Mutant huntingtin aggregates do not sensitize cells to apoptotic stressors

FEBS Lett. 2002 Mar 27;515(1-3):61-5. doi: 10.1016/s0014-5793(02)02436-5.

Abstract

It has been postulated that neuronal inclusions composed of mutant huntingtin may play a causative role in the pathogenesis of Huntington's disease. To study the putative role of aggregates in modulating apoptotic vulnerability, SH-SY5Y cell lines stably expressing truncated huntingtin with 18 (wild-type) (N63-18Q) or 82 (mutant) (N63-82Q) glutamine repeats were established. Aggregates were observed in approximately 13% of the N63-82Q cells; no aggregates were observed in the N63-18Q cells. In response to apoptotic stimuli such as staurosporine or hyperosmotic stress, caspase-3 activity was significantly greater in the N63-82Q cells compared to the N63-18Q cells. However, double immunostaining for huntingtin and active caspase-3 revealed that the presence of aggregates did not correlate with the presence of active caspase-3, indicating that aggregates do not contribute to the increase in apoptosis in the N63-82Q cells.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Apoptosis* / drug effects
  • Caspase 3
  • Caspases / metabolism
  • Enzyme Activation / drug effects
  • Enzyme Inhibitors / pharmacology
  • Humans
  • Huntingtin Protein
  • Huntington Disease / etiology
  • Immunoblotting
  • Macromolecular Substances
  • Nerve Tissue Proteins / genetics*
  • Nerve Tissue Proteins / metabolism*
  • Nerve Tissue Proteins / pharmacology
  • Neuroblastoma / drug therapy
  • Neuroblastoma / metabolism
  • Neuroblastoma / pathology
  • Nuclear Proteins / genetics*
  • Nuclear Proteins / metabolism*
  • Nuclear Proteins / pharmacology
  • Osmolar Concentration
  • Poly(ADP-ribose) Polymerases / metabolism
  • Sorbitol / pharmacology
  • Staurosporine / pharmacology
  • Transgenes
  • Trinucleotide Repeat Expansion / genetics
  • Tumor Cells, Cultured

Substances

  • Enzyme Inhibitors
  • HTT protein, human
  • Huntingtin Protein
  • Macromolecular Substances
  • Nerve Tissue Proteins
  • Nuclear Proteins
  • Sorbitol
  • Poly(ADP-ribose) Polymerases
  • CASP3 protein, human
  • Caspase 3
  • Caspases
  • Staurosporine