The effect of neural stem cell transplantation on the hindlimb motor function and caspase-3 expression of motor cortex in spinal cord transected rats

Abstract

Objective To observe the effect of neural stem cell (NSC)transplantation on the hindlimb motor function and caspase-3 expression of motor cortex (MC) in spinal cord transected (SCT) rats. Methods S prague-Dawley (SD) rats were randomly divided into sham operated group, operation group( T9 transection), and subacute NSC transplantation group. The MC of each group( n= 8 )was harvested 7 days post operation (dpo), then western blot was employed to detect the level of caspase-3( β-actin was used as control ). The left 5 animals of each group were subjected to BBB score evaluation at 16th week,then the animals were sacrificed and the MC was harvested and performed immunostain by using caspase-3 rabbit antibody. Results Following NSC transplanta tion, BBB scores( ( 7.58 ± 0. 99 ) ) increased significantly than seen in the SCT animals( ( 5.16 ± 1.19) ). The expressional level of caspase-3 at 7day post operation was( (0.89 + 0.12)) in MC of SCT rats,while it decreased significantly to( (0.76 + 0.11 ) ) in NSC transplantation rats(P＜0.05). The immunoreactive stain of caspase-3 was seen in the cytoplasm of pyramidal neuron in the cortex. Conclusion NSC engraft can downregulate the expression of caspase-3, corresponding to a significant improvement in hindlimb motor function. These findings indicate that NSC transplantation probably regulate the expression of apoptosis genes in MC to promote neurological function recovery in rats subjected SCT. Key words: Neural stem cells; Spinal cord transection; Transplantation; Apoptosis gene; Rat