title: Differences in Reperfusion-Induced Mitochondrial Oxidative Stress and Cell Death Between Hippocampal CA1 and CA3 Subfields Are Due to the Mitochondrial Thioredoxin System.
abstract: OBJECTIVE
  The susceptibility of CA1 over CA3 to damage from cerebral ischemia may be related to the differences in reactive oxygen species (ROS) production/removal between the two hippocampal subfields. We aimed to measure CA1/CA3 differences in net ROS production in real time in the first 30 min of reperfusion in pyramidal cells. We aimed to determine the underlying cause of the differential vulnerability of CA1 and CA3.
  
  
  RESULTS
  Real-time determinations of mitochondrial H2O2and, independently, glutathione (GSH) redox status from roGFP-based probes in individual pyramidal cells in organotypic hippocampal cultures during oxygen-glucose deprivation (OGD)-reperfusion (RP) demonstrate a significantly more oxidizing environment during RP in CA1 than CA3 mitochondria. Protein levels (immunohistochemistry and Western blots), roGFP2-based probe measurements during controlled mitochondrial production of ROS, and thioredoxin reductase (TrxR) inhibition by auranofin are consistent with a more effective mitochondrial thioredoxin (Trx) system in CA3. Inhibition of TrxR eliminates the differences in redox status and cell death between the regions. Overexpression of cytosolic Trx1 does not influence mitochondrial H2O2production.
  
  
  METHODS
  Real-time changes of mitochondrial H2O2and GSH in tissue cultures during early RP, and also during controlled production of superoxide and peroxide, reveal significant differences between CA1 and CA3. The mitochondrial Trx system is responsible for the observed differences during RP as well as for delayed cell death 18 h afterward.
  
  
  CONCLUSIONS
  Greater mitochondrial Trx efficacy in CA3 pyramidal cells results in less vulnerability to ischemia/reperfusion because of the less oxidizing environment in CA3 mitochondria during RP. Antioxid. Redox Signal. 27, 534-549.
authors.affiliation: 1 Department of Chemistry, University of Pittsburgh , Pittsburgh, Pennsylvania.
authors.forename: Bocheng
authors.initials: B
authors.lastname: Yin
authors.affiliation: 2 Department of Neuroscience, University of Pittsburgh , Pittsburgh, Pennsylvania.
authors.forename: Germán
authors.initials: G
authors.lastname: Barrionuevo
authors.affiliation: 3 Department of Radiation Oncology, Duke University Medical Center , North Carolina.
authors.forename: Ines
authors.initials: I
authors.lastname: Batinic-Haberle
authors.affiliation: 4 Department of Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg , Göteborg, Sweden .
authors.forename: Mats
authors.initials: M
authors.lastname: Sandberg
authors.affiliation: 1 Department of Chemistry, University of Pittsburgh , Pittsburgh, Pennsylvania.
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Weber
mesh_terms: D000818:Animals; D002545:Brain Ischemia / Q000209:etiology / Q000378:metabolism*; D016923:Cell Death; D005978:Glutathione / Q000032:analysis; D006624:Hippocampus / Q000166:cytology / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000032:analysis; D008297:Male; D008928:Mitochondria / Q000378:metabolism*; D009924:Organ Culture Techniques; D018384:Oxidative Stress; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D015427:Reperfusion Injury / Q000150:complications / Q000378:metabolism*; D013880:Thioredoxin-Disulfide Reductase / Q000378:metabolism
chemical_list: D017382:Reactive Oxygen Species; D006861:Hydrogen Peroxide; D013880:Thioredoxin-Disulfide Reductase; D005978:Glutathione
keywords: OGD-RP; ROS; glutathione; hippocampal pyramidal cell; mitochondria; thioredoxin