[Apoptosis and caspase-12 expression in progressive compressive spinal cord injury: experiment with rats].
OBJECTIVE
To investigate the apoptosis and caspase-12 expression in progressive compression of spinal cord (PCSC).


METHODS
120 adult Wistar rats were randomly divided into 2 equal groups, experimental group, undergoing operation so as to establish PCSC models, and control group, undergoing sham operation. 1, 3, 7, 14, 21, and 28 days after the operation, 5 rats from each group were anesthetized with their spinal cords taken out. TUNNEL method was used to observe the apoptosis of the neurons in the compressed segments. Another 5 rats from each group at different time points were anesthetized with their spinal cords as well. Immunohistochemistry was used to detect the mRNA expression of caspase-12 in the compressed segments. Western blotting was used to detect the protein expression of caspase-12.


RESULTS
The apoptotic rates of neurons and gliocytes 1, 3, 7, 14, 21, and 28 days after were 12.5% +/- 2.3%, 13.0% +/- 3.6%, 17.2% +/- 4.3%, 29.4% +/- 4.4%, 36.1% +/- 6.5%, and 2.3% +/- 7.9% respectively, with significant differences among the values 14, 21, and 28 days and those at other time points after the operation (all P < 0.05). Immunohistochemistry showed that the number of caspase-12 positive neurons increased since 1 day after, and became remarkably high 14, 21, and 28 days after with significant differences among different time points (all P < 0.05). Western blotting showed that the protein expression of caspase-12 was low 1, 3, and 7 days after, and peaked 14 days after, and then gradually decreased, however, the expression levels 21 and 28 days after were still significantly higher then those 1, 3, and 7 days after (all P < 0.05).


CONCLUSIONS
Caspase-12 is involved in the apoptosis of neurons in PCSC.
Department of Neurobiology, Chongqing Medical University, Chongqing 400016, China.
Yi-jian
YJ
Liang
Shan-quan
SQ
Sun
Ke-jian
KJ
Wang
Gui-qiong
GQ
He
Mao-ping
MP
Li
Bo-nan
BN
Huang
Wei-hua
WH
Yu
Mei
M
Yang
D000818:Animals; D017209:Apoptosis; D015153:Blotting, Western; D053454:Caspase 12 / Q000096:biosynthesis*; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D009474:Neurons / Q000378:metabolism / Q000473:pathology; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D013117:Spinal Cord Compression / Q000378:metabolism* / Q000473:pathology; D013119:Spinal Cord Injuries / Q000378:metabolism* / Q000473:pathology
D053454:Caspase 12