Effects of cryopreserved neural stem cell transplantation on rat axonal regeneration after spinal cord injury:Retrograde tracing observation / 中国组织工程研究

ABSTRACT

AIM:There are some reports about the treatment of spinal cord injury with neural stem cells(NSCs) transplantation,but the ideas about the transplantation time and patterns and detection indexes are still different.In this study,the effects of cryopreserved NSC transplantation on the axonal regeneration after the spinal cord injury in rats were observed.METHODS:The experiment was carried out in the experimental animal center of China Medical University from June 2005 to June 2006.①Thirty-six adult Wistar rats,either male or female and 250-300 g,were provided by the experimental animal department of China Medical University.Neural stem cells were isolated from 10 neonate rats and cultured.All treatments for animals were accorded with the animal ethical criteria.②NSCs at logarithmic phase were cryopreserved at-70 ℃ for 2 weeks and labeled with 5-bromodeoxyuridine(Brdu) after rewarming.After the models of spinal cord injury were established,the NSCs were transplanted into the injured site immediately.Thirty-six rats were randomly divided into NSC transplantation group,DMEM solution group,and control group.③NSC survival and migration were detected by immunohistochemistry,and the reconstruction of spinal cord were detected by horseradish peroxidase(HRP) staining.RESULTS:Of the 36 spinal injured model rats,4 died of overdose of anesthesia,and 5 died of infection,but all were supplemented.Brdu-labeled positive NSCs were detected in the injured spinal cord after transplantation on the 7th day,and increased on the 14th day,then gradually decreased since the 28th day till disappeared.The number of HRP positive cells in transplantation group was significantly higher than DMEM solution.CONCLUSION:Cryopreserved NSCs can survive in the injured site after transplantation and promote the reconstruction of axoplasm pathway of injured spinal cord.