Featured Research

from universities, journals, and other organizations

Researchers Link Failed Cell Division, Alzheimer's Disease

Date:
April 19, 2001
Source:
Case Western Reserve University
Summary:
Researchers have uncovered a key piece of missing evidence in the proof that nerve cell death in Alzheimer's disease is caused by a failed attempt at cell division. They have found a significant number of brain cells in Alzheimer's patients with extra copies of chromosomes, showing attempts at cell division in cells that are not supposed to divide.

CLEVELAND -- Researchers have uncovered a key piece of missing evidence in the proof that nerve cell death in Alzheimer's disease is caused by a failed attempt at cell division. They have found a significant number of brain cells in Alzheimer's patients with extra copies of chromosomes, showing attempts at cell division in cells that are not supposed to divide. This effort to divide is the likely cause of the nerve degeneration and dementia in Alzheimer's disease, say the researchers.

"It's almost as if Alzheimer's disease were a novel form of cancer," says Karl Herrup, senior author of the findings published in a paper by researchers from Case Western Reserve University's School of Medicine and University Hospitals of Cleveland in the April 15 issue of the Journal of Neuroscience. Cancer is characterized by uncontrolled cell division. In this study, scientists found uncontrolled cell division, arrested in the midst of the process, is the likely cause of the nerve cell destruction.

"We've been able to show that the duplication of the DNA has occurred in neurons in the Alzheimer's disease brain. By looking at four locations in the genome, we can be pretty confident that the DNA duplicated completely, not just in a few spots," says Herrup, a professor of neurosciences.

According to Herrup, memory loss in Alzheimer's disease is always associated with the accumulation of strange deposits in the brain known as plaques and tangles. Most investigators agree that these deposits are central to the disease, but are not in and of themselves the cause of memory loss. The clinical symptoms are more closely tied to the nerve cell death, but the links between plaques and death were unclear. "The simplest view is that plaques are directly toxic to neurons. The cell division hypothesis puts a different spin on this idea," he says.

While previous studies from this team and others have provided indirect evidence of cell division in Alzheimer's disease through the detection of proteins usually involved in cell division, this paper supplies direct evidence of cell division. The scientists found a significant number of cells in brain tissue from Alzheimer's patients which had four copies of chromosomes in them, whereas normal cells have two, and only two, copies.

Cells normally make extra copies of chromosomes when they divide, but the extra copies are passed on equally to their offspring cells. The brain cells of Alzheimer's patients apparently enter the cell division process, make the extra chromosomes, but never create new cells to pass on the extra copies.

Says Herrup, "We know now almost precisely where the cell is stopped in the division process and we know something even more important: Because it's stopped there and not able to proceed, its nucleus is basically out of balance with its surrounding cell structures. Normally, the cell machinery expects two copies of a given gene, but in Alzheimer's disease there are four because the DNA is replicated. Since the cell hasn't divided it is sitting with twice as much DNA as it should have. We speculate that is the root cause of the nerve cell death."

The researchers do not know what triggers the cells to begin a cycle for which they are not programmed, but a theory they put forth with other CWRU/UHC colleagues hypothesizes that the plaques which are a hallmark of Alzheimer's disease brain cells trigger an inflammatory response in the brain, and that this response brings with it proteins that trigger cell division.

Herrup said the findings of the paper open new doors to develop therapeutics that could prevent signals for the inflammatory response from reaching the cells or to prevent the cells from responding to the signals to divide.

The other authors are Yan Yang and David Geldmacher, both also with CWRU and UHC. Herrup is the director of the University Alzheimer Center at CWRU and UHC.


Story Source:

The above story is based on materials provided by Case Western Reserve University. Note: Materials may be edited for content and length.


Cite This Page:

Case Western Reserve University. "Researchers Link Failed Cell Division, Alzheimer's Disease." ScienceDaily. ScienceDaily, 19 April 2001. <www.sciencedaily.com/releases/2001/04/010418071807.htm>.
Case Western Reserve University. (2001, April 19). Researchers Link Failed Cell Division, Alzheimer's Disease. ScienceDaily. Retrieved August 22, 2014 from www.sciencedaily.com/releases/2001/04/010418071807.htm
Case Western Reserve University. "Researchers Link Failed Cell Division, Alzheimer's Disease." ScienceDaily. www.sciencedaily.com/releases/2001/04/010418071807.htm (accessed August 22, 2014).

Share This




More Health & Medicine News

Friday, August 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Newsy (Aug. 21, 2014) An experimental drug used to treat Marburg virus in rhesus monkeys could give new insight into a similar treatment for Ebola. Video provided by Newsy
Powered by NewsLook.com
Two US Ebola Patients Leave Hospital Free of the Disease

Two US Ebola Patients Leave Hospital Free of the Disease

AFP (Aug. 21, 2014) Two American missionaries who were sickened with Ebola while working in Liberia and were treated with an experimental drug are doing better and have left the hospital, doctors say on August 21, 2014. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
Cadavers, a Teen, and a Medical School Dream

Cadavers, a Teen, and a Medical School Dream

AP (Aug. 21, 2014) Contains graphic content. He's only 17. But Johntrell Bowles has wanted to be a doctor from a young age, despite the odds against him. He was recently the youngest participant in a cadaver program at the Indiana University NW medical school. (Aug. 21) Video provided by AP
Powered by NewsLook.com
American Ebola Patients Released: What Cured Them?

American Ebola Patients Released: What Cured Them?

Newsy (Aug. 21, 2014) It's unclear whether the American Ebola patients' recoveries can be attributed to an experimental drug or early detection and good medical care. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins