknown. Object: The aim of this study was to investigate the relationship between Bile acid metabolism (BCM) and inflammation in colonic tissues and to identify potential therapeutic targets for modulating immune responses. Methods: A total of 2,318 differentially expressed genes (DEGs) and 35 BCM-associated DEGs were obtained, and the results of gene ontology analysis showed that DEGs were significantly enriched in the positive regulation of NK cell and T cell activation. Fifteen types of immune cells were identified in inflamed colon tissues. Results: Five BCM-associated DEGs (APOA1, AMACR, PEX19, CH25H, and AQP9) were highly correlated with immune-associated DEGs and all were significantly up/down-regulated in immune cells. And we further found at the cellular level that AQP9 gene expression may be regulated by IFN-γ- JAK signaling pathway promotes CD8+T cell activation. Conclusion: This study contributes to the understanding of the pathogenesis and the mechanism of BCM in UC immune cells.