Propofol with bone marrow mesenchymal stem cell transplantation improves the hind limb function and electrophysiological changes in rats with spinal cord injury / 中国组织工程研究

ABSTRACT

BACKGROUND:Bone marrow mesenchymal stem cels can be used to repair neurons, but have no ideal outcomes on nervous system injuries. OBJECTIVE:To investigate the effects of bone marrow mesenchymal stem cel transplantation combined with propofol on the hind limb function and electrophysiological changes of rats with spinal cord injury. METHODS:Eighty adult Wistar rats were selected to make animal models of spinal cord injury, and then randomized into four groups (n=20): bone marrow mesenchymal stem cel group, control group, combination group, propofol group. At 6 hours after modeling, rats in these four groups were injectedvia the tail vein with bone marrow mesenchymal stem cel suspension, cel culture medium, bone marrow mesenchymal stem cel suspension+propofol solution, and propofol solution using a 1 mL syringe, respectively. Rat motor function was assessed by Basso Beattie Bresnahan score, modified Tarlov score and inclined plane test before and at 1 day, 3 days, 1-4 weeks after modeling. Under fluorescence microscope, the survival and distribution of PKH-26-labeled bone marrow mesenchymal stem cels were observed at 4 weeks after modeling, and meanwhile, hematoxylin-eosin staining was used for pathological observation. Horseradish peroxidase tracer analysis was performed to analyze regeneration of nerve fibers, and motor and somatosensory evoked potentials were used to analyze the neurophysiological recovery of rats. RESULTS AND CONCLUSION:(1) The motor function of the rat hind limb recovered best in the combination group, better in the bone marrow mesenchymal stem cel group and propofol group, but worse in the control group. (2) There were a smal amount of nerve axon-like structures and smal syringomyelia in the bone marrow mesenchymal stem cel group and propofol group, but the combination group had more axon-like structures and no syringomyelia. In the control group, no axons but spinal cord defects and syringomyelia formed. (3) The amount of horseradish peroxidase-positive nerve fibers and the number of PKH-26 positive cels were ranked as folows: control group propofol group and bone marrow mesenchymal stem cel group > combination group, and there were significant differences between the groups (P < 0.05). (5) Amplitudes of motor and somatosensory evoked potentials were arranged as folows: control group < propofol group and bone marrow mesenchymal stem cel group < combination group, and the differences were statisticaly significant (P < 0.05). These findings indicate that both propofol and bone marrow mesenchymal stem cels can promote synaptic regeneration and improve the electrophysiological function and motor function of rats with spinal cord injury. Their combination has a better role than propofol and bone marrow mesenchymal stem cels used alone.