Platelet-derived growth factor regulates the proliferation and differentiation of human melanocytes in a differentiation-stage-specific manner.

BACKGROUND: Although many kinds of keratinocyte-derived factors are known to regulate the proliferation and differentiation of human melanocytes, it is not well defined whether dermis-derived factors work in a similar way.

OBJECTIVE: The aim of this study is to clarify whether dermal factors are involved in regulating the proliferation and differentiation of human melanocytes.

METHODS: Human epidermal melanoblasts were cultured serially in a serum-free growth medium. Platelet-derived growth factor-BB (PDGF-BB) was supplemented to the medium, and the effects on the proliferation of melanoblasts/melanocytes and the differentiation of melanocytes were studied.

RESULTS: PDGF-BB stimulated the proliferation of melanoblasts cultured in melanoblast-proliferation medium, but inhibited the proliferation of melanocytes cultured in melanocyte-proliferation medium. By contrast, PDGF-BB stimulated the differentiation, dendritogenesis, and melanogenesis of melanocytes through the stimulation of tyrosinase activity and the expressions of tyrosinase and tyrosinase-related protein-1.

CONCLUSION: These results suggest that PDGF-BB regulates the proliferation and differentiation of human melanocytes in a differentiation-stage-specific manner. PDGF-BB seems to be one of the dermal factors that regulate the proliferation and differentiation of human melanocytes.