DNA甲基化和PI3K/AKT信号通路在五味子木脂素抗阿尔茨海默病中的作用及机制

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder which do harm to old age in physical and mental health. So it is very necessary for medicine and society to study the pathogenesis and treatment of AD. Schisandra is a kind of chinese medicine or mongolian medicine which can be used in the treatment of AD. It is well know that DNA methylation play an important role in pathogenesis of AD. But it is unclear whether schisandra can cure AD through change the DNA methylation induced by PI3K/AKT signal pathway. The AD cell and AD animal model that treated by sehizandrol A and shiandrin B will be used in this study. Some techniques such as 5-methylcytosine immunofluorescence assay, Q-PCR, Western Blot, High-throughput sequencing and so on will be employed to reveal the change of the global DNA methylation, the mRNA and protein levels of three kinds of DNA methyltransferase, the mRNA and protein levels of NEP and the promoter DNA methylation of NEP in culture neuron and relative brain zone. Using AD rat which treated sehizandrol A and shiandrin B treatment, the learning and memory ability in Morris water maze, the relationship between Aβ and the survive of neuron, the relationship between DNA methylation and learning and memory ability, will be study too. To study the effects and mechanisms of lignanoids within Schisandra on DNA methylation in AD may provide a new strategy and scientific theory for clinical treatment in AD by traditional chinese or Mongolia medicine. This study will promote the development and use of Chinese and Mongolia medicine.

阿尔茨海默病（AD）严重危害老年人身心健康，针对AD的发病机理和治疗进行研究有重要的医学和社会意义。五味子是对AD有治疗作用的中蒙药，DNA甲基化在AD发病过程中扮演了重要的角色，五味子木脂素类成分对AD的治疗是否通过PI3K/AKT信号通路介导的DNA甲基化途径来实现的尚未见报道。本课题拟从AD细胞和动物模型两方面进行研究，分别用五味子醇甲、五味子乙素处理AD神经元模型和治疗模型动物，应用5-甲基胞嘧啶免疫荧光法、Q-PCR、Western Blot和二代测序等方法，检测神经元和相关脑区基因组DNA整体甲基化水平、三种DNMT mRNA和蛋白表达以及NEP甲基化水平、NEP表达变化的影响；利用Morris水迷宫检测大鼠学习记忆能力；并研究甲基化与大鼠学习记忆能力、神经元存活及Aβ产生的关系。探讨DNA甲基化在五味子木脂素类成分抗AD中的作用及其机制，为AD治疗和新药的研发提供新思路,本研

阿尔茨海默病（AD）严重危害老年人身心健康，针对AD的发病机理和治疗进行研究有重要的医学和社会意义。五味子是对AD有治疗作用的中蒙药，DNA甲基化在AD发病过程中扮演了重要的角色，五味子木脂素类成分对AD的治疗是否通过PI3K/AKT信号通路介导的DNA甲基化途径来实现需深入研究。本研究利用五味子木脂素处理AD神经细胞模型和治疗模型动物，应用Q-PCR、Western Blot和二代测序等方法，检测神经细胞和相关脑区基因组DNA三种DNMT mRNA和蛋白表达、PI3K/Akt信号通路蛋白及下游相关产物的表达变化；利用Morris水迷宫检测大鼠学习记忆能力；并研究甲基化与大鼠学习记忆能力、神经元存活及tau蛋白磷酸化的关系。结果：①AD模型存在DNA甲基化异常；五味子木脂素类成分能够对Aβ诱导的AD模型损伤具有保护作用，其机制主要是通过提高DNMT3A和DNMT1的表达水平来实现的。②五味子木脂素类成分和Xanthones类化合物可以拮抗Aβ1-42诱导的AD模型细胞损伤，其机制可能是通过激活PI3K/Akt信号通路并上调通路下游靶分子p-Akt和p-GSK-3β的活性、抑制tau蛋白磷酸化，从而保护神经细胞。③五味子木脂素类成分通过上调PI3K/Akt信号通路，调节DNA甲基化水平，并由此途径发挥对AD的防治作用。④用Aβ处理人SH-SY5Y细胞建立AD模型，经二代RNA测序并经Real-time PCR验证发现，AD模型细胞中有484个lncRNAs表达上调，483个表达下调，其中非常显著上调的lncRNAs有SNHG1、H19、BC200等，非常显著下调的lncRNAs有SNHG16、RP11-617F23.1、RP11-600F24.7等。研究结果将为AD的治疗和新药的研发提供新思路，促进中蒙药的开发和利用，也为下一步研究打下了基础。