Effects of hyperbaric oxygen on MMP-2 and MMP-9 expression and spinal cord edema after spinal cord injury.
OBJECTIVE
To evaluate the effects of hyperbaric oxygen (HBO) therapy on MMP-2 and MMP-9 expression and spinal cord edema after acute spinal cord injury (SCI).


METHODS
Ninety-six healthy adult Sprague − Dawley rats were randomly divided into 4 groups: sham, sham + HBO, SCI, and SCI + HBO. Each group was subdivided into 4 subgroups of 6 rats each: 24 h, 48 h, 72 h, and 5 d post-injury. The expression levels of matrix metalloproteinase-2 (MMP-2), MMP-9, interleukin (IL-6), and vascular endothelial growth factor (VEGF) were measured using ELISA. The water content of the spinal cord was also measured by Elliot equation.


RESULTS
MMP-2 and MMP-9 levels and spinal cord water content increased significantly in the SCI group compared to those in the sham and sham + HBO groups at different time points after SCI (P < 0.01). The MMP-2 level was significantly different between the SCI and SCI + HBO groups at 72 h after SCI (P < 0.05), while the MMP-9 level was significantly different at 48 h, 72 h, and 5 d (P < 0.05). The water content of the spinal cord was significantly higher in the SCI group at 5 d after SCI (P < 0. 01). MMP-2 (P < 0.05) and MMP-9 (P < 0.01) levels were positively correlated with spinal cord water content.


CONCLUSIONS
HBO reduced SCI-induced spinal cord edema, stabilized the blood-spinal cord barrier, and promoted recovery of neuronal function by down regulating the expression of IL-6, MMP-2, and MMP-9 and up regulating the expression of VEGF.
Jing
J
Yang
Guozhong
G
Wang
Chunjin
C
Gao
Guiqiang
G
Shao
Nan
N
Kang
D000818:Animals; D001812:Blood-Brain Barrier; D004487:Edema / Q000378:metabolism / Q000628:therapy*; D006931:Hyperbaric Oxygenation; D015850:Interleukin-6 / Q000097:blood; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013119:Spinal Cord Injuries / Q000378:metabolism* / Q000628:therapy*; D042461:Vascular Endothelial Growth Factor A / Q000097:blood
D015850:Interleukin-6; D042461:Vascular Endothelial Growth Factor A; C467498:vascular endothelial growth factor A, rat; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9