Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers find pathways linking caloric restriction to aging process

18.11.2005


Researchers at the University of Washington have found a genetic pathway linking nutrient response and the aging process, they report in the Nov. 18 issue of the journal Science. Scientists have long known that dramatically reducing food intake boosts the lifespan of model organisms such as mice, but the new results point to a possible mechanism through which drastic calorie restriction affects aging.



As scientists learn more about the biochemical processes that affect lifespan, they might one day be able to target those processes to reduce the effects of age-related diseases like heart disease or diabetes.

The UW researchers conducted a genome-wide screen of yeast cells to find which genes, and their corresponding proteins, affect lifespan. Two of the proteins, called Tor1 and Sch9, are signaling molecules that are linked to nutrient uptake in many different organisms. Their results suggest that the same proteins, or very similar ones, may be related to both nutrient response and the aging process in humans.


"The idea is to identify pathways in yeast that are involved in aging, and take them to higher organisms like mice and eventually people," explained Brian Kennedy, assistant professor of biochemistry at the UW School of Medicine and one of the study’s main authors. He collaborated on the project with Matt Kaeberlein, a postdoctoral researcher in the lab of Stanley Fields, professor of genome sciences at the UW and Howard Hughes Medical Institute investigator.

After finding ten genes that regulate lifespan, the researchers tested two – Tor1 and Sch9 – to confirm their connection to caloric restriction. One test combined caloric restriction with the genetic mutation to Tor1 that reduced signaling on the TOR pathway. They saw lifespan increases in the resulting yeast cells that were about the same as a cell that had just the Tor1 mutation, indicating that the mutation was doing the same thing as caloric restriction.

"The TOR pathway is evolutionarily conserved, meaning it is common to many lifeforms," said Kaeberlein. "We’d like to know if this is the pathway through which caloric restriction affects lifespan. We think this may be why mice live longer with calorie restriction, because of TOR pathway down-regulation."

The two researchers plan to find out that very thing by studying further the TOR pathway in mice. Unlike yeast, though, that gene is essential for mice to live, so they can’t delete the gene entirely. But mice have two copies of the TOR gene, which means the researchers can knock out one copy, essentially cutting activity on the TOR pathway in half. They can then study the lifespan of those mice compared to others, and also look at the progression of age-related conditions in the mutants to see if reducing TOR signaling affects those diseases.

The other signaling protein the researchers found in the yeast study, Sch9, is the yeast version of another signaling protein called AKT, which is found in humans and other mammals. AKT is related to the regulation of the insulin and insulin-like growth factor (IGF-1) pathways, and has also been found to affect lifespan in other model organisms. "Having this pathway implicated in lifespan is consistent with the theory about insulin/IGF-1 response in animals and humans," explained Kaeberlein. "That theory basically says that high nutrient levels make the organism grow faster and bigger, but also reduce lifespan. This may be one reason why calorie-restricted mice live longer, but are smaller than other mice."

The researchers admit that there might be multiple ways to increase the lifespan of model organisms and humans. However, extreme calorie restriction has been shown to be the one process that affects aging universally. It doesn’t just make the organism live longer overall, it also reduces the debilitating effects of aging and age-related diseases. Calorie-restricted mice don’t just live longer, they live healthier for longer.

"Caloric restriction is acting at the root level of the aging mechanism," said Kennedy. "If we can understand how that works, then maybe you can target the genes or proteins that regulate those processes, and you can alter aging and its effects without reducing caloric intake."

Justin Reedy | EurekAlert!
Further information:
http://www.washington.edu

More articles from Life Sciences:

nachricht Meadows beat out shrubs when it comes to storing carbon
23.11.2017 | Norwegian University of Science and Technology

nachricht Migrating Cells: Folds in the cell membrane supply material for necessary blebs
23.11.2017 | Westfälische Wilhelms-Universität Münster

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: New proton record: Researchers measure magnetic moment with greatest possible precision

High-precision measurement of the g-factor eleven times more precise than before / Results indicate a strong similarity between protons and antiprotons

The magnetic moment of an individual proton is inconceivably small, but can still be quantified. The basis for undertaking this measurement was laid over ten...

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Heidelberg Researchers Study Unique Underwater Stalactites

24.11.2017 | Earth Sciences

Species may appear deceptively resilient to climate change

24.11.2017 | Ecology, The Environment and Conservation

Lightning, with a chance of antimatter

24.11.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>