直流电刺激对鼠坐骨神经切断后脊髓运动神经元凋亡相关基因表达的影响(英文)

Influence of direct-current stimulation on apoptosis-associated gene expression of spinal cord motor neurons after rat sciatic nerve transection

背景:周围神经损伤能致脊髓神经元的凋亡,严重影响神经修复后功能的恢复。电刺激能有效促进神经的再生,但对神经元凋亡的影响研究较少。目的:观察直流电场对鼠坐骨神经切断后脊髓运动神经元bcl-2,bcl-X/L,bax及c-jun表达的作用,探讨电刺激对预防细胞凋亡的机制。设计:采用随机对照实验研究。地点和对象:实验在上海同济大学附属铁路医院骨科完成,对象为雄性SD大鼠30只,6周龄,体质量180～220g。干预:将雄性SD大鼠随机分为对照组和实验组,每组15只大鼠。用10g/L硫喷妥钠(5mg/100g)腹腔麻醉后,在大鼠右侧臀肌间隙显露坐骨神经,距梨状肌下缘0.5cm处将坐骨神经切断,近端以5-0尼龙线作双重结扎,远端切除1cm后埋入股二头肌中,关闭切口。沿棘突后方正中切口,在T10～L3右侧椎板及棘突间钝性剥离骶棘肌,切除椎板,将电刺激器阳性盘状电极板置入T10椎板下硬膜囊之腹侧,阴性盘状电极板置入L3椎板上硬膜囊背侧,对照组置入无输出电流的刺激器,分批于术后1,4,7,14,28d取材。实验操作由同一组人员完成。主要观察指标:脊髓bcl-2,bcl-X/L,bax及c-jun的阳性运动神经元数。结果:坐骨神经切断后4,7,14d,电刺激组脊髓运动神经元bcl-2阳性数分别为(28.67±1.53),(34.67±1.53),(41.33±1.53)个;bcl-X/L阳性数分别为(23.00±4.36),

BACKGROUND:The injury of peripheral nerve would induce apoptosis of spinal neu ron, which affect severely recovery of nerve function after rehabilitation.It is proved that current stimulation can promote regeneration of nerve, but it is sc arcely reported on the effect of current stimulation on neuron apoptosis.OBJECTIVE:To observe the effect of direct-current field stimulation on bcl-2 ,bcl-X/L,bax and c-jun gene expression in spinal cord neurons after transectio n of sciatic nerve and to discuss the mechanism of preventive effect of electric stimulation on apoptosis.DESIGN:A randomized controlled experiment conducted.SETTING and PARTICIPANTS:The experiment was performed in the Department of Ort hopaedics,the Affiliated Railway Hospital,Tongji University.A total of 30 male S D rats(6-week old,body mass of 180-220 g) were experimental objects.INTERVENTIONS:Thirty male SD rats were divided into experimental group and co ntrol group randomly, 15 rats in each group. After abdominal anaesthetizing with penthiobarbital of 10 g/L concentration, the sciatic nerve was exposed at the i nterspace of right gluteus. It was transected 0.5 cm inferior to piriformis with proximal end ligtured by two nylon thread of 5-0 and distal end cut off by 1 c m length and embedded into biceps formoris. Then the incision was closed. Anothe r median incision was made along spinal process. The muscle on right lamina and spinal process of T10-L3 was blunt dissected. After laminectomy, the discal ano de of stimulator was put into the abdominal side of the dura under lamina of T10 , the cathode dorsal side of dura under lamina of L3.In the control group, stimu lators without deferent current were put in the same way. The specimens were tak en 1,4,7,14 and 28 days after operation.Experiments were performed by the same g roup of people.MAIN OUTCOME MEASURES:With immunohistochemistry method (ABC method), the gene expression of bcl-2,bcl-X/L,bax and c-jun would be investigated and motoneuro ns of spinal cord were numbered under light microscope.RESULTS:4,7,14 days after operation in the experimental group ,the number of p ositive spinal cord motor neurons with bcl-2,and bcl-X/L gene expression were 28.67±1.53,34.67±1.53,41.33±1.53 and 23.00±4.36,32.67±2.52,44.33±2.08,h igher than controlled group(19.67±1.53,25.67±2.08,33.67±1.53;15.33±0.58, 36.33±2.52,33.00±4.36). 4,7,14 and 28 days after operation, the number of pos itive spinal cord motor neurons with bax were lower than controlled group.4,7, 2 8 days after operation, the number of positive spinal cord motor neurons with c -jun were lower than controlled group.CONCLUSION:Direct-current field may modulate the expression of bcl-2,bcl-X/ L,bax and c-jun gene after sciatic nerves transection in rats.