A beta 25-35 induces presynaptic changes in organotypic hippocampal slice cultures.
Memory loss in Alzheimer's disease (AD) may be related to synaptic defects in damaged hippocampal neurons. We investigated the relationship between amyloid peptide A beta 25-35-induced neuronal death pattern and presynaptic changes in organotypic hippocampal slice cultures. In propidium iodide (PI) uptake and annexin V labeling, A beta 25-35-induced neuronal damage dramatically increased in a concentration dependent manner, indicating both types of cell death. In ultrastructural analysis, apoptotic features in CA1 and CA3 area and synaptic disruption in stratum lucidum were detected in A beta 25-35-treated slices. Immunofluorescence and Western blot analysis for caspase-3 showed A beta 25-35 concentration dependently induced caspase-3 activation. Immunofluorescence and Western blot analysis to determine changes in presynaptic marker proteins demonstrated that expression of synaptosomal-associated protein-25 (SNAP-25) and synaptophysin were reduced by A beta 25-35 in CA1, CA3 and DG area at concentrations >2.5 microM. In conclusion, A beta 25-35-induced apoptotic cell death and caspase-3 activation at relatively low concentration, and induced synaptic disruption and loss of synaptic marker protein at concentrations >2.5 microM in organotypic hippocampal slice cultures. These suggest that A beta 25-35-induced apoptosis via triggering caspase-3 activation and lead to synaptic dysfunction in organotypic hippocampal slice cultures.
Suh
Eun Cheng
EC
Department of Pharmacology, Medical Research Institute, School of Medicine, Ewha Womans University, 911-1, Mok-6-Dong, Yangcheon-Gu, Seoul, South Korea.
Jung
Yeon Joo
YJ
Kim
Yul A
YA
Park
Eun Mi
EM
Lee
Kyung Eun
KE
D016229:Amyloid beta-Peptides / Q000494:pharmacology*; D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D017304:Annexin A5 / Q000378:metabolism; D053148:Caspase 3 / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D006624:Hippocampus / Q000166:cytology* / Q000187:drug effects*; D046529:Microscopy, Electron, Transmission / Q000379:methods; D009474:Neurons / Q000166:cytology* / Q000187:drug effects; D009924:Organ Culture Techniques; D010446:Peptide Fragments / Q000494:pharmacology*; D017729:Presynaptic Terminals / Q000187:drug effects* / Q000648:ultrastructure; D051381:Rats; D017207:Rats, Sprague-Dawley; D016708:Synaptophysin / Q000378:metabolism; D050825:Synaptosomal-Associated Protein 25 / Q000378:metabolism
D016229:Amyloid beta-Peptides; D017304:Annexin A5; D010446:Peptide Fragments; D016708:Synaptophysin; D050825:Synaptosomal-Associated Protein 25; C074636:amyloid beta-protein (25-35); D053148:Caspase 3