Identification of Ferro‐Aging‐Related Biomarkers for Ulcerative Colitis Through Integrated Machine Learning, Single‐Cell Analysis, and Spatial Transcriptomics

Ulcerative colitis (UC) is characterized by chronic mucosal inflammation, epithelial injury, oxidative stress, and marked molecular heterogeneity. Ferro-aging has recently been proposed as an ACSL4-associated, iron-dependent aging-related state in primates, but whether its associated transcriptional features are relevant to chronic mucosal inflammatory disease remains unclear. Here, we integrated bulk transcriptomics, machine learning, single-cell RNA sequencing, spatial transcriptomics, and immunohistochemical validation of clinical tissue samples to characterize ferro-aging-related features in UC and identify associated biomarkers. Ferro-aging-related activity was quantified using GSVA and GSEA and was increased in UC, particularly in active disease, with strong associations with inflammatory response, oxidative stress, epithelial injury, and immune-cell infiltration. Transcriptomic stratification further identified a ferro-aging-high state characterized by enhanced inflammatory and tissue-remodeling signatures. WGCNA and LASSO logistic regression generated a five-gene diagnostic model that showed strong performance in the discovery and validation cohorts and was further validated in an independent external cohort (AUC = 0.992, 95% CI 0.979-1.000). Single-cell analysis localized ferro-aging-related activity and prioritized genes mainly to endothelial, fibroblast, and myeloid compartments, while CellChat suggested enhanced myeloid-centered communication involving MIF-CD74/CD44 and collagen-CD44 interactions. Spatial transcriptomics and immunohistochemistry further supported increased CHST15 and MSN expression in UC mucosa. Exploratory candidate-ligand analyses additionally identified Chst15-IN-1 and Polyphyllin VII for future experimental investigation. Collectively, these findings identify CHST15 and MSN as ferro-aging-related biomarkers linking mucosal inflammation, immune-stromal remodeling, and disease-associated tissue organization in UC.