Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Protein that boosts longevity may protect against diabetes

09.08.2012
Sirtuins help fight off disorders linked to obesity, new MIT study shows.

A protein that slows aging in mice and other animals also protects against the ravages of a high-fat diet, including diabetes, according to a new MIT study.

MIT biology professor Leonard Guarente ’74 discovered SIRT1’s longevity-boosting properties more than a decade ago and has since explored its role in many different body tissues. In his latest study, appearing in the Aug. 8 print edition of the journal Cell Metabolism, he looked at what happens when the SIRT1 protein is missing from adipose cells, which make up body fat.

When put on a high-fat diet, mice lacking the protein started to develop metabolic disorders, such as diabetes, much sooner than normal mice given a high-fat diet.

“We see them as being poised for metabolic dysfunction,” says Guarente, the Novartis Professor of Biology at MIT. “You’ve removed one of the safeguards against metabolic decline, so if you now give them the trigger of a high-fat diet, they’re much more sensitive than the normal mouse.”

The finding raises the possibility that drugs that enhance SIRT1 activity may help protect against obesity-linked diseases.

Guarente first discovered the effects of SIRT1 and other sirtuin proteins while studying yeast in the 1990s. Since then, these proteins have been shown to coordinate a variety of hormonal networks, regulatory proteins and other genes, helping to keep cells alive and healthy.

In recent years, Guarente and his colleagues have deleted the gene from organs such as brain and liver to pinpoint its effects more precisely. Their previous work has revealed that in the brain, SIRT1 protects against the neurodegeneration seen in Alzheimer’s, Huntington’s and Parkinson’s diseases.

SIRT1 is a protein that removes acetyl groups from other proteins, modifying their activity. The possible targets of this deacetylation are numerous, which is likely what gives SIRT1 its broad range of protective powers, Guarente says.

In the Cell Metabolism study, the researchers analyzed the hundreds of genes that were turned on in mice lacking SIRT1 but fed a normal diet, and found that they were almost identical to those turned on in normal mice fed a high-fat diet.

This suggests that in normal mice, development of metabolic disorders is a two-step process. “The first step is inactivation of SIRT1 by the high-fat diet, and the second step is all the bad things that follow that,” Guarente says.

The researchers investigated how this occurs and found that in normal mice given a high-fat diet, the SIRT1 protein is cleaved by an enzyme called caspase-1, which is induced by inflammation. It’s already known that high-fat diets can provoke inflammation, though it’s unclear exactly how that happens, Guarente says. “What our study says is that once you induce the inflammatory response, the consequence in the fat cells is that SIRT1 will be cleaved,” he says.

That finding “provides a nice molecular mechanism to understand how inflammatory signals in adipose tissue could lead to rapid derangement of metabolic tissue,” says Anthony Suave, an associate professor of pharmacology at Weill Cornell Medical College, who was not part of the research team.

Drugs that target that inflammatory process, as well as drugs that enhance sirtuin activity, might have some beneficial therapeutic effect against obesity-related disorders, Suave says.

The researchers also found that as normal mice aged, they were more susceptible to the effects of a high-fat diet than younger mice, suggesting that they lose the protective effects of SIRT1 as they age. Aging is known to increase inflammation, so Guarente is now studying whether that age-related inflammation also provokes SIRT1 loss.

This research was funded by the National Institutes of Health, the Glenn Medical Foundation and the American Heart Association.

Written by: Anne Trafton, MIT News Office

Sarah McDonnell | EurekAlert!
Further information:
http://www.mit.edu

More articles from Life Sciences:

nachricht New catalyst controls activation of a carbon-hydrogen bond
21.11.2017 | Emory Health Sciences

nachricht The main switch
21.11.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

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...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

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

Previous evidence of water on mars now identified as grainflows

21.11.2017 | Physics and Astronomy

NASA's James Webb Space Telescope completes final cryogenic testing

21.11.2017 | Physics and Astronomy

New catalyst controls activation of a carbon-hydrogen bond

21.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>