title: Preconditioning with hyperbaric oxygen induces tolerance against oxidative injury via increased expression of heme oxygenase-1 in primary cultured spinal cord neurons.
abstract: Hyperbaric oxygen (HBO) preconditioning can induce ischemic tolerance in the spinal cord. The effect can be attenuated by the administration of an oxygen free radical scavenger or by inhibition of antioxidant enzymes. However, the mechanism underlying HBO preconditioning of neurons against ischemic injury remains enigmatic. Therefore, in the present study primary cultured spinal cord neurons were treated with HBO and then subjected to a hydrogen peroxide (H(2)O(2)) insult. The results show that H(2)O(2) stimulation of the cultured spinal neurons caused severe DNA damage and decreased cell viability, and that these neurons were well protected against damage after a single exposure to HBO preconditioning (0.35 MPa, 98% O(2), 37 degrees C, 2 h). The protective effect started 4 h after pretreatment and lasted for at least 24 h. The cultured neurons after HBO treatment also exhibited increased heme oxygenase-1 (HO-1) expression at both the protein and mRNA levels, which paralleled the protective effect of HBO. Treatment with tin-mesoporphyrin IX (SnMP), a specific HO-1 inhibitor, before HBO pretreatment abolished the HBO-induced adaptive protection noted in the cultured spinal neurons. In conclusion, HBO preconditioning can protect primary cultured spinal cord neurons against oxidative stress, and the upregulation of HO-1 expression plays an essential role in HBO induced preconditioning effect.
authors.affiliation: Department of Aerospace Hygiene and Health Service, School of Aerospace Medicine, Fourth Military Medical University, Xi'an, Shaanxi, 710032, China.
authors.forename: Qingbo
authors.initials: Q
authors.lastname: Li
authors.forename: Jinsheng
authors.initials: J
authors.lastname: Li
authors.forename: Lifan
authors.initials: L
authors.lastname: Zhang
authors.forename: Bairen
authors.initials: B
authors.lastname: Wang
authors.forename: Lize
authors.initials: L
authors.lastname: Xiong
mesh_terms: D000818:Animals; D015153:Blotting, Western; D018929:Cell Culture Techniques; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D020552:Comet Assay; D004249:DNA Damage; D051547:Heme Oxygenase-1 / Q000096:biosynthesis*; D006931:Hyperbaric Oxygenation; D051379:Mice; D009474:Neurons / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects*; D010100:Oxygen / Q000494:pharmacology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013116:Spinal Cord / Q000166:cytology* / Q000196:embryology
chemical_list: D051547:Heme Oxygenase-1; D010100:Oxygen