[Analysis of chronergy for treatment of spinal cord injury with the allogeneic bone mesenchymal stem cells (BMscs) transplantation in rats].

OBJECTIVE: To observe the change of behavior, pathological change of the spinal cord,and expression of brain-derived neurotrophic factor (BDNF) and brain-derived neurotrophic factor (NGF) on rats with spinal cord injury in order to explore the optimal time of BMSCs transplantation. METHODS: Eighty health SD rats were randomly divided into 8 groups (group A,B,C,D,E,F,G,H), 10 rats in each group. According to the modified Allen method,the rat model of spinal cord injury was built. Group A as non-injured group only exposed the spinal cord but not result in blast injury. BMSCs of vitro culture were respectively infunded the region of spinal cord injury in group C, D, E, F, G, H (as transplantation groups) at the 0 h, 6 h, 24 h,3 d,5 d,7 d after model made. Group B as single model group was infunded the equal cell culture fluid. BBB score was used to evaluate the function of spinal cord at the 1st,2nd and 4th weeks after injury. The morphological changes of the tissue of spinal cord injury were observed by HE stain and the expression of BDNF and NGF were detected by Elisa method at the 4th weeks after BMSCs transplantation. RESULTS: In non-injured group,BBB score was highest than that of other 7 groups at the 1st, 2nd and 4th weeks after injury (P<0.01). There was no significant difference in BBB score between single model group and transplantation groups at the 1st week after BMSCs transplantation (P>0.05). BBB score in transplantation groups were higher than that of single model group at the 2nd and 4th weeks after BMSCs transplantation (P<0.05). At the 2nd week after injury, BBB score from high to low was group F,E,G,D,H,C,but there was no significant difference among the groups (P>0.05). At the 4th week after injury,there was significant differences in BBB score between group F and other transplantation groups (group C,D,E,G,H)(P 0.05). The levels of BDNF and NGF in group F was highest at the 4th week after BMSCs transplantation (P<0.05). In non-injured group,HE staining showed the struction of spinal cord was clear and complete,no neutrophil was found. But in other 7 groups,HE staining showed obviously oedema at local tissue,juncture of gray and white matter was undefined,and different gliocyte proliferation and inflammatory cell infiltrate cound be found. CONCLUSION: Allogeneic BMSCs transplantation is effective to stimulate the recovery of spinal cord function in rats with spinal cord injury,and the optimal time of BMSCs transplantation maybe at the 3 d after injury.