The brains of Alzheimer patients have high accumulations of the material beta-amyloid, which appear in the form of plaques. The precursors of these plaques are believed to be the underlying cause of the nerve cell loss that leads to the disruptions in memory that characterize Alzheimer's disease.
The main aim of many Alzheimer therapies is therefore to inhibit the formation of beta-amyloid. Since beta-amyloid is cleaved from the so-called amyloid precursor protein (APP), scientists have focused on stopping the two enzymes that attack the precursor protein. These act like molecular scissors and cut out the beta-amyloid fragment. Blocking these scissors precludes the formation of beta-amyloid.
DZNE and LMU researchers have succeeded in identifying an enzyme known as alpha secretase, which cleaves the amyloid precursor protein (APP) without forming beta-amyloid. Up to this point three different candidates for this function had been under consideration, but the research team has now been able to show that the enzyme ADAM10 alone is responsible for the specific cleavage. Dr. Stefan Lichtenthaler and his team developed highly specific antibodies that can identify the different cleavage products of the precursor protein in the brain cells of mice and in human cell cultures. Using a special technique called RNA interference, the researchers managed to block each of the three genes that code for the three ADAM enzymes under suspicion. An analysis of the cleavage products revealed that the ADAM10 gene was the only one able to prevent the formation of beta-amyloids. They confirmed their results using mass spectrometry.
"In ADAM10 we have identified a target molecule that plays a central role in the development of the molecular processes in Alzheimer's disease. We know that ADAM10 is less active in Alzheimer patients," says Dr. Lichtenthaler. When ADAM10 is less active, the precursor protein is more likely to be cleaved in a way that promotes the formation of beta-amyloids.
"It is possible that less ADAM10 activity could increase susceptibility to Alzheimer's disease. If that is the case, stimulating ADAM10 could be an important mechanism for therapy. But our antibodies also open up new possibilities for diagnosing and preventing the disease," says Lichtenthaler. The antibodies could be used to measure ADAM10 activity in spinal fluid and, by extension, identify persons who may have an increased risk of developing Alzheimer's disease. A series of experiments to examine this possibility is already underway.
Peer-Hendrik Kuhn, Huanhuan Wang, Bastian Dislich, Alessio Colombo, Ulrike Zeitschel, Joachim W. Ellwart, Elisabeth Kremmer, Steffen Roßner, and Stefan F. Lichtenthaler, EMBO Journal, published online, 30 July 2010 doi:10.1038/emboj.2010.167
Contact:Dr. Stefan Lichtenthaler
Sonja Juelich-Abbas | EurekAlert!
Transport of molecular motors into cilia
28.03.2017 | Aarhus University
Asian dust providing key nutrients for California's giant sequoias
28.03.2017 | University of California - Riverside
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
28.03.2017 | Life Sciences
28.03.2017 | Information Technology
28.03.2017 | Physics and Astronomy