ABSTRACT
Objective To establish an ultraviolet-irradiation damage model in cultured fibroblasts derived from human skin and to explore the potential protective effects and mechanisms of amyloid precursor protein 17-met peptide (APP17-mer peptide) on the oxidative damage and collagen metabolism in cultured fibroblasts after ultraviolet irradiation. Methods Human dermal fibroblast cultures were established by outgrowth from foreskin biopsies of a healthy donor and were irradiated by a single exposure to ultraviolet rays and cultured in a series of concentrations of APP17-mer peptide (0, 20, 40, 80 μmol/L).The activity of fibroblasts was detected by the assay of MTT. The intracellular ROS level was measured with a confocal microscope. The expression of MMP-1 mRNA was analyzed real-time quantitatively following RT-PCR. Results Primary cultures of human skin fibroblasts were established from human foreskin in DMEM supplemented with 10 % fetal bovine serum. UV irradiation depressed cellular activity and increased intracellular level of ROS (P<0.05). 40μmol/L and 80μmol/L APP17-mer peptide increased the cellular activity in both UV irradiated fibroblasts and unirradiated fibroblasts (P<0.05), however,20 μmol/L did not show such protective effects (P>0. 05). 40μmol/L APP17-mer peptide could depress the level of ROS in irradiated libroblasts. A single exposure of fibroblasts to UV irradiation resulted in 1.78 foldup-regulation of MMP-1 mRNA compared with unirradiated sample, 40μmol/L and 80μmol/L APP17-mer peptide decreased the expression of MMP-1 mRNA (P<0.05 and P<0.01, respectively).Conclusion APP17-mer peptide can enhance cellular activity under UV-induced oxidative stress and in-hibit collagen degradation in fibroblasts irradiated with ultraviolet rays. Inhibition of ROS production may be involved in the protective mechanism of APP17 peptide.