NCF2 as a Novel Diagnostic Biomarker in Ulcerative Colitis: Linking Macrophage Infiltration to Immune Dysregulation via Multi-Omics Analysis

Background: Ulcerative colitis (UC) is a debilitating inflammatory condition with growing global prevalence. While immune dysregulation is a known hallmark, the specific molecular drivers and their link to fibrosis remain incompletely characterized. To address this, we conducted a study combining bioinformatic analyses of public datasets with experimental validation to identify and validate key biomarker candidates involved in UC pathogenesis. Methods: Three publicly available ulcerative colitis gene expression datasets (GSE38713, GSE87466, GSE119600) were retrieved from the Gene Expression Omnibus (GEO). Immune cell infiltration was evaluated using ssGSEA, with significant cell types identified by Wilcoxon test and LASSO regression. DEGs were screened and analyzed using GO, KEGG, and PPI networks. Hub genes were identified using cytoHubba and validated via ROC curves. RT-qPCR, WB, and IHC validated findings in UC rat models and clinical samples. Results: The differentially expressed genes (DEGs) were evaluated using ten distinct algorithms, resulting in the identification of eight common DEGs following an intersection analysis. 4 hub genes were further identified through validation using the GSE119600 dataset, namely Cluster of Differentiation 274 (CD274), Matrix Metallopeptidase 1 (MMP1), neutrophil cytosolic factor 2 (NCF2), Plasminogen Activator Urokinase (PLAU). Notably, NCF2 demonstrated the highest specificity and sensitivity for diagnosing ulcerative colitis (UC), suggesting its potential utility as a diagnostic biomarker. Additionally, a distinct immune cell type exhibited significant differences between UC patients and healthy controls (HC). Correlation analyses utilizing bioinformatics techniques revealed that the hub genes CD274, MMP1, NCF2, and PLAU were positively associated with macrophage infiltration, highlighting their potential role in the immune response in UC. Conclusion: CD274, MMP1, NCF2, PLAU can serve as hub genes associated with UC. Among these, NCF2 stands out as a particularly promising target for further research into the underlying mechanisms of UC. Additionally, NCF2 may play a role in the development and progression of UC by modulating macrophage infiltration.