ObjectiveTo explore the differentially expressed genes (DEGs) in venous leg ulcer (VLU) by bioinformatics, and further explore the molecular mechanism of the disease, predict early diagnostic markers and treatment targets.MethodsThe expression profiles of VLU were downloaded from the gene expression omnibus (GEO) database, the DEGs of VLU and inflammatory phase of normal skin healing were identified by R software and used to perform gene ontology (GO) and KEGG pathway enrichment analysis, obtaining the key genes of the pathway. We analyzed the proteins of protein interaction (PPI) network by STRING database and Cytoscape 3.2.1 software to obtain hub genes.ResultsA total of 409 DEGs were obtained, including 173 upregulted genes and 236 downregulted genes. The GO analysis showed that the upregulated DEGs mainly distributed in collagen-containing extracellular matrix (ECM), cornified envelope and collagen trimer, involved in biological processes such as skin development, keratinocyte differentiation and cornification, which mediated molecular functions such as ECM structural constituent, ECM structural constituent conferring tensile strength and integrin binding. The downregulated DEGs mainly distributed in tertiary granule, secretory granule membrane and tertiary granule membrane cornification, involved in biological processes such as response to chemokine, leukocyte migration and neutrophil chemotaxis, which mediated molecular functions such as chemokine activity, chemokine receptor binding and cytokine activity. KEGG pathway enrichment analysis results showed that the upregulated DEGs were mainly enriched in ECM-receptor interaction and protein digestion and absorption pathways, collagen type Ⅰ alpha1 chain (COL1A1), collagen type Ⅰ alpha2 chain (COL1A2), and collagen type Ⅵ alpha 6 chain (COL6A6) were the key genes of pathway; the downregulated DEGs were mainly enriched in Staphylococcus aureus infection, Toll-like receptor signaling pathway and leukocyte transendothelial migration pathways, interleukin (IL)-1β, C-X-C motif chemokine ligand 8 (CXCL8), IL-10, matrix metalloproteinase (MMP)1, and MMP9 were the key genes of pathway. The hub core genes of the PPI network were formyl peptide receptor (FPR)1, FPR2, IL-1β, IL-10, and CXCL8.ConclusionsThe results of this study indicate that the genes and signaling pathways involved in COL1A1, COL1A2, COL6A6, IL-1β, CXCL8, IL-10, MMP1, and MMP9 affect the healing of VLU. FPR1, FPR2, IL-1β, IL-10, and CXCL8 can be used as potential therapeutic targets.