A Lower IL-34 Expression is Associated with Non-Healing Diabetic Foot Ulcers

Background The non-healing of diabetic foot ulcers (DFU) is a major cause of high disability, morbidity, and mortality. Thus, new therapeutic targets and methods to help healing in patients with DFUs are major research hotspots.Objective This study examined the molecular differences between healing and non-healing DFUs to identify genes associated with DFU healing.Methods Differentially expressed genes (DEGs) were identified by bioinformatics. Samples were collected from patients with healing (n=10) and non-healing (n=10) DFUs from September 2021 to September 2022. Interleukin (IL)-34 expression was measured by ELISA and qRT-PCT. The fibroblasts from healing and non-healing DFU were divided according to their gene signatures and subdivided based on their gene expression profile differences.Results A comparison of fibroblast subpopulation characteristics revealed that the proportion of subpopulation 4 was significantly higher in non-healing DFUs than in healing DFUs. Subpopulation 4 had 254 upregulated genes and 2402 downregulated genes in the non-healing compared with the healing DFUs. The DEGs were involved in several biological functions, including cytokine activity, receptor-ligand activity, signaling receptor activator activity, and receptor regulator activity. IL-34 was downregulated in non-healing compared with healing DFUs, suggesting a possible role of IL-34 in DFU healing. In the clinical specimens, IL-34 was significantly downregulated in non-healing DFUs, consistent with the bioinformatics results.Conclusion IL-34 expression is downregulated in non-healing DFU. IL-34 appears to be involved in DFU healing, but the exact causal relationship remains to be explored.