孕期慢性应激通过NMDAR/CaMKⅡ信号通路致子代学习记忆能力损伤机制  

Chronic stress during pregnancy triggers learning and memory impairment of offspring through the NMDAR/CaMKⅡsignaling pathway

作　　者：刘红娅 陈小惠 马淑琴[3] 戚发秋 付有娟 赵枫 关素珍 LIU Hong-ya;CHEN Xiao-hui;MA Shu-qin;QI Fa-qiu;FU You-juan;ZHAO Feng;GUAN Su-zhen(School of Public Health and Management,Ningxia Medical University,Yinchuan,Ningxia 750004,China;不详)

机构地区：[1]宁夏医科大学公共卫生与管理学院,宁夏银川750004 [2]宁夏环境因素与慢性病控制重点实验室,宁夏银川750004 [3]宁夏医科大学总医院,宁夏银川750003

出　　处：《中国职业医学》2022年第1期22-28,共7页China Occupational Medicine

基　　金：国家自然科学基金地区项目(81960591);宁夏医科大学科学研究基金(XZ2020002,XT2018001)。

摘　　要：目的探讨N-甲基-D-天门冬氨酸受体(NMDAR)/钙调蛋白激酶Ⅱ(CaMKⅡ)信号通路在孕期慢性应激所致子代大鼠学习记忆障碍中的作用机制。方法采用28 d慢性不可预知温和应激(在应激第7天受孕)建立孕期慢性应激大鼠模型。采用放射免疫测定法检测应激前1天和应激第1、7、14、21、28天孕鼠血浆皮质酮水平。在仔鼠出生后28和42 d称体质量,并检测血浆皮质酮水平;采用Morris水迷宫实验检测仔鼠学习记忆能力后,处死仔鼠,分离海马组织进行透射电子显微镜观察,采用实时荧光定量聚合酶链式反应和蛋白质印迹法检测海马组织NMDAR/CaMKⅡ信号通路相关蛋白mRNA和蛋白表达水平。结果模型组孕鼠血浆皮质酮水平在应激第14、21和28天均高于同时间点对照组(P值均<0.05);提示孕鼠孕期慢性应激模型成功建立。模型组仔鼠体质量低于对照组(P<0.01);模型组仔鼠出生后28和42 d血浆皮质酮水平均高于同时间点对照组(P值均<0.05)。Morris水迷宫实验结果显示,模型组仔鼠在训练的第3、4和5天逃避潜伏期均长于同时间点对照组(P值均<0.05),且呈时间依赖性缩短(P值均<0.05);模型组仔鼠跨越平台次数少于对照组(P<0.01)。与对照组比较,模型组仔鼠出现海马神经元细胞和突触超微结构病变。与对照组比较,模型组仔鼠海马组织中NMDAR 2B亚基(NR2B)、突触后致密蛋白95(Psd95)、CaMKⅡ、环磷酸腺苷反应元件结合蛋白(Creb)mRNA和NR2B、PSD95、磷酸化CaMKⅡ(p-CaMKⅡ)、磷酸化CREB(p-CREB)蛋白的相对表达水平均下降(P值均<0.05),p-CaMKⅡ/CaMKⅡ比值和p-CREB/CREB比值也下降(P值均<0.05)。结论孕期慢性应激致子代学习记忆能力下降,其机制可能与NMDAR/CaMKⅡ信号通路传导有关。Objective To investigate the mechanism of chronic stress during pregnancy induced learning and memory impairment of offspring through N-methyl-D-aspartate receptor(NMDAR)/calmodul independent protein kinaseⅡ(CaMKⅡ)signaling pathway.Methods Continuous chronic unpredictable mild stress for 28 days(conception on the 7 th day of stress)was used to establish the chronic stress model.The plasma corticosterone levels of pregnant rats were measured by radioimmunoassay one day before stress and 1,7,14,21,28 days after stress.Body weight and plasma corticosterone level of offspring were measured at 28 and 42 days after birth.Morris water maze was used to measure the learning and memory ability before the pups were sacrificed.The hippocampus tissues were isolated and observed by transmission electron microscopy.The mRNA and protein expression levels of NMDAR/CaMKⅡsignaling pathway were measured by real-time fluorescence quantitative polymerase chain reaction and Western blotting.Results The plasma corticosterone level in maternal rats of model group was higher than that in control group at the same time points on the 14 th,21 th and 28 th day after stress(all P<0.05),indicating that the chronic stress during pregnancy model of pregnant rats was established successfully.The body weight of offspring rats in model group was lower than that of control group(P<0.01).The plasma corticosterone level in model rats was higher than that in control group at the same time point at 28 and 42 days after birth(all P<0.05).Morris water maze test showed that the escape latency of offspring rats in model group was longer than that in control group at the same time point on day 3,4 and 5 of training(all P<0.05),and decreased in a time-dependent manner(all P<0.05).The number of crossing platform in model group was less than that in control group(P<0.01).Hippocampal neurons and synaptic ultrastructural changes were observed in the offspring of model group compared with the control group.The mRNA relative expression of NMDAR subunit 2 B(NR

关 键 词：慢性应激 子代 学习记忆 皮质酮 N-甲基-D-天门冬氨酸受体 钙调蛋白激酶Ⅱ 信号通路 大鼠 

分 类 号：R135[医药卫生—劳动卫生] R114[医药卫生—公共卫生与预防医学]