Treatment Of Spinal Cord Injury By C3 Transferase Combined With Schwann Cells Transplantation In Rats

Objective:To investigate the effects of C3 transferase combined with intravenous transplantation of Schwann cells on spinal cord injuries in adult wistar rats.Method:Female Wistar rats weighing 50±10g, The bilateral sciatic nerves of wistar rats were separated in viro, SCs were cultured by the tissue clot method, SCs identification were positive for S-100 immunofluorescent staining, SCs were marked by Hoechst33342 before transplantation.The rat's SCI model was made by impactor model-Ⅱtype weight drop apparatus at T10, Then sixty female Wistar rats were randomly divided into 4 groups, DMEM control group(n=15,group A), C3 Transferase group(n=15,group B),SCs transplantation group(n=15,group C), and combined transplantation group(n=15,group D), C3 Transferase group (group B) and combined transplantation group (group D):C3 transferase 10μl were injected into the injured epicenter of spinal cord after injury immediately and three days after injury respectively,SCs group (group C) and combined transplantation group (group D):1ml SCs suspension (1×106)were transplantated by tail vein respectively 1 week after injury, control group(group A):lml DMEM was injected by tail vein as control. Preoperative Id, postoperative 1d,3d,1 week and every week after injury The Basso Beattie Bresnahan(BBB)score and footprint analysis were carried out to evaluate functional recovery of injuried rat's hind limbs. To reveal the migration of SCs, Hoechst33342 positive cells were detected in spinal cord of the injured rats at 1,2,4 weeks after intravenous transplantation. Two rats in each group were injected with 10%biotinylated dextran amine(BDA)in the double cerebra cortex for anterograde labeling of CST 12 weeks after injury. HE staining, immunofluorescence staining (NSE and GFAP) around the injured epicenter was measured respectively at 13 weeks after transplantation.Results:A amount of Schwann cells grow out three days after cultured, the final SCs purities reached 95%. After injection, Hoechst33342 positive cells were observed throughout the injured epicenter and the nearby regions of spinal cord at 1,2, and 4 weeks. statistical difference of BBB score happened among four groups four weeks after injury(p<0.05), and the BBB scores of groups C and D were higher than that of groups A and B. statistical difference of footprint analysis appeared between group D and group B C eight weeks after injury(p<0.05). HE staining showed the formation of cavity in each group, but the area of group A were the biggest. The immunofluorescence staining indicated that the expression of GFAP were more intense in group A and B than group C and D,the expression of NSE was more intense in group D than other groups.There was statistical difference in GFAP and NSE expression between groups C, D and group A, B (p<0.05). The regenerated nerve fiber stained by BDA was more intensive in groups C and D, and group D was significiant.Conclusion:Schwann cells can reach the injured epicenter of spinal cord through blood-spinal cord barrier, improve micro-environment and promote the repair of damaged nerve fibers. Schwann cells co-transplantation of C3 transferase have better effects for spinal cord injuries in rats.