title: Hyperbaric oxygen intervention reduces secondary spinal cord injury in rats via regulation of HMGB1/TLR4/NF-κB signaling pathway.
abstract: BACKGROUND
  To investigate whether hyperbaric oxygen (HBO) intervention affects the expressions of inflammatory cytokines, HMGB1/TLR4/NF-κB, and arrests secondary spinal cord injury (SCI).
  
  
  METHODS
  One hundred and twenty healthy adult SD rats were randomly divided into four groups: sham, sham + HBO, SCI, and SCI + HBO. Each group was then randomly divided into five subgroups of 6 rats each according to the following time points: 1, 2, 3, 7, and 14 d post injury. Functional recovery of the hindlimb was assessed by Basso, Beattie, and Bresnahan (BBB) scores at different time points after SCI. The expression of HMGB1, TLR4, and NF-κB in the spinal cord tissue was determined by fluorescence quantitative PCR, western blot, immunohistochemistry, and ELISA.
  
  
  RESULTS
  The gene expressions of TLR4, HMGB1, and NF-κB (P < 0.01) and the TLR4 protein expression were significantly high after SCI. HBO intervention significantly decreased all the four parameters at 3, 7, and 14 d post injury (P < 0.05). A significant positive correlation (P < 0.01) was observed between the following: HMGB1 mRNA, TLR4 mRNA and TLR4 protein; HMGB1 mRNA and NF-κB mRNA; and TLR4 protein and NF-κB mRNA. BBB score was negatively correlated with HMGB1, TLR4 protein and NF-κB levels. HBO intervention significantly improved the BBB scores at 7 and 14 d post injury (P < 0.05).
  
  
  CONCLUSIONS
  Hyperbaric oxygen reduced the expressions of HMGB1, TLR4, and NF-κB and reduced secondary SCI as measured using BBB scores.
authors.affiliation: Department of Orthopaedics, Beijing Chao-Yang Hospital, Capital Medical University Beijing 100020, P.R. China.
authors.forename: Nan
authors.initials: N
authors.lastname: Kang
authors.affiliation: Department of Orthopaedics, Beijing Chao-Yang Hospital, Capital Medical University Beijing 100020, P.R. China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Hai
authors.affiliation: Department of Hyperbaric Oxygen, Beijing Chao-Yang Hospital, Capital Medical University Beijing 100020, P.R. China.
authors.forename: Jing
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Hyperbaric Oxygen, Beijing Chao-Yang Hospital, Capital Medical University Beijing 100020, P.R. China.
authors.forename: Fang
authors.initials: F
authors.lastname: Liang
authors.affiliation: Department of Hyperbaric Oxygen, Beijing Chao-Yang Hospital, Capital Medical University Beijing 100020, P.R. China.
authors.forename: Chun-Jin
authors.initials: CJ
authors.lastname: Gao
mesh_terms: D000818:Animals; D024243:HMGB1 Protein / Q000378:metabolism*; D006931:Hyperbaric Oxygenation; D009043:Motor Activity / Q000502:physiology; D016328:NF-kappa B / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020127:Recovery of Function / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology*; D013116:Spinal Cord / Q000378:metabolism; D013119:Spinal Cord Injuries / Q000378:metabolism / Q000628:therapy*; D051197:Toll-Like Receptor 4 / Q000378:metabolism*
chemical_list: D024243:HMGB1 Protein; D016328:NF-kappa B; D051197:Toll-Like Receptor 4
keywords: Hyperbaric oxygen; spinal cord injury; toll-like receptor 4