Metabolomic Analyses of Brain Tissue in Sepsis Induced by Cecal Ligation Reveal Specific Redox Alterations--Protective Effects of the Oxygen Radical Scavenger Edaravone

Shock. 2015 Dec;44(6):578-84. doi: 10.1097/SHK.0000000000000465.

Abstract

The pathophysiology of sepsis-associated encephalopathy (SAE) is complex and remains incompletely elucidated. Dysregulated reactive oxygen species (ROS) production and mitochondrial-mediated necrotic-apoptotic pathway have been proposed as part of the pathogenesis. The present study aimed at analyzing the preventive effect of the free radical scavenger edaravone on sepsis-induced brain alterations. Sepsis was induced by cecal ligation and puncture (CLP) and the mice were divided into three groups-CLP vehicle (CLPV), CLP and edaravone (MCI-186, 3-methyl-1-phenyl-2-pyrazolin-5-one) (CLPE), and sham-operated (Sham). Mice in CLPV and CLPE were injected with saline or edaravone intraperitoneally at a dose of 10 mg/kg twice daily. The treatments were initiated 4 days prior to the surgical procedure. Mortality, histological changes, electron microscopy (EM), and expression of Bcl-2 family genes (Bcl-2 and Bax) were analyzed in selected brain regions. CLPE showed significant improvement in survival compared with CLPV 18 h postinduction of sepsis (P < 0.05). At the same time point, pathohistological analysis also showed marked reduction of neuronal cell death in both parietal cortex and hippocampus in the CLPE (P < 0.05). RT-PCR and immunoblotting directed at the Bcl-2 family revealed increased Bax mRNA levels in hippocampus at 12 h in CLPV as well as an increased Bax/Bcl-2 protein ratio, changes that were significantly suppressed in CLPE. In conclusion, our study suggests that sepsis induced by cecal ligation alters cerebral redox status and supports a proapoptotic phenotype. The free radical scavenger edavarone reduces mortality of septic mice and protects against sepsis-induced neuronal cell death.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antipyrine / analogs & derivatives*
  • Antipyrine / therapeutic use
  • Apoptosis
  • Brain / drug effects
  • Brain / pathology*
  • Cecum / surgery
  • Cell Death
  • Edaravone
  • Free Radical Scavengers / therapeutic use*
  • Ligation
  • Metabolomics
  • Mice
  • Microscopy, Electron
  • Neurons / pathology
  • Oxidation-Reduction*
  • Oxygen / chemistry
  • Phenotype
  • Polymerase Chain Reaction
  • Proto-Oncogene Proteins c-bcl-2 / metabolism
  • Reactive Oxygen Species / metabolism
  • Sepsis / physiopathology*
  • bcl-2-Associated X Protein / metabolism

Substances

  • Bax protein, mouse
  • Free Radical Scavengers
  • Proto-Oncogene Proteins c-bcl-2
  • Reactive Oxygen Species
  • bcl-2-Associated X Protein
  • Bcl2 protein, mouse
  • Edaravone
  • Oxygen
  • Antipyrine