肿瘤坏死因子α拮抗剂联合酪氨酸激酶C基因修饰神经干细胞移植治疗脊髓损伤

Tumor necrosis factor-alpha antagonist combined with tyrosine kinase C genemodified neural stem cell transplantation for spinal cord injury

背景:脊髓损伤在控制损伤后炎症反应的同时联合神经干细胞移植,是否能够提高脊髓损伤的治疗效果,目前尚不明确。目的:实验旨在检测早期应用肿瘤坏死因子α拮抗剂Etanercept联合酪氨酸激酶C基因修饰移植治疗后大鼠脊髓组织修复,髓鞘再生和神经轴突再生,运动功能恢复情况及其可能机制。方法:利用慢病毒转染技术构建酪氨酸激酶C过表达的神经干细胞,制备大鼠脊髓横断损伤模型,采用肿瘤坏死因子α拮抗剂Etanercept联合酪氨酸激酶C基因修饰神经干细胞移植。利用尼氏染色、免疫荧光及免疫印迹等方法测定损伤后神经元数目和神经再生情况;利用BBB功能学评分和诱发电位来检测大鼠运动功能;利用电镜检测和甲苯胺蓝染色来检测治疗后各组髓鞘再生情况。结果与结论:损伤后28 d,与其他组相比,Etanercept联合酪氨酸激酶C-神经干细胞移植组损伤脊髓尾端处有更多前角运动神经元存活(P<0.05),具备髓鞘包绕的轴突数量增高(P<0.05),损伤后运动功能评分相对更高(P<0.05),运动诱发电位的振幅恢复更大(P<0.05),潜伏期相对更短(P<0.05)。结果证实,大鼠脊髓损伤后早期应用肿瘤坏死因子α拮抗剂联合酪氨酸激酶C-神经干细胞移植,可有效促进大鼠神经元轴突及髓鞘再生,进而促进运动功能恢复。

BACKGROUND： Whether controlling of post-injury inflammatory response combined with neural stem cell（NSC） transplantation can improve the curative efficacy for spinal cord injury still remains unclear. OBJECTIVE： To investigate the repair of spinal cord tissue, myelin regeneration, axon regeneration, motor function recovery and the possible mechanism after early application of tumor necrosis factor α antagonist（Etanercept） combined with tyrosine kinase C（Trk C） gene-modified NSC transplantation. METHODS： Trk C-overexpressed NSCs（Trk C-NSCs） were constructed by lentiviral transfection technique. The rat models of spinal cord transection injury were prepared, and then subjected to Etanercept combined with Trk C-NSCs transplantation. The number of neurons and neuroregeneration after injury were measured by Nissl＇s staining, immunofluorescence and western blot. The rat motor function was detected by Basso Beattie Bresnahan score and evoked potential. The myelin regeneration was detected by electron microscopy and toluidine blue staining. RESULTS AND CONCLUSION： Compared with the other groups, the Etanercept combined with Trk C-NSCs transplantation group had more survived anterior horn motor neurons at 28 days after injury, more myelin-encapsulated axons, higher Basso Beattie Bresnahan score, greater amplitude of the evoked potentials, and relatively shorter latency（all P 0.05）. These findings indicate that early application of tumor necrosis factor-α antagonist combined with Trk C-NSCs transplantation after spinal cord injury in rats can effectively promote myelin regeneration, axon regeneration, and further promote motor function recovery.