Amino acid starvation induced autophagic cell death in PC-12 cells: evidence for activation of caspase-3 but not calpain-1

Apoptosis. 2006 Sep;11(9):1573-82. doi: 10.1007/s10495-006-7690-6.

Abstract

While the apoptotic and necrotic cell death pathways have been well studied, there lacks a comprehensive understanding of the molecular events involving autophagic cell death. We examined the potential roles of the apoptosis-linked caspase-3 and the necrosis/apoptosis-linked calpain-1 after autophagy induction under prolonged amino acid (AA) starvation conditions in PC-12 cells. Autophagy induction was observed as early as three hours following amino acid withdrawal. Cell death, measured by lactate dehydrogenase (LDH) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays occurred within 24 h following starvation and was accompanied by an upregulation in caspase-3 activity but not calpain-1. The cell death that occurred following AA starvation was significantly alleviated by treatment with the autophagy inhibitor 3-methyl adenine but not with the broad spectrum caspase inhibitors. Thus, this study demonstrates that 3-methyladenine-sensitive autophagic cell death due to AA starvation in PC-12 cells is mechanistically and biochemically similar to, yet distinct from, classic caspase dependent apoptosis.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Amino Acids / metabolism*
  • Animals
  • Autophagy / physiology*
  • Calpain / antagonists & inhibitors
  • Calpain / metabolism*
  • Caspase 3 / metabolism*
  • Caspase Inhibitors
  • Cathepsins / metabolism
  • Cell Nucleus / ultrastructure
  • L-Lactate Dehydrogenase / metabolism
  • Rats
  • Spectrin / metabolism
  • Starvation / metabolism*
  • Time
  • Tumor Cells, Cultured

Substances

  • Amino Acids
  • Caspase Inhibitors
  • Spectrin
  • L-Lactate Dehydrogenase
  • Cathepsins
  • Calpain
  • Caspase 3