Scientists have been trying to figure out how the apolipoprotein E4 (APOE4) allele increases a person’s risk for late-onset Alzheimer’s disease (AD) since the seminal discovery in 1993. Recent data suggest that APOE4 also increases the risk of dementia caused by vascular factors.
Now, a team of scientists at Weill Cornell Medicine contend they have the answer, at least in animals: the human variant reduces the number of small cerebral blood vessels, and the blood vessels that remain are not as responsive to the demands on the brain. The result is that the brains of the animals are more vulnerable to damage.
In the current study, the scientists reported that the APOE4 transgenic animals subjected to cerebral hypoperfusion performed worse on behavioral tests compared to animals with two copies of the human version of APOE3.
It is the first time that scientists have mounted evidence for the link between APOE4 and the white matter lesions common in vascular dementia, as well as Alzheimer’s disease. The study was published in the September 19 issue of Nature Communications.
Source: Neurology Today | October 18, 2018