Background: Pericytes (PCs), the critical components of vessels, are implicated in wound repair. This study aimed to explore the roles of PCs in wound healing and angiogenesis.
Methods: Skin PCs and human dermal microvascular endothelial cells (HDMECs) were isolated from patients' upper eyelid skin. Immunofluorescence staining was used to characterize the morphology of PCs. Tube formation and transwell chemotaxis assays were performed to explore PC's tube-forming capability and chemotaxis. Finally, we investigated the effects of PCs and endothelial cells on wound repair using skin wound of a rat model.
Results: Skin PCs exhibited a double-protrusion structure and characteristic antigen expression of neural/glial antigen 2 (NG2)+/platelet-derived growth factor receptor-β (PDGFR-β)+/alpha-smooth muscle actin (α-SMA)+/CD31-. Skin PCs could directly form lumen-like structures in a two dimensional (2D) culture environment, and mild hypoxia and starvation promoted the lumen-like structure formation. Furthermore, skin PCs quickly formed more stable lumen-like structures than HDMECs in matrigel, and they recruited HDMECs in a three dimensional (3D) culture environment. Transwell chemotaxis assay showed that PCs and HDMECs were chemotactic to each other. PCs could develop lumen-like structures in the skin wounds of rat models. The number of PCs mounted in wounded skin was compared to normal skin. The ratio of PCs to endothelial cells gradually increased after skin injury and reached its maximum on the 3rd day.
Conclusions: Skin PCs have an excellent tube-forming capability and chemotaxis to endothelial cells. PCs might promote wound repair by recruiting endothelial cells.
Keywords: angiogenesis; chemotaxis; pericytes; tube formation assay; wound repair.