Beeg Marten, Rocutto Beatrice, Battocchio Elisabetta, Dacomo Letizia, Corbelli Alessandro, Fiordaliso Fabio, Balducci Claudia, Gobbi Marco
Laboratory of Pharmacodynamics and Pharmacokinetics, Istituto di Ricerche Farmacologiche Mario Negri IRCCS Via Mario Negri 2, 20156 Milan, Italy.
Laboratory of Biology of Neurodegenerative Disorders, Istituto di Ricerche Farmacologiche Mario Negri IRCCS Via Mario Negri 2, 20156 Milan, Italy.
Int J Mol Sci. 2024 Dec 4;25(23):13020. doi: 10.3390/ijms252313020.
Amyloid-β1-42 (Aβ42) forms highly stable and insoluble fibrillar structures, representing the principal components of the amyloid plaques present in the brain of Alzheimer's disease (AD) patients. The involvement of Aβ42 in AD-associated neurodegeneration has also been demonstrated, in particular for smaller and soluble aggregates (oligomers). Based on these findings and on genetic evidence, Aβ42 aggregates are considered key players in the pathogenesis of AD and targets for novel therapies. Different approaches are currently used to detect the various aggregation states of Aβ peptide, including spectrophotometric methods, imaging techniques, and immunoassays, but all of these have specific limitations. To overcome them, we have recently exploited the peculiar properties of surface plasmon resonance (SPR) to develop an immunoassay capable of selectively detecting monomers and oligomers, discriminating them also from bigger fibrils in a mixture of different aggregated species, without any manipulation of the solution. In the present study, we extended these previous studies, showing that the SPR-based immunoassay makes it possible to unveil the fibril fragmentation induced mechanically, a result difficult to be conveniently and reliably assessed with other approaches. Moreover, we show that SPR-recognized fibril fragments are more toxic than the larger fibrillar structures, suggesting the relevance of the proposed SPR-based immunoassay.
淀粉样β蛋白1-42（Aβ42）形成高度稳定且不溶性的纤维状结构，是阿尔茨海默病（AD）患者大脑中淀粉样斑块的主要成分。Aβ42参与AD相关神经退行性变也已得到证实，尤其是对于较小的可溶性聚集体（寡聚体）。基于这些发现和遗传学证据，Aβ42聚集体被认为是AD发病机制中的关键因素以及新型疗法的靶点。目前使用不同方法来检测Aβ肽的各种聚集状态，包括分光光度法、成像技术和免疫测定法，但所有这些方法都有特定局限性。为克服这些局限性，我们最近利用表面等离子体共振（SPR）的独特性质开发了一种免疫测定法，该方法能够选择性检测单体和寡聚体，还能在不同聚集物种的混合物中区分它们与更大的纤维，且无需对溶液进行任何处理。在本研究中，我们扩展了之前的研究，表明基于SPR的免疫测定法能够揭示机械诱导的纤维断裂，而这一结果很难用其他方法方便且可靠地评估。此外，我们表明SPR识别的纤维片段比更大的纤维状结构毒性更强，这表明所提出的基于SPR的免疫测定法具有重要意义。
