Abstract:Background and Aims Impaired wound healing in diabetic foot ulcers (DFUs) is a major cause of amputation and mortality in affected patients, and its underlying molecular regulatory mechanisms remain incompletely understood. This study aimed to identify key microRNAs (miRNAs) associated with DFU healing through the integration of a competing endogenous RNA (ceRNA) network and weighted gene co-expression network analysis (WGCNA), and to investigate their biological functions in DFU.Methods Expression profile datasets of circRNAs, lncRNAs, miRNAs, and mRNAs related to DFU were obtained from the Gene Expression Omnibus (GEO) database. Differentially expressed RNAs were identified using the limma package, and a ceRNA regulatory network was constructed. WGCNA was subsequently performed to identify key modules and hub genes associated with DFU healing, followed by the establishment of a hub ceRNA subnetwork. Quantitative real-time PCR (qRT-PCR) was used to determine the expression levels of candidate miRNAs in DFU and control tissues. An in vitro high-glucose model was established using human umbilical vein endothelial cells (HUVECs). Following transfection with miRNA mimics or inhibitors, the effects of hsa-miR-155-5p on cell proliferation, migration, invasion, and angiogenesis were evaluated. Western blot analysis was performed to detect the expression of proteins involved in the PI3K/Akt signaling pathway.Results A total of 66 differentially expressed miRNAs were identified, and a DFU-related ceRNA regulatory network was constructed. WGCNA identified a key module significantly associated with DFU healing and six hub genes, namely PDE9A, PADI2, PRR15L, B3GALT5, TMPRSS2, and NWD1. Integration of the ceRNA network further identified hsa-miR-155-5p, hsa-miR-204-5p, and hsa-miR-302d-3p as candidate miRNAs. qRT-PCR validation demonstrated that hsa-miR-155-5p expression was significantly lower in DFU tissues than in control tissues (P<0.05). In vitro experiments showed that overexpression of hsa-miR-155-5p significantly enhanced the proliferation, migration, invasion, and tube formation abilities of HUVECs under high-glucose conditions, while simultaneously increasing the expression levels of phosphorylated PI3K and Akt proteins (both P<0.05).Conclusion Integrated analysis based on the ceRNA network and WGCNA identified hsa-miR-155-5p as a key miRNA associated with DFU healing. hsa-miR-155-5p may promote endothelial cell function and angiogenesis through activation of the PI3K/Akt signaling pathway, suggesting its potential as a therapeutic target for DFU.