Repair of spinal cord injury using Schwann cells in rats: Feasibility and superiority of intravenous transplantation / 中国组织工程研究

ABSTRACT

BACKGROUND: Emerging studies have focused on cell transplantation. Schwann cells (SCs) can secrete various neurotrophic factors and improve local environment around injury. Plenty of documents have demonstrated that SCs could promote functional recovery following spinal injury. Many transplanting methods are available for treating spinal cord injury, and the intravenous cell transplantation is profitable for easy operation and avoidance of additional trauma. OBJECTIVE: To investigate the effects of intravenous transplantation of SCs on spinal cord injury in rats. METHODS: The bilateral sciatic nerves of Wistar rats were separated in vitro, cultured by tissue clot method, identified by S-100 and labeled by Hoechst33342. Sixty rat models with T10 spinal cord injury were prepared using impactor model- II type weight drop apparatus. Then the injured rats were randomly divided into 3 groups blank control, DMEM control and SCs transplantation groups. No treatment was performed in the blank control group. Totally 1 mL DMEM and or SCs was injected into rats of DMEM control and SCs transplantation groups by tail vein respectively. Basso Beattie Bresnahan (B6B) scores were performed at 1 day before and 1, 3 days, 1 week and weekly after operation. The migration of transplanted SCs was observed at 2 weeks and 4 after transplantation. The expressions of glial fibrillary acidic protein (GFAP) and neuron specific enolase (NSE) were detected by haematoxylin-eosin staining and immune-fluorescence staining.RESULTS AND CONCLUSION: The purity of SCs reached 95%. Hoechst33342 positive cells were observed throughout the injured and the nearby region of spinal cord at 1, 2, and 4 weeks after transplantation. The statistical difference of BBB score among the SCs transplantation, blank control, and the DMEM control groups displayed at 4 weeks after transplantation (P < 0.05), and the BBB scores of the SCs transplantation were higher than other groups. Haematoxylin-eosin staining showed the cavity formed in each group at 8 weeks after transplantation, but the area of SCs transplantation was smaller than that of the blank control and DMEM control groups. The immunofluorescence staining indicated that the expression of GFAP were more intense in the blank control group and DMEM control than SCs transplantation (P < 0.05), while the expression of NSE was more intense in SCs transplantation than other groups (P< 0.05). It implied that intravenous transplantation of SCs promotes regeneration of axon and improves neurological functions after spinal cord injury in rats.