| 27-Oct-2004 - Research Uncovers
Role Of Apolipoprotein E In Alzheimer’s Disease
Inhibiting Apolipoprotein E Possible
Means of Therapeutic Intervention for Alzheimer’s Disease
(Tampa, FL) - Johnnie B. Byrd, Sr. Alzheimer’s Center
& Research Institute in Tampa, in cooperation with The University
of South Florida, announces significant advancements in the means of therapeutic
intervention to treat Alzheimer’s Disease (AD).
Led by Huntington Potter, Ph.D. Professor of Biochemistry
and Molecular Biology and Pfeiffer Endowed Chair in Alzheimer's Research
at USF, and CEO of the Byrd Institute, the researchers have uncovered
where the protein Apolipoprotein E exerts its ill affects on Alzheimer's
disease.
Research shows that individuals possessing the E4 variant
of the protein, Apolipoprotein E (ApoE), is the greatest risk factor for
developing Alzheimer’s Disease (AD), besides age. ApoE comes in
three different variations E2, E3, and E4, and the progression of AD can
be accelerated by over a decade if one has two copies of ApoE4 (humans
have two copies of every gene, and can therefore have any combination
of the E2, E3, and E4 ApoE variations).
In the first paper*, research by the Byrd Alzheimer’s
Center has shown that ApoE impacts amyloid plaque deposition, the major
pathological hallmark of Alzheimer’s disease [amyloid plaques are
deposits of protein found in the brain of AD patients, and are made primarily
of the Amyloid-beta protein (Aß). Specifically, it was found that
apoE is responsible for converting Aß into filamentous amyloid such
that there is over 3200 times more amyloid in mice with ApoE than those
without the gene. Diffuse brain deposits of Aß can occur in the
elderly in the absence of AD, and is thought to be a normal aspect of
aging, while filamentous amyloid is a pathogenic product of Alzheimer’s
disease.
In the second paper**, further studies by the Institute
researchers indicate that the process of turning Aß from the diffuse
deposition pathway into filamentous amyloid is necessary for inducing
cognitive decline. Through spatial memory testing, mice with AD showed
cognitive deficits only when the ApoE gene is present.
The implication of these studies is that the amyloid-promoting
activity of apoE is essential for the development of both Alzheimer pathology
and cognitive decline. Thus, preventing ApoE from acting upon Aß
may prove to be an effective means of therapeutic intervention.
Dr. Huntington Potter’s research findings will be
published in the October edition of the Journal of Alzheimer’s Disease,
Volume 6, p. 509–514 and the October edition of Neurobiology of
Aging, Volume 25, p. 1153-1167.
* First Paper: Costa, David A., Nilsson, Lars N. G., Bales,
Kelly R., Paul, Steven M., Potter, Huntington. Apolipoprotein E is required
for the formation of filamentous amyloid but not for amorphous Aß
deposition, in an Aß PP/PS double transgenic mouse model of Alzheimer’s
disease. Journal of Alzheimer’s Disease 6 (2004) 509–514
**Second Paper: Nilsson, Lars N. G., Arendash, Gary W.,
Leighty, Ralph E., Costa, David A., Garcia, Marcos F., Cracciola, Jennifer
R., Rojiani, Amyn, Wu, Xin, Bales, Kelly R., Paul, Steven M., Potter,
Huntington. Cognitive impairment in PDAPP mice depends on ApoE and ACT-catalyzed
amyloid formation. Neurobiology of Aging 25 (2004) 1153–1167
NOTES TO EDITORS:
The co-first authors of the papers are David Costa, Lars Nilsson and Gary
Arendash, who contributed equally to the work.
Full Release - http://www.eurekalert.org/pub_releases/2004-10/uosf-rur102904.php
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