Porzoor Afsaneh, Alford Benjamin, Hügel Helmut M, Grando Danilla, Caine Joanne, Macreadie Ian
School of Applied Sciences, RMIT University, Bundoora, Victoria 3083, Australia.
School of Applied Sciences, RMIT University, Melbourne, Victoria 3000, Australia.
Biomolecules. 2015 Apr 17;5(2):505-27. doi: 10.3390/biom5020505.
A family of 21 polyphenolic compounds consisting of those found naturally in danshen and their analogues were synthesized and subsequently screened for their anti-amyloidogenic activity against the amyloid beta peptide (Aβ42) of Alzheimer's disease. After 24 h incubation with Aβ42, five compounds reduced thioflavin T (ThT) fluorescence, indicative of their anti-amyloidogenic propensity (p < 0.001). TEM and immunoblotting analysis also showed that selected compounds were capable of hindering fibril formation even after prolonged incubations. These compounds were also capable of rescuing the yeast cells from toxic changes induced by the chemically synthesized Aβ42. In a second assay, a Saccharomyces cerevisiae AHP1 deletant strain transformed with GFP fused to Aβ42 was treated with these compounds and analyzed by flow cytometry. There was a significant reduction in the green fluorescence intensity associated with 14 compounds. We interpret this result to mean that the compounds had an anti-amyloid-aggregation propensity in the yeast and GFP-Aβ42 was removed by proteolysis. The position and not the number of hydroxyl groups on the aromatic ring was found to be the most important determinant for the anti-amyloidogenic properties.
合成了一个由丹参中天然存在的21种多酚类化合物及其类似物组成的家族，随后对其针对阿尔茨海默病淀粉样β肽（Aβ42）的抗淀粉样蛋白生成活性进行了筛选。与Aβ42孵育24小时后，有五种化合物降低了硫黄素T（ThT）荧光，表明它们具有抗淀粉样蛋白生成倾向（p < 0.001）。透射电子显微镜（TEM）和免疫印迹分析还表明，即使经过长时间孵育，所选化合物也能够阻碍纤维形成。这些化合物还能够使酵母细胞从化学合成的Aβ42诱导的毒性变化中恢复。在第二项试验中，用这些化合物处理用与Aβ42融合的绿色荧光蛋白（GFP）转化的酿酒酵母AHP1缺失菌株，并通过流式细胞术进行分析。与14种化合物相关的绿色荧光强度显著降低。我们将这一结果解释为这些化合物在酵母中具有抗淀粉样蛋白聚集倾向，并且GFP-Aβ42通过蛋白水解被去除。发现芳环上羟基的位置而非数量是抗淀粉样蛋白生成特性的最重要决定因素。
