神经干细胞移植对脊髓全横断大鼠运动行为和大脑运动皮质Caspase-3表达的影响

目的 探讨神经干细胞移植对脊髓全横断大鼠运动行为和大脑运动皮质Caspase-3表达的影响.方法 建立成年SD大鼠脊髓全横断(SCT,T9)模型.分假手术组、SCT组、NSC移植组,每组13只动物.其中每组8只动物于NSC移植后7d时用蛋白免疫印迹法检测MC内Caspase-3蛋白的表达变化(β-actin作内参照).另5只动物于NSC移植后16周时进行后肢运动功能(BBB)评分,处死动物用免疫组织化学技术检测Caspase-3在MC的细胞定位分布.结果 与假手术组比较(21±0)分],大鼠SCT 16周时后肢运动功能BBB评分为(5.16±1.19)分];而脊髓内NSC移植组BBB评分为(7.58±0.99)分],组间比较有统计学意义(P＜0.05);Caspase-3蛋白在MC运动神经元表达,免疫阳性反应物分布于细胞浆.SCT导致MC区Caspsse-3蛋白表达(0.89+0.12)较假手术组(0.61+0.10)明显上调(P＜0.05),而NSC移植明显降低MC区Caspase-3表达水平(0.76+0.11)(P＜0.05).结论 NSC脊髓内移植能有效下调皮质运动区Caspase-3表达水平,并促进SCT大鼠后肢运动功能改善.

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

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.