Effects of transforming growth factor beta 1 on the secretion of insulin-like growth factor 1, keratinocyte growth factor, and vascular endothelial cell growth factor from skin fibroblasts following ultraviolet irradiation in vitro

BACKGROUND: Studies demonstrates that aging is not completely consistent with the expression of growth factor under photoaging, but the relation between growth factor and skin aging has attracted more attention. OBJECTIVE: To investigate the effects of transforming growth factor beta 1 (TGF- β 1) on the expression of insulin-like growth factor 1 (IGF-1), keratinocyte growth factor (KGF), and vascular endothelial cell growth factor (VEGF) after ultraviolet (UVA) irradiation. DESIGN, TIME AND SETTING: A randomized repeated experiment based on cultivate cells was performed at the Key Laboratory, Institute of the Plastic Surgery, Fourth Military Medical University from July 2006 to March 2008. MATERIALS: Fibroblasts were harvested from the prepuce of patients of Department of Outpatient, Institute of the Plastic Surgery, Fourth Military Medical University and cultured with tissue block method. METHODS: Skin fibroblasts were irradiated with different doses of UVA (0 J/cm2, 5 J/cm2, 10 J/cm2, 20 J/cm2), and the mass concentration of IGF-1, KGF, and VEGF in the supernatant was measured by enzyme-linked immunosorbent assay (ELISA). UVC irradiation dose was 15 J/cm 2. TGF- β 1 with low, medium and high dose (0.1 μ g/L, 1.0 μ g/L, 10.0 μ g/L, especially) was added to irradiate the fibroblasts. MAIN OUTCOME MEASURES: The expression of IGF-1, KGF, as well as VEGF after irradiated with different doses of UVA. RESULTS: The secretion level of IGF-1, KGF was decreased, and VEGF was increased in cultured skin fibroblasts after UVA irradiation. The levels of IGF-1, KGF and VEGF were increased after adding TGF- β 1, which showed a dose-dependent manner. Contents of IGF-1, KGF, and VEGF in the large dose group were significantly higher than those of the UVA irradiation group (P < 0.01). CONCLUSION: In vitro UVA can inhabit the expression of IGF-1 and KGF in skin fibroblasts, meanwhile, can increase VEGF expression. TGF- β 1 can elevate levels of IGF-1, KGF, and VEGF secreted by UVA irradiated dermal fibroblasts, which in favor of the restore and reestablishment of dermal structures.