Treatment of autologous neural differentiated and undifferentiated mesenchymal stem cells co-transplantation in spinal cord injury

[Objective]To evaluate the capability of bone marrow mesenchymal stem cells(MSCs) differentiation into neuron-like cells,and investigate the effects of a combination of the two cells in treatment of spinal cord injury(SCI) in rats.[Methods]Sixty-two three-months-old female SD rats were selected.Mesenchymal stem cells were taken and their cell differentiation was studied in two rats,the others were made for SCI models at T9～11 levels by using a modified Allen’s stall,which were randomly divided into 4 groups(n=15,each):control group(A),MSCs transplantation group(B),neurons group(C)and co-transplantation group(D).Immunofluorescence technology was used to detect the expression of the specific markers of the induced cells.Each group of the cells were labeled by Hoechst33342 and transplanted into the injured spinal cord with local injection first week post-injury.At 1,2,4,and 6 weeks after surgery,Basso-Beattie-Bresnahan(BBB)scorces were recorded in order to evaluate the functional recovery of the hindlimbs each group.The presence and differentiation of MSCs in vivo were observed by HE,fluorescence microscopy and immunofluorescence technology.[Results]At 2,4,6 weeks after sugery,there were significant improvement of BBB scores in groups B,C and D compared with group A(P0.05),The score of group D was higher than groups B and C(P0.05).There were no differences between groups B and C(P0.05).HE staining revealed that the area of spinal cavity in groups B,C and D,especially in group D,were smaller 6 weeks post-operation compared with group A.The fluorescence microscopy showed that the transplanted cells survived in the injured region.Immunofluorescence of the surface specific marker such as the neuron specific enolase(NSE) and neuroflament 200(NF-200) were positive in induced cells and transplanted cells survival in vivo.The expression of glial fibrillary acidic protein(GFAP) was just weakly positive.A large number of NSE and NF-200 cells were detected in the lesioned area in group D,making a contrast with group B and C.[Conclusion]Under certain conditions MSCs could differentiate into neuron-like cells in vitro and in vivo.MSCs and neuron-like cells can be transplanted for the treatment of spinal cord injury,and their co-transplantation may be the best option.