Deciphering the macrophage ferroptosis regulatory network: construction of an ulcerative colitis diagnostic model and investigation of the immune microenvironment based on single-cell and transcriptomic data.

Background: Ulcerative colitis (UC) is a chronic inflammatory bowel disease manifested as persistent mucosal inflammation and immune dysregulation. As key regulators of intestinal immune homeostasis, macrophages are pivotal in the amplification of inflammation and tissue repair in UC. However, the molecular mechanisms associated with ferroptosis in macrophages remain unclear. Method: We integrated single-cell and bulk colonic transcriptomes to map ferroptosis-associated programs in UC macrophages, prioritized candidate regulators using network/ML frameworks, and performed targeted experimental validation. Results: We identified a ferroptosis-associated transcriptional program enriched in UC macrophages and derived a four-gene signature (HIF1A, S100A8, CYBB, GLS) linked to redox/iron stress. Among them, CYBB encodes NOX2 (the catalytic subunit of NADPH oxidase), and emerged as a key node associated with enhanced oxidative/iron stress and coordinated changes in ferroptosis-related markers in macrophages. Conclusion: This study systematically delineates the ferroptosis-associated transcriptional network in macrophages of UC, providing a systems-level framework linking macrophage redox/iron imbalance to ferroptosis vulnerability in UC and nominating CYBB-centered pathways for mechanistic interrogation and stratification-oriented biomarker development, thereby offering novel theoretical insights for immune metabolism mechanisms and targeted therapies in UC.