Involvement of a caspase-3-like cysteine protease in 1-methyl-4-phenylpyridinium-mediated apoptosis of cultured cerebellar granule neurons

J Neurochem. 1997 Oct;69(4):1382-8. doi: 10.1046/j.1471-4159.1997.69041382.x.

Abstract

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.

MeSH terms

  • 1-Methyl-4-phenylpyridinium / pharmacology*
  • Animals
  • Apoptosis / physiology*
  • Caspase 3
  • Caspases*
  • Cell Survival / drug effects
  • Cells, Cultured
  • Cerebellum / cytology
  • Cerebellum / drug effects*
  • Cysteine Endopeptidases / metabolism*
  • Cysteine Proteinase Inhibitors / pharmacology
  • Cytochrome c Group / metabolism
  • Cytoplasm / metabolism
  • Dose-Response Relationship, Drug
  • Neurons / drug effects*
  • Neurons / physiology
  • Neurotoxins / pharmacology*
  • Oligopeptides / pharmacology
  • Osmolar Concentration
  • Rats
  • Rats, Sprague-Dawley
  • Time Factors

Substances

  • Cysteine Proteinase Inhibitors
  • Cytochrome c Group
  • Neurotoxins
  • Oligopeptides
  • acetyl-aspartyl-glutamyl-valyl-aspartal
  • L 709049
  • Casp3 protein, rat
  • Caspase 3
  • Caspases
  • Cysteine Endopeptidases
  • 1-Methyl-4-phenylpyridinium