Effects of Wharton's jelly cell transplant on acute spinal cord injury in rats and expressions of TNF-α and BDNF in spinal cord tissue

Aim: To explore the effect of Wharton's jelly cells( WJCs) transplant on the expressions of tumor necrosis factor alpha( TNF-α) and brain-derived neurotrophic factor( BDNF) in rats with acute spinal cord injury( SCI),and to investigate the function of WJCs in the inflammatory response and nerve repair after acute SCI. Methods: A total of 81 rats were allocated into sham operation group,model group and WJCs group( 27 rats in each group). In the WJCs group,200μL WJCs cell suspension( about 1 × 106cells) was injected by femoral vein at 10 min after the injury. Neurologic function was accessed by BBB score at 1 d,3 d,7 d,14 d,21 d and 28 d respectively after transplantation; the ultrastructures of injured spinal cord were detected by transmission electron microscopy; the mRNA and protein expressions of BDNF in the spinal cord tissue were detected by real-time quantitative PCR and Western blot,respectively at 28 d,and those of TNF-αlevel were detected at 0 h,3 h,6 h,12 h,24 h,72 h,168 h after transplantation. Results: Neural function was recovered to some extent both in WJCs group and model group,and the former was much better. Compared with model group,the structure of SCI area of WJCs group was relatively intact. Compared with the sham operation group,the expressions of BDNF protein and TNF-α mRNA and protein were increased significantly both in model group and WJCs group( P 0. 05);compared with model group,the expressions of TNF-α mRNA and protein decreased( P 0. 05),while that of BDNF increased in the WJCs group( P 0. 05). Conclusion: WJCs transplantation can change the microenvironment of the injured spinal cord by inhibiting the expression of TNF-α while promoting the expression of BDNF in the lesion,therefore reducing secondary spinal cord injury,which may be a potential mechanism underlying the recovery of motor function of injured rats.