自噬对面神经损伤大鼠面神经元的保护作用  

Autophagy protects neurons against facial nerve injury in rats

作　　者：段坤岭 费静 李雷激 Duan Kunling;Fei Jing;Li Leiji(Department of Otorhinolaryngology,Head and Neck Surgery,Affiliated Hospital of Southwest Medical University,Luzhou 646000,Sichuan Province,China)

机构地区：[1]西南医科大学附属医院耳鼻咽喉头颈外科,四川省泸州市646000

出　　处：《中国组织工程研究》2024年第27期4378-4382,共5页Chinese Journal of Tissue Engineering Research

基　　金：泸州市科技计划项目(2021-SYF-30),项目负责人:李雷激。

摘　　要：背景:周围性面神经损伤后,胶质细胞源性神经营养因子(glial cell-derived neurotrophic factor,GDNF)可发挥面神经元保护作用,有研究发现,GDNF可通过哺乳动物雷帕霉素靶蛋白调控自噬水平,面神经损伤后其是否能通过腺苷酸活化蛋白激酶/Unc-51样激酶1(AMPK/ULK1)信号通路调控面神经元尚不清楚。目的:建立SD大鼠面神经损伤模型,探讨自噬在面神经再生中的作用及GDNF/AMPK/ULK1信号通路促进面神经损伤修复的机制。方法:72只SD大鼠随机分成假手术组、模型组及3-甲基腺嘌呤组,每组24只。假手术组仅暴露面神经主干,其余2组制作面神经干压榨损伤模型。造模成功后,模型组予以腹腔注射生理盐水,3-甲基腺嘌呤组腹腔注射自噬抑制剂3-甲基腺嘌呤15 mg/kg,1次/d,连续7 d。术后1,4,7,14,21,28 d进行行为学评分,术后7,14,21,28 d进行尼氏染色观察面神经元细胞形态及数量,Western blot法检测面神经元组织p-AMPK、p-ULK1、Beclin1、GDNF蛋白表达水平。结果与结论:①行为学评分显示:3-甲基腺嘌呤组面瘫症状改善较模型组差且晚(P<0.05);②尼氏染色显示,3-甲基腺嘌呤组面神经元尼氏体的形态及数量较模型组恢复差且少(P<0.05);③Western blot检测显示模型组Beclin1及p-AMPK蛋白表达高于3-甲基腺嘌呤组和假手术组(P<0.05),模型组p-ULK1蛋白表达低于3-甲基腺嘌呤组和假手术组(P<0.05),假手术组和模型组GDNF蛋白表达高于3-甲基腺嘌呤组(P<0.05);④结果表明,自噬抑制剂延缓面神经损伤后的修复可能与下调GDNF表达,使AMPK失活,磷酸化ULK1,进而抑制神经元自噬水平有关。BACKGROUND:After peripheral facial nerve injury,glial cell-derived neurotrophic factor(GDNF)can play a protective role in facial neurons.It has been found that GDNF can regulate the level of autophagy through mammalian target of rapamycin(mTOR),but it is unclear whether it can regulate facial neurons through the adenylate-activated protein kinase/Unc-51-like kinase 1(AMPK/ULK1)signaling pathway after facial nerve injury.OBJECTIVE:To establish a facial nerve injury model in Sprague-Dawley rats and explore the role of autophagy in facial nerve regeneration and the mechanism by which the GDNF/AMPK/ULK1 signaling pathway promotes facial nerve repair after injury.METHODS:Seventy-two Sprague-Dawley rats were randomly divided into sham group,model group and autophagy inhibitor 3-methyladenine(3-MA)group,with 24 rats in each group.Only the main trunk of the facial nerve was exposed in the sham group,while the remaining two groups were modeled for the compression injury of the facial nerve trunk.After successful modeling,the model group was given intraperitoneal injection of normal saline(15 mg/kg),and the 3-MA group was given intraperitoneal injection of 3-MA(15 mg/kg),both once daily for 7 days.The rats in each group were scored on the Simone 10-point behavioral scale at 1,4,7,14,21 and 28 days after surgery.Nissl staining was performed to observe the morphology and number of facial neuron cells at 7,14,21,and 28 days.The expression levels of p-AMPK,p-ULK1,Beclin1 and GDNF in the facial neuron tissues of rats were detected by western blot assay.RESULTS AND CONCLUSION:Behavioral scoring showed that the improvement of facial paralysis symptoms in the 3-MA group was worse and later than that in the model group(P<0.05).Nissl staining showed that the morphology and number of Nissl bodies in facial neurons in the 3-MA group recovered poorly and the number was less than that in the model group(P<0.05).Western blot detection results showed that the expression of p-AMPK and Beclin1 in the model group was higher than that in the

关 键 词：面神经损伤 周围性面瘫 自噬 面神经元 胶质细胞源性神经营养因子 AMPK ULK1 BECLIN1 尼氏体 

分 类 号：R459.9[医药卫生—治疗学] R318[医药卫生—临床医学] Q421[生物学—神经生物学]