The ε4 allele of apolipoprotein E (apo E) is associated with an increased risk for developing Alzheimer's disease (AD). This may be due to interactions between apo E and the amyloid-β protein (Aβ). To assess the effects of human apo E isoforms on Aβ deposition in vivo, we bred apo E3 and apo E4 hemizygous (+/–) transgenic mice expressing apo E by astrocytes to mice homozygous (+/+) for a mutant amyloid precursor protein (APPV717F) transgene that develop age-dependent AD neuropathology. All mice were on a mouse apo E null (–/–) background. By nine months of age, APPV717F+/–, apo E–/– mice had developed Aβ deposition, and, as reported previously, the quantity of Aβ deposits was significantly less than that seen in APPV717F+/– mice expressing mouse apo E. In contrast to effects of mouse apo E, similar levels of human apo E3 and apo E4 markedly suppressed early Aβ deposition at nine months of age in APPV717F+/– transgenic mice, even when compared with mice lacking apo E. These findings suggest that human apo E isoforms decrease Aβ aggregation or increase Aβ clearance relative to an environment in which mouse apo E or no apo E is present. The results may have important implications for understanding mechanisms underlying the link between apo E and AD.
David M. Holtzman, Kelly R. Bales, Shan Wu, Priyanka Bhat, Maia Parsadanian, Anne M. Fagan, Louis K. Chang, Yuling Sun, Steven M. Paul
Usage data is cumulative from October 2020 through October 2021.
Usage information is collected from two different sources: this site (JCI) and Pubmed Central (PMC). JCI information (compiled daily) shows human readership based on methods we employ to screen out robotic usage. PMC information (aggregated monthly) is also similarly screened of robotic usage.
Various methods are used to distinguish robotic usage. For example, Google automatically scans articles to add to its search index and identifies itself as robotic; other services might not clearly identify themselves as robotic, or they are new or unknown as robotic. Because this activity can be misinterpreted as human readership, data may be re-processed periodically to reflect an improved understanding of robotic activity. Because of these factors, readers should consider usage information illustrative but subject to change.