SORL1基因敲除小鼠可作为散发性阿尔茨海默病模型

Verification of a sporadic Alzheimer disease model in SORL1 gene knockout mice

目的通过与正常小鼠、淀粉样前体蛋白(APP)/PSE1双转基因小鼠行为学和病理学的比较,证明SORL1敲除小鼠可作为1种散发性阿尔茨海默病模型。方法 Crispr/Case9技术对小鼠受精卵SORL1基因进行编辑,通过检测小鼠DNA序列和Western blot检测SORL1等方法筛选和鉴定SORL1-/-小鼠。实验分为对照组、SORL1-/-组、APP/PSE1组。Morris水迷宫检测小鼠的学习记忆能力、免疫组化和Western blot分别检测小鼠脑组织中APP、β淀粉样蛋白的表达。结果 SORL1-/-小鼠的DNA测序结果是两条染色体SORL1基因CAAT碱基缺失,而正常小鼠SORL1基因无CAAT碱基的缺失;Western blot检测SORL1-/-组小鼠脑组织无SOLR1表达。在Morris水迷宫的定位航行实验中,与对照组比较,SORL1-/-组和APP/PSE1组小鼠平均逃避潜伏期均明显延长(P<0.05),SORL1-/-组和APP/PSE1组比较,小鼠的平均逃避潜伏期差异无统计学意义(P>0.05);在Morris水迷宫的空间探索实验中,与对照组比较,SORL1-/-组和APP/PSE1组小鼠平均穿越平台次数均减少(P<0.05),SORL1-/-组和APP/PSE1组比较,小鼠平均穿越平台次数差异无统计学意义(P>0.05)。免疫组化和Western blot检测结果均显示SORL1-/-组小鼠脑组织中APP和Aβ表达明显较对照组多,SORL1-/-组与APP/PSE1组脑组织的APP和β淀粉样蛋白表达差异无统计学意义。结论SORL1-/-小鼠可出现APP/PSE1小鼠相似的行为学和病理学的改变,可作为一种散发性阿尔茨海默病模型。

Objective To compare the behavioral and pathological features of SORL1 gene knockout mice with those of normal mice and APP/PSE1 mice to verify the feasibility of using SORL1 knockout mice as a model of sporadic Alzheimer disease.Methods SORL1 gene of fertilized mouse eggs were edited using Crispr/Case9 technique. SORL1-/-mice were screened and identified by detecting the DNA sequence, and Western blotting was used to detect the expression of SORL1. SORL1-/-mice,control mice and APP/PSE1 mice all underwent Morris water maze test to assess their learning and memory abilities with positioning navigation and space exploration experiments. The expression of APP and Aβ in the brain of the mice was detected using immunohistochemistry and Western blotting, respectively. Results DNA sequencing showed CAAT deletion in SORL1 gene in two chromosomes of SORL1-/-mice, and the control mice had intact SORL1 gene without the deletion; Western blotting did not detect the expression of the SORL1 in the brain of SORL1-/-mice. Morris water maze test showed that in positioning navigation experiment, the average avoidance latency was similar between SORL1-/-mice and APP/PSE1 mice（P〈0.05） but increased significantly in both mice as compared with the control group（P〈0.05）; similar results were obtained in the space exploration experiment. Immunohistochemistry and Western blotting revealed significantly increased APP and Aβ expression in the brain tissue of both SORL1-/-mice and APP/PSE1 mice compared with the control mice without significant differences between the two transgenic mice. Conclusion SORL1-/-mice exhibit similar behavioral and pathological changes with APP/PSE1 mice and can be used as a model of sporadic Alzheimer＇s disease.