Modulation of vascular endothelial growth factor receptors in melanocytes

Exp Dermatol. 2005 Aug;14(8):625-33. doi: 10.1111/j.0906-6705.2005.00345.x.

Abstract

Vascular endothelial growth factor (VEGF) is constitutively produced by keratinocytes, but has no known epidermal target cell. We now report that normal human melanocytes (Mc) maintained in serum-free, hormone-, and growth factor-supplemented medium lacking phorbol ester and choleragen constitutively express VEGF receptor-1 (VEGFR-1), VEGFR-2, and neuropilin-1. Furthermore, stimulation of Mc with VEGF165 isoform leads to phosphorylation of VEGFR-2, the receptor responsible for most of the VEGF-mediated effects in endothelial cells, suggesting that the receptor is functional. Interestingly, in Mc, VEGFR-2 expression is induced by ultraviolet irradiation and is downregulated by VEGF and tumor necrosis factor-alpha. Prolonged culture (>8 weeks) in the presence of phorbol ester abrogates VEGFR-2 expression, explaining previous reports that Mc do not express VEGFR-1 and VEGFR-2. These data suggest that VEGF may play a role in Mc behavior in skin.

MeSH terms

  • Blotting, Western
  • Cells, Cultured
  • Down-Regulation
  • Endothelium, Vascular / cytology
  • Humans
  • Immunoblotting
  • Melanocytes / cytology
  • Melanocytes / metabolism*
  • Neuropilin-1 / biosynthesis
  • Neuropilin-1 / metabolism
  • Phorbol Esters / metabolism
  • Receptors, Vascular Endothelial Growth Factor / metabolism*
  • Signal Transduction
  • Skin / metabolism
  • Skin / pathology
  • Time Factors
  • Tumor Necrosis Factor-alpha / metabolism
  • Ultraviolet Rays
  • Up-Regulation
  • Vascular Endothelial Growth Factor A / metabolism
  • Vascular Endothelial Growth Factor Receptor-1 / biosynthesis
  • Vascular Endothelial Growth Factor Receptor-2 / biosynthesis

Substances

  • Phorbol Esters
  • Tumor Necrosis Factor-alpha
  • Vascular Endothelial Growth Factor A
  • Neuropilin-1
  • Receptors, Vascular Endothelial Growth Factor
  • Vascular Endothelial Growth Factor Receptor-1
  • Vascular Endothelial Growth Factor Receptor-2