Expression of lactylation-related genes and their correlation with diabetic foot ulcer occurrence and immune infiltration.

Background: Diabetic foot ulcers (DFUs) represent a severe complication of diabetes, often leading to chronic non-healing wounds and high amputation risk. Lactylation, a recently recognized post-translational modification driven by lactate metabolism, has emerged as a key regulator of immune response and gene expression. However, its role in DFU pathogenesis remains largely unexplored. This study aims to systematically investigate lactylation-related genes and their association with immune dysregulation in DFUs. Methods: Transcriptomic data from three GEO datasets (GSE134431, GSE80178, GSE68183) were integrated and normalized to identify differentially expressed genes (DEGs). A lactylation-related gene set was compiled from published literature. Machine learning approaches, including LASSO regression and Random Forest, were applied to screen for core genes. Immune infiltration profiles were assessed using ssGSEA. Experimental validation was conducted in high-glucose-stimulated macrophages and human DFU tissues via qPCR, Western blot, immunohistochemistry, and immunofluorescence. Results: We integrated three transcriptomic datasets comprising 25 DFU and 14 normal tissues, identifying 1,234 differentially expressed genes (DEGs). Among these, 38 overlapped with lactylation-related genes, with 27 significantly downregulated in DFU. Machine learning algorithms identified three core lactylation-associated genes: CHD4, EEF1A1, and EEF1G, which exhibited significant downregulation in DFU and demonstrated high within cohort classification performance with AUC values of 0.860, 0.926, and 0.989, respectively. Immune infiltration analysis revealed these genes positively correlated with natural killer cells and negatively correlated with neutrophil infiltration. Experimental validation in high glucose-treated macrophages and human DFU tissues confirmed their reduced expression at both transcriptional and protein levels, particularly noting marked loss of EEF1A1 in epidermal layers and infiltrating CD68+ macrophages. Direct measurement of lysine lactylation (Kla) confirmed increased global lactylation under diabetic conditions. Conclusion: This study identifies CHD4, EEF1A1, and EEF1G as key lactylation-related genes involved in DFU progression, with significant classificational potential and close links to immune microenvironment dysregulation. These findings highlight lactylation as a promising regulatory mechanism in diabetic wound pathology and support further development of lactylation-targeted biomarkers and therapeutic strategies for DFU management, and require external validation and functional mechanistic studies.