Skin graft take rates, granulation, and epithelialization: dependence on myeloid cell hypoxia-inducible factor 1alpha.

Abstract

OBJECTIVE: To compare the "take" rates of skin grafts between myeloid-selective hypoxia-inducible factor (HIF) 1alpha knockout (KO) and wild-type (WT) mice. Production of the alpha subunit of HIF-1alpha is increased in healing wounds, which stimulates expression of vascular endothelial growth factor (VEGF) to promote angiogenesis. Therefore, the take rate of skin grafts may be closely associated with the presence or absence of HIF-1alpha production in the recipient bed. DESIGN: The percentage of healthy graft areas obtained by planimetry and scores for epithelialization and granulation tissue formation obtained by histopathologic analysis were compared in 12 KO and 12 WT mice following skin grafting. RESULTS: The graft take rate was significantly impaired in the KO group (P = .009), whereas epithelialization (P = .46) or granulation (P = .41) tissue formation scores did not reveal any significant differences. CONCLUSION: Hypoxia-inducible factor 1alpha in myeloid cells may be an important molecule for revascularization of avascular tissues such as skin grafts, probably owing to its stimulating effect on angiogenesis.