The 5-Lipoxygenase Inhibitor Zileuton Confers Neuroprotection against Glutamate Oxidative Damage by Inhibiting Ferroptosis

Biol Pharm Bull. 2015;38(8):1234-9. doi: 10.1248/bpb.b15-00048.

Abstract

5-Lipoxygenase (5-LOX) inhibitors have been shown to be protective in several neurodegenerative disease models; however, the underlying mechanisms remain unclear. We investigated whether 5-LOX inhibitor zileuton conferred direct neuroprotection against glutamate oxidative toxicity by inhibiting ferroptosis, a newly identified iron-dependent programmed cell death. Treatment of HT22 mouse neuronal cell line with glutamate resulted in significant cell death, which was inhibited by zileuton in a dose-dependent manner. Consistently, zileuton decreased glutamate-induced production of reactive oxygen species but did not restore glutamate-induced depletion of glutathione. Moreover, the pan-caspase inhibitor Z-Val-Ala-Asp(OMe)-fluoromethyl ketone (ZVAD-fmk) neither prevented HT22 cell death induced by glutamate nor affected zileuton protection against glutamate oxidative toxicity, suggesting that zileuton did not confer neuroprotection by inhibiting caspase-dependent apoptosis. Interestingly, glutamate-induced HT22 cell death was significantly inhibited by the ferroptosis inhibitor ferrostatin-1. Moreover, zileuton protected HT22 neuronal cells from erastin-induced ferroptosis. However, we did not observe synergic protective effects of zileuton and ferrostatin-1 on glutamate-induced cell death. These results suggested that both the 5-LOX inhibitor zileuton and the ferropotosis inhibitor ferrostatin-1 acted through the same cascade to protect against glutamate oxidative toxicity. In conclusion, our results suggested that zileuton protected neurons from glutamate-induced oxidative stress at least in part by inhibiting ferroptosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects*
  • Arachidonate 5-Lipoxygenase / metabolism
  • Cell Line
  • Cyclohexylamines / pharmacology
  • Glutamic Acid / metabolism*
  • Hydroxyurea / analogs & derivatives*
  • Hydroxyurea / pharmacology
  • Iron / metabolism
  • Lipoxygenase Inhibitors / pharmacology*
  • Mice
  • Neurons / cytology
  • Neurons / drug effects*
  • Neurons / metabolism
  • Neuroprotection*
  • Neuroprotective Agents / pharmacology
  • Oxidative Stress / drug effects*
  • Phenylenediamines / pharmacology
  • Reactive Oxygen Species / metabolism

Substances

  • Cyclohexylamines
  • Lipoxygenase Inhibitors
  • Neuroprotective Agents
  • Phenylenediamines
  • Reactive Oxygen Species
  • ferrostatin-1
  • Glutamic Acid
  • Iron
  • Arachidonate 5-Lipoxygenase
  • zileuton
  • Hydroxyurea