Integrated Analysis of Ferroptosis and Immune Infiltration in Ulcerative Colitis Based on Bioinformatics

Introduction: Ulcerative colitis (UC) is an inflammatory bowel disease influenced by genetic, immune, and environmental factors. This study investigates the link between ferroptosis, a cell death process related to oxidative stress and iron metabolism, and immune infiltration in UC. Materials and Methods: We analyzed UC patient transcription data from the Gene Expression Omnibus (GEO) and identified ferroptosis-related genes using FerrDB. Using STRING and Cytoscape, we analyzed protein-protein interactions to identify hub UC Differentially Expressed Genes (UCDEGs) and performed functional enrichment with GO and KEGG pathways. Machine learning helped further identify key UC Differentially Expressed Ferroptosis-related genes (UCDE-FRGs), which were validated using additional GEO datasets and immunohistochemical staining. Results: A total of 11 hub UCDEGs ( CCL2, ICAM1, TLR2, CXCL9, MMP9, CXCL10, IL1B, CXCL8, PTPRC, FCGR3A , and IL1A ) and 3 key UCDE-FRGs ( DUOX2, LCN2 and IDO1 ) were identified. GO and KEGG functional enrichment indicates that these genes play a role in immunity and ferroptosis. Analysis of immune cell infiltration showed that there were a large number of Plasma cells, Monocytes, M0/M1 Macrophages and Neutrophils in the UC. Correlation analysis revealed 3 key UCDE-FRGs associated with immune-infiltrated cells in UC. IHC results showed that the expression levels of 3 key UCDE-FRGs in UC were all higher than that in the healthy controls. Conclusion: In summary, this study identified three key genes related to UC ferroptosis and immunity, namely DUOX2, IDO1 and LCN2 . These findings suggest that immune infiltration plays an important role in UC caused by ferroptosis, and that there is mutual regulation between UC and immune-infiltrated cells. Our research revealed the potential application of immune and ferroptosis in the diagnosis, treatment and prognosis of UC, providing new strategies for clinical management. Keywords: ulcerative colitis (UC), inflammatory bowel disease (IBD), machine learning, immune-infiltrated cells, bioinformatics