Cell death induced by beta-amyloid 1-40 in MES 23.5 hybrid clone: the role of nitric oxide and NMDA-gated channel activation leading to apoptosis.
The molecular events associated with beta-amyloid-induced neuronal injury remain incompletely characterized. Using a substantia nigra/neuroblastoma hybrid cell line (MES 23.5) synthetic beta-amyloid 1-40 induced a time and dose-dependent apoptotic cell death which was characterized by cell shrinkage and fragmentation of DNA, and was inhibited by aurintricarboxylic acid (ATA), and cycloheximide (CHX). Following beta-amyloid 1-40 treatment, cyclic GMP, an index of NO synthesis, was increased in MES 23.5 cells. The NO scavenger hemoglobin, as well as the NO synthase inhibitors NG-monomethyl-L-arginine acetate (L-NMMA) and L-N5-(1-iminoethyl)ornithine hydrochloride (L-NI0) attenuated such increases. These same inhibitors and scavengers also significantly prevented cytotoxicity. beta-Amyloid also induced an early and transient increase in intracellular calcium as monitored with laser scanning confocal microscopy and Fluo-3 imaging. These induced calcium transients could be significantly blocked by the N-methyl-D-aspartic acid (NMDA) receptor antagonist MK-801. Pretreatment with MK-801 or removal of extracellular Ca2+ also reduced beta-amyloid-induced NO production and neurotoxicity. Furthermore, beta-amyloid neurotoxicity was greatly enhanced in the absence of Mg2+ or in the presence of glutamate or NMDA. These data suggest that beta-amyloid can lead to apoptotic cell death through a NO mediated process possibly triggered by Ca2+ entry through activated NMDA-gated channels.
Le
W D
WD
Baylor College of Medicine, Department of Neurology, Houston, TX 77030, USA.
Colom
L V
LV
Xie
W J
WJ
Smith
R G
RG
Alexianu
M
M
Appel
S H
SH
D016229:Amyloid beta-Peptides / Q000633:toxicity*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D016923:Cell Death / Q000187:drug effects; D002999:Clone Cells / Q000187:drug effects / Q000378:metabolism; D016291:Dizocilpine Maleate / Q000494:pharmacology; D006822:Hybrid Cells / Q000187:drug effects / Q000378:metabolism; D015640:Ion Channel Gating / Q000187:drug effects*; D016202:N-Methylaspartate / Q000037:antagonists & inhibitors*; D009447:Neuroblastoma; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D009569:Nitric Oxide / Q000096:biosynthesis / Q000502:physiology*; D010446:Peptide Fragments / Q000633:toxicity*; D051381:Rats; D014407:Tumor Cells, Cultured
D016229:Amyloid beta-Peptides; D010446:Peptide Fragments; C078592:amyloid beta-protein (1-40); D009569:Nitric Oxide; D016202:N-Methylaspartate; D016291:Dizocilpine Maleate