Pawlik M, Fuchs E, Walker L C, Levy E
Department of Pharmacology, New York University Medical Center, NY 10016, USA.
Neurobiol Aging. 1999 Jan-Feb;20(1):47-51. doi: 10.1016/s0197-4580(99)00017-2.
A central pathological feature of Alzheimer's disease is the profuse deposition of amyloid-beta protein (Abeta) in the brain parenchyma and vessel walls. Abeta also forms deposits in the brains of a variety of mammals, including all aged non-human primates studied to date. The sequence of Abeta in these animals is identical to that in humans. No Abeta deposits have been found in the brains of wild-type rats and mice, suggesting that the three amino acid differences between their Abeta and that of amyloid-bearing mammals impedes the fibrillogenicity of Abeta. Analysis of the primary sequence of the beta-amyloid precursor protein in tree shrews revealed a 98% similarity and 97% identity with the human protein. Furthermore, the predicted amino acid sequence of Abeta in tree shrews is identical to that in humans. However, immunohistochemical analysis failed to reveal beta-amyloid deposits in the neural parenchyma or vasculature of eight aged (7-8 years) tree shrews (Tupaia belangeri). The lack of correlation between the Abeta sequence and amyloid formation suggests that other factors contribute to cerebral amyloid deposition in aged animals.
阿尔茨海默病的一个核心病理特征是β淀粉样蛋白（Aβ）在脑实质和血管壁中大量沉积。Aβ也在多种哺乳动物的大脑中形成沉积物，包括迄今为止研究过的所有老年非人灵长类动物。这些动物体内Aβ的序列与人类的相同。在野生型大鼠和小鼠的大脑中未发现Aβ沉积物，这表明它们的Aβ与携带淀粉样蛋白的哺乳动物的Aβ之间的三个氨基酸差异阻碍了Aβ的纤维形成。对树鼩β淀粉样前体蛋白的一级序列分析显示，其与人类蛋白的相似性为98%，同一性为97%。此外，树鼩中Aβ的预测氨基酸序列与人类的相同。然而，免疫组织化学分析未能在8只老年（7 - 8岁）树鼩（笔尾树鼩）的神经实质或脉管系统中发现β淀粉样沉积物。Aβ序列与淀粉样蛋白形成之间缺乏相关性表明，其他因素导致了老年动物大脑中的淀粉样蛋白沉积。
