title: Wnt inhibitory factor (WIF)-1 promotes melanogenesis in normal human melanocytes.
abstract: Wnt signaling plays a role in the differentiation as well as the development of melanocytes. Using a microarray analysis, hyperpigmentary skin of melasma expressed high levels of Wnt inhibitory factor-1 (WIF-1) compared with perilesional normal skin. In this study, the expression and functional roles of WIF-1 on melanocytes were investigated. WIF-1 was expressed both in the melanocytes of normal human skin and in cultured melanocytes. The upregulation of WIF-1 on cultured normal human melanocytes significantly induced expressions of MITF and tyrosinase, which were associated with increased melanin content and tyrosinase activity. Consistent with the stimulatory effect of WIF-1, WIF-1 siRNA reduced melanogenesis in the cells. Moreover, WIF-1 increases pigmentation in melanocytes co-cultured with WIF-1-overexpressed fibroblasts and of organ-cultured human skin. These findings suggest that melanocytes express WIF-1 constitutively in vivo and in vitro and that WIF-1 promotes melanogenesis in normal human melanocytes.
authors.affiliation: Department of Biochemistry, Ajou University School of Medicine, Suwon, Korea; Department of Biomedical Science, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Tae Jun
authors.initials: TJ
authors.lastname: Park
authors.forename: Misun
authors.initials: M
authors.lastname: Kim
authors.forename: Hyeran
authors.initials: H
authors.lastname: Kim
authors.forename: Sun Yi
authors.initials: SY
authors.lastname: Park
authors.forename: Kyoung-Chan
authors.initials: KC
authors.lastname: Park
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Ortonne
authors.forename: Hee Young
authors.initials: HY
authors.lastname: Kang
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000096:biosynthesis* / Q000235:genetics; D002478:Cells, Cultured; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D005786:Gene Expression Regulation / Q000502:physiology*; D006801:Humans; D008297:Male; D008544:Melanocytes / Q000166:cytology / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D012097:Repressor Proteins / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D012097:Repressor Proteins; C485569:WIF1 protein, human
keywords: Wnt inhibitory factor-1; melanocytes; melanogenesis; melasma