Effects of fibroblast-derived factors on the proliferation and differentiation of human melanocytes in culture.

BACKGROUND

Although keratinocyte-derived factors are known to promote the proliferation and differentiation of human epidermal melanocytes, it is not fully understood whether fibroblast-derived factors work in a similar way.

OBJECTIVE

The aim of this study is to clarify whether fibroblast-derived factors are involved in regulating the proliferation and differentiation of human melanocytes with or without keratinocytes using serum-free culture system.

METHODS

Human epidermal melanoblasts and melanocytes were cultured in a serum-free growth medium supplemented with fibroblast-derived factors such as keratinocyte growth factor (KGF) with or without keratinocytes, and the effects of KGF on the proliferation and differentiation of melanocytes were studied.

RESULTS

KGF stimulated the proliferation of melanoblasts in the presence of dibutyryl cAMP (DBcAMP), basic fibroblast growth factor (bFGF), transferrin (Tf), and endothelin-1 (ET-1). Although KGF stimulated the differentiation, melanogenesis, and dendritogenesis in the presence of DBcAMP, Tf, and ET-1 without keratinocytes, KGF required the presence of keratinocytes for the stimulation of melanocyte proliferation.

CONCLUSION

These results suggest that fibroblast-derived KGF stimulates the proliferation of human melanoblasts in synergy with cAMP, bFGF, Tf, and ET-1, the differentiation of melanocytes in synergy with cAMP, Tf, and ET-1, and the proliferation of melanocytes in synergy with cAMP, Tf, ET-1, and undefined keratinocyte-derived factors.