Bone Mesenchymal Stem Cells Transplantation For Treating Spinal Cord Injury In Rats

OBJECTIVE:To explore the effects and mechanisms of bone marrow mesenchymal stem cells (BMSCs) locally transplanted into rats with spinal cord injury on neurological recovery.METHODS:BMSCs were separated with density gradient centrifugation and cell attachment.10 mg/L BrdU was used for labeling before cell transplantation. Adult female Wistar rats were used to establish spinal cord injury models using an aneurysm clip, and they were then randomly divided into control group, saline group and transplantation group. In the transplantation group, BMSCs were transplanted into the damaged spinal cord by stereotaxis at day 7 following damage. In the saline group, an equal volume of saline was utilized. In the control group, the rats were left intact. Basso, Beattie and Bresnahan (BBB) locomotor rating scale was used before and at 7,14,30,60 and 90 days following damage. Rats were sacrificed at day 90. BrdU-positive cells, Brdu+neuron specific enolase, Brdu+glial fibrillary acidic protein (GFAP), Brdu+basic fibroblast growth factor (bFGF), and Brdu+brain-derived nerve growth factor (BDNF) immunohistochemistry double-staining cells and simple staining positive cells were observed.RESULTS:The recovery of BBB function score was better in the transplantation group than in the control group (P< 0.05). The recovery speed of BBB function score was slower in the saline group than in the control group at 30 days following damage (P< 0.05). No significant difference was determined at day 90 compared with the control group (P> 0.05). BrdU-positive cells and double-staining cells of immunohistochemistry could be found at the center of damage site and 1 cm from caudal end to damaged site in rats of the transplantation group. The number of NSE, GFAP, bFGF and BDNF simple staining cells was significantly greater in the transplantation group than in the control and saline groups (P< 0.05).CONCLUSION:Results indicated that BMSC transplantation can improve the recovery of nervous function of rats with spinal cord injury. Its mechanism may be correlated with the differentiation of transplanted cells into neuron-like and glial cell-like cells, secretion or promoting secretion of neurotrophic factors in host.