Brain-derived neurotrophic factor exerts neuroprotective actions against amyloid β-induced apoptosis in neuroblastoma cells

Alzheimer's disease (AD) brains demonstrate decreased levels of brain-derived neurotrophic factor (BDNP) and increased levels of beta-amyloid peptide (A beta), which is neurotoxic. The present study assessed the impact of BDNF on the toxic effects of A beta(25.35)-induced apoptosis and the effects on BDNF-mediated signaling using the MTT assay, western blotting and reverse transcription quantitative polymerase chain reaction. A beta(25.35) was found to induce an apoptosis, dose-dependent effect on SH-SY5Y neuroblastoma cells, which peaked at a concentration of 20 mu M after 24 h. A combination of A beta(25-35) and BDNF treatment increased the levels of Akt and decreased the level of glycogen synthase kinase-3 beta (GSK3 beta) in SH-SY5Y neuroblastoma cells. These findings indicated that BDNF administration exerted a neuroprotective effect against the toxicity of the A beta(25-15)-induced apoptosis in these cells, which was accompanied by phosphoinositide 3-kinase/Akt activation and GSK3 beta phosphorylation. The mechanisms and signaling pathways underlying neuronal degeneration induced by the A beta peptide remain to be further elucidated,