Caspase-3-like proteases and 6-hydroxydopamine induced neuronal cell death

• Published in: Brain research. Molecular brain research. 1999-01, Vol.64 (1), p.141-148
• Main Authors: Dodel, Richard C., Du, Yansheng, Bales, Kelly R., Zaodong Ling, Carvey, Paul M., Paul, Steven M.
• Format: Article
• Language: English
• Subjects: 1-Methyl-4-phenylpyridinium - pharmacology; 6-Hydroxydopamine; Ageing, cell death; Amino Acid Chloromethyl Ketones - pharmacology; Animals; Apoptosis; Apoptosis - drug effects; Apoptosis - physiology; Biological and medical sciences; Caspase; Caspase 3; Caspases - analysis; Cell physiology; Cells, Cultured; Cerebellar granule cell; Cerebellum - cytology; Cysteine Proteinase Inhibitors - pharmacology; Cytochrome c; Cytochrome c Group - analysis; Cytochrome c Group - metabolism; DNA Fragmentation; Dopamine Agents - pharmacology; Fundamental and applied biological sciences. Psychology; Mitochondria - enzymology; Molecular and cellular biology; Neuronal death; Neurons - cytology; Neurons - drug effects; Neurons - enzymology; Oligopeptides - pharmacology; Oxidopamine; Parkinson Disease, Secondary - chemically induced; Parkinson Disease, Secondary - metabolism; Parkinson's disease; Rats; Rats, Sprague-Dawley; Sympatholytics
• ISSN: 0169-328X; 1872-6941
• DOI: 10.1016/S0169-328X(98)00318-0

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.