基于Aβ通路研究阿里红多糖对老年性痴呆的干预及其机制

Aβ pathway is a common way to induce AD by various reasons, it is the key factor in the formation and development of AD.Fomes officinalis is one of the specialty Uygur medicine resources of Xinjiang.As the previous study showed, fomes officinalis polysaccharides had a good effect on resistance in senile dementia.On the basis of our previous work, FOP-a and FOP-b as research object,applies APP/PS1 double transgenic mice as AD animal model,HE staining、immunohistochemistry、real time PCR，Western blot will be used to study cognitive behavior、 pathological changes、expression of Aβ, PS-lmRNA, APP and Tau protein of APP/PS1 double transgenic mice.PC12 cell to simulate AD disease neuron apoptosis model, using CCK-8 and lactate dehydrogenase kit respectively to detect the cell vitality and LDH leakage，the apoptosis rate and mitochondrial membrane potential were evaluated by flow cytometry method；And to further explore the relationship between AD and TLR4、NF-κB signal transduction pathway，seeks to clarify the effects of fomes officinalis polysaccharides on AD Prevention and Treatment and its molecular mechanism. To provide the basis for exploring AD intervention reagent.

Aβ通路是各种原因诱导AD的共同途径，是AD形成和发展的关键因素。阿里红是新疆具有特色的维药资源，前期研究发现阿里红多糖（FOP）具有较好的抗老年性痴呆（AD）作用。本项目拟在前期工作基础上，以阿里红中分离的2个多糖组分FOP-a与FOP-b为研究对象，运用APPswe／PSl dE9双转基因小鼠模拟AD疾病模型，采用HE染色、免疫组化、Real time PCR法和Western blot等方法研究对APP／PSl双转基因小鼠认知行为、病理改变、Aβ、PS-lmRNA、APP、Tau蛋白的表达；同时，应用PC12细胞模拟AD疾病神经元细胞凋亡的模型，采用流式细胞术等方法检测Aβ25～35诱导PC12细胞存活能力、LDH漏出率、细胞凋亡率和线粒体跨膜电位的影响；并进一步探讨AD与 TLR4/ NF-κB信号传导通路的关系，旨在阐明阿里红多糖防治AD作用及其分子机制。

阿里红多糖组分（FOPSa与FOPSb）作为阿里红中生物活性物质之一，具有神经保护作用。本项目首先应用全基因组测序技术对FOPSa和FOPSb就作用于PC12细胞筛选出的显著性表达差异基因进行分析，预测结果显示FOPSa与FOPSb均能通过调节多个基因及多个信号通路的活性参与AD的生物学过程，包括细胞凋亡、线粒体损伤和氧化应激等途径；其次，不同剂量的FOPSa及FOPSb干预AD细胞模型后，能明显改善细胞中线粒体的损伤和降低氧化应激反应的细胞毒性；同时，靶向探针追踪Aβ25-35在PC12细胞中的作用部位，发现FOPSa与FOPSb可进入到细胞的线粒体内，通过激活Nrf2信号通路显著改善Aβ25-35对线粒体造成的损伤；另外，体内实验表明两种多糖组分均可提高APP/PS1双转基因小鼠学习记忆能力，降低其脑组织海马区AD病发的Aβ、Tuo蛋白的表达量，并通过提高抗氧化酶的活性，降低脂质过氧化产物的含量，参与线粒体和氧化应激通路，起到神经保护作用，进而发挥治疗AD的功能。通过本项目已发表论文8篇（SCI收录1篇）；培养博士生1人、硕士生5人。