Involvement of a caspase-3-like cysteine protease in 1-methyl-4-phenylpyridinium-mediated apoptosis of cultured cerebellar granule neurons.
Exposure of various neuronal cells or cell lines to high concentrations of 1-methyl-4-phenylpyridinium (MPP+), the active metabolite of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), results in cell death. Recently, it has been reported that low concentrations of MPP+ induce apoptosis in susceptible neurons. We have further characterized MPP+-mediated toxicity of cultured cerebellar granule neurons (CGNs) and found that exposure of CGNs to relatively low concentrations of MPP+ results in apoptosis, whereas higher concentrations result in necrosis. Cotreatment of CGNs with MPP+ and the tetrapeptide inhibitor of caspase-3-like proteases, acetyl-DEVD-CHO, markedly attenuates apoptotic but not necrotic death of these neurons. The more specific inhibitor of caspase-1-like proteases, acetyl-YVAD-CHO, however, was ineffective against MPP+ neurotoxicity. Moreover, cytoplasmic extracts prepared from MPP+-treated CGNs contain markedly increased protease activity that cleaves the caspase-3 substrate acetyl-DEVD-p-nitroaniline. Finally, the cytoplasmic concentration of the apoptogenic protein cytochrome c was increased in a time-dependent fashion in MPP+-treated CGNs before the onset of apoptosis. Our data confirm that the neurotoxicity of MPP+ is due to both necrosis and apoptosis and suggest that the latter is mediated by activation of a caspase-3-like protease.
Du
Y
Y
Neuroscience Discovery Research, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana 46285, U.S.A.
Dodel
R C
RC
Bales
K R
KR
Jemmerson
R
R
Hamilton-Byrd
E
E
Paul
S M
SM
D015655:1-Methyl-4-phenylpyridinium / Q000494:pharmacology*; D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D053148:Caspase 3; D020169:Caspases; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002531:Cerebellum / Q000166:cytology / Q000187:drug effects*; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D003574:Cytochrome c Group / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D009498:Neurotoxins / Q000494:pharmacology*; D009842:Oligopeptides / Q000494:pharmacology; D009994:Osmolar Concentration; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
D015853:Cysteine Proteinase Inhibitors; D003574:Cytochrome c Group; D009498:Neurotoxins; D009842:Oligopeptides; C099158:acetyl-aspartyl-glutamyl-valyl-aspartal; C096429:L 709049; C505410:Casp3 protein, rat; D053148:Caspase 3; D020169:Caspases; D003546:Cysteine Endopeptidases; D015655:1-Methyl-4-phenylpyridinium