社会隔离对小鼠认知功能及海马星形胶质细胞表型转换的影响  

Effects of social isolation on cognitive function and phenotypic transition of hippocampal astrocytes in mice

作　　者：时萌萌 许晓帆 张圆 霍雅洁 徐杨 曹文宇 Shi Mengmeng;Xu Xiaofan;Zhang Yuan;Huo Yajie;Xu Yang;Cao Wenyu(Clinical Anatomy&Reproductive Medicine Application Institute,Hengyang Medical School,University of South China,Hengyang 421001,China;Hunan Provincial Key Laboratory of Tumor Cell and Molecular Pathology,Cancer Institute Medical College,University of South China,Hengyang 421001,China;Department of Physiology&Institute of Neuroscience,Hengyang Medical School,University of South China,Hengyang 421001,China)

机构地区：[1]南华大学衡阳医学院应用解剖与生殖医学研究所,衡阳421001 [2]南华大学衡阳医学院肿瘤研究所肿瘤细胞和分子病理学湖南省重点实验室,衡阳421001 [3]南华大学衡阳医学院生理学教研室和神经科学研究所,衡阳421001

出　　处：《中华行为医学与脑科学杂志》2022年第6期481-489,共9页Chinese Journal of Behavioral Medicine and Brain Science

基　　金：湖南省自然科学基金(2018JJ3429);湖南省卫生健康委科研课题(202102011871)。

摘　　要：目的探讨社会隔离(social isolation,SI)对小鼠认知行为及海马星形胶质细胞表型转换的影响。方法20只3~4周龄雄性C57BL/6小鼠根据随机数字表法分为正常群居组(group house,GH组)和社会隔离组(SI组),SI组小鼠单笼饲养8周建立社会隔离模型,GH组小鼠5只/笼正常饲养。采用新旧事物识别实验和新旧位置识别实验检测小鼠认知功能;采用免疫组织化法、RT-PCR和Western blot分别检测小鼠海马星形胶质细胞标志物胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP)的表达变化;Sholl Analysis定量分析星形胶质细胞形态变化;RT-PCR和Western blot法检测海马A1和A2型星形胶质细胞标志物蛋白酶体亚单位β-8(proteasome subunit beta 8,PSMB8)以及钙结合蛋白S100家族的成员(a member of the S100 family of Ca^(2+)-binding proteins,S100A10)的表达。采用GraphPad Prism 6.0软件进行统计分析,两组间比较采用t检验。结果认知功能结果显示,SI组小鼠新事物识别指数[(-5.54±3.30)%,(33.42±7.14)%;t=4.680,P=0.001]和新位置识别指数[(-7.96±4.81)%,(23.55±8.20)%;t=3.670,P=0.008]均低于GH组。免疫组化结果显示,SI组小鼠海马GFAP阳性细胞数明显低于GH组[(369.90±42.97)个,(544.90±57.64)个;t=2.480,P=0.023]。Sholl分析结果显示,SI组小鼠海马星形胶质细胞突起回缩,突起分支与同心圆交点数目减少,在距离星形胶质细胞胞体6、8、10、12、14、16μm处,两组间比较均差异有统计学意义(均P<0.05)。Western blot结果显示,SI组GFAP蛋白的表达低于GH组[(0.85±0.05),(1.03±0.06);t=2.527,P=0.028];PCR结果显示,SI组GFAP mRNA表达低于GH组[(0.83±0.05),(1.00±0.03);t=2.970,P=0.018];SI组小鼠海马区A1表型标志物PSMB8 mRNA表达[(1.58±0.17),(1.00±0.06);t=2.931,P=0.011]和A2表型标志物S100A10 mRNA表达[(1.52±0.14),(1.00±0.07);t=3.121,P=0.007]均高于GH组。SI组营养因子IGF-1 mRNA表达低于GH组[(0.73±0.07),(1.00±0.08);t=2.327,P<0.05],而SI组LCN2 mRNA、IL-1βObjective To explore the effect of social isolation(SI)on cognitive function and the phenotypic transition of hippocampal astrocytes in mice.Methods Twenty male C57BL/6 mice aged 3-4 weeks were randomly divided into normal group house(GH group)and social isolation group(SI Group).The mice in SI group were fed one per cage for 8 weeks to establish a social isolation model,and the mice in GH group were fed five per cage.The cognitive function of mice was detected by the novel object recognition test and novel location recognition test.The expression of astrocyte marker glial fibrillary acidic protein(GFAP)was detected by immunohistochemistry,RT-PCR and Western blot.The astrocyte morphology change was quantitatively analyzed by Sholl Analysis.The expression of the hippocampal A1-A2 astrocytes markers proteasome subunit beta 8(PSMB8)and a member of the S100 family of Ca^(2+)-binding proteins(S100A10)were determined by RT-PCR and Western blot.Statistical analysis was performed using GraphPad Prism 6.0 software,and t-test was used for comparison between two groups.Results The results of cognitive function showed that the exploration index of novel object((-5.54±3.30)%,(33.42±7.14)%;t=4.680,P=0.001)and the exploration index of novel location((-7.96±4.81)%,(23.55±8.20)%;t=3.670,P=0.008)in SI group were both lower than those in GH group.Immunohistochemical results showed that the number of GFAP positive cells in hippocampus of SI group was significantly lower than that of GH group((369.90±42.97),(544.90±57.64);t=2.480,P=0.023).The results of Sholl analysis showed that the protuberance of hippocampal astrocytes in SI Group retracted.There were significant differences in the number of intersections between the two groups at 6,8,10,12,14 and 16μm away from astrocyte cell body(all P<0.05).Western blot showed that the expression of GFAP protein in SI group was lower than that in GH group((0.85±0.05),(1.03±0.06);t=2.527,P=0.028).The results of PCR showed that the expression of GFAP mRNA in SI group was lower than that

关 键 词：社会隔离 认知功能障碍 星形胶质细胞 海马 小鼠 

分 类 号：R749.1[医药卫生—神经病学与精神病学]