In vitro ultraviolet A irradiation decreases both release ability and gene-expression of vascular endothelial growth...

Ultraviolet A (UVA) rays penetrate the dermis, influencing the function of different cells, including mast cells, able to produce angiogenic factors. We investigated vascular endothelial growth factor (VEGF) release and gene-expression from mast cells (MCs), after UVA irradiation in vitro. The release of VEGF-A by Human MCs-1 (HMC-1) was induced by calcium ionophore A23187 and phorbol 12 myristate 13 acetate (PMA). Half of the cells received increasing doses of UVA (5, 25 and 50 J/cm(2)), the unirradiated HMC-1 served as controls. VEGF release and VEGF's messenger ribonucleic acid (mRNA) were detected respectively by enzyme-linked immunoabsorbent assay (ELISA) and reverse transcription-polymerase chain reaction (RT-PCR) analysis. Results showed a UVA dose-dependent inhibitory effect on VEGF-A release from HMC-1. In particular, the release ability was reduced by 71.2% with 5 J/cm(2); 85% with 25 J/cm(2) and 86.3% with 50 J/cm(2). The VEGF-A RNA expression was reduced after UVA irradiation with 5 J/cm(2). We speculated that, at least in vitro and at our experimental conditions, UVA irradiation decreases mast cells-VEGF release and gene-expression.