神经生长因子对创伤性脊髓损伤大鼠膀胱功能和轴突损伤修复的作用  

Improvement of bladder function and repair of axonal injury in rats with traumatic spinal cord injury via MAPK/ERK pathway by nerve growth factor

作　　者：石胜柳 丁桃[1] 孙瑜[1] 盛祖桃 徐婧[1] 蔡晶[1] 王增亮[3] SHI Shengliu;DING Tao;SUN Yu;SHENG Zutao;XU Jing;CAI Jing;WANG Zengliang(Department of Rehabilitation Medicine,The First Affiliated Hospital of Kunming Medical University,Kunming 650031;Heart Function Room,Heart Center of Yunnan Boya Hospital,Kunming 650031;Department of Neurosurgery,The First Affiliated Hospital of Xinjiang Medical University,Urumqi 830000,China)

机构地区：[1]昆明医科大学第一附属医院康复医学科,云南昆明650031 [2]云南博亚医院心脏中心心功能室,云南昆明650031 [3]新疆医科大学第一附属医院神经外科,新疆乌鲁木齐830000

出　　处：《西安交通大学学报（医学版）》2021年第5期700-705,共6页Journal of Xi’an Jiaotong University（Medical Sciences）

基　　金：国家自然科学基金资助项目(No.81801232)。

摘　　要：目的探究神经生长因子(nerve growth factor,NGF)对创伤性脊髓损伤(traumatic spinal cord injury,t-SCI)大鼠膀胱功能和脊髓神经轴突损伤修复的影响,并探讨其分子机制。方法选取30只雄性SD大鼠,通过改良Allen’s击打法构建创伤性脊髓损伤模型,随机分为假手术组、损伤组和NGF组,每组10只。采用BBB评分观察术前、术后大鼠的后肢运动功能;BL-420生物仪实验系统检测尿动力学;甲苯胺蓝染色吻合口远端截取的左侧腰6前根,计算有髓轴突数量;采用HE染色大鼠膀胱组织;TUNEL染色大鼠损伤严重的脊髓,观察脊髓凋亡率;蛋白质印迹法(Western blotting)检测脊髓组织中Raf-1、p-MEK-2、MEK-2、ERK1/2和p-ERK1/2的蛋白表达。结果BBB评分结果显示,术前假手术组、损伤组和NGF组的评分无差异,而术后与假手术组比较,损伤组和NGF组的评分显著降低(P<0.05)。损伤组的最大逼尿压力和脊髓有髓轴突数量显著低于假手术组和NGF组(P<0.05),但损伤组的残余尿量和膀胱细胞凋亡率显著高于假手术组和NGF组(P<0.05)。HE染色结果显示,损伤组的膀胱水肿严重,逼尿肌结构疏松,而NGF组有减轻膀胱损伤。Western blotting结果显示,与假手术组比较,损伤组的p-ERK1/2/ERK1/2和p-MEK-2/MEK-2蛋白比值以及Raf-1表达量显著高于假手术组和NGF组(P<0.05)。但假手术组和NGF组在最大逼尿压力、髓轴突数量、残余尿量、膀胱细胞凋亡率和蛋白差异均无统计学意义(P>0.05)。结论NGF可能阻碍MAPK/ERK通路的传导,从而促进轴突损伤的修复,改善t-SCI大鼠膀胱功能。Objective To explore the effects of nerve growth factor(NGF)on bladder function and axon injury repair in rats with traumatic spinal cord injury(t-SCI)so as to explore its molecular mechanism.Methods Traumatic spinal cord injury model was constructed in 30 male SD rats by modified Allen’s beating method.The rats were randomly divided into sham-operation group,injury group and NGF group,with 10 rats in each group.We used the BBB score to observe the motor function of the rats’hind limbs before and after the operation.The BL-420 biometer experimental system detected the urodynamics.Six anterior roots of the left lumbar taken from the distal end of the anastomosis were stained with toluidine blue,and the number of myelinated axons was counted.We used HE to stain rat bladder tissue,TUNEL to stain the rats’severely injured spinal cord,and observed the spinal cord apoptosis rate.Western blotting was used to detect the protein expressions of Raf-1,p-MEK-2,MEK-2,ERK1/2,and p-ERK1/2 in spinal cord tissue.Results The BBB score results showed that there was no difference in the scores of the sham-operation group,the injury group and the NGF group before the operation.After the operation,the scores of the injury group and the NGF group were significantly lower than those in the sham-operation group(P<0.05).The maximum detrusive pressure and the number of axons were significantly lower in the injury group than in the sham-operation group and the NGF group(P<0.05),but the residual urine volume and bladder cell apoptosis rate in the injury group were notablely higher than those in the other two groups(P<0.05).HE staining results showed that bladder edema in the injury group was severe and the detrusor muscle structure was loose,while the NGF group had reduced bladder injury.Western blot results showed that the protein ratio of p-ERK1/2/ERK1/2 and p-MEK-2/MEK-2 and the expression of Raf-1 in the injury group were significantly higher than those in the sham operation group and NGF group(P<0.05).However,there was no signific

关 键 词：创伤性脊髓损伤 神经生长因子 MAPK/ERK通路 膀胱 轴突 

分 类 号：R543.5[医药卫生—心血管疾病]