外周胰岛素抵抗对MAPT转基因小鼠认知损害和大脑Tau蛋白磷酸化的影响  

Peripheral insulin resistance aggravated cognitive impairment and phosphorylated Tau protein in MAPT transgenic mice

作　　者：熊静[1] 邢维昊 李舒婷 张晓琳 巫晓宇 刘凤 Xiong Jing;Xing Weihao;Li Shuting;Zhang Xiaolin;Wu Xiaoyu;Liu Feng

机构地区：[1]昆明医科大学附属第二医院神经内科,昆明650101

出　　处：《中华行为医学与脑科学杂志》2022年第4期298-305,共8页Chinese Journal of Behavioral Medicine and Brain Science

基　　金：云南省医疗卫生单位内设研究机构科研项目(2017NS287);云南省卫健委医学学科带头人培养计划(D-2017028);云南省教育厅科学研究基金(2020J0186)。

摘　　要：目的探讨长期高脂饮食引起的胰岛素抵抗对pR5株系MAPT Tau转基因小鼠的认知功能和大脑Tau蛋白磷酸化的影响。方法8周龄雌性pR5 MAPT转基因小鼠分为标准饮食(standard diet,STD)组(pR5 STD,n=8)和高脂饮食(high-fat diet,HFD)组(pR5 HFD,n=8),以STD喂养的雌性野生型(wild type,WT)C57BL/6小鼠为对照组(WT STD,n=8),连续干预30周,直到小鼠老龄。实验期间小鼠每周测量1次体质量,每2周测量1次空腹血糖。30周后进行葡萄糖耐量实验、胰岛素耐量实验;采用强迫游泳实验和悬尾实验评估小鼠抑郁样行为,高架十字迷宫实验评估焦虑样行为,Morris水迷宫空间探索实验评估记忆行为;Western blot检测大脑组织总Tau蛋白和磷酸化Tau蛋白H7-tau、p-tau-Ser396和p-tau-Thr231表达水平。采用SPSS 17.0进行统计分析,葡萄糖耐量数据和胰岛素耐量数据采用重复测量方差分析,其他数据多组间比较采用单因素方差分析,进一步两两比较采用LSD检验。结果高脂饮食30周时,三组小鼠的体质量和空腹血糖均差异有统计学意义(F=808.31,1117.18,均P<0.01)。pR5 HFD组小鼠的体质量[(54.35±2.52)g]高于pR5 STD组[(24.95±1.15)g]和WT STD组[(23.86±1.10)g](均P<0.01),pR5 HFD组小鼠空腹血糖[(8.12±0.24)mmol/L]高于pR5 STD组[(4.64±0.13)mmol/L]和WT STD组[(4.45±0.22)mmol/L](均P<0.01)。葡萄糖耐量实验显示,三组小鼠注射葡萄糖后的120 min内,血糖值存在显著时间和组别交互作用(F=113.30,P<0.01),pR5 HFD组小鼠注射葡萄糖后血糖升高的峰值延迟,提示pR5 HFD组小鼠葡萄糖耐量受损。胰岛素耐量实验显示,三组小鼠的胰岛素耐量存在显著的时间和组别的交互作用(F=209.92,P<0.01)。pR5 HFD组小鼠注射胰岛素后,血糖下降较慢,在60 min时即达谷值,之后血糖显著回升,提示pR5 HFD组小鼠对胰岛素的敏感性显著降低。三组小鼠强迫游泳不动时间百分比和悬尾不动时间百分比均差异有统计学意义(F=37.05,59.2Objective To investigate the effects of insulin resistance induced by long-term high-fat diet on cognitive function and brain phosphorylated Tau protein in pR5 MAPT Tau transgenic mice.Methods Eight-week-old female pR5 MAPT transgenic mice were divided into standard diet(STD)group(pR5 STD,n=8)and high-fat diet(HFD)group(pR5 HFD,n=8).Female wild-type C57BL/6 mice fed with STD were used as control group(WT STD,n=8).The experiment was carried out for 30 weeks until the mice were old.During the experiment,the weight of mice was measured once a week and fasting blood glucose was measured once every two weeks.Thirty weeks later,glucose tolerance test and insulin tolerance test were carried out.Forced swimming test and tail suspension test were used to evaluate the depressive behavior of mice,and elevated plus maze test was used to evaluate the anxiety behavior,Morris water maze test was used to evaluate spatial memory behavior.The levels of total Tau protein and phosphorylated Tau proteins H7-tau,p-tau-Ser396 and p-tau-Thr231 were detected by Western blot.SPSS 17.0 software was used for statistical analysis,repeated measurement ANOVA was used for the data of glucose tolerance test and insulin tolerance test,one-way ANOVA was used for multi group comparison,and LSD test was used for further pairwise comparison.Results After 30 weeks of high-fat diet,there were significant differences in body weight and fasting blood glucose among the three groups(F=808.31,1117.18,both P<0.01).The body weight of mice in pR5 HFD group((54.35±2.52)g)was higher than those in pR5 STD group((24.95±1.15)g)and WT STD group((23.86±1.10)g)(both P<0.01),and the fasting blood glucose of mice in pR5 HFD group((8.12±0.24)mmol/L)was significantly higher than those in pR5 STD group((4.64±0.13)mmol/L)and WT STD group((4.45±0.22)mmol/L)(both P<0.01).Glucose tolerance test showed that within 120 minutes after injection of glucose,there was a significant time and group interaction in the blood glucose value among the three groups(F=113.30,P<0.01).Aft

关 键 词：认知障碍 胰岛素抵抗 肥胖 2型糖尿病 TAU蛋白磷酸化 小鼠 

分 类 号：R749.1[医药卫生—神经病学与精神病学]