6-Hydroxydopamine (6-OHDA) induces Drp1-dependent mitochondrial fragmentation in SH-SY5Y cells

Free Radic Biol Med. 2008 Jun 1;44(11):1960-9. doi: 10.1016/j.freeradbiomed.2008.03.009. Epub 2008 Mar 20.

Abstract

Mitochondrial alterations have been associated with the cytotoxic effect of 6-hydroxydopamine (6-OHDA), a widely used neurotoxin to study Parkinson's disease. Herein we studied the potential effects of 6-OHDA on mitochondrial morphology in SH-SY5Y neuroblastoma cells. By immunofluorescence and time-lapse fluorescence microscopy we demonstrated that 6-OHDA induced profound mitochondrial fragmentation in SH-SY5Y cells, an event that was similar to mitochondrial fission induced by overexpression of Fis1p, a membrane adaptor for the dynamin-related protein 1 (DLP1/Drp1). 6-OHDA failed to induce any changes in peroxisome morphology. Biochemical experiments revealed that 6-OHDA-induced mitochondrial fragmentation is an early event preceding the collapse of the mitochondrial membrane potential and cytochrome c release in SH-SY5Y cells. Silencing of DLP1/Drp1, which is involved in mitochondrial and peroxisomal fission, prevented 6-OHDA-induced fragmentation of mitochondria. Furthermore, in cells silenced for Drp1, 6-OHDA-induced cell death was reduced, indicating that a block in mitochondrial fission protects SH-SY5Y cells against 6-OHDA toxicity. Experiments in mouse embryonic fibroblasts deficient in Bax or p53 revealed that both proteins are not essential for 6-OHDA-induced mitochondrial fragmentation. Our data demonstrate for the first time an involvement of mitochondrial fragmentation and Drp1 function in 6-OHDA-induced apoptosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects*
  • Apoptosis / physiology
  • Cell Line, Tumor
  • Cytochromes c / metabolism
  • Embryo, Mammalian / drug effects
  • Embryo, Mammalian / metabolism
  • Fibroblasts / drug effects
  • Fibroblasts / metabolism
  • Fluorescent Antibody Technique
  • GTP Phosphohydrolases / metabolism*
  • Humans
  • Hydroxydopamines / pharmacology*
  • Membrane Potential, Mitochondrial
  • Mice
  • Mice, Knockout
  • Microtubule-Associated Proteins / metabolism*
  • Mitochondria / metabolism*
  • Mitochondrial Proteins / metabolism*
  • Neuroblastoma / metabolism*
  • Neuroblastoma / pathology
  • Tumor Suppressor Protein p53 / physiology
  • bcl-2-Associated X Protein / physiology

Substances

  • Bax protein, mouse
  • Hydroxydopamines
  • Microtubule-Associated Proteins
  • Mitochondrial Proteins
  • Tumor Suppressor Protein p53
  • bcl-2-Associated X Protein
  • Cytochromes c
  • GTP Phosphohydrolases
  • DNM1L protein, human