Regulation of epidermal keratinocytes by growth factors

Epidermal keratinocytes are the main component cells of the epidermis and their function is regulated by various kinds of growth factors, cytokines, and chemokines. Of these, members of the epidermal growth factor and fibroblast growth factor families, as wells as hepatocyte growth factor and insulin-like growth factor, play central roles in keratinocyte proliferation, while transforming growth factor-beta, vitamin D3, and interferon-gamma are important inhibitors of keratinocyte growth. Keratinocytes are known to produce many of the currently identified growth factors, cytokines and chemokines. Keratinocyte-derived growth factors and cytokines regulate immune and inflammatory responses, and play important roles in pathological skin conditions. This review focuses on the regulation of keratinocytes by growth factors, cytokines, and chemokines.