Down-regulation of exosomal miR-200c derived from keratinocytes in vitiligo lesions suppresses melanogenesis.

Vitiligo is a refractory disfiguring skin disease. However, the aetiology and pathogenesis of vitiligo have not been fully defined. Previous studies have shown that exosomes from normal human keratinocytes improve melanogenesis by up-regulating the expression of melanogenesis-related proteins. Several microRNAs (miRNAs) have been demonstrated to be effective in modulating melanogenesis via exosomes. In the present study, it was found that the effect of exosomes derived from keratinocytes in vitiligo lesions in regulating melanin synthesis is weakened. Furthermore, miR-200c was detected to be significantly down-regulated in exosomes from keratinocytes in vitiligo lesions. In addition, miR-200c enhanced the expression of melanogenesis-related genes via suppressing SOX1 to activate β-catenin. In conclusion, our study revealed that the effect of exosomes secreted by keratinocytes in vitiligo lesions exhibited a weaker capacity in promoting melanogenesis of melanocytes. Moreover, the expression of miR-200c, which mediates melanogenesis in exosomes secreted by keratinocytes in vitiligo lesions, is down-regulated, which may be one of the pathogenesis in vitiligo. Therefore, keratinocyte-derived exosomal miR-200c may be a potential target for the treatment of vitiligo.