Robb Elysia, Perez Keyla, Hung Lin W, Masters Colin L, Barnham Kevin J, Cherny Robert A, Bush Ashley I, Adlard Paul A, Finkelstein David I
The Florey Institute of Neuroscience and Mental Health, Division of Mental Health, Parkville, VIC, Australia.
The Florey Institute of Neuroscience and Mental Health, Division of Mental Health, Parkville, VIC, Australia The Department of Pharmacology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, VIC, Australia.
J Alzheimers Dis. 2015;44(1):69-78. doi: 10.3233/JAD-132024.
Oligomeric forms of amyloid-β (Aβ) are thought to be responsible for the pathogenesis of Alzheimer's disease. While many oligomers of Aβ are thought to be naturally occurring in the brain of humans and/or transgenic animals, it is well known that Aβ oligomers are also readily produced in vitro in the laboratory. In recent studies, we discovered that synthetic monomeric Aβ (4.7 kDa) could be transformed by microdialysis to higher molecular weight species (approximately 56 kDa, by western blot). Surface-enhanced laser desorption/ionization mass spectrometry and electron microscopy further identified these species' as potential Aβ oligomers. The production of similar species could also be produced by centrifugal filtration and this formation was concentration and pore-size dependent. These higher order species of Aβ were resistant to dissolution in NaOH, HFIP, formic acid, urea, and guanidine. We postulate that we have identified a novel way of producing a high order species of oligomeric Aβ and we provide evidence to suggest that Aβ oligomers can quite easily be a product of normal laboratory practices. These data suggest that the experimental detection of higher order oligomers in tissues derived from Alzheimer's disease brains or from animal models of disease could, in some cases, be a product the method of analysis.
淀粉样β蛋白（Aβ）的寡聚体形式被认为是阿尔茨海默病发病机制的原因。虽然许多Aβ寡聚体被认为天然存在于人类和/或转基因动物的大脑中，但众所周知，Aβ寡聚体在实验室中也很容易在体外产生。在最近的研究中，我们发现合成的单体Aβ（4.7 kDa）可以通过微透析转化为更高分子量的物种（通过蛋白质印迹法测定约为56 kDa）。表面增强激光解吸/电离质谱和电子显微镜进一步确定这些物种为潜在的Aβ寡聚体。通过离心过滤也可以产生类似的物种，并且这种形成取决于浓度和孔径。这些更高阶的Aβ物种在氢氧化钠、六氟异丙醇、甲酸、尿素和胍中难以溶解。我们推测我们已经确定了一种产生高阶寡聚体Aβ物种的新方法，并且我们提供证据表明Aβ寡聚体很容易成为正常实验室操作的产物。这些数据表明，在某些情况下，对来自阿尔茨海默病大脑或疾病动物模型的组织中高阶寡聚体的实验检测可能是分析方法的产物。
