神经生长因子对大鼠脊髓损伤后神经元凋亡的影响  

Effects of nerve growth factor on the neuronal apoptosis after spinal cord injury in rats

作　　者：曹晓建[1] 汤长华[1] 罗永湘[2] 

机构地区：[1]南京医科大学第一附属医院骨科,10029 [2]华中科技大学同济医学院附属同济医院骨科

出　　处：《中华实验外科杂志》2001年第6期578-579,共2页Chinese Journal of Experimental Surgery

基　　金：国家自然科学基金资助项目 (3980 0 1 76)

摘　　要：目的　探讨神经生长因子 (NGF)对脊髓损伤保护作用的分子机制。方法　采用Allen’s法以 2 5gcm力致伤大鼠T8脊髓 ,经蛛网膜下腔导管于术后即刻、2、4、8、12、2 4h各注入NGF溶液 ,并与生理盐水组 (NS组 )和正常对照组作对照 ,采用免疫组织化学方法和末端单位标记法 (TUNEL)原位末端标记法分别检测bcl 2、bax蛋白在脊髓神经元的表达及神经元凋亡情况。结果正常组中脊髓灰质bax蛋白阳性细胞吸光度 (A )值为 34 .5 1± 4.47,NS组中bax蛋白表达增加 ,以 2h及 12h最为显著 ,而NGF组与NS组相比 ,bax蛋白表达明显减少 ( P <0 .0 1)。正常组中脊髓灰质bcl 2蛋白表达的A值为 19.72± 2 .92 ,NS组中bcl 2表达下降 ,而NGF组与NS组相比较 ,bcl 2蛋白表达明显增多 (P <0 .0 1)。TUNEL检测结果显示 ,正常对照组中未见神经元凋亡 ,NS组中自 2h后可见神经元凋亡 ,NGF组与NS组相比 ,神经元凋亡指数明显减少 (P <0 .0 1)。结论　NGF能通过抑制bax蛋白的表达 ,促进bcl 2表达抑制脊髓损伤后神经元凋亡 ,从而保护损伤的脊髓组织 ,这可能是NGF对脊髓损伤具有保护作用的机制之一。Objective To explore the protective mec hanisms of nerve growth factor (NGF) on spinal cord injury.Methods The spinal cord injury (SCI) of the Wistar rats was induced with Allen 's way by a 10g×2.5cm impact on the posterior T_8 spina l cord.NGF was given to the treatment group rats by subarachnoid space tube at o nce,2,4,8,12,24h after SCI.The expression levels of bax and bcl-2 protei n in rat spinal cord were detected by immunohistochemistry assay.The apoptosis m otor neurons in spinal cord were investigated by the methods of in situ terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labelin g of DNA fragments reaction.Results The strong expression of bax protein was found in rat spinal cord of the normal group animals.The levels of bax protein in the no rmal saline group were significantly increased as compared with those in the nor mal group.The levels of bax protein in the NGF group were significantly decrease d as compared with those in the normal saline group (P<0.01).The strong expression of bcl-2 protein was found in rat spinal cord of the normal group animals.The levels of bcl-2 protein in the normal saline group were decreased as compared with those in the normal group.The levels of bcl-2 protein in the NGF group were significantly increased as compared with those in the normal sali ne group (P<0.01).The neurons with apoptosis were reduced in spinal cord of the injured rats,as compared with that in the control group.The number of ap optosis neurons in the NGF group were significantly greater than in the normal s aline group (P< 0.01).Conclusion NGF can protect spinal cord from injury in viv o.One of mechanisms is that NGF can inhibit apoptosis after spinal cord injury.

关 键 词：脊髓损伤 神经生长因子 BAX Bcl-2 脱噬作用 细胞凋亡 大鼠 NGF 

分 类 号：R651.2[医药卫生—外科学]