Cooperative action of JNK and AKT/mTOR in 1-methyl-4-phenylpyridinium-induced autophagy of neuronal PC12 cells

J Neurosci Res. 2012 Sep;90(9):1850-60. doi: 10.1002/jnr.23066. Epub 2012 Apr 19.

Abstract

Parkinson's disease has been widely related to both apoptosis and oxidative stress. Many publications relate the loss of mitochondrial potential to an apoptosis-mediated cell death in different in vivo and in vitro models of this pathology. The present study used the dopaminegic specific neurotoxin 1-methyl-4-phenylpyridinium (MPP(+) ) on neuron-like PC12 cells, which is a well-accepted model of Parkinson's disease. Results showed an early increase in oxidants, which drives the modulation of c-Jun N-terminal kinase (JNK) and AKT/mammalian target of rapamycin (mTOR) pathways, mimicking peroxide treatment. However, the cell death found in neuronal PC12 cells treated with MPP(+) was not a caspase-associated apoptosis. Electron microscopic images illustrated autophagic cell death, which was confirmed by a Beclin-1 and ATG expression increase, accumulation of acidic vesicles, and rescue by an autophagy inhibitor. In conclusion, the boost in oxidants from MPP(+) treatment in neuronal PC12 is modulating both survival (AKT/mTOR) and death (JNK) pathways, which are the perpetrators of an autophagic cell death.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine / pharmacology
  • Animals
  • Autophagy / physiology*
  • Blotting, Western
  • MAP Kinase Kinase 4 / metabolism*
  • Neurons / drug effects
  • Neurons / metabolism*
  • Neurotoxins / toxicity
  • Oxidative Stress / physiology
  • PC12 Cells
  • Proto-Oncogene Proteins c-akt / metabolism*
  • Rats
  • Signal Transduction / physiology
  • TOR Serine-Threonine Kinases / metabolism*

Substances

  • Neurotoxins
  • 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine
  • Proto-Oncogene Proteins c-akt
  • TOR Serine-Threonine Kinases
  • MAP Kinase Kinase 4