Influence of pigment epithelium-derived factors on H(2)O(2)-induced oxidative damage and melanin synthesis in Melan-a cells.

BACKGROUND: Previous studies have demonstrated that oxidative stress and melanogenesis are regulated by the Wnt/β-catenin signaling pathway. However, the precise mechanism by which the PEDF/Wnt/β-catenin axis modulates apoptosis and melanogenesis remains unclear. METHODS: Cell viability and mortality rates were assessed using CCK-8 assays and lactate dehydrogenase (LDH) release assays. Mitochondrial ultrastructural changes were analyzed by transmission electron microscopy (TEM). Changes in the mitochondrial membrane potential (ΔΨm) were assessed using the JC-1 fluorescent probe. The effects of PEDF on protein and gene expression were evaluated by Western blotting and quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS: As the concentration of H(2)O(2) increased, the cell survival rate decreased, which activated the Wnt/β-catenin signaling pathway and increased the apoptosis rate and melanin production. PEDF reversed the H(2)O(2)-induced decrease in cell viability and increase in mortality rate in Melan-a cells while ameliorating the impairment of the mitochondrial membrane potential. PEDF ameliorated H(2)O(2)-induced protein damage and lipid peroxidation and reduced apoptosis in Melan-a cells. PEDF treatment significantly decreased the protein expression levels of β-catenin, Wnt3a, and Dvl2 (P < 0.05) and reduced the protein levels of Bax and Caspase-3 (P < 0.01) in H(2)O(2)- and BML-284-treated Melan-a cells. Furthermore, PEDF significantly reduced the H(2)O(2)- and BML-284-induced increases in the MITF and TYR protein levels (P < 0.01). CONCLUSIONS: These results suggest that PEDF can reduce H(2)O(2)-induced oxidative damage and melanin production in Melan-a cells by inhibiting the activation of Wnt/β-catenin signaling pathway activation. These findings provide a theoretical basis for human oxidative stress and pigment deposition-related diseases.