The 308-nm excimer laser stimulates melanogenesis via the wnt/β-Catenin signaling pathway in B16 cells.

Background: The mechanism of the 308-nm excimer laser in vitiligo treatment has not yet been adequately studied. In this study, we explored the role of the 308-nm excimer laser in treatment of vitiligo and the molecular mechanisms underlying melanin biosynthesis in melanocytes after 308-nm excimer laser radiation. Materials and methods: The B16 cells were irradiated at doses of 0 mJ/cm2, 100 mJ/cm2, 300 mJ/cm2 and 600 mJ/cm2 using a 308-nm excimer laser and then cultured for an additional 24, 48 or 72 hours. Melanogenesis and tyrosinase activity in cells were measured by biochemical methods. The expression of tyrosinase, MITF, Wnt3α and β-catenin was analyzed by Western blotting. Results: Cell irradiation with the 308-nm excimer laser not only significantly elevated the melanin content (p < .01) but also stimulated the activity of tyrosinase (p < .01). The expressions of tyrosinase and MITF were also significantly increased in cells after 308-nm excimer laser irradiation. We also defined the signaling pathway by which the 308-nm excimer laser stimulates melanin biosynthesis. Increased Wnt3α and β-catenin expression was observed by Western blot analysis. Conclusion: Activation of the Wnt/β-catenin pathway likely led to the activation of MITF and tyrosinase transcription, as well as, the subsequent induction of melanin synthesis.