The Prothetic Effect Of Neurotrophin-3 On Spinal Cord Injury And The Effect On P53 And Caspase-3 Gene Expression

Objective: To study the effect of neurotrophin-3(NT-3) on p53 gene and caspase-3 gene expression after rat spinal cord injury(SCI); TO discuss the effect of neurotrophin-3(NT-3) during repair of spinal cord injury(SCI).Method: Ninety adult health Sprague-Dawley(SD) rats were randomly divided into tow groups: (1) NT-3 injectinon group(n=45) and (2) NS control group(n=45), then each group was divided into BDA anterograde neuronal tracing group and gene detecting group. The laminectomy was performed on all animals at spinal levels of T8. In the control and NT-3 groups, the dorsal 2/3 of the spinal cord were cut with a pair of microscissors to sever the dorsal parts of the corticospinal tract. Behavior test was carried out on the 5 rats from each group at 1 day before spinal cord surgery, 1day, 1week, 2weeks, 3weeks after surgery and just before sacrifice using the BBB(Basso, Beattle, Bresnahan) scores and observe the axis regeneration using BDA anterograde neuronal tracing.In the other rats of the control and NT-3 groups, myeloid tissue were taken at 2, 4, 6, 8 hours and 1, 3, 7, 14 days after spinal cord injury to detect expression of p53 and caspase-3 gene. 5 rats were operated at each time point. All the results were analyzed by paired t-test and analysis of variance. Result: (1) All animals in the injury group showed a paralysis on their hindlimbs. The BBB scores at the time points of 2w and 3w groups were obviously higher than control group There was a significant statistically difference between them (P＜0.05). (2) The transcriptional levels of p53 and caspase-3 gene increased after spinal cord injury. (3) Compared with the control group, the transcriptional level of p53 and caspase-3 gene of NT-3 group were decreased obviously (P＜0.05). (4) BDA anterograde neuronal tracing results show that positive fabrics through injury scar tissues in NT-3 group is much more than control group.Conclusion: (1) Utilizing NT-3, the transcriptional level of p53 and caspase-3 gene were decreased; (2) Compared with control group, movement reablement of NT-3 group is much better; (3) NT-3 can protect the spinal cord and promote its repair after spinal cord injury, maybe through affecting the transcriptional level of p53 and caspase-3 gene.