Division of Molecular Biotechnology, Department of Physics, Chemistry and Biology, Linköping University, Sweden.
Biochem Biophys Res Commun. 2012 Apr 20;420(4):895-900. doi: 10.1016/j.bbrc.2012.03.097. Epub 2012 Mar 27.
The formation of amyloid-β peptide (Aβ) aggregates at an early stage during the self-assembly process is an important factor in the development of Alzheimer's disease. The toxic effect is believed to be exerted by prefibrillar species of Aβ. It is therefore important to identify which prefibrillar species are toxic and characterize their distinct properties. In the present study, we investigated the in vitro aggregation behavior of Aβ-derived peptides possessing different levels of neurotoxic activity, using fluorescence spectroscopy in combination with transmission electron microscopy. The toxicity of various Aβ aggregates was assessed by using cultures of human neuroblastoma cells. Through combined use of the fluorescence probe 8-anilino-1-napthalenesulfonate (ANS) and the novel luminescent probe pentamer formyl thiophene acetic acid (p-FTAA), we were able to identify those Aβ peptide-derived prefibrillar species which exhibited cellular toxicity. In particular, species, which formed early during the aggregation process and showed strong p-FTAA and ANS fluorescence, were the species that possessed toxic activities. Moreover, by manipulating the aggregation conditions, it was possible to change the capacity of the Aβ peptide to form nontoxic versus toxic species.
淀粉样β肽 (Aβ) 聚集物在自组装过程的早期形成是阿尔茨海默病发展的一个重要因素。有毒作用被认为是由 Aβ 的原纤维前体发挥的。因此，确定哪种原纤维前体具有毒性并描述其独特的性质非常重要。在本研究中，我们使用荧光光谱结合透射电子显微镜研究了具有不同神经毒性水平的 Aβ 衍生肽的体外聚集行为。通过用人神经母细胞瘤细胞培养物评估各种 Aβ 聚集物的毒性。通过联合使用荧光探针 8-苯胺-1-萘磺酸 (ANS) 和新型发光探针五聚甲酰基噻吩乙酸 (p-FTAA)，我们能够识别出表现出细胞毒性的 Aβ 肽衍生的原纤维前体。特别是在聚集过程早期形成且具有强 p-FTAA 和 ANS 荧光的物质，是具有毒性的物质。此外，通过操纵聚集条件，可以改变 Aβ 肽形成无毒与有毒物质的能力。
