Apoptosis induced by β-amyloid_25-35 in acetylcholinesterase-overexpressing neuroblastoma cells

AIM: To examine the relationship between apoptosis induced by β-amyloid fragment 25-35 (Aβ_25-35) and the activity of acetylcholinesterase (AChE) in AChE over-expresser-SC42 cells. METHODS: Cell survival was measured by microscopy and MTT reduction; DNA laddering was observed by electrophoresis; AChE activity was determined by spectrophotometry. RESULTS: Aβ_25-35 1 μmol/L exposure for 24-48 h caused a significant decrease in cell viability, along with changes in morphology and DNA fragmentation. AChE activity was affected in an inverse manner, increasing gradually to a level that was 1.7-fold higher than control at the 48-h time point. No change in the cytotoxicity of Aβ_25-35 was observed when the increased AChE activities were effectively inhibited by huperzine A throughout the 48-h exposure period. CONCLUSION: Although Aβ _25-35 can induce apoptosis in SC42 cells and simultaneously increase AChE activity, the capacity of AChE to hydrolyze acetylcholine is not involved in this apoptosis model.