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:6/25/2016)... ... June 25, 2016 , ... ... non-athletes recover from injury. Recently, he has implemented orthobiologic procedures as a method ... —Johnson is one of the first doctors to perform the treatment. Orthobiologics are ...
(Date:6/24/2016)... ... June 24, 2016 , ... Those who have experienced ... feelings, many turn to unhealthy avenues, such as drug or alcohol abuse, as a ... has released tools for healthy coping following a traumatic event. , Trauma sufferers tend ...
(Date:6/24/2016)... ... ... Global law firm Greenberg Traurig, P.A. announced that 20 Florida attorneys are ... for this recognition are considered among the top 2 percent of lawyers practicing within ... of this year’s Legal Elite Hall of Fame: Miami Shareholders Mark D. Bloom, ...
(Date:6/24/2016)... TX (PRWEB) , ... June 24, 2016 , ... People ... part in Genome magazine’s Code Talker Award, an essay contest in which patients and ... an award to be presented at the 2016 National Society of Genetic Counselors (NSGC) ...
(Date:6/24/2016)... ... June 24, 2016 , ... ... the Frederick area economy by obtaining investment capital for emerging technology companies. ... years that have already resulted in more than a million dollars of capital ...
Breaking Medicine News(10 mins):
(Date:6/24/2016)... SOUTH SAN FRANCISCO, Calif. , June 24, ... GBT ), a biopharmaceutical company developing novel ... with significant unmet needs, today announced the closing ... 6,400,000 shares of common stock, at the public ... the shares in the offering were offered by ...
(Date:6/24/2016)... , June 24, 2016 Dehaier Medical Systems ... "Company"), which develops, markets and sells medical devices and ... , signed a strategic cooperation agreement with Hongyuan Supply ... Supply Chain") on June 20, 2016, to develop Dehaier,s ... strategic cooperation agreement, Dehaier will leverage Hongyuan Supply Chain,s ...
(Date:6/24/2016)... , June 24, 2016 VolitionRx ... of Dr. Edward Futcher to the ... effective June 23, 2016.Dr. Futcher was also appointed ... Governance Committees.  As a non-executive member of the ... and strategic counsel to VolitionRx in connection with ...
Breaking Medicine Technology: