Caspase-3-like proteases and 6-hydroxydopamine induced neuronal cell death.
Neurotoxicity induced by 6-hydroxydopamine (6-OHDA) is believed to be due, in part, to the production of reactive oxygen species (ROS) and/or an inhibition of mitochondrial function. However, little is known about the ensuing intracellular events which ultimately result in cell death. Here we show that exposure to relatively low concentrations of 6-OHDA induces apoptosis of cerebellar granule neurons (CGN). 6-OHDA-induced apoptosis of CGN is associated with activation of a caspase-3-like protease. Western blots of cytosolic extracts from 6-OHDA-treated CGN reveal a translocation of cytochrome c from mitochondria to the cytosol, which precedes activation of the protease detected by Ac-DEVD-pNA. DNA laddering can be blocked by caspase inhibitors zVAD-FMK and Ac-DEVD-CHO, however cell death can only be attenuated for a short time period in the presence of these inhibitors. Our data suggest that 6-OHDA-induced apoptosis of CGN involves activation of a caspase-3-like protease. In contrast to the neurotoxicity induced by MPP+, however, the peptide inhibitors zVAD-FMK and Ac-DEVD-CHO can only attenuate early neuronal death induced by 6-OHDA. At later time points, neuronal death lacking DNA laddering occurs even in the presence of the peptide inhibitor zVAD-FMK or Ac-DEVD-CHO.
Dodel
R C
RC
Department of Pharmacology and Toxicology, Indiana University School of Medicine, 655 Barnhill Drive, Indianapolis, IN 46202, USA.
Du
Y
Y
Bales
K R
KR
Ling
Z
Z
Carvey
P M
PM
Paul
S M
SM
D015655:1-Methyl-4-phenylpyridinium / Q000494:pharmacology; D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D053148:Caspase 3; D020169:Caspases / Q000032:analysis*; D002478:Cells, Cultured; D002531:Cerebellum / Q000166:cytology; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D003574:Cytochrome c Group / Q000032:analysis / Q000378:metabolism; D053938:DNA Fragmentation; D015259:Dopamine Agents / Q000494:pharmacology; D008928:Mitochondria / Q000201:enzymology; D009474:Neurons / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology*; D009842:Oligopeptides / Q000494:pharmacology; D016627:Oxidopamine; D010302:Parkinson Disease, Secondary / Q000139:chemically induced / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013565:Sympatholytics
D000590:Amino Acid Chloromethyl Ketones; D015853:Cysteine Proteinase Inhibitors; D003574:Cytochrome c Group; D015259:Dopamine Agents; D009842:Oligopeptides; D013565:Sympatholytics; C099158:acetyl-aspartyl-glutamyl-valyl-aspartal; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; D016627:Oxidopamine; C505410:Casp3 protein, rat; D053148:Caspase 3; D020169:Caspases; D015655:1-Methyl-4-phenylpyridinium