Abstract: Objective · To investigate the mechanism of 640 nm red light promoting keratinocyte migration preliminarily. Methods · Human keratinocytes were cultured in vitro and assigned to 4 groups according to different interventions, i.e. control group, sitagliptin group (CD26 inhibited), 640 nm red light group (8 J/cm2) and 640 nm red light+sitagliptin group. The levels of CD26 mRNA and protein in keratinocytes were measured with realtime-PCR and Western blotting, respectively. Cell migration was observed with Transwell assay and scratch assay. Results · The level of CD26 mRNA and the of CD26 protein in 640 nm red light group obviously increased compared with control group, while those of sitagliptin group significantly decreased (all P<0.05). Migration ability of keratinocytes increased in 640 nm red light group and decreased in sitagliptin group observedTranswell assay and scratch assay. Conclusion · The of CD26 in keratinocytes is promotedthe 640 nm red light, which can accelerate keratinocyte migration to facilitate re-epithelialization.

Key words: 640 nm red light, CD26, keratinocyte, wound healing, re-epithelialization