The experimental study of human nerve growth factor gene modified schwann cells for therapy of spinal cord injury

Objective Nerve growth factor can promote the repair of peripheral nerve injury.Schwann cells may provide appropriate microenvrionment for repairing central nerve system.Object Schwann cells(SCs) which were modified by human nerve growth factor gene were injected into the injured spinal cord,the aim was to observe the functional recovery of hind limb and the expression of GAP-43 after spinal cord injury,and to explore the mechanism of SCs on the spinal cord injury.Methods 52 SD rats were divided into four groups randomly:EGFP-N1-NGF transfected SCs transplantation group(group A) 16 rats,SCs transplantation group(group B) 16 rats,PBS control group(group C) 12 rats and sham group(group D) 8 rats.The modified Allen method was used to make spinal coed injury(SCI) model.BBB scores were used to evaluate the behavior improvement and EMG to detect the velocity of the central nerve at 7 d,14 d,21 d and 28 d,respectively.Then the animals were killed and the SCI areas were embedded by paraffin,tissue section and immunostaining of GAP-43 to evaluate the histology recovery after spinal cord injury.Results The result of BBB scores is group D group A group B group C;There is significantly difference between group A,B and C,but it were longer than group D for the velocity of the central nerve of EMG,the p value is lower than 0.05.Conclusion The immunostaining of GAP-43 showed that group A group B group C,the group D have little expression.Our study confirmed that NGF gene modified SCs could promote the recovery of spinal cord injury,probably by promoting the growth of the nerve axon.