黄酮类小分子漆黄素抑制Aβ诱导RAGE介导的小胶质细胞炎症通路研究

Studies have identified the activation of microglia and the accompanied cerebral inflammation triggered by Aβ takes an important role in the AD mechanism. The binding of RAGE and Aβ takes an important role in it, so its binding domain will be a promising target for drug designing. We established a screening method for inhibitor of RAGE-Aβ by SPR, then we got a series of flavonoids which related pharmacological effect have not been reported before, such as Baicalein, Fisetin and Luteolin, and the binding mode of them were also identified preliminary. Our project is going to use the flavonoid-fisetin as probes, adopting SPR Study and HCS array research platform, using molecular simulation and neuron-microglia co-incubation strategy: ①Study the SAP of the RAGE-Aβ binding site to find its conformation characteristics; ②Evaluation of the effects of fisetin on the activating of the downstream signal pathways in MG induced by Aβ oligomer; ③Study the effect of fisetin to attenuate the Aβ oligomer induced imbalance of the neuron-microglia co-incubation system; ④Study the inhibitory effect of fisetin on the RAGE- Aβ related inflammatory signal pathways. Study if fisetin have positive effects on the disease modifying and on the modulating of the pathology at the mice model. This project will provide chemicobiology information for new AD drugs designing with high performance and specificity.

研究表明Aβ激活小胶质细胞触发的脑内炎症是AD的重要病理特征，RAGE受体在其中发挥关键作用，RAGE-Aβ结合位点是极有前景的治疗靶点。本课题组用SPR方法建立了RAGE-Aβ抑制剂筛选模型并以此获得了漆黄素等一系列黄酮类小分子抑制剂，且初步确认了其作用位点，该类小分子相似药理作用未见报道。本项目拟应用SPR和高内涵平台,分子模拟、神经元-小胶质细胞共培养等技术，在前期工作基础上以漆黄素为探药：①研究漆黄素、RAGE和Aβ结合动力学，探明RAGE-Aβ结合位点结构特征；②评价漆黄素对传代及原代小胶质细胞下游信号通路的影响；③建立神经元-小胶质细胞共培养体系，检验漆黄素通过抑制RAGE-Aβ通路发挥的神经保护作用；④观察漆黄素对模型动物RAGE-Aβ介导的炎症通路的影响，及对改善阿尔茨海默氏痴呆、调节其病理进程的意义。本研究将为AD治疗中新靶标候选药物的研发提供化学生物学信息。

Aβ激活小胶质细胞触发的脑内炎症是AD的重要病理特征，RAGE受体与Aβ结合位点是极有前景的治疗靶点，但目前基于该靶点的小分子药物研发非常有限。. 通过分子模拟与化学生物学实验的结合，以漆黄素、黄芩素、木犀草素为探药进行了构效学研究和递进式筛选，得到新的候选探针--小分子化合物α-倒捻子素，且证实了α-倒捻子素抑制RAGE-Aβ结合的分子动力学特征，该小分子相似药理作用未见报道。通过建立小胶质细胞激活模型，证实小胶质细胞中RAGE-Aβ激活的下游通路与炎症小体相关。通过细胞实验证实了α-倒捻子素能增加小胶质细胞对Aβ的摄取和清除，模型动物实验证实α-倒捻子素对AD相关神经炎症具有改善作用，对AD相关Aβ沉积和整体认知功能具有改善作用。. 综上，本研究将为后续以α-倒捻子素为先导物探索AD新靶标候选药物提供理论依据。