Cuproptosis-driven reprogramming of fibroblast communication by GK is associated with the immune microenvironment in diabetic foot ulcers.

Background: Diabetic foot ulcers (DFUs) involve chronic inflammation and impaired healing. Emerging evidence implicates copper-dependent regulated cell death (cuproptosis) in immune microenvironment regulation, but its role in DFU fibroblast-immune crosstalk remains unknown. Methods: We analyzed scRNA-seq datasets (GSE231643, GSE134431) from DFU/healthy skin. After quality control (25,198 cells retained) and clustering, fibroblasts with elevated cuproptosis scores were identified via ssGSEA. Fibroblast-specific DEGs were screened (Wilcoxon rank-sum; |log Results: Through scRNA-seq analysis of 33,095 cells (25,198 post-quality control), fibroblasts exhibited the highest cuproptosis-related pathway scores. A total of 543 fibroblast-specific DEGs were identified, significantly enriched in pathways such as PI3K-Akt, chemokine signaling, NF-κB, IL-17 signaling, and AGE-RAGE signaling. GO analysis revealed enrichment in processes associated with extracellular matrix organization, inflammation regulation, and immune signaling. Integrated analyses involving bulk transcriptomics and machine learning identified GK as a robust cuproptosis-associated diagnostic biomarker (AUC=0.929, 95% CI: 0.714-1.000). GK expression positively correlated with neutrophil infiltration (R=0.95, p=0.00081) and negatively correlated with CD8 Conclusions: Our data indicate that the cuproptosis-related gene GK is associated with alterations in DFU immune communication through fibroblast-centric networks, as reflected by correlations with immune infiltration and predicted ligand-receptor crosstalk. GK therefore represents a promising candidate diagnostic biomarker and a potential therapeutic target for DFUs that warrants further functional validation.