Umbilical cord blood neural stem cells transplantation for treatment of spinal cord injury in rats and differential expression gene

Abstract

Objective To assess the recovery of hind limbs function in rats with spinal cord injury (SCI) after being treated with umbilical cord blood neural stem cells (UCBNSCs) transplantation,and analyze the relationship between the differentially expressed genes identified by gene chips and functional recovery of the spinal cord to lay foundation for gene therapy of spinal cord injury.Methods Fifty healthy female SD rats were randomly divided into sham-operated group (n=10),PBS injection control group (n=20) and UCBNSCs transplantation group (n=20).Only opening the T9-11 vertebral plate was performed in sham-operated group under microscope,while the spinal cords of PBS injection control group and UCBNSCs transplantation group were cut offafter opening the T9-11 vertebral plate to induce rat models of spinal cord transection,UCBNSCs transplantation was performed through ventricular puncture (1 × 109/L cell suspension 10 μL) one week after the model making.Blood brain barrier (BBB) behavior scale of three groups was carried out 1 d and 1,2,4,6 and 8 w after transplantation.Seven SD rats from PBS control group and UCBNSCs transplantation group were sacrificed to get spinal cord injury tissue samples at 8 w after transplantation; gene chip analysis was used to identify the differentially expressed genes.Results The hind limbs function of SD rats did not appear obvious damage in sham-operated group.Symptoms of paralysis,tail activity obstacle and urination dysfunction appeared in PBS injection control group and UCBNSCs transplantation group.As time went on,the function of hind limbs slowly recovered:1 d and 1 w after transplantation,BBB scale scores showed no statistical difference between PBS injection control group and UCBNSCs transplantation group (P＞0.05); statistical significance appeared at 2,4,6 and 8 w after transplantation between the two groups (P＜0.05).Twenty-four differentially expressed genes were identified,including 20 being up-regulated and 4 being down-regulated.Conclusions UCBNSCs transplantations in the treatment of SCI have exact effect.With gene chip analysis,it is supposed that UCBNSCs may differentiate into neurons,increase the output of neurotrophic factor expression in the microenvironment,inhibit the local inflammation reaction and promote the oxygen supply,so as to boost the recovery of neurological function. Key words: Umbilical cord blood neural stem cell; Spinal cord injury; Differentially genes