Navigation Links
Protein that boosts longevity may protect against diabetes
Date:8/8/2012

CAMBRIDGE, MA. -- 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 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.

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.


'/>"/>
Contact: Sarah McDonnell
s_mcd@mit.edu
617-253-8923
Massachusetts Institute of Technology
Source:Eurekalert

Related medicine news :

1. Warwick scientists uncover how checkpoint proteins bind chromosomes
2. Specific protein triggers changes in neurons in brain reward center linked to cocaine addiction
3. Unusual protein helps regulate key cell communication pathway
4. Protein prevents DNA damage in the developing brain and might serve as a tumor suppressor
5. RANK protein promotes the initiation, progression and metastasis of human breast cancer
6. Protein may represent a switch to turn off B cell lymphoma
7. Protein RAL associated with aggressive characteristics in prostate, bladder and skin cancers
8. Breast cancer clinical trial tests combo of heat shock protein inhibitor and hormonal therapy
9. Pivotal role for proteins -- from helping turn carbs into energy to causing devastating disease
10. New molecular structure offers first picture of a protein family vital to human health
11. Wayne State University researcher examines proteins role in diabetic retinopathy
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/24/2017)... ... March 24, 2017 , ... The law firm of ... N.Y., is pleased to announce Westchester resident Lauren C. Enea has joined the firm ... the firm, will concentrate her practice in elder law, Medicaid planning and applications, and ...
(Date:3/24/2017)... ... 2017 , ... Viewers who like to educate themselves on current issues and ... services, and societal issues tend to appreciate and love the "Informed" series, hosted by ... running events for causes around the world. , Running for charity has ...
(Date:3/24/2017)... (PRWEB) , ... March 24, 2017 , ... ... ( http://www.hygieacare.com ) announced their partnership to prep patients for colonoscopy at the ... Endoscopy Centers in 87th Ave., Miami, FL. , The HyGIeaCare® Prep, ...
(Date:3/24/2017)... Texas (PRWEB) , ... March 24, 2017 , ... ... 2017 the year of enhancements, upgrading their training and leads programs. , In ... University. Reserved for elite sales agents, Performance Partners is designed to teach how ...
(Date:3/24/2017)... ... March 24, 2017 , ... ... Certified Medical Reiki™ Master in Frederick, MD. Judy says, “I am passionate about ... what is often a very difficult and challenging time.” , A Certified Medical ...
Breaking Medicine News(10 mins):
(Date:3/23/2017)... , March 23, 2017  Digital Pharmacist ... ), a rapidly growing digital health company, ... mobile app that allows patients to manage their ... locations such as Denver Health Pharmacy, USave Pharmacy ... acquisition helps Digital Pharmacist accelerate its product development ...
(Date:3/23/2017)... , March 23, 2017  Ethicon* today ... Medical, Inc., a privately held medical device company ... System for the surgical treatment of Gastroesophageal Reflux ... strategy of expanding its portfolio of minimally invasive ... medical conditions. Financial terms of the transaction have ...
(Date:3/23/2017)... -- A research report by Mordor Intelligence indicates ... USD 7.2 billion by the end of 2021 and growing ... in which a sample is preserved prior to its analysis. ... the methods are often allowing repeated testing. The report explains ... procedures in the lab. In many life science labs, it ...
Breaking Medicine Technology: