Cytotoxic Effects of Amyloid-beta Species

HT 22 cell was purchased from the Korean Cell line Bank (Seoul National University, Republic of South Korea) and cultured in the Dulbecco’s Modified Eagle’s medium (DMEM) (Thermo Fisher Scientific, USA) with 10% foetal bovine serum and 1% penicillin. The cytotoxic effect of synthesized Aβ_1-42, Aβ_4-42, and Aβ_pE3-42 was investigated using the previously reported MTT assay protocol^{24 (link)}. Cultured HT22 cell (8 × 10³ cells/well) was seeded on a 96-well plate. Each Aβ variant (10 μM) was prepared in starvation medium (0.5% foetal bovine serum and 1% penicillin in DMEM) and treated on the plate for 24 h at 37  ${}^{\circ }$ C. 15 μL of MTT reagent (Promega, USA) was added to each well and incubated for additional 4 h at 37  ${}^{\circ }$ C. Finally, 100 μl of solubilization solution (Promega, USA) was added for 30 min at 37  ${}^{\circ }$ C. The absorbance was measured at 570 nm.