Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Study links Alzheimer’s disease to abnormal cell division


A new study in mice suggests that Alzheimer’s disease (AD) may be triggered when adult neurons try to divide. The finding helps researchers understand what goes wrong in the disease and may lead to new ways of treating it. The study was funded in part by the National Institute of Neurological Disorders and Stroke (NINDS), part of the National Institutes of Health, and appears in the January 18, 2006 issue of The Journal of Neuroscience.*

For unknown reasons, nerve cells (neurons) affected by AD and many other neurodegenerative diseases often start to divide before they die. The new study shows that, in animal models of AD, this abnormal cell division starts long before amyloid plaques or other markers of the disease appear. Cell division occurs through a process called the cell cycle. "If you could stop cell cycling, you might be able to stop neurons from dying prematurely. This could be a fresh approach to therapy for Alzheimer’s and other diseases, including stroke, amyotrophic lateral sclerosis [also known as Lou Gehrig’s disease], and HIV dementia," says Karl Herrup, Ph.D., of Case Western Reserve University in Cleveland, who led the study.

The researchers compared the brains of three different mouse models of AD to brains from normal mice, looking specifically for markers of cell cycling. They found that, in the AD mouse models, cell cycle-related proteins appeared in neurons 6 months before the first amyloid plaques or disease-related immune reactions developed in the brain. Many of the neurons also had increased numbers of chromosomes, which is typical of cells that have begun to divide. These changes were not seen in normal mice. The regions of the brain most affected by the neuronal cell cycling were the cortex and the hippocampus – the same regions most affected in AD. The cortex is important for thought and reasoning, while the hippocampus plays a key role in learning and memory. Some parts of the brainstem also showed evidence of cell cycling.

While the cell cycling appeared to be necessary for neurons to die, it was not an immediate cause of cell death in the mouse models of AD. Instead, the affected neurons appeared to live for many months in a near-functional state, with the mice showing only mild behavioral changes during that time. This suggests that another type of cellular problem, still unidentified, must damage the neurons in order for them to die.

The findings shed new light on the theory that the accumulation of amyloid beta in the brain causes the neuron death in AD. Because the abnormal cell cycling begins months before the formation of amyloid plaques, it is unlikely that the plaques themselves trigger the disease process. However, tiny clumps made up of several amyloid beta molecules (called micro-molecular aggregates) form before the plaques and may trigger the disease. Since the three mouse models tested in this study all had mutations in the gene that codes for amyloid precursor protein, the similarity between affected brain regions in these mice and in people with AD also supports the amyloid hypothesis.

While previous studies have linked AD to abnormal cell cycling, this is the first study to examine the link using standard mouse models of AD. The results indicate that the mice, which do not develop neurofibrillary tangles or the severe behavioral symptoms of AD, are accurate models of the early cellular processes that lead to the disease. "The cell cycle markers mimic the human situation rather well," says Dr. Herrup. "This opens a range of new experimental possibilities using the cell cycle events as indicators of neuronal distress."

Dr. Herrup and his colleagues are now trying to determine if feeding the mouse models the drug ibuprofen can stop abnormal cell cycling in neurons and halt neurodegeneration. Ibuprofen is an anti-inflammatory drug that reduces production of amyloid beta, and some studies have suggested that it may reduce the risk of AD. The researchers are also planning additional studies to identify why neurons start to divide when they are diseased and why entering the cell cycle appears to trigger cell death.

Natalie Frazin | EurekAlert!
Further information:

More articles from Studies and Analyses:

nachricht Diagnoses: When Are Several Opinions Better Than One?
19.07.2016 | Max-Planck-Institut für Bildungsforschung

nachricht High in calories and low in nutrients when adolescents share pictures of food online
07.04.2016 | University of Gothenburg

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

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

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

First-time reconstruction of infectious bat influenza viruses

25.10.2016 | Life Sciences

Novel method to benchmark and improve the performance of protein measumeasurement techniques

25.10.2016 | Life Sciences

Amazon rain helps make more rain

25.10.2016 | Life Sciences

More VideoLinks >>>