[Reactive astrocytes and nestin expression in adult rats following spinal cord compression injury].
OBJECTIVE
To observe the expressions of nestin and glial fibrillary acidic protein (GFAP) and their association with reactive astrocytes following spinal cord injury in adult rats.


METHODS
Adult rats with compression injury of the spinal cord were divided into 7 groups (n=6) and examined at 1, 3, and 5 days and at 1, 2, 4 and 8 weeks after the injury. The recovery of the locomotor function after the injury was evaluated with Basso, Beattie and Bresnahan (BBB) scale, and the degree and scope of the spinal injury were assessed using toluidine blue staining. Immunohistochemistry, double immunofluorescent labeling and an image analysis system were employed to observe nestin and GFAP expression and cell proliferation in different regions of the spinal cord.


RESULTS
The bilateral hind limb locomotor function of the rats declined severely 24 h after the spinal cord injury and underwent substantial recovery in 1 or 2 weeks after the injury, but followed by rather slow recovery afterwards. Toluidine blue staining of the spinal cord 24 h after the injury showed significant pathological changes in the neurons. The extension of the tissue injury increased with time till 1 week after the spinal cord injury. The site of injury and the adjacent tissues presented with markedly increased nestin and GFAP expressions 24 h after the injury, and nestin+/GFAP(-) cells dominated in the ependymal region around the central canal, whereas nestin+/GFAP+ dominated in the in other regions, showing significant difference from the control group. Nestin and GFAP expression reached the peak level 3 to 7 days after the injury and declined gradually till reaching nearly the control level at 2 weeks.


CONCLUSIONS
Compression injury of the spinal cord induces up-regulated expressions of nestin and GFAP, and nestin expression is positively correlated to the reactive astrocytes, which, along with the neural stem cells, respond to spinal nerve injury and possibly play a role in repair of the central nervous system injury.
Yang
Ping-lin
PL
Department of Orthopedics, Second Affiliated Hospital, Xi'an Jiaotong University College of Medicine, Xi'an 710004, China. yplyplypl1974@163.com
He
Xi-jing
XJ
Li
Hao-peng
HP
Lan
Bin-shang
BS
Wang
Dong
D
Wang
Guo-yu
GY
Xu
Si-yue
SY
Liu
Yi-heng
YH
D000818:Animals; D001253:Astrocytes / Q000473:pathology*; D005904:Glial Fibrillary Acidic Protein / Q000096:biosynthesis / Q000235:genetics; D007381:Intermediate Filament Proteins / Q000096:biosynthesis* / Q000235:genetics; D008297:Male; D009419:Nerve Tissue Proteins / Q000096:biosynthesis* / Q000235:genetics; D064231:Nestin; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013119:Spinal Cord Injuries / Q000378:metabolism* / Q000473:pathology*; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*; D015854:Up-Regulation
D005904:Glial Fibrillary Acidic Protein; D007381:Intermediate Filament Proteins; D009419:Nerve Tissue Proteins; C577486:Nes protein, rat; D064231:Nestin