Researchers link gene to cholesterol

Oct 11, 2007

MIT researchers have discovered a link between a gene believed to promote long lifespan and a pathway that flushes cholesterol from the body.

The finding could help researchers create drugs that lower the risk of diseases associated with high cholesterol, including atherosclerosis (clogged arteries) and Alzheimer's disease.

The study focused on a gene called SIRT1, which the researchers found prevents cholesterol buildup by activating a cellular pathway that expels cholesterol from the body via HDL (high density lipoprotein or “good cholesterol”).

“SIRT1 is an important mediator of cholesterol efflux, and as such it's predicted to play a role in the development of age-associated diseases where cholesterol is a contributing factor,” said Leonard Guarente, MIT professor of biology and senior author of a paper on the work to be published in the Oct. 12 issue of Molecular Cell.

Drugs that enhance the effects of SIRT1 could lower the risk of cholesterol-related diseases, Guarente said. Potential drugs could be based on polyphenols, which are found in red wine and have been shown to enhance SIRT1. However, the quantities naturally found in red wine are not large enough to have a significant impact on cholesterol levels.

In earlier studies, Guarente has shown that high levels of SIRT1 can be achieved with extreme calorie restriction, but that is unappealing for most people.

“If you had a drug that could increase expression of SIRT1, that could replicate the effects of calorie restriction,” Guarente said. “This is not going to replace the need for a healthy lifestyle, but it's a supplement that could potentially make you healthier.”

SIRT1 is the mammalian homologue to SIR2, a gene that has been shown to slow aging in yeast and roundworms. Researchers have been curious to find out whether SIRT1 has similar effects.

In the new MIT study, researchers found that low SIRT1 levels in mice lead to cholesterol buildup in cells such as macrophages, a type of immune cell, due to reduced activity of a protein called LXR (liver X receptor).

LXR is responsible for transporting cholesterol out of macrophage cells. When full of cholesterol, the macrophages can generate plaques that clog arteries. SIRT1 boosts LXR activity, so that cholesterol is expelled from macrophages and out of the body by HDL.

Source: Massachusetts Institute of Technology

Explore further: Assortativity signatures of transcription factor networks contribute to robustness

add to favorites email to friend print save as pdf

Related Stories

FIXD tells car drivers via smartphone what is wrong

53 minutes ago

A key source of anxiety while driving solo, when even a bothersome back-seat driver's comments would have made you listen: the "check engine" light is on but you do not feel, smell or see anything wrong. ...

Team pioneers strategy for creating new materials

2 hours ago

Making something new is never easy. Scientists constantly theorize about new materials, but when the material is manufactured it doesn't always work as expected. To create a new strategy for designing materials, ...

Shell files new plan to drill in Arctic

2 hours ago

Royal Dutch Shell has submitted a new plan for drilling in the Arctic offshore Alaska, more than one year after halting its program following several embarrassing mishaps.

Aging Africa

2 hours ago

In the September issue of GSA Today, Paul Bierman of the University of Vermont–Burlington and colleagues present a cosmogenic view of erosion, relief generation