Effects of BMP signalling in regulation of melanogenesis, pigment transfer and melanocyte migration

Abstract

Vitiligo is a severe skin depigmentation disorder due to its visible nature and psychological burden. UV-induced migration of melanocytes can be achieved by phototherapy to trigger interfollicular re-pigmentation. However, this process is costly and requires repeated UVB exposure. To unravel the possibility in enhancing the treatment, we utilized our in vitro models to study the role of BMP signalling in melanocyte function. Here, we observed that BMP4 decreases both melanin production and migratory rate of melanocytes. To determine the functional role of BMP signalling in follicular re-pigmentation in vivo, we UV-induced melanocyte migration into the interfollicular epidermis (IFE) using a novel mouse model and subsequently quantified it with histological staining and melanin assay. We found that ablation of BMP4 results in the enhancement of melanocyte migration and managed to validate it by rescuing the phenotype. Finally, to elucidate the molecular mechanism, we isolated the MeSC from our mouse model and performed whole transcriptome analysis. Through the analysis, we identified candidates involved, with some candidates having direct transcription regulation by BMP4. Overall, we discovered the role of BMP signalling in regulating melanin concentration and melanocyte migration.