五味子中活性成分Schizantherin B靶向sirt-3诱导线粒体自噬的抗PD机制研究

Schisandra chinensis，a kind of Traditional Chinese medicine (TCM), has good nerve protective effect, but the mechanisms of it are still unclear. Based on "medicinal materials - compounds - target proteins - diseases" research model in early research, we found that the lignans in methanol extract (SC) of Schisandra chinensis was targeted to regulate 5-HT1AR protein to improve the symptoms of insomnia rats. Fortunately, the studies showed that the SC combined with a good protection effect of cells in Parkinson's disease (PD) in vitro model may via the inducing of protection autophagy. After the detailed analysis of RNAseq and several kinds of bioinformatics networks，we forecasted that the anti-Parkinson effect of Schisandra chinensis may via targeting sirt-3 protein. After that, compound Schizantherin B (S1) was picked out as the best one, accompanied with good agonist effect in in vitro enzyme activity assay and good anti-Parkinson effect in PD model. Combined with the above research foundations and the experimental results, this study will further evaluate the mechanism of S1 cures PD via the potential agonist effect of sirt-3 protein to induce mitophagy. This study is expected to clarify whether the active compounds represented by S1 is the material base of Schisandra for the treatment of PD. Furthermore, it is significant for the development and utilization of Schisandra chinensis and meaningful for the development of new safe and effective drug for the treatment of PD.

传统中药五味子具有良好的神经保护作用，但具体作用机制不详。课题组前期基于 “药材-化合物-靶蛋白-疾病”研究模式，发现五味子甲醇提取物（SC）中的木脂素类成分靶向调控5-HT1AR改善大鼠失眠症状。同时我们发现SC对体外帕金森病（PD）模型有良好保护作用，并能诱导PD模型细胞发生保护性自噬。结合RNAseq和多种生物信息学网络技术分析结果，预测五味子可能靶向sirt-3产生抗PD作用。随后，通过多种活性评价方法，筛选出化合物Schizantherin B (S1)，其具有良好的体外sirt-3酶激动剂作用和体外抗PD作用。结合上述研究基础，本研究将进一步利用体内外PD模型评价S1靶向调节sirt-3蛋白诱导线粒体自噬产生抗PD作用的机制，有望阐明S1为代表的活性化合物是否为五味子抗PD作用的物质基础，为中药五味子的开发利用和新型、安全、有效的抗 PD 药物的研发提供科学依据。

本研究发现活性化合物S1对MPP+诱导损伤的SY5Y细胞具有一定的保护作用。S1可能激动sirt-3蛋白通过PINK/Parkin通路诱导线粒体自噬，进而改善线粒体膜电位和细胞内ROS水平，清除受损的线粒体，最终产生潜在的抗PD作用。基于上述的研究发现，我们进一步利用MPTP诱导C57小鼠构建体内PD模型，并初步评价S1的体内抗PD作用，深入研究其作用机制。在PD小鼠模型中，活性化合物S1治疗后，小鼠的四肢运动协调能力，包括爬杆时间、悬挂得分；和认知探索能力，包括开场实验中的站立次数、休息时间、移动距离等均有一定程度的改善。同时结合病理学研究结果，发现S1能一定程度改善黑质区神经元细胞的缺失现象，但是对其他主要脏器并无显著毒性。综上，活性化合物S1可能通过靶向激动sirt-3蛋白诱导线粒体自噬进而清除受损的线粒体，保护神经元细胞，改善神经元细胞的缺失现象，表现出潜在的抗PD活性。该研究首次对于五味子中的活性成分S1抗PD的作用机制进行了较为系统的研究，为抗PD活性成分以及新骨架结构药物的开发奠定了一定基础。其次，该研究从传统中药中寻找潜在的抗PD活性成分，为中药药用价值的开发提供重要参考。