沉默海马LINGO-1对小鼠学习记忆以及有髓神经纤维的影响  

The effects of silencing hippocampal LINGO-1 on learning and memory and myelinated fibers in mice

作　　者：周宇宁 蒋林[3] 杨浩 何琦[2] 王舜 綦英强 晁凤蕾 唐勇 ZHOU Yuning;JIANG Lin;YANG Hao;HE Qi;WANG Shun;QI Yingqiang;CHAO Fenglei;TANG Yong(Department of Histology and Embryology,School of Basic Medicine,Chongqing Medical University,Chongqing 400016,China;Laboratory of Stem Cells and Tissue Engineering,School of Basic Medicine,Chongqing Medical University,Chongqing 400016,China;Experimental Teaching Center,Chongqing Medical University,Chongqing 400016,China;Department of Electron Microscopy,School of Basic Medicine,Chongqing Medical University,Chongqing 400016,China)

机构地区：[1]重庆医科大学基础医学院组织学与胚胎学教研室,重庆400016 [2]重庆医科大学基础医学院干细胞与组织工程学研究室,重庆400016 [3]重庆医科大学实验教学中心,重庆400016 [4]重庆医科大学基础医学院电镜教研室,重庆400016

出　　处：《神经解剖学杂志》2023年第1期23-30,共8页Chinese Journal of Neuroanatomy

基　　金：国家自然科学基金(82171522,81871073,82002227);重庆市自然科学基金(cstc2020jcyj-msxmX0125)。

摘　　要：目的:研究沉默海马含亮氨酸重复序列和免疫球蛋白结构域的蛋白-1(LINGO-1)对APP/PS1小鼠空间学习和记忆能力以及海马有髓神经纤维的影响。方法:随机选取18只雄性APP/PS1小鼠,随机分为对照组和rAAV-LINGO-1-shRNA组,通过海马立体定位注射表达LINGO-1-shRNA的重组腺相关病毒rAAV-LINGO-1-shRNA,运用Morris水迷宫方法测试小鼠的空间学习和记忆能力;运用免疫荧光染色和real time RT-PCR分析小鼠海马内LINGO-1表达水平;运用real time RT-PCR分析小鼠海马内LINGO-1下游分子RhoA和ROCK的表达水平;运用无偏体视学方法结合透射电子显微镜技术对小鼠海马(CA1~3和齿状回)的体积,海马内有髓神经纤维的长度、髓鞘体积及其损伤情况进行定量研究。结果:与对照组小鼠相比,rAAV-LINGO-1-shRNA组小鼠的逃避潜伏期显著性缩短,穿台次数显著增多,而目标象限游泳时间及目标象限游泳路程比无显著性改变;与对照组相比,rAAV-LINGO-1-shRNA组海马内LINGO-1显著下调,同时其下游RhoA和ROCK的表达水平降低;对照组和rAAV-LINGO-1-shRNA组海马体积无显著性差异;与对照组相比,rAAV-LINGO-1-shRNA组海马内有髓神经纤维的长度和正常髓鞘的体积显著性增加,受损的有髓神经纤维占比和受损的髓鞘占比均显著降低。结论:沉默海马LINGO-1能够有效改善APP/PS1小鼠海马依赖的空间学习和记忆能力,抑制RhoA/ROCK的表达,减轻海马内有髓神经纤维及其髓鞘的损伤,这将为阿尔茨海默病的发病及治疗提供新的方向。Objective:To investigate the effects of silencing hippocampal leucine-rich repeat and Ig domain containing-1(LINGO-1)on the spatial learning and memory abilities and the myelinated nerve fibers in APP/PS1 mice.Methods:Eighteen male APP/PS1 mice were selected at random and divided into control and rAAV-LINGO-1-shRNA groups.Mice in the control group performed stereotaxic injection of the recombinant adeno-associated virus(rAAV)without any silenced sequence in the hippocampus,while mice in rAAV-LINGO-1-shRNA group performed stereotaxic injection of the rAAV-LINGO-1-shRNA in the hippocampus.The spatial learning and memory abilities of mice were tested using the Morris water maze test.The expression levels of LINGO-1 in the hippocampus were analyzed using real time RT-PCR and immunofluorescence staining,and its downstream molecules were analyzed using real time RT-PCR.The volume of hippocampus(CA1-3 fields and dentate gyrus),and the length of myelinated nerve fibers,the volume of myelin sheaths in the hippocampus were estimated using unbiased stereology combined with transmission electron microscopy.Results:The escape latency was significantly shortened and the number of times crossing the platform was significantly increased in the rAAV-LINGO-1-shRNA group when compared to the control group,while there were no significant changes in the swimming time and distance ratio of the target quadrant.Compared with the control group,LINGO-1 was significantly down-regulated,and the expression levels of its downstream RhoA and ROCK were decreased in the hippocampus of the rAAV-LINGO-1-shRNA group.The total volume of hippocampus was no significant difference between the control and rAAV-LINGO-1-shRNA groups.Compared with the control group,the length of myelinated nerve fibers and the volume of normal myelin sheath in the hippocampus of the rAAV-LINGO-1-shRNA group were significantly increased,and the proportion of damaged myelinated nerve fibers and damaged myelin sheath were significantly decreased.Conclusion:Silencing LINGO-1 i

关 键 词：含亮氨酸重复序列和免疫球蛋白结构域的蛋白-1 髓鞘 有髓神经纤维 海马 阿尔茨海默病 小鼠 

分 类 号：R749.16[医药卫生—神经病学与精神病学]