The Center for Terahertz Waves, School of Precision Instrument and Opto-Electronics Engineering, Tianjin University, Tianjin 300072, China.
State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin 300072, China.
Int J Mol Sci. 2023 Mar 6;24(5):5039. doi: 10.3390/ijms24055039.
The pathophysiology of Alzheimer's disease is thought to be directly linked to the abnormal aggregation of β-amyloid (Aβ) in the nervous system as a common neurodegenerative disease. Consequently, researchers in many areas are actively looking for factors that affect Aβ aggregation. Numerous investigations have demonstrated that, in addition to chemical induction of Aβ aggregation, electromagnetic radiation may also affect Aβ aggregation. Terahertz waves are an emerging form of non-ionizing radiation that has the potential to affect the secondary bonding networks of biological systems, which in turn could affect the course of biochemical reactions by altering the conformation of biological macromolecules. As the primary radiation target in this investigation, the in vitro modeled Aβ42 aggregation system was examined using fluorescence spectrophotometry, supplemented by cellular simulations and transmission electron microscopy, to see how it responded to 3.1 THz radiation in various aggregation phases. The results demonstrated that in the nucleation aggregation stage, 3.1 THz electromagnetic waves promote Aβ42 monomer aggregation and that this promoting effect gradually diminishes with the exacerbation of the degree of aggregation. However, by the stage of oligomer aggregation into the original fiber, 3.1 THz electromagnetic waves exhibited an inhibitory effect. This leads us to the conclusion that terahertz radiation has an impact on the stability of the Aβ42 secondary structure, which in turn affects how Aβ42 molecules are recognized during the aggregation process and causes a seemingly aberrant biochemical response. Molecular dynamics simulation was employed to support the theory based on the aforementioned experimental observations and inferences.
阿尔茨海默病的病理生理学被认为与β-淀粉样蛋白（Aβ）在神经系统中的异常聚集直接相关，是一种常见的神经退行性疾病。因此，许多领域的研究人员都在积极寻找影响 Aβ聚集的因素。大量研究表明，除了化学诱导 Aβ聚集外，电磁辐射也可能影响 Aβ聚集。太赫兹波是一种新兴的非电离辐射形式，有可能影响生物系统的次级键网络，从而通过改变生物大分子的构象来影响生化反应的进程。在这项研究中，作为主要辐射目标，使用荧光分光光度法检查了体外模拟的 Aβ42 聚集系统，并辅以细胞模拟和透射电子显微镜，以观察它在不同聚集阶段如何对 3.1 THz 辐射作出反应。结果表明，在成核聚集阶段，3.1 THz 电磁波促进 Aβ42 单体聚集，并且这种促进作用随着聚集程度的加剧而逐渐减弱。然而，在寡聚体聚集到原始纤维的阶段，3.1 THz 电磁波表现出抑制作用。这使我们得出结论，太赫兹辐射会影响 Aβ42 二级结构的稳定性，进而影响 Aβ42 分子在聚集过程中的识别方式，并导致看似异常的生化反应。分子动力学模拟基于上述实验观察和推断来支持这一理论。
