title: [Influence of nuclear factor erythroid 2-related factor 2 genotype on tumor necrosis factor-α and metalloproteinase-9 expression in spinal cord after spinal cord injury in mice].
abstract: OBJECTIVE
  To investigate the role of nuclear factor erythroid 2-related factor 2 (Nrf2) as a key transcription factor of cytoprotection against inflammation in the spinal cord upregulation of matrix metalloproteinase-9 (MMP-9), tumor necrosis factor-α(TNF-α) after spinal cord injury (SCI).
  
  
  METHODS
  Wild-type Nrf2(+/+) and Nrf2(-/-)-deficient mice were subjected to a murine SCI model induced by the application of vascular clips (force of 10 g) to the dura after a three-level T8-T10 laminectomy. The wet/dry weight ratio was used to reflect the percentage of water content of impaired spinal cord tissue at 48 h after SCI. The mRNA levels of MMP-9 were determined using reverse-transcriptase polymerase chain reaction (RT-PCR), and the protein levels of TNF-α and MMP-9 were detected by enzyme-linked immunosorbent assay at 24 h after SCI. Furthermore, gelatin zymography analysis was used to show MMP-9 activity of spinal cord tissue at 24 h after SCI. Software SPSS 16.0 was used for the statistical analysis.
  
  
  RESULTS
  After SCI, spinal cord water content, the expression of TNF-α and MMP-9 all increased in both injured Nrf2(+/+) and Nrf2(-/-) mice compared with their respective sham-operated mice. However, Nrf2(-/-) mice were shown to have more severe spinal cord edema, more TNF-α expression, more production and activity of MMP-9 compared with their wild-type Nrf2(+/+) counterparts after SCI (P < 0.05).
  
  
  CONCLUSIONS
  The results suggest that Nrf2 plays an important protective role in limiting the spinal cord upregulation of TNF-α and MMP-9 after SCI. It may be a new therapeutic target of SCI.
authors.affiliation: Department of Neurosurgery, Nanjing General Hospital of Nanjing Military Command, Nanjing 210002, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Mao
authors.forename: Han-dong
authors.initials: HD
authors.lastname: Wang
authors.forename: Xiao-liang
authors.initials: XL
authors.lastname: Wang
authors.forename: Liang
authors.initials: L
authors.lastname: Qiao
authors.forename: Hong-xia
authors.initials: HX
authors.lastname: Yin
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D005838:Genotype; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D051379:Mice; D008813:Mice, Inbred ICR; D018345:Mice, Knockout; D051267:NF-E2-Related Factor 2 / Q000235:genetics*; D013116:Spinal Cord / Q000378:metabolism; D013119:Spinal Cord Injuries / Q000235:genetics / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
chemical_list: D051267:NF-E2-Related Factor 2; C495636:Nfe2l2 protein, mouse; D014409:Tumor Necrosis Factor-alpha; D020780:Matrix Metalloproteinase 9; C501830:Mmp9 protein, mouse