gms | German Medical Science

Background: Our previous studies suggested that apolipoprotein (Apo) A-I mimetic peptides, as D-4F and L-4F, reduce pathological lipid deposits in the bruch‘s membrane (BRM), and in the sub-RPE space. In this study we investigated the effect of D-4F on RPE cell proliferation and oxidative stress-induced lipid peroxidation in RPE cells in vitro.

Materials and methods: The RPE cells in third passage culture were treated with different concentrations of D-4F (0–4000 μg/ml) and after 48hrs cell proliferation was examined with MTT assay. Lipid peroxidation was induced by addition of hydrogen peroxide (H₂O₂) (1 mM) in the confluent RPE cells, which were exposed to D-4F (0, 1, 10, 100 μg/ml) for the previous 24 hrs. After 24 hrs, intracellular 4-HNE (4-hydroxy-2-nonenal), a lipid peroxidation end-product, was measured with 4-HNE adduct Elisa kit.

Results: D-4F concentrations between 10 and 100 μg/ml increased, and the concentrations ≥250 μg/ml reduced RPE cell proliferation signicantly. Intracellular 4-HNE (μg/mg protein) was reduced in the cells treated with 10 and 100 μg/ml of D4F (93% and 78%, respectively, p<0.05). H₂O₂ increased intracellular 4-HNE by 11%, and this effect was partially suppressed by D4F-pretreatment.

Conclusion: The results show that D-4F concentration between 10 and 100 μg/ml might have the effects of activating cell proliferation and reducing intracellular lipid peroxidation. Since lipid peroxidation end-products such as 4-HNE could lead to the additional oxidative stress, D-4F may have a protective effect against oxidative stress in RPE cells.