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 Colorectal cancer risk factors decrypted
13.07.2018 | Max-Planck-Institut für Stoffwechselforschung

nachricht Algae Have Land Genes
13.07.2018 | Julius-Maximilians-Universität Würzburg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Research finds new molecular structures in boron-based nanoclusters

13.07.2018 | Materials Sciences

Algae Have Land Genes

13.07.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>