Figure 1.

Amyloid β_1-42 (Aβ_1-42) induced PC12 cell model of Alzheimer's disease (AD) in gradient concentrations and times. (A) PC12 cells were cultured with Aβ_1-42 0, 2.215, 4.43, 8.86, 17.72 μM; Aβ_1-42 decreased cell viability and increase cytotoxicity in a dose-dependent manner; 1/2 LD₅₀ was 7 μM (Quest Graph™ LD₅₀ Calculator. (B) PC12 cells were cultured with 7 μM Aβ_1-42 for 6, 12, 24, 48, and 72 h; 12h was the best as 1/2 LD_50. (C) Cell morphology was also clearly changed while the cells were cultured by Aβ_1-42 for 12 h (×150), scale bar 100 μm; the appearances of cells were shrinking and flat, and protuberances disappeared. (D) Cellular senescence (green) was observed by fluorescence microscopy (excitation: 488 nm, emission: 500–600 nm), scale bar 100 μm. Senescent cells also increased in model group. The experiments were repeated twice independently with similar results.