Basic fibroblast growth factor from human keratinocytes is a natural mitogen for melanocytes.

Abstract

Abstract. To survive and proliferate in pure culture, human melanocytes require basic fibroblast growth factor (bFGF) and cAMP. Without these factors, even in the presence of serum, the cells die. Melanocytes cultured in the presence of keratinocytes, however, survive for weeks without added bFGF and cAMP. We show here that the growth factor for melanocytes produced by human keratinocytes is bFGF because its activity can be abolished by neutralizing antibodies to bFGF and by a bFGF synthetic peptide that inhibits the binding of the growth factor to its receptor. The melanocyte mitogen in keratinocytes is cell associated and increases after irradiation with ultraviolet B. Northern blots reveal bFGF gene transcripts in keratinocytes but not melanocytes. These studies demonstrate that bFGF elaborated by keratinocytes in vitro sustains melanocyte growth and survival, and they suggest that keratinocyte-derived bFGF is the natural growth factor for normal human melanocytes in vivo.

Acidic fibroblast growth factor is present in regenerating limb blastemas of axolotls and binds specifically to blastema tissues

“…This hypothesis is in accord with data related to the production of FGF by normal keratinocytes (Halaban et al, 1988) and agrees with the fact that the epiderma1 cap delays chondrogenesis in regenerating limbs (Globus et al, 1980) and that FGF stimulates the synthesis of a molecule involved in the control of chondrogenesis, namely, hyaluronic acid (Toole, 1982;Toole et ab, 1984) in both regenerating (Mescher and Munaim, 1986) and developing limbs (Toole et ah, 1989). It also explains the stimulation of proliferation of blastema cells with FGF when the wound epidermis of amputated limbs was replaced by a full thickness skin flap (Chew and Cameron, 1983).…”

Inhibitory Mechanism of an Extract of Althaea officinalis L. on Endothelin-1-Induced Melanocyte Activation.

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When the skin is irradiated with UVB light, various cytokines are released, act on normal human melanocytes (NHMC), and induce them to synthesize melanin pigment, to proliferate and to differentiate, which leads to increased pigmentation.1-3) Endothelin-1 (ET-1), 2,4) basic fibroblast growth factor (b-FGF), 5) and a-melanocyte-stimulating hormone, [6][7][8] all of which are produced by normal human keratinocytes (NHKC) and are up-regulated following UVB irradiation, act as mitogens for NHMC. Furthermore, an increase in ET-1 expression 3) in human skin after UVB irradiation has also been reported, and it has been suggested that ET-1 plays an important role in UVB-induced pigmentation.

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Ultraviolet Radiation in Wound Care: Sterilization and Stimulation

“…To see this illustration in color, the reader is referred to the web version of this article at www.liebertpub.com/wound stimulate melanocyte growth, and regulate both the distribution and morphology of melanocytes, and stimulate production of melanin. 13,14 Interestingly, keratinocyte-induced melanocyte proliferation cannot be substituted by the keratinocyte-conditioned medium, but rather requires close cell-to-cell contact in which melanocytes interact via dendritic processes with adjacent keratinocytes. 7 There is some evidence that in turn, keratinocyte proliferation, which is essential for wound closure can be stimulated by melanocytes.…”