胶质细胞源性神经营养因子基因修饰的施万细胞复合胶原-壳聚糖神经支架对大鼠坐骨神经缺损的修复作用

Transplantation of Collagen-chitosan Nerve Conduits Filled with Glial Cell Line-derived Neurotrophic Factor Gene-Modified Schwann Cells for the Repair of Sciatic Nerve Defect

目的探讨胶质细胞源性神经营养因子(GDNF)基因修饰的施万细胞复合胶原-壳聚糖神经支架移植对大鼠坐骨神经长距离缺损的修复作用。方法建立大鼠左侧坐骨神经8 mm缺损模型,并随机分为3组,分别给予GDNF基因修饰的施万细胞复合胶原-壳聚糖多孔支架移植(GDNF-Sch组)、施万细胞复合胶原-壳聚糖多孔支架移植(Sch组)和自体神经移植(对照组),每组6只。分别于术后第3、6、12周行坐骨神经功能指数(SFI)检测,并在术后第12周解剖暴露桥接段坐骨神经行再生神经形态学和电生理检测,并测量胫前肌湿重。结果术后6和12周,3组大鼠术侧SFI间差异有统计学意义(P均<0.05),随着治疗时间延长,GDNF-Sch组SFI恢复情况更接近于对照组,明显优于Sch组。术后12周,GDNF-Sch组和Sch组的感觉神经传导速度明显低于对照组(P<0.05),两组间差异无统计学意义(P>0.05);GDNF-Sch组和Sch组的感觉神经波幅也明显低于对照组(P<0.05),GDNF-Sch组则明显高于Sch组(P<0.05);GDNFSch组和对照组的运动神经传导速度和波幅均明显高于Sch组(P均<0.05),但两组间差异均无统计学意义(P均>0.05)。术后12周,对照组、Sch组和GDNF-Sch组大鼠桥接侧胫前肌湿重分别为(0.360±0.020)、(0.250±0.018)和(0.310±0.025)g,均明显低于对照侧(0.440±0.031)、(0.420±0.024)和(0.430±0.027)g(P均<0.05);GDNFSch组和对照组桥接侧胫前肌湿重均明显高于Sch组(P均<0.05),但两组间差异无统计学意义(P>0.05)。结论 GDNF基因修饰的施万细胞复合胶原-壳聚糖神经支架能够显著增强大鼠坐骨神经长距离缺损的修复作用,这种修复效果与自体神经移植术相似。

Objective To explore the effects of the transplantation of collagen-chitosan nerve scaffold containing glial cell line-derived neurotrophic factor （GDNF） gene modified schwann cells on the recovery of long-distance sciatic nerve defect. Methods The rat models of 8 mm long-distance sciatic nerve defect were es- tablished and divided into three groups, with 6 rats in each group. In GDNF-Sch group, the defect was repaired by GDNF modified Schwann cells combined with collagen-chitosan nerve scaffold. In Sch group, the defect was repaired by Schwann cells combined with collagen-chitosan nerve scaffold. In the control group, the defect was repaired by autologous nerve graft. Sciatic function index （SFI） was detected 3, 6, and 12 weeks after surger- y. After 12 weeks, the tibialis anterior muscle wet weight, electrophysiology, and regenerated nerve morphology were detected. Results The SFI in the operated side significantly differed among these three groups after 6 and 12 weeks （P 〈0. 05） . Along with prolonged treatment, the GDNF-Sch group had similar SFI recovery with the control group but significantly better SFI recovery than Sch group. After 12 weeks, the sensory nerve conduction velocity in the GDNF-Sch and Sch group was not significantly different （ P 〉 O. 05 ） but was significantly lower than that in the control group （ P 〈 0. 05 ） . Both the GDNF-Sch group and Sch group had significantly lower sen- sory nerve amplitude comparing with the Control group （ P 〈 O. 05 ）, whereas that in the GDNF-Sch group was significantly higher than that in the Sch group （P 〈 0. 05 ） . GDNF-Sch group and the control group had signifi- cantly higher motor nerve conduction velocity and amphtude than Sch group （ P 〈 O. 05 ）, while no such statisti- cally significant difference was seen between the two groups （P 〉0. 05） . After 12 weeks, the wet weight of the bridging side of the tibial muscle in the control group, Sch group, and GDNF-Sch group was （0. 360 ± 0. 020）, （ O. 250 ± 0. 018 ）, and （0. 310 ± 0. 025 ） g; which were significantly lower than the control side [ （0. 440 ± 0. 031 ）, （0. 420 ± 0. 024）, and （0. 430 ± 0. 027 ） g, respectively （ P 〈 O. 05 ） ] . Muscle wet weight in bridge side of GDNF-Sch group and the control group were significantly higher than in Sch group （P 〈 0. 05 ）, but it was not significantly different between the GDNF-Sch group and the control group （P 〉 0. 05） . Conehmlon Transplan- tation of collagen-chitosan nerve scaffold containing GDNF gene modified Schwann cells can remarkably facilitate sciatic nerve defect recovery, with a milimar effectiveness as autologous nerve grafting.