Wnt Inhibitory Factor (WIF)-1 Promotes Melanogenesis in Normal Human Melanocytes

Abstract

Background: Wnt inhibitory factor-1 (WIF-1) acts as a suppressor of Wnt antagonists. There is no study available on melanogenesis effect of human melanocytes.

Objectives: In this study, we investigated the expression of WIF-1 in human melanocytes and the effects of WIF-1 on melanogenesis.

Method: To determinutese whether WIF-1 is expressed in human melanocytes, we used immunocytochemistry, immunhistochemistry, western blot analysis and reverse transcription polymerase chain reaction. The cell proliferation was measured using the coulter counter. The effects on pigmentation were investigated with measurement of melanin contents, tyrosinase activity and its expression.

Result: WIF-1 was expressed in melanocytes. WIF-1 inhibited proliferation of human melanocytes in a dose-dependent manner. WIF-1 also appeared to stimulate the melanin synthesis of human melanocytes. This increase in pigmentation was due to stimulation of the tyrosinase activity and increased expression of MITF and tyrosinase.

Conclusion: We demonstrated that WIF-1 was expressed in human melanocytes. Our findings suggest that WIF-1 may play a role in melanogenesis.