Primate-like amyloid-beta sequence but no cerebral amyloidosis in aged tree shrews.
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.
Pawlik
M
M
Department of Pharmacology, New York University Medical Center, NY 10016, USA.
Fuchs
E
E
Walker
L C
LC
Levy
E
E
D000375:Aging / Q000378:metabolism*; D000595:Amino Acid Sequence; D016229:Amyloid beta-Peptides / Q000737:chemistry / Q000378:metabolism*; D016564:Amyloid beta-Protein Precursor / Q000737:chemistry / Q000378:metabolism; D000686:Amyloidosis / Q000473:pathology*; D000818:Animals; D005260:Female; D006801:Humans; D008252:Macaca fascicularis; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D011323:Primates / Q000378:metabolism*; D012453:Saimiri; D014418:Tupaiidae / Q000378:metabolism*
D016229:Amyloid beta-Peptides; D016564:Amyloid beta-Protein Precursor