Figure 4. RAGE-mediated p38 MAPK signaling contributes to endocytosis of Aβ in RPE.

A. RPE cells were treated OAβ₄₂ 2 μM or 10 μM for 30 min. Phosphorylation of p38 MAPK is increased at 30 min. B. RAGE siRNA was transfected in ARPE-19 cells. Negative siRNA was used as a control. RPE cells were treated OAβ₄₂ 10 μM for indicated time (30 min and 24 h). Phosphorylation of p38 MAPK and intracellular Aβ uptake are decreased in RPE with RAGE siRNA compared to RPE with negative siRNA. C. RPE cells were pretreated with anti-RAGE neutralizing antibody (20 μg/ml, 2h) and SB 203580 (10 μM, 30 min) and were treated with OAβ₄₂ 10 μM for indicated time (30 min and 24 h). Anti-RAGE neutralizing antibody and SB 203580 decrease intracellular Aβ in RPE. β-actin was used as an internal control. Figures were selected as representative data from three independent experiments.