Featured Research

from universities, journals, and other organizations

Neuronal Death And Processing Of Tau Protein In Alzheimer's Disease

Date:
April 1, 2005
Source:
International School For Advanced Studies In Trieste
Summary:
In a new study, researchers show that a processed form of tau protein induces neuronal death by apoptosis (programmed cell death) when expressed in cultured rat hippocampal neurons. Pathological changes in the microtubule associated protein tau are a major hallmark of the human dementias collectively defined as tauopathies, including Alzheimer's disease.

In a research report recently published in the Journal of Alzheimer's Disease (http://www.j-alz.com), published by IOS Press, a research group from the International School for Advanced Studies (ISASSISSA) in Trieste (Luisa Fasulo, Gabriele Ugolini e Antonino Cattaneo) showed that a processed form of tau protein induces neuronal death by apoptosis (programmed cell death) when expressed in cultured rat hippocampal neurons. Pathological changes in the microtubule associated protein tau are a major hallmark of the human dementias collectively defined as tauopathies, including Alzheimer's disease (AD). In Fronto-Temporal Dementia with Parkinsonism linked to Chromosome 17 (FTDP-17), several mutations in the tau gene were identified showing that primary malfunction of tau can lead to neurodegeneration. Such findings shed new light on the role of post-translational modifications of tau protein occurring in other tauopathies (such as AD), including aberrant proteolysis. In AD, tau protein aggregates in intraneuronal deposits known as "neurofibrillary tangles" (NFT), one of the two hallmarks of the disease. Tau molecules normally associate to microtubules (major cytoskeletal structures); in AD, tau proteins dissociate from microtubules and aggregate into NFTs.

Inappropriate neuronal apoptosis (or neuronal cell death) is present in AD, as well as in other neurodegenerative diseases. In a previous study, the authors showed that tau is a substrate for the apoptotic protease caspase-3 (an enzyme involved in cell death processes) and an effector of apoptosis itself, in established cell lines. Moreover, the cleavage of tau by caspase-3 has been recently confirmed to occur "in vivo" in AD brain as an early event. The study shows the apoptotic properties of tau fragments in cultured hippocampal neurons, a neuronal subpopulation precociously affected by AD pathology.

According to the authors, neurodegeneration would be perpetuated by an "autocatalytic process" in which any modest proapoptotic stimulus (activating caspase-3) would promote tau cleavage generating the proapoptotic fragments. The authors also show that this effect is significantly potentiated by incubation with the amyloid peptide A-beta 25-35, a peptide included in the A-beta fragment (the constituent of extraneuronal senile plaques, another hallmark of the disease). One of the intersections between amyloid and neurofibrillary pathological pathways in AD might rely on caspase-3 cleavage of tau. Intriguingly, the authors find that one of the tau mutations described in FTDP-17, potentiates the apoptotic capacity of tau fragments; such finding has no relevance in understanding the molecular pathogenesis of FTDP-17. However, since the mutation is located in a region important for the affinity to microtubules, this observation suggests that this region is likely to be involved in the apoptotic properties of tau. These results are of general interest, since they provide insights into the pathogenetic mechanism of AD.


Story Source:

The above story is based on materials provided by International School For Advanced Studies In Trieste. Note: Materials may be edited for content and length.


Cite This Page:

International School For Advanced Studies In Trieste. "Neuronal Death And Processing Of Tau Protein In Alzheimer's Disease." ScienceDaily. ScienceDaily, 1 April 2005. <www.sciencedaily.com/releases/2005/03/050329135203.htm>.
International School For Advanced Studies In Trieste. (2005, April 1). Neuronal Death And Processing Of Tau Protein In Alzheimer's Disease. ScienceDaily. Retrieved September 2, 2014 from www.sciencedaily.com/releases/2005/03/050329135203.htm
International School For Advanced Studies In Trieste. "Neuronal Death And Processing Of Tau Protein In Alzheimer's Disease." ScienceDaily. www.sciencedaily.com/releases/2005/03/050329135203.htm (accessed September 2, 2014).

Share This




More Mind & Brain News

Tuesday, September 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Can You Train Your Brain To Eat Healthy?

Can You Train Your Brain To Eat Healthy?

Newsy (Sep. 1, 2014) New research says if you condition yourself to eat healthy foods, eventually you'll crave them instead of junk food. Video provided by Newsy
Powered by NewsLook.com
Coffee Then Napping: The (New) Key To Alertness

Coffee Then Napping: The (New) Key To Alertness

Newsy (Aug. 30, 2014) Researchers say having a cup of coffee then taking a nap is more effective than a nap or coffee alone. Video provided by Newsy
Powered by NewsLook.com
Young Entrepreneurs Get $100,000, If They Quit School

Young Entrepreneurs Get $100,000, If They Quit School

AFP (Aug. 29, 2014) Twenty college-age students are getting 100,000 dollars from a Silicon Valley leader and a chance to live in San Francisco in order to work on the start-up project of their dreams, but they have to quit school first. Duration: 02:20 Video provided by AFP
Powered by NewsLook.com
Baby Babbling Might Lead To Faster Language Development

Baby Babbling Might Lead To Faster Language Development

Newsy (Aug. 29, 2014) A new study suggests babies develop language skills more quickly if their parents imitate the babies' sounds and expressions and talk to them often. 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