BACKGROUND:Endothelial progenitor cels are widely used in the treatment of various vascular diseases, and early exercise training contributes to restore motor function after spinal cord injury. However, the therapeutic effects of endothelial progenitor cel transplantation or early exercise training alone are unfavorable. OBJECTIVE:To observe the influence of transplantation of endothelial progenitor cels combined with early exercise training on blood vessel regeneration and hind limb function in rats after spinal cord injury. METHODS:Eighty adult Sprague-Dawley rats were enroled to establish spinal cord injury models using the modified Alen’s method, and then randomly divided into four groups. Rats were respectively given culture mediumvia the tail vein, injection of endothelial progenitor cels (3×106)via the tail vein, roler and treadmil trainings for 2 weeks, or injection of endothelial progenitor celsvia the tail vein folowed by 2 weeks of roler and treadmil trainings in the model, cel transplantation, exercise and combined groups. RESULTS AND CONCLUSION:At 2 weeks after transplantation, the hindlimb motor function of rats in the combined group was better than that in the cel transplantation group and exercise group, and moreover, the percentage of CM-Dil positive cels, the number of horseradish peroxidase-positive nerve fibers, capilary density and expression of vascular endothelial growth factor and brain-derived neurotrophic factor were also significantly higher in the combined group than the cel transplantation group and exercise group. These findings indicate that early exercise training has a neuroprotective role in spinal cord injury; endothelial progenitor cel transplantation combined with early exercise training can promote regeneration of synapses and blood vessels and improve hindlimb motor function of rats, probably by increasing expression levels of vascular endothelial growth factor and brain-derived neurotrophic factor.

BACKGROUND:Studies have shown that neural stem cel transplantation combined with exercise training can promote the recovery of hindlimb motor function from spinal cord injury in rats, but its mechanism of action has not been fuly elucidated. OBJECTIVE:To investigate the effects of early exercise training combined with neural stem cel transplantation on the recovery of hindlimb motor function in rats with spinal cord injury. METHODS:Sixty Sprague-Dawley rats with spinal cord injury were randomly divided into three groups: control group (n=20, given conventional treatment after injury), cel transplantation group (n=20, given neural stem cel transplantation after injury), experimental group, (n=20, given neural stem cel transplantation combined with early exercise training after injury). Recovery of the hindlimb motor function was assessed by Basso, Beattie and Bresnahan scale and inclined plane test before and at 1, 7, 14, 21 days after injury. Western blot assay was used to detect caspase-3 and myeloperoxidase expression. Hematoxylin-eosin staining was done at 21 days after injury to observe the structure changes of the injured spinal cord. RESULTS AND CONCLUSION:(1) Scores of Basso, Beattie and Bresnahan scale and inclined plane test were significantly better in the experimental group than the cel transplantation group folowed by the control group (P < 0.05). (2) In the control group, the expression of caspase-3 and myeloperoxidase was significantly increased at 14 days after injury. In the cel transplantation, the expression of caspase-3 and myeloperoxidase was significantly higher than the experimental group (P < 0.05). (3) Pathological inflammation was reduced most in the experimental group folowed by the cel transplantation group. In the experimental group, the structure of injured spinal cord was improved and became relatively clear and intact. These findings indicate that neural stem cell transplantation combined with early exercise training can effectively promote the recovery of hindlimb motor function from spinal cord injury in rats, by reducing the expression of caspase-3 and myeloperoxidase and alleviating secondary lesion of the spinal cord.