Mechanism of bone mesenchymal stem cells transplantation promoting recovery of injured spinal cord / 中华创伤杂志

ABSTRACT

Objective To investigate the effects of bone mesenchymal stem cells (BMSCs)transplantation on the neurological function recovery of injured spinal cord and the underlying mechanism.Methods Rats were subjected to contusive spinal cord injury by using NYU spinal cord contusive impactor system ( NYC lmpactor).Seven days after spinal cord injury,the transplantation of BMSCs ( BMSCs group) or injection of PBS ( PBS group) was performed around the epicenter of injured spinal cord in rats.Basso-Beattie-Bresnahan (BBB) score was used to evaluate the function of spinal cord.The cavity volume of the injured spinal cord was measured and the axons in the injury center of spinal cord were examined under transmission electron microscopy.The BMSCs of the green fluorescent protein (GFP)transgenic rats were used to trace the transplanted cells and the survivor of BMSCs in the injured spinal cord and their differentiation into neural cells were observed.A mini-channel implantation model was employed to further investigate the role of BMSCs transplantation on the axonal regeneration.Results The BMSCs group showed a higher BBB score and a smaller lesion volume as compared with the PBS group.Transmission electron microscopy examination displayed that the number of axons in the BMSCs group was far more than that in the PBS group.A great number of BMSCs-GFP were founded around the center of the injured spinal cord at 4 weeks after BMSCs transplantation.lmmunohistochemistry showed that the implanted BMSCs-GFP did not express the surface marker of neurons,astrocytes and oligodendrocytes.In the mini-channel implantation model,NF-positive nerve fibers grew into the BMSCs-seeded channel,while there were no nerve fibers in the channel without seeding of BMSCs.Conclusions The BMSCs transplantation for the injured spinal cord promotes its functional recovery,and the related mechanism is in correlation with BMSCs transplantation inducing axonal regeneration.