妊娠期高糖饮食对子代学习记忆及海马神经细胞凋亡的影响

发布时间：2018-10-24 11:57

【摘要】：第一部分妊娠期高糖饮食对子代脑发育及学习记忆的影响目的：妊娠期高糖饮食不利于胎儿及子代的正常生长和器官发育，并可能引起一定的功能改变。本实验着眼于研究妊娠期高糖饮食对子代脑发育的影响，并进一步探究其子代脑功能，如学习记忆能力是否改变。方法：采用本实验室已建立成熟的妊娠期高糖饮食模型，将怀孕母鼠随机分为妊娠期高糖饮食组（高糖组，HS）和正常饮食组（对照组，C）。高糖组母鼠妊娠期全程（第1-21天）给予20%蔗糖水和正常标准饲料，对照组母鼠妊娠期全程给予正常饲料和淡水。出生后子代鼠均给予标准化饲料和淡水。监测孕鼠在妊娠期的饮水饮食及体重变化；于妊娠第21天检测孕鼠空腹血糖、羊水含糖量及胎鼠血糖，子代大鼠标准化饲养，检测1月龄及2月龄大鼠空腹血糖；分别称量胎鼠、1月龄及2月龄子代鼠的体重、脑重，并计算脑/体重比值；采用Morris水迷宫实验检测1月龄及2月龄子代大鼠的空间学习记忆能力。结果：高糖组母鼠在妊娠期的饮水饮食及体重增长与对照组相比均无明显差异；妊娠第21天，高糖组孕鼠的空腹血糖显著高于对照组，羊水含糖量在两组间无统计学差异，高糖组胎鼠、1月龄及2月龄子代鼠的空腹血糖均显著高于对照组；高糖组2月龄子代鼠脑重显著下降，胎鼠、1月龄及2月龄子代鼠的脑/体重比值均显著低于对照组，而体重均显著升高；Morris水迷宫训练结果显示，暴露于妊娠期高糖饮食的子代大鼠在定位航行实验中需要更长的时间和游更长的距离才能找到平台，两组大鼠在空间搜索实验中的穿越平台次数及目标象限停留时间均无统计学差异。结论：妊娠期高糖饮食对胎儿及子代的生长和脑发育具有一定影响，该影响在子代中可表现为学习记忆能力的下降。第二部分妊娠期高糖饮食对子代海马神经元凋亡的影响及其可能的机制目的：通过组织学及分子生物学手段，研究妊娠期高糖饮食对子代海马脑区神经元凋亡的影响，并进一步探究其可能的机制。方法：妊娠期高糖饮食模型的建立同第一部分；取2月龄子代大鼠的新鲜脑组织进行冰冻切片，采用一步法TUNEL染色检测两组大鼠海马脑区（CA1，CA2，CA3）的细胞凋亡，，并于荧光显微镜下记录两组切片阳性染色细胞数；以Westernblotting法检测两组2月龄子代大鼠海马组织内凋亡相关蛋白（IGF-1，PI3K，Akt，p-Akt，caspase-3，Bcl-2，NR2B）的表达。结果：组织学染色结果显示，与对照组相比，高糖组2月龄子代大鼠海马CA1，CA2，CA3区域的TUNEL染色阳性细胞数均显著增加；Western blotting结果显示，高糖组2月龄子代鼠海马组织内的IGF-1，PI3K和p-Akt的蛋白表达量均显著低于对照组，而caspase-3和NR2B的蛋白表达量均显著高于对照组，Bcl-2和Akt的蛋白表达量在两组间无统计学差异。结论：妊娠期高糖饮食可引起子代的海马神经元细胞凋亡增加，海马组织中IGF-1/PI3K/Akt抗凋亡信号通路蛋白表达的改变可能在该影响中起着重要作用。
[Abstract]:Effects of high sugar diet on brain development and learning and memory of offspring in the first part of pregnancy Objective: High sugar diet during pregnancy is not conducive to normal growth and organ development of fetus and offspring, and may cause some functions. This experiment aims to study the effect of high sugar diet on the development of children's brain, and further explore its offspring's brain function, such as learning and memory ability. Methods: The pregnant female rats were randomly divided into high sugar diet group (high sugar group, HS) and normal diet group (P <0.05). In the whole course of pregnancy (Days 1-21), 20% sucrose water and normal standard feed were given during pregnancy (day 1-21). Feed and fresh water. Children born after birth are standardized Feed and fresh water. Monitor the drinking water diet and weight changes of pregnant rats during pregnancy; detect fasting blood glucose, amniotic fluid flow rate and fetal blood sugar in pregnant rats on Day 21 of gestation, standardized feeding of offspring rats, and detect the age of 1 month and 2 months old. Fasting blood glucose in rats; weighing fetal rats, 1-month and 2-month-old children's body weight, brain weight, and calculating brain/ body weight ratio; using Morris water maze test to detect the spatial learning of children in 1 month and 2 months of age Results: Compared with the control group, the fasting blood glucose of the pregnant rats of the high sugar group was significantly higher than that of the control group. There was no statistical difference among the groups, and the fasting blood glucose was significantly higher in children with high sugar group, 1-month and 2-month-old. The brain/ body weight ratio of fetal rats, fetal rats, 1-month-old and 2-month-old children was significantly lower than that in control group. Body weight increased significantly; Morris water maze training showed that children exposed to high sugar diet in pregnancy needed longer time and longer swim in the positioning navigation experiment The distance can be found for the platform, and the number of crossing platforms and the target quadrant of the two groups of rats in the space search experiment are stopped. Conclusion: High sugar diet during pregnancy has a certain effect on the growth and brain development of fetus and offspring, which can be seen in offspring. The second part of pregnancy high sugar diet is the offspring's hippocampus. Objective: To study the effect of high sugar diet on neurons in hippocampus of children by histological and molecular biological methods. Methods: The establishment of the high sugar diet model in pregnancy was the same as that of the first part; the fresh brain tissue of the 2-month-old offspring rat was frozen section, and the two groups of rat hippocampus were detected by one-step staining method. The apoptosis of the brain regions (CA1, CA2, CA3) and the number of positive staining cells were recorded under the fluorescence microscope. The apoptosis-related proteins (IGF-1, PAF, Akt, p-Akt, casp) in the hippocampus of two groups of 2-month-old children were detected by Western blotting. Results: Compared with the control group, the number of TUNEL staining positive cells in CA1, CA2 and CA3 regions of the hippocampus CA1, CA2 and CA3 of the rats with high sugar group increased significantly compared with the control group, and the Western blotting result The expression levels of IGF-1, p27 and p-Akt in hippocampus were significantly lower than that in control group, and the expression levels of caspase-3 and NR2B were significantly higher than those in control group. There was no statistical difference between the expression of l-2 and Akt in the two groups. Conclusion: High sugar diet in pregnancy can cause apoptosis of hippocampal neurons in offspring and IGF-1/ Thr/ Akt in hippocampus.
【学位授予单位】：苏州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R714;Q42

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