Impact of intense pulsed light irradiation on cultured primary fibroblasts and a vascular endothelial cell line

The aim of this study was to determine the effects of intense pulsed light (IPL) on cell proliferation and the secretion of vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMPs) in human fibroblasts and vascular endothelial cell lines, and to investigate the effects of IPL on the mRNA expression levels of type I and III procollagens in cultured human fibroblasts. Foreskin fibroblasts and a vascular endothelial cell line (ECV034) were cultured and treated with various wavelengths and doses of IPL irradiation. After culture for 1, 12, 24 and 48 h following IPL irradiation, fibroblasts and the vascular endothelial cell line were harvested for investigation of morphological changes by light microscopy, cell proliferation viability by MTT assay, and VEGF and MMP secretions by ELISA. The mRNA expression levels of type I and III procollagens in the fibroblasts were detected by RT-PCR. No marked morphological changes were observed in the cultured fibroblasts compared with the control. Cell growth and cellular viability were increased in fibroblasts 24 and 48 h after IPL irradiation. The levels of type I and III procollagen mRNA expression in fibroblasts increased in a time-dependent manner. However, the IPL management had no impact on VEGF and MMP secretion levels in fibroblasts and the ECV034 cell line at any time-point after irradiation as well as cell morphology and cellular proliferation. IPL irradiation may induce cellular proliferation and promote the expression of procollagen mRNAs directly in cultured primary fibroblasts, which may primarily contribute to photorejuvenation.