Neuronal apoptosis is accompanied by amyloid beta-protein accumulation in the endoplasmic reticulum

J Alzheimers Dis. 2002 Feb;4(1):31-7. doi: 10.3233/jad-2002-4104.

Abstract

A series of evidences suggests that enhanced susceptibility to programmed cell death (PCD) is a major pathogenetic factor in Alzheimer's disease (AD). We investigated this issue, analyzing amyloid beta-protein (A beta) production in a model of neuronal PCD, induced by staurosporine in a murine neuroblastoma cell line. When PCD was induced, a 280-290% secreted A beta occurred, in spite of a 20% metabolism and an unchanged A betaPP expression. The increased intracellular A beta reactivity largely colocalized with a marker of ER. Inhibition of caspases blocked the cleavage at the C-terminus of beta PP, but only partially rescued A beta overproduction caused by staurosporine treatment. Our findings suggest that PCD fosters the physiological pathways of A beta production characteristic of neuronal cells, and they confirm the theory that unbalance of PCD is a central event in AD pathogenesis. Moreover, our data indicate that still unidentified cellular mechanisms, other than caspases activation, are responsible of the specific alteration of A betaPP processing during PCD.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amyloid beta-Peptides / metabolism*
  • Amyloid beta-Protein Precursor / metabolism
  • Animals
  • Apoptosis / physiology*
  • Cytosol / pathology
  • Endoplasmic Reticulum / pathology*
  • Humans
  • Mice
  • Neuroblastoma
  • Neurons / pathology*
  • Tumor Cells, Cultured

Substances

  • Amyloid beta-Peptides
  • Amyloid beta-Protein Precursor