title: Cyclo-oxygenase-2 mediates hyperbaric oxygen preconditioning-induced neuroprotection in the mouse model of surgical brain injury.
abstract: OBJECTIVE
  We investigated the role of cyclo-oxygenase-2 (COX-2) in mechanisms of hyperbaric oxygen preconditioning (HBO-PC) in the mouse model of surgical brain injury (SBI).
  
  
  METHODS
  C57BL mice were administered 100% oxygen for 1 hour at 2.5 atmosphere absolute for 5 consecutive days and subjected to SBI. Neurological status and brain edema were evaluated at 24 hours and 72 hours after the brain insult. Fluorescent immunostaining and Western blotting were performed to study hypoxia-inducible factor-1alpha and COX-2, respectively. Two doses of COX-2 inhibitor, NS398 (3 mg/kg and 10 mg/kg) were used to verify the role of COX-2 signaling pathway in the mechanism of HBO-PC.
  
  
  RESULTS
  HBO-PC improved neurological status and decreased brain edema at 24 hours and 72 hours after SBI. HBO-PC by itself and SBI independently increased COX-2 levels by 2-fold and 4-fold, respectively. HBO-PC, however, reduced increase in hypoxia-inducible factor-1alpha and COX-2 expression after SBI. The HBO-PC-induced improvement in neurological status and brain edema was reversed by a suboptimal dose of the COX-2 inhibitor, NS398 (10 mg/kg intraperitoneally; 1/4th of dose shown to provide neuroprotection), which itself had no effect on investigated end points.
  
  
  CONCLUSIONS
  HBO-PC attenuates postoperative brain edema and improves neurological outcomes after SBI. The HBO-PC-induced neuroprotection is mediated through COX-2 signaling pathways.
authors.forename: Vikram
authors.initials: V
authors.lastname: Jadhav
authors.forename: Robert P
authors.initials: RP
authors.lastname: Ostrowski
authors.forename: Wenni
authors.initials: W
authors.lastname: Tong
authors.forename: Brenden
authors.initials: B
authors.lastname: Matus
authors.forename: Rachel
authors.initials: R
authors.lastname: Jesunathadas
authors.forename: John H
authors.initials: JH
authors.lastname: Zhang
mesh_terms: D000818:Animals; D001929:Brain Edema; D001930:Brain Injuries / Q000201:enzymology* / Q000209:etiology; D051546:Cyclooxygenase 2 / Q000096:biosynthesis*; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D015971:Gene Expression Regulation, Enzymologic; D006931:Hyperbaric Oxygenation; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000096:biosynthesis; D008297:Male; D051379:Mice; D009578:Nitrobenzenes / Q000494:pharmacology; D015398:Signal Transduction; D013449:Sulfonamides / Q000494:pharmacology; D013514:Surgical Procedures, Operative / Q000009:adverse effects*; D013997:Time Factors
chemical_list: D016861:Cyclooxygenase Inhibitors; C497443:Hif1a protein, mouse; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D009578:Nitrobenzenes; D013449:Sulfonamides; C080955:N-(2-cyclohexyloxy-4-nitrophenyl)methanesulfonamide; C077623:Ptgs2 protein, mouse; D051546:Cyclooxygenase 2