In vitro investigation of sitagliptin on HaCaT keratinocyte migration and proteomics analysis for wound healing applications.

Sitagliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor commonly used to treat diabetes, has been linked to improved wound healing in diabetic patients. However, its direct effects on skin repair are not well understood and its underlying mechanisms remain unclear. This study investigated the concentration dependent effects of sitagliptin on HaCaT keratinocytes and primary fibroblasts in vitro and explored the molecular pathways involved. Sitagliptin enhanced keratinocyte migration at 150 μg/mL, without affecting proliferation, while no significant effects were observed on fibroblast proliferation and migration, indicating a cell-type specific response. Sitagliptin treatment induced morphological changes in HaCaT keratinocytes, including elongated actin filaments and increased cell surface area, consistent with cytoskeletal changes that support motility. Proteomic analysis revealed keratin remodeling (Keratin5 (KRT5), Keratin 16 (KRT16), Keratin 17 (KRT17) upregulation and Keratin6A (KRT6A) downregulation), increased Enkurin domain-containing protein 1 (ENKD1), Family with sequence similarity 83 member H (FAM83H) and epidermal growth factor receptor (EGFR), and reduced β-catenin (CTNNB1), suggesting cytoskeletal reorganization and reduced intercellular adhesion associated with enhanced keratinocyte migration. Targeted RT-qPCR validation confirmed these transcriptional changes and identified integrin β1 (ITGB1) as an induced network hub in the associated protein-protein interaction network. Overall, sitagliptin enhances keratinocyte migration in association with changes in cytoskeletal and cell-adhesion-related proteins, although a direct causal relationship between these molecular changes and enhanced migration remains to be established. These findings provide preliminary evidence that, beyond glycemic control, sitagliptin may have therapeutic potential for wound healing applications to accelerate skin repair and tissue regeneration.