从Aβ的构象、聚集和降解核心病理环节探讨清肝解郁法防治阿尔茨海默病的分子机制

Alzheimer's disease (AD) is a typical neurodegenerative protein conformation disease, which is initially triggered by Aβ misfolding, aggregation and deposition. Beyond the traditional palliative treatment, the new strategy targeting Aβ misfolding, aggregation and deposition may have great potential to be radical treatment for AD. Because of the similar pathophysiological mechanisms between “Gan Yu Qi Zhi Tang Jie” and “Aβ misfolding, aggregation and deposition” in the pathogenesis of AD, we have proposed a new hypothesis that Gan Yu Qi Zhi Tang Jie is correlated with Aβ misfolding, aggregation and deposition. Our previous studies have showed that Qinggan Jieyu prescription (mainly consisting of uncaria, berberine, and turmeric), is effective in therapeutic intervention of AD major pathological products. However, the molecular mechanism remains to be elucidated. To elucidate its molecular mechanism and to verify the proposed hypothesis, we are planning to investigate 1) the effect of active ingredient of Qinggan Jieyu prescription on Aβ misfolding and aggregation in vitro; 2) whether the Qinggan Jieyu prescription could maintain the cellular metal homeostasis and inhibit Aβ aggregation in vivo; 3) whether it could regulate the autophagy-lysosome pathway to mediated clearance of Aβ aggregates in vivo. If yes and so how? Our study will provide scientific basis for the TCM clinical intervention of AD and could shed light on exploring and designing novel effective anti AD drugs, therefore it is of great value and significance.

阿尔茨海默病（AD）是一种严重且典型的由Aβ的构象改变、聚合沉积和降解清除不利始发而导致的神经变性构象病。不同于传统的姑息疗法, 靶向Aβ的构象、聚合和降解的新干预策略可能具有根治性的意义。基于对AD患者肝郁气滞痰结与Aβ聚合沉积的内在机制类同的观察，我们提出了AD“肝郁气滞痰结-Aβ聚合沉积关联”病理新假说。前期研究发现清肝解郁法组方（由钩藤、黄连、郁金组成）对AD核心病理产物的干预效果显著，但其分子机制尚有待揭示。为阐述其分子机制及验证上述假说，课题首次系统探讨1 该组方活性分子体外对Aβ构象及聚合的影响；2 组方药对维持细胞金属稳态平衡及抑制Aβ聚集的作用；3 对激活细胞自噬溶酶体降解途径以促进对Aβ的降解等AD核心病理环节的调控作用。旨在阐明其防治AD的分子机制和药效标靶, 为其临床应用提供科学实验依据, 并为创新发展中医药防治AD开辟新思路。因而具有重要的学术价值和研究意义。

阿尔茨海默病 (AD)是由Aβ聚合沉积和降解清除不利始发而导致威胁全球老年人的健康的重大疾病。基于对AD患者肝郁气滞痰结与Aβ聚合沉积的内在机制类同的观察，我们提出了AD“肝郁气滞痰结-Aβ聚合沉积关联”病理新假说。本项目从AD 的中医病机出发，以清肝解郁方（主要由黄连、钩藤、郁金中药组成）对Aβ联合Al诱导的AD细胞和动物模型进行干预研究。干预结果证明组方改善了AD模型鼠的认知功能，研究发现Al诱导Aβ的聚合，然组方中的活性成分姜黄素呈剂量依赖性地抑制Aβ寡聚体形成，提示清肝解郁（QGJY）中的药活性分子可能通过阻断金属稳态失衡衡引起的Aβ的聚合，从而缓解AD。利用基因芯片比较了干预组与模型组的大鼠海马区差异表达基因，结果显示金属稳态基因组如Manla，Rnf113a2，Cdh22，Ephx2等有显著差异富集。进一步说明了清肝解郁对AD的维持金属稳态中发挥着重要作用。对组方的网络药理学研究发现其通过激活Akt信号通路对Aβ诱导的神经细胞凋亡起到预防作用，抑制Aβ诱导的神经细胞毒性。通过进一步的细胞实验的验证了组方中芍药苷的神经保护作用与LC3-II蛋白的上调密切相关，而LC3-II蛋白在自噬液泡的形成中紧密关联。此外本项目还构建了AD中医临床指南的心肝证、痰阻证、血瘀证、肾海不足证、脾肾两虚证对应的5个中药方剂靶点和AD相关靶点的PPI网络。比较了中医临床上5个中药方剂的共同靶点和特异性靶点对AD发挥治疗作用，进一步验证了“肝郁气滞痰结-Aβ聚合沉积关联”病理新假说。本项目的开展为进一步研究中药复方关于AD的致病机理以及开发不同证型中药复方生物的生物实质及作为AD患者的替代治疗方法提供了新的途径。