Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Tiny but toxic: MBL researchers discover a mechanism of neurodegeneration in Alzheimer's disease

31.03.2009
Tiny, toxic protein particles severely disrupt neurotransmission and inhibit delivery of key proteins in Alzheimer's disease, two separate studies by Marine Biological Laboratory (MBL) researchers have found.

The particles are minute clumps of amyloid beta, which has long been known to accumulate and form plaques in the brain of Alzheimer's patients.

"These small particles that haven't aggregated into plaques—these are increasingly being seen as the really toxic species of amyloid beta," says Scott Brady of University of Illinois College of Medicine, who has been an MBL investigator since 1982.

Brady and his colleagues found that these particles inhibit neurons from communicating with each other and with other target cells in the body.

"The disease symptoms for Alzheimer's are associated not with the death of the neurons – that is a very late event – but with the loss of functional connections. It's when the neuron is no longer talking to its targets that you start to get the memory deficits and dementia associated with the disease," Brady says.

The amyloid beta particles activate an enzyme, CK2, which in turn disrupts the "fast axonal transport" system inside the neuron, Brady found. This transport system has motor proteins that move various kinds of cargo (including neurotransmitters and the associated protein machinery for their release) from place to place in the neuron on microtubule tracks.

Brady's findings are complemented by a new study by Rudolfo Llinás of New York University School of Medicine. Brady and Llinás both conduct neuroscience research at the MBL using the giant nerve cell of the Woods Hole squid, Loligo paeleii, as a model system.

Llinás found that activation of CK2 blocks neurotransmission at the synapse – the point where the neuron connects to its target.

"Disruptions in the fast axonal transport system are probably key elements in the pathogenesis of Alzheimer's and other adult-onset neurodegenerative diseases, such as Parkinson's and ALS," says Brady. "It doesn't mean that is the only thing going on, or that it is the triggering feature of the disease. But we do know that changes in the fast axonal transport system are sufficient to cause the 'dying back' of neurons that is characteristic of these diseases."

The new findings suggest the possibility of designing a drug to inhibit CK2 activation in Alzheimer's patients. However, a prior study by Brady found that activation of another enzyme, GSK3, in Alzheimer's also disrupts the fast axonal transport system. It may therefore be necessary to inhibit both enzymes.

"There haven't yet been any therapies designed for Alzheimer's with the idea of protecting the fast axonal transport system," says Brady. "But if there were, they would have to inhibit the activation of both CK2 and GSK3. We can't think of it as a single thing going wrong. There are several things going wrong."

Citations:

Pigino, G., et al. (2009) Disruption of fast axonal transport is a pathogenic mechanism for intraneuronal amyloid beta. PNAS: doi 10.1073/pnas0901229106.

Moreno, H. et al. (2009) Synaptic transmission block by presynaptic injection of oligomeric amyloid beta. PNAS: doi 10.1073/pnas09000944106.

Background information:

Lapointe, N.E., et al. (2009) The amino terminus of tau inhibits kinesin-dependent axonal transport: Implications for filament toxicity. J. Neurosci. Res. 87(2): 440-451.

The MBL is a leading international, independent, nonprofit institution dedicated to discovery and to improving the human condition through creative research and education in the biological, biomedical and environmental sciences. Founded in 1888 as the Marine Biological Laboratory, the MBL is the oldest private marine laboratory in the Western Hemisphere.

Diana Kenney | EurekAlert!
Further information:
http://www.mbl.edu

More articles from Life Sciences:

nachricht Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

Im Focus: Newly proposed reference datasets improve weather satellite data quality

UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration

"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...

Im Focus: Repairing defects in fiber-reinforced plastics more efficiently

Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.

Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Multiregional brain on a chip

16.01.2017 | Power and Electrical Engineering

New technology enables 5-D imaging in live animals, humans

16.01.2017 | Information Technology

Researchers develop environmentally friendly soy air filter

16.01.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>