title: Lipopolysaccharide-induced preconditioning protects against traumatic spinal cord injury by upregulating Nrf2 expression in rats.
abstract: OBJECTIVE
  Lipopolysaccharide (LPS)-induced preconditioning protects neurons against traumatic spinal cord injury (TSCI) in rats. This study sought to test whether Nrf2, a transcription factor, mediated LPS-induced preconditioning.
  
  
  METHODS
  The TSCI model was established using a standardized NYU impactor on adult female rats. Rats were pretreated with LPS (0.2mg/kg, IP; 72h before injury). Nrf2 was silenced by injecting a lentivirus encoding RNAi against Nrf2 into injured spinal cords. Neurologic function was assessed by Basso, Beattie and Bresnahan (BBB) scores 6h, 12h, 24h, 48h, 72h, 7d and 14d after TSCI. Neuronal apoptosis was measured by a TUNEL staining. Ultrastructure was observed using transmission electron microscope (TEM). The protein expression of HO-1, NQO1 and GCLC was examined using immunohistochemistry and immunoblotting.
  
  
  RESULTS
  The injection of a lentivirus effectively transfected GFP into injured spinal cords. The expression of Nrf2 was significantly decreased in spinal cords receiving a lentivirus encoding RNAi against Nrf2. BBB scores showed that TSCI markedly impaired nervous function, which was markedly preserved by LPS pretreatment. Nrf2 knockdown significantly suppressed LPS pretreatment-induced protection of nervous function. TEM images and TUNEL staining showed an increase in apoptotic cells when Nrf2 was silenced. Moreover, immunohistochemistry and immunoblotting analysis exhibited that LPS pretreatment significantly upregulated the expression of anti-oxidative proteins including HO-1, NQO1 and GCLC, which was suppressed when Nrf2 expression was silenced in injured spinal cords.
  
  
  CONCLUSIONS
  LPS preconditioning effectively alleviates TSCI-induced impairment and preserves nervous function in a Nrf2-dependent manner.
authors: Faculty of Medical Science, Kunming University of Science and Technology, Kunming, China; Department of Orthopedic Surgery, First People's Hospital of Yunnan Province, Affiliated Hospital of Kunming University of Science and Technology, Kunming, China.. Electronic address: liweichao0394@sina.com.
authors: Weichao
authors: W
authors: Li
authors: Department of Orthopedic Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.
authors: Dianming
authors: D
authors: Jiang
authors: Department of Cardiovascular Medicine, Internal Medicine, University of Iowa, Iowa City, IA 52242, USA.
authors: Qiuxia
authors: Q
authors: Li
authors: Department of Orthopedic Surgery, First People's Hospital of Yunnan Province, Affiliated Hospital of Kunming University of Science and Technology, Kunming, China.. Electronic address: gukeyshp@sina.com.
authors: Shaoping
authors: S
authors: Yao
authors: Faculty of Medical Science, Kunming University of Science and Technology, Kunming, China; Department of Orthopedic Surgery, First People's Hospital of Yunnan Province, Affiliated Hospital of Kunming University of Science and Technology, Kunming, China.
authors: Xianrun
authors: X
authors: Sun
authors: Department of Orthopedic Surgery, First People's Hospital of Yunnan Province, Affiliated Hospital of Kunming University of Science and Technology, Kunming, China.
authors: Yong
authors: Y
authors: Yang
authors: Department of Orthopedic Surgery, First People's Hospital of Yunnan Province, Affiliated Hospital of Kunming University of Science and Technology, Kunming, China.
authors: Zengdong
authors: Z
authors: Meng
authors: Department of Orthopedic Surgery, First People's Hospital of Yunnan Province, Affiliated Hospital of Kunming University of Science and Technology, Kunming, China.
authors: Wei
authors: W
authors: Liu
mesh_terms: D000818:Animals; D005260:Female; D005822:Genetic Vectors; D005721:Glutamate-Cysteine Ligase / Q000378:metabolism; D051547:Heme Oxygenase-1 / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology*; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000378:metabolism; D051267:NF-E2-Related Factor 2 / Q000235:genetics*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013119:Spinal Cord Injuries / Q000378:metabolism / Q000517:prevention & control*; D014162:Transfection; D015854:Up-Regulation
chemical_list: D008070:Lipopolysaccharides; D051267:NF-E2-Related Factor 2; C495637:Nfe2l2 protein, rat; D051547:Heme Oxygenase-1; D016660:NAD(P)H Dehydrogenase (Quinone); C507703:NQO1 protein, rat; D005721:Glutamate-Cysteine Ligase; C544143:GCLC protein, rat
keywords: Anti–oxidant; Lipopolysaccharide; Nrf2; Traumatic spinal cord injury