Figure 9.

TFEB expression enhances lysosomal degradation of APP. A–F, Immunoblot (A) with quantitation of APP (B), α-CTF (C), β-CTF (D), Aβ40 (E), and Aβ42 (F) in N2a-APP695 cells transfected with TFEB or vector control and cultured in the presence of bafilomycin A1 (Baf) or diluent for 4 h. P values shown are by post hoc test after one-way ANOVA. G, N2a-APP695 cells were transfected with TFEB or vector control and treated with cycloheximide (CHX; 50 μg/ml) at t = 0. Cells were collected at the indicated times to evaluate APP abundance. H, APP abundance expressed as a percentage of baseline (t = 0 after addition of cycloheximide) in cells treated as in C. N = 3 per group. Inset shows half-life of APP; *p < 0.05. I, N2a-APP695 cells were transfected with TFEB or vector control, and were pretreated with bafilomycin A1 or diluent (100 nm for 30 min) and treated with cycloheximide (50 μg/ml) at t = 0. Cells were collected at the indicated times to evaluate APP abundance. J, K, Quantitation of APP abundance at various times in cells treated as in I, in the vector-transfected (J) or TFEB-transfected (K) groups. N = 4 per group. L, Half-life of APP in bafilomycin A1-treated cells expressed as a percentage of diluent-treated group. N = 4 per group; *p < 0.05.