褪黑素联合丰富环境对SAMP8小鼠学习记忆能力的影响及机制  

Effects and mechanisms of melatonin combined with enriched environment on learning and memory ability of SAMP8 mice

作　　者：杜鹃 刘俊杰 李建民 刘少鹏 徐继伟 张宇新 Du Juan;Liu Junjie;Li Jianmin;Liu Shaopeng;Xu Jiwei;Zhang Yuxin(Hebei Key Laboratory of Chronic Diseases,School of Basic Medical Sciences,North China University of Science and Technology,Tangshan 063210,China;Experimental Center of Clinical Medical College,North China University of Science and Technology,Tangshan 063210,China;Emergency Department of Affiliated Hospital of North China University of Science and Technology,Tangshan 063000,China)

机构地区：[1]华北理工大学基础医学院河北省慢性疾病重点实验室,唐山063210 [2]华北理工大学临床医学院实验中心,唐山063210 [3]华北理工大学附属医院急诊科,唐山063000

出　　处：《中华行为医学与脑科学杂志》2022年第6期490-498,共9页Chinese Journal of Behavioral Medicine and Brain Science

基　　金：河北省财政厅河北省卫生健康委员会2019年政府资助临床医学优秀人才培养项目。

摘　　要：目的探讨褪黑素联合丰富环境对快速老化小鼠(senescence-accelerated mouse prone 8,SAMP8)学习记忆能力的影响及可能机制。方法48只4月龄雄性SAMP8小鼠按照随机数字表法分为模型组、丰富环境组、褪黑素组和褪黑素联合丰富环境组(联合干预组),每组12只。褪黑素组和联合干预组小鼠按8 mg·kg^(-1)·d^(-1)剂量皮下注射褪黑素,模型组和丰富环境组小鼠给予等量生理盐水;模型组和褪黑素组小鼠饲养于标准环境,丰富环境组和联合干预组饲养于丰富环境;共干预28 d。小鼠在干预前、干预28 d后进行老化度评分,Morris水迷宫实验检测小鼠学习记忆能力,尼氏染色、TUNEL染色分别观察小鼠海马CA1区尼氏染色阳性细胞、凋亡细胞情况,ELISA检测小鼠海马组织白细胞介素-1β(IL-1β)、白细胞介素-6(IL-6)和肿瘤坏死因子-α(TNF-α)含量,Western blot检测小鼠海马组织β-淀粉样蛋白(amyloidβ-protein,Aβ)1~42、在苏氨酸(Thr)205位点磷酸化的微管相关蛋白tau(tau pT205)、Toll样受体4(toll-like receptor 4,TLR4)、核转录因子κB(nuclear factor-κB,NF-κB)p65蛋白表达水平,qRT-PCR检测小鼠海马组织TLR4、NF-κB p65 mRNA表达水平。采用SPSS 22.0进行统计分析,分别用单因素方差分析、LSD检验和重复测量方差分析进行数据处理。结果(1)老化度评分:干预后,各组小鼠老化度评分差异有统计学意义(F=120.601,P<0.01),丰富环境组、褪黑素组和联合干预组小鼠老化度评分均低于模型组(均P<0.05),其中联合干预组小鼠老化度评分显著低于丰富环境组和褪黑素组(均P<0.05)。(2)定位航行实验结果显示:四组小鼠逃避潜伏期的时间-组别交互作用显著(F=30.524,P<0.001);第2~4天,丰富环境组、褪黑素组和联合干预组小鼠的逃避潜伏期均低于模型组(均P<0.05)。空间探索实验结果显示:四组小鼠目标象限停留时间和穿越平台次数均差异有统计学意义(F=291.328,113.482,均Objective To explore the effects and possible mechanisms of melatonin combined with enriched environment on the learning and memory ability of senescence-accelerated mouse prone 8(SAMP8).Methods Forty-eight SAMP8 male mice aged 4 months were randomly divided into model group,enriched environment group,melatonin group and melatonin combined with enriched environment group(combined intervention group)by random number table method,with 12 mice in each group.Mice in the melatonin group and combined intervention group were subcutaneously injected with melatonin at a dose of 8 mg·kg^(-1)·d^(-1),and the mice in the model group and the enriched environment group were given the same amount of normal saline instead.The mice in model group and melatonin group were raised in a standard environment,and the mice in enriched environment group and combined intervention group were raised in an enriched environment.The intervention lasted 28 days.The aging degree of mice was scored before and 28 days after the intervention.Morris water maze test was used to detect the learning and memory ability of mice.Nissl staining and TUNEL staining were used to observe the Nissl staining positive cells and apoptotic cells in the CA1 area of hippocampus.ELISA was used to detect the levels of interleukin-1β(IL-1β),interleukin-6(IL-6)and tumor necrosis factor-α(TNF-α)in the hippocampus of mice.Western blot was used to detect the levels of amyloidβ-protein(Aβ)1-42,microtubule-associated protein tau(tau)phosphorylated at threonine(Thr)205(Tau pT205),Toll-like receptor 4(TLR4),and nuclear factor-κB(NF-κB)p65 protein in the hippocampus of mice.qRT-PCR was used to detect the levels of TLR4,NF-κB p65 mRNA in the hippocampus of mice.SPSS 22.0 statistical software was used for repeated measure ANOVA,one-way ANOVA and LSD test.Results(1)Aging score:after intervention,the aging scores of mice in the four groups were significantly different(F=120.601,P<0.01).The aging scores of mice in the enriched environment group,melatonin group,and combined

关 键 词：褪黑素 丰富环境 快速老化小鼠 神经炎性反应 信号通路 学习记忆 

分 类 号：R338[医药卫生—人体生理学]