【作者】 孟凡涛；

【导师】 周江宁；

【作者基本信息】 中国科学技术大学 ， 神经生物学， 2011， 博士

【摘要】 载脂蛋白E(ApoE)是一个34KD的蛋白,它主要参与脑内脂质和胆固醇等在体内的运输和重新分配。在人体中,ApoE主要由三种亚型(ε2,ε3, andε4)。其中,ApoE4被认为是散发型阿尔兹海默病(AD)及其它一些疾病的风险因子。本论文中,我们主要进行了以下方面的研究:1不同ApoE基因型对焦虑样行为的影响ApoE4作为阿尔兹海默病的一个重要的风险基因也常被认为参与了精神类疾病发病机制之中。本课题中,我们旨在研究不同亚型ApoE对小鼠焦虑样行为的影响,并揭示其中可能的机制。我们的结果显示,与ApoE3型转基因小鼠相比,三月龄的ApoE4转基因小鼠在多个行为学任务中表现出焦虑样行为。为评估下丘脑-垂体-肾上腺轴的功能,我们检测了在束缚应激条件下皮质酮的分泌情况。应对束缚应激反应,ApoE3和ApoE4型转基因小鼠中的皮质酮分泌都都有所升高,然而,我们并没有发现不同亚型之间的显著差异。进一步实验,显示ApoE4抑制了雌激素的生物合成。同时,我们发现多种相关受体在ApoE4型新生和成年小鼠的下丘脑和前额叶中有所上调,而在老年组中这种多受体的上调消失。小结,ApoE影响了雌激素的生物合成和多种受体的表达平衡,进而影响焦虑样行为。2慢性应激对不同ApoE小鼠行为学影响有证据表明,遗传基因和环境因素在阿尔茨海默氏病(AD)发病进程中都起到了重要的作用。本研究旨在探讨在慢性应激条件下,不同的人类ApoE转基因小鼠的行为变化和病理进程的改变。我们的结果显示,8月龄ApoE4的小鼠与ApoE3小鼠相比,自主活动能力和探索行为减少,而焦虑样行为增多。经历慢性应激后,ApoE3型转基因小鼠表现出较少的自主活动和探索行为,和较高的焦虑水平;而ApoE4小鼠的自主活动和探索行为有所增加,并且焦虑样行为有所减少。在新物体识别任务中,我们发现,慢性应激操作的ApoE4型小鼠在一小时间隔的任务中显示出认知功能障碍;在24小时间隔的任务中,慢性应激处理的ApoE3和ApoE4小鼠均表现出表现出认知功能缺陷。在Y -迷宫任务中,正常的8月龄ApoE4的小鼠和慢性应激的ApoE3小鼠在自发选择新臂时出现了认知功能的障碍。然而,我们发现在8月龄时,不管是ApoE基因型还是慢性应激都没有显著地改变突触蛋白的表达水平。综上所述,与ApoE3相比,ApoE4导致了小鼠自主活动和探索行为的减少以及焦虑样行为的增多;慢性应激使ApoE3小鼠的自主活动和探索行为的减少以及焦虑样行为的增多,而ApoE4小鼠的自主活动和探索行为的增加以及焦虑样行为的减少。3载脂蛋白E基因多态性与中国女性生理周期特征相关性研究目的:初潮年龄和绝经年龄受到多种遗传因素影响,本研究旨在中国女性中研究ApoE不同基因型与初潮和绝经年龄之间可能存在的相关性。结果:老年组:单因素方差分析表明ApoE基因型与自然绝经年龄之间存在显著地相关性(P = 0.010)。与ApoE3/3型携带者相比,ApoE3/4型携带女性的自然绝经年龄延迟了约1.8年。不同ApoE基因型携带者的E2,LH和FSH水平没有显著地差异。年轻组:ApoE单个等位基因阳性/阴性分析显示,与ApoEε4阴性携带者相比,ApoEε4携带者的初潮年龄有所提前(P=0.048).结论:我们的研究显示ApoE基因型与自然绝经年龄显著相关,与初潮年龄轻度相关。这些结果表明ApoEε4与延长了中国女性的生育期。更多还原

