Navigation Links
New findings contradict dominant theory in Alzheimer's disease
Date:10/28/2011

For decades the amyloid hypothesis has dominated the research field in Alzheimer's disease. The theory describes how an increase in secreted beta-amyloid peptides leads to the formation of plaques, toxic clusters of damaged proteins between cells, which eventually result in neurodegeneration. Scientists at Lund University, Sweden, have now presented a study that turns this premise on its head.

The research group's data offers an opposite hypothesis, suggesting that it is in fact the neurons' inability to secrete beta-amyloid that is at the heart of pathogenesis in Alzheimer's disease.

The study, published in the October issue of the Journal of Neuroscience, shows an increase in unwanted intracellular beta-amyloid occurring early on in Alzheimer's disease. The accumulation of beta-amyloid inside the neuron is here shown to be caused by the loss of normal function to secrete beta-amyloid.

Contrary to the dominant theory, where aggregated extracellular beta-amyloid is considered the main culprit, the study instead demonstrates that reduced secretion of beta-amyloid signals the beginning of the disease.

The damage to the neuron, created by the aggregated toxic beta-amyloid inside the cell, is believed to be a prior step to the formation of plaques, the long-time hallmark biomarker of the disease.

Professor Gunnar Gouras, the senior researcher of the study, hopes that the surprising new findings can help push the research field in a new direction.

"The many investigators and pharmaceutical companies screening for compounds that reduce secreted beta-amyloid have it the wrong way around. The problem is rather the opposite, that it is not getting secreted. To find the root of the disease, we now need to focus on this critical intracellular pool of beta-amyloid.

"We are showing here that the increase of intracellular beta-amyloid is one of the earliest events occurring in Alzheimer's disease, before the formation of plaques. Our experiments clearly show a decreased secretion of beta-amyloid in our primary neuron disease model. This is probably because the cell's metabolism and secretion pathways are disrupted in some way, leading beta-amyloid to be accumulated inside the cell instead of being secreted naturally", says Davide Tampellini, first author of the study.

The theory of early accumulation of beta-amyloid inside the cell offers an alternate explanation for the formation of plaques. When excess amounts of beta-amyloid start to build up inside the cell, it is also stored in synapses.

When the synapses can no longer hold the increasing amounts of the toxic peptide the membrane breaks, releasing the waste into the extracellular space. The toxins released now create the seed for other amyloids to gather and start forming the plaques.


'/>"/>
Contact: Gunnar Gouras
Gunnar.Gouras@med.lu.se
46-462-220-309
Lund University
Source:Eurekalert

Related medicine news :

1. Python Findings Shed Light on Human Heart Health
2. Contrary to earlier findings, excess body fat in elderly decreases life expectancy
3. Findings could lead to a blood test for lung cancer
4. Mayo Clinic reports new findings on noninvasive test for pancreatic cancer
5. Most adults with autism go undiagnosed -- new findings
6. Researchers present new findings on cancer and gene therapy
7. UPCI, Pitt researchers present findings of cancer studies at AACR 102nd Annual Meeting
8. New findings on drug tolerance in TB suggest ideas for shorter cures
9. Latest findings of Dartmouth HIV/AIDS study could turn treatment on its head
10. Research provides new findings on drug delivery with nanoparticles
11. SMFM highlights significance of spina bifida research findings
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/27/2016)... ... June 27, 2016 , ... "FCPX editors can now reveal ... Final Cut Pro X," said Christina Austin - CEO of Pixel Film Studios. ... Cut Pro X users can now reveal the media of their split screens ...
(Date:6/27/2016)... NY (PRWEB) , ... June 27, 2016 , ... ... using cutting edge technology to revolutionize the emergency ambulance transport experience for the ... are aware of how Uber has disrupted the taxi industry through the use ...
(Date:6/26/2016)... ... June 26, 2016 , ... On June 10-11, 2016, A Forever Recovery, ... Festival and World’s Longest Breakfast Table in Battle Creek, MI, where the rehabilitation facility ... home to some of the world’s leading providers of cereal and other breakfast foods. ...
(Date:6/26/2016)... ... ... Brent Kasmer, a legally blind and certified personal trainer is helping to develop a weight ... app plans to fix the two major problems leading the fitness industry today:, ... program , They don’t eliminate all the reasons people quit their exercise program ...
(Date:6/25/2016)... (PRWEB) , ... June 25, 2016 , ... Austin residents ... the American College of Mohs Surgery and to Dr. Russell Peckham for medical and ... highly effective treatment for skin cancer. The selective fellowship in Mohs Micrographic Surgery completed ...
Breaking Medicine News(10 mins):
(Date:6/23/2016)... 2016 Research and Markets has announced ... report to their offering. ... a favourable commercial environment for MedImmune to enter. The US ... will serve to drive considerable growth for effective anti-influenza medications. ... cap sales considerably, but development is still in its infancy. ...
(Date:6/23/2016)... 23, 2016  Astellas today announced the establishment of Astellas Farma Colombia (AFC), a new affiliate with operations headquartered ... Latin America . ... ... ... ...
(Date:6/23/2016)... -- Research and Markets has announced the ... (United States, China, Japan, Brazil, United Kingdom, Germany, France, ... Surgical Procedure Volumes: ... provides surgical procedure volume data in a geographic context. ... analysis of growth drivers and inhibitors, including world population ...
Breaking Medicine Technology: