Beta-amyloid (Aβ) peptide influences on mitochondria and cell metabolism. (A) PrP expression in wild-type (WT) cells detected with Saf32 in the proliferating cells treated for 24 hours and in differentiated cells treated for 7 days. (B-I) Proliferating cells were treated for 24 hours with 1 μM of each of the Aβ species. (B) Cell metabolism as determined by MTS. (C) Cellular ATP content. (D) Western blots for the mitochondrial outer membrane translocase protein TOMM22. (E) Densitometry of the TOMM22 detection in Aβ-treated cells. (F) Western blots for the cell cycle protein Pin1. (G) Densitometry of Pin1 western blots. (H) Densitometry of p53 western blots. Data are represented as mean ± SEM. *P < 0.05, **P < 0.01. (I) Immunofluorescent images of Aβ1-42 (1 μM; WO2 red) and PrP (03R19 green) incubation with knock-out (KO) and WT neural stem cells for 0 to 60 minutes. Background red staining is endogenous amyloid precursor protein reactivity (endogenous Aβ cannot be detected in these cells; data not shown). DAPI nuclear staining is shown in blue, Scale bars = 25 μm.