Objective To observe the effect of electroacupuncture(EA)on the differentially expressed proteins in the spinal cord at different time courses after acute spinal cord injury(ASCI)in the rat

so as to study its underlying mechanism in improving spinal traumatic injury.Methods A total of 105 male SD rats were randomized into normal control

model-6 h

EA-6 h

model-24 h

EA-24 h

model-48 h

EA-48 h groups

with 15 cases in each.ASCI model was established by using modified Allen's method.EA(2 Hz

2-5 mA)was applied to "Mingmen"(GV 4)and "Dazhui"(GV 14)for 30 min.The injured spinal cord tissue(T10-T11)was collected 6 h

24 h and 48 h after ASCI and EA treatment

weighted and stored under-80 ℃ till detection.Two-dimensional gel electrophoresis(2-DE)was used to separate total proteins of the spinal tissue

followed by protein extraction and quantitation

2-D gel image analysis

matrix assisted laser desorption ionisation time-of-flight mass spec-trometry(MALDI-TOF-MS)

and databases-searching for identification of the differentially-expressed proteins.Results A total of 10 differentially expressed proteins were identified in the present study.At 6 h

compared with control group

of the 5 types of spinal differential proteins

4 were upregulated in the expression after ASCI

and the rest one was downregulated;while after EA

ASCI-induced expression changes in 4 of the 5 differential proteins were reversed.At 24 h after ASCI

7 types of differential proteins were identified.Compared with control group

6 differential proteins were upregulated

and the rest one was downregulated in model group.Compared with model group

ASCI-induced expression changes in 6 of the 7 differential proteins were reversed by EA.At 48 h after ASCI

a total of 8 types of differential proteins were identified.Compared with control group

6 differential proteins were upregulated in the expression

and the rest two downregulated in model group.Compared with model group

ASCI-induced expression changes in 5 of the 8 differential proteins were reversed by EA.Along with the increased time and treatment

24 h vs 6 h

two more differential proteins were identified

i.e.

nucleoside diphosphate kinase and triosephosphate isomerase 1(TPI 1).48 h vs 24 h

3 more differential proteins were identified

i.e.

dihydrolipoamide dehydrogenase

malate dehydrogenase 1

and glyceraldehyde-3-phosphate dehydrogenase(GAPDH);but two proteins disappeared

i.e.

nucleoside diphosphate kinase

and ubiquitin-conjugating enzyme E2N.The identified differential proteins involving the effects of EA in regulating cellular energy metabolism

DNA repair

cellular generation

differentiation

apoptosis

etc.Conclusion Proteome analysis indicates that in ASCI rats

some differentially expressed proteins involving energy metabolism

neuronal apoptosis reduction

protein-degradation inhibition may contribute to the effect of EA in repairing the traumatic spinal tissue.