Lipocalin-type prostaglandin D synthase protects against oxidative stress-induced neuronal cell death

Biochem J. 2012 Apr 1;443(1):75-84. doi: 10.1042/BJ20111889.

Abstract

L-PGDS [lipocalin-type PGD (prostaglandin D) synthase] is a dual-functional protein, acting as a PGD2-producing enzyme and a lipid transporter. L-PGDS is a member of the lipocalin superfamily and can bind a wide variety of lipophilic molecules. In the present study we demonstrate the protective effect of L-PGDS on H2O2-induced apoptosis in neuroblastoma cell line SH-SY5Y. L-PGDS expression was increased in H2O2-treated neuronal cells, and the L-PGDS level was highly associated with H2O2-induced apoptosis, indicating that L-PGDS protected the neuronal cells against H2O2-mediated cell death. A cell viability assay revealed that L-PGDS protected against H2O2-induced cell death in a concentration-dependent manner. Furthermore, the titration of free thiols in H2O2-treated L-PGDS revealed that H2O2 reacted with the thiol of Cys65 of L-PGDS. The MALDI-TOF (matrix-assisted laser-desorption ionization-time-of-flight)-MS spectrum of H2O2-treated L-PGDS showed a 32 Da increase in the mass relative to that of the untreated protein, showing that the thiol was oxidized to sulfinic acid. The binding affinities of oxidized L-PGDS for lipophilic molecules were comparable with those of untreated L-PGDS. Taken together, these results demonstrate that L-PGDS protected against neuronal cell death by scavenging reactive oxygen species without losing its ligand-binding function. The novel function of L-PGDS could be useful for the suppression of oxidative stress-mediated neurodegenerative diseases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Motifs
  • Apoptosis*
  • Cell Line, Tumor
  • Cell Survival / drug effects
  • Computer Simulation
  • Cysteine / chemistry
  • Cytoprotection
  • DNA Fragmentation
  • Humans
  • Hydrogen Peroxide / chemistry
  • Hydrogen Peroxide / pharmacology
  • Intramolecular Oxidoreductases / chemistry
  • Intramolecular Oxidoreductases / genetics
  • Intramolecular Oxidoreductases / metabolism*
  • Lipocalins / chemistry
  • Lipocalins / genetics
  • Lipocalins / metabolism*
  • Models, Molecular
  • Mutagenesis, Site-Directed
  • Neurons / drug effects
  • Neurons / enzymology
  • Neurons / physiology*
  • Oxidants / chemistry
  • Oxidants / pharmacology
  • Oxidation-Reduction
  • Oxidative Stress*
  • Protein Structure, Tertiary
  • Structural Homology, Protein
  • Tryptophan / chemistry

Substances

  • Lipocalins
  • Oxidants
  • Tryptophan
  • Hydrogen Peroxide
  • Intramolecular Oxidoreductases
  • prostaglandin R2 D-isomerase
  • Cysteine