FIG. 6.

Ape1/Ref-1 expression increases the GDNF-induced differentiation and survival of Neuro2a cells. (A) Vector/Neuro2a cells and mock-, control-, or GFRα1 siRNA-transfected Neuro2a/Ape1 cells were serum starved for 24 h and then incubated with or without 30 ng of GDNF/ml for an additional 24 h and visualized by microscopy. (B and C) The mean of the longest neurite (B) and the percentage of neurite-bearing cells (C) were determined for each culture based on measurements taken from 200 neurons in three different experiments. Each data point represents the mean ± the SD (**, P < 0.01). (D and E) Vector/Neuro2a (vector) and Neuro2a/Ape1 cells were cultured with 15 μM β-amyloid peptide (D) or 20 μM H₂O₂ (E) in the presence or absence of 30 ng of GDNF/ml, and cell survival was calculated as the percentage of untreated vector/Neuro2a cells (adjusted to 100%). Each value is the mean ± the SD from three separate experiments (**, P < 0.01).