【Abstract】 Apolipoprotein (ApoE) is a 34 KD protein that participates in the transport of plasma lipids and redistribution of lipoproteins and cholesterol. There are three isoforms of ApoE in human, (ε2,ε3, andε4). Of the three common human ApoE isoform, inheritance of ApoE4 is a great genetic risk factor for the development of sporadic Alzheimer’s disease (AD) and other diseases. In the present study, we investigated the role of ApoE in the following aspects:1 The role of ApoE in the anxiety-like behaviorAnxiety symptoms occur in a large part of AD patients. ApoE4, as a great risk factor of AD, also has been recognized as an important contributor for psychiatric disorders. In the present study, we aimed to investigate anxiety related behavior changes in different ApoE isoforms transgenic mice. Our results show that 3mons ApoE4 transgenic mice showed more anxiety-like behaviors than that in ApoE3 mice. To assess the function of Hypothalamic-pituitary-adrenal axis (HPA), we measured corticosterone secretion responsed to acute restraint stress. The level of corticosterone secretion increased rapidly reponsed to stress in both ApoE3 and ApoE4 transgenic mice. However, no significant difference was found between the ApoE3 and ApoE4 mice. We measured the estrogen level in the central never system. We found a lower estrogen level in ApoE4 transgenic mice than that in ApoE3 mice. Also, we found that several receptors were dysregulated in ApoE4 postnatal mice and 3mons adult mice compared with ApoE3 mice, rather than in aged mice. In summary, ApoE4 inbibited CRH expression by dowregulating biosynthesis of estrogen, which mediated by the ERE in the promoter of CRH.2 The behavior changes in ApoE mice response to chronic stressThere is evidence that both genetic and environmental factors may play a role in the pathogenesis of Alzheimer’s disease (AD). This study was designed to investigate the behavioral and synapse changes under chronic stress administration in different human ApoE transgenic mice. We found that the exploration and locomotor activity were lower in ApoE4 mice compared with that in ApoE3 mice. After chronic stress treatment, ApoE3 mice showed a lower level of exploration and locomotor activity, while ApoE4 mice became more active in exploration and travel. A higher level of anxiety-like behaviors was found in non-stressed ApoE4 mice than that in non-stressed ApoE3 mice. After chronic stress treatment, both ApoE3 and ApoE4 mice became anxious in the light dark box test. In the open field test, stressed ApoE3 mice showed a higher level of anxiety, while stressed ApoE4 mice, unexpectedly, became less anxious. In the novel object recognition task, we found that stressed ApoE4 mice showed impairment in novel object recognition in one-hour interval task and both stressed ApoE3 and ApoE4 mice showed cognitive deficits in twenty-four hour interval task. In the Y-maze, impairment in spontaneous alternation to the novel arm was found in non-stressed ApoE4 mice and stressed ApoE3 mice. However, we did not find any significant difference in the expression of synapsinI and PSD95 among the four groups. In summary, we found that chronic stress decreased the spontaneous locomotor activity and exploration behavior, increased anxiety-like behavior in ApoE3 mice; and increased locomotor activity and exploration behavior, decreased anxiety-like behavior in ApoE4 mice.3 Association of ApoE genotypes with the age at natural menopause in Chinese femalesObjective: The age at natural menarche and menopause are influenced by several genetic factors. This study aimed to investigate possible relationship between ApoE genotype and the age at menarche and natural menopause in Chinese females. Results: Elderly group: one-way ANOVA analysis revealed that ApoE genotype was significantly associated with the age at natural menopause (P = 0.010). Compared with ApoEε3/3 carriers, ApoEε3/4 female showed a delay about 1.8 year (P=0.002) at the age of natural menopause. Young group: ApoE single allele positive/negative analysis showed the age at menarche in ApoEε4 carriers was slightly earlier than ApoEε4 negative carriers’(P=0.048). Conclusions: We demonstrated that ApoE genotype is linked to the age at natural menopause significantly and the age at menarche slightly. The results indicate that ApoEε4 is associated with prolonged reproductive period in Chinese females.更多还原