鞘内移植神经干细胞对慢性缩窄性损伤模型大鼠脊髓背角和背根神经节胶质细胞源性神经营养因子表达的影响

目的神经病理性疼痛在临床中很常见,但治疗效果欠佳。文中应用鞘内移植神经干细胞(neural stem cells,NSC)治疗坐骨神经慢性缩窄性损伤模型(chronic constriction injury,CCI)大鼠,并观察脊髓背角和背根神经节(dorsal root gan-glion,DRG)胶质细胞源性神经营养因子(glial cell line-derived neurotrophic factor,GDNF)表达的变化。方法成年SD大鼠72只,随机均分为A组(假手术+细胞培养液)、B组(CCI+细胞培养液)和C组(CCI+NSC),然后各组再随机分为:A1、B1和C1组(CCI后3 d鞘内移植组)和A2、B2和C2组(CCI后10 d鞘内移植组),每组12只。分别于术前1 d和术后1、3、7、14、21 d测机械痛阈(mechanical withdrawal threshold,MWT)和热痛阈(thermal withdrawal latency,TWL)。术后7 d、14 d和21 d采用免疫组织化学染色和Real-time PCR技术观察DRG、脊髓背角中GDNF的表达变化。结果①与A组相比,B1、B2、C1、C2组术前1 d、术后1 d和21d MWT和TWL差异无统计学意义(P>0.05);术后3d MWT和TWL逐渐降低,至术后7d降低至最低点,在此期间各时间点痛阈与A1组比较,B1、B2、C1、C2组数值均有显著降低(P<0.01),之后缓慢升高,于术后21 d恢复至术前水平;与B组比较,C组术后7d、14dMWT和TWL明显上升(P<0.01)。②与B组比较,A组术后7d、14d和21d各组大鼠GDNF的表达呈低水平(P<0.05);术后7 d,C1组GDNF的表达量较B1组明显升高(P<0.05);术后14 d和21 d,C1、C2组GDNF的表达量高于B1、B2组(P<0.05)。结论鞘内移植NSC可通过提高脊髓背角和DRG中的GDNF表达量,从而对CCI模型引起的神经病理性疼痛起预防和治疗作用。

Intrathecal neural stem cell transplantation increases glial cell line-derived neurotrophic factor expression in cornu dorsal medullae spinalis and dorsal root ganglion in rats with chronic constriction injury

Objective Neuropathic pain is common clinically,but responds poorly to treatment.This study is to investigate the changes in the expression of the glial cell line-derived neurotrophic factor(GDNF) in the cornu dorsal medullae spinalis and dorsal root ganglion(DRG) in rats with chronic constriction injury(CCI) treated by intrathecal transplantation of neural stem cells(NSC).Methods Seventy two adult Sprague-Dawley rats were randomized into groups A(sham operation + cell culture fluid),B(chronic constrained injury + cell culture fluid) and C(chronic constrained injury + NSC).Then,they were again randomly divided into six subgroups of 12 in each: Groups A1,B1 and C1(intrathecal transplantation 3 d after CCI),and groups A2,B2 and C2(intrathecal transplantation 10 d after CCI).The mechanical withdrawal threshold(MWT) and thermal withdrawal latency(TWL) were determined 1 d before and 1,3,7,14 and 21 d after the operation.The expression of GDNF in cornu dorsal medullae spinalis and DRG were detected by immunohistochemistry and real-time PCR at 14 and 21 d postoperatively.Results Compared with group A,groups B1,B2,C1 and C2 showed no significant changes in MWT and TWL at 1 d preoperatively and at 1 and 21 d postoperatively(P>0.05).Both MWT and TWL decreased on postoperative day 3,7 and 14,and reached the nadir on postoperative day 7 in groups B1,B2,C1 and C2(P<0.01),and then began to increase slowly,back to the preoperative level at 21 d.Group B exhibited significantly lower levels of MWT and TWL than group C at 7 and 14 d after the operation(P<0.01).The expression of GDNF was markedly lower at 7,14 and 21 in group A than in B(P<0.05),but remarkably higher at 7 d in C1 than in B1(P<0.05),and at 14 and 21 d in C1 and C2 than in B1 and B2(P<0.05).Conclusion Intrathecal NSC transplantation can prevent and treat neuropathic pain from CCI by increasing the expression of GDNF in the cornu dorsal medullae spinalis and dorsal root ganglion.