The Study Of The Repairable Effects Of Transplanting The Marrow Mesenchymal Stem Cells On The Neural Function In Rats With Spinal Cord Injury

Objective:To investigate the repairable effects of transplanting the marrow mesenchymal stem cells(MSCs) on the neural function in rats with spinal cord injury (SCI).Methods:Bone marrow tissues were collected and the MSCs were separated with density gradient centrifugation and screening the cells adherent to the plastic surface. The MSCs were cultivated in specified medium.MSCs labeled by bromodeoxyuridine(BrdU) were transplanted into the vena caudalis 7days after the model rats with spinal Cord injury were established.The rats with SCI were randomly divided into two groups.A group,control group,the injury was recovered naturally after injury.B group,treated group,10ul BMSCs suspension(approximately 1.0×10~6) was transplanted 7 days after injury through vena caudalis.BBB function score, somatosensory evoked potential(SEP) and motor evoked potential(MEP) tests were performed before injury,14 days,60days and 90 days after injury.The pathologic examination and immunohistochemical double stain were used to observe the survival, migration and differentiation of the transplanted MSCs in vivo.Results:1.The results showed that by gradient centrifugation and adhesion culture,MSCs could be isolated and culture-expanded.MSCs primary identification can be accomplished by flow cytometry.2.BBB function score:There were not significant differences between A group and B group 6 days after injury(P＞0.05).Behavioral score of B group was significantly higher than that of A group(P＜0.05) 30 days after injury,as well as 60,90 days after injury.It was shown that the behavioral score of model rats was significantly improved in the treated group.3.MEP examination:There were not significant differences among the normal MEP latent periods of two groups before injury(P＞0.05).All the MEP of two groups disappeared 6 days after injury.All the MEP of two groups appeared 3 months after injury and the MEP latent periods of A group were prolonger than B group(P＜0.05).The MEP latent period of each group was prolonged compared with each group before injury respectively(P＜0.05).4.SEP examination:There were not significant differences among the normal SEP latent periods of two groups before injury(P＞0.05).All the MEP of two groups disappeared 6 days after injury.The SEP of two groups gradually appeared,but the SEP latent period of each group was prolonged compared with each group before injury respectively(P＜0.05).5.Pathology and immunohistochemical double stain:BrdU-positive cells could be detected in the spinal cord of rats in B group.It was shown that MSCs could survive and migrate in vivo.BrdU+NSE and BrdU+GFAP double-positive cells could be observed in the injured spinal cord of rats in B group.It was suggested that MSCs could differentiate into neurons and astrocytes in vivo.Conclusion:MSCs can be isolated and expanded in vitro.MSCs transplanted by vena caudalis can survive and differentiate into neuron like cells and neuroglia like cells, and can improve neurological function.The levels of BDNF and bFGF were much higher in the transplanted group and can make recovery of neurological function of SCI rats.The treatment with MSCs can promote the recovery of behavioral score and neural electrophysiology in rats of SCI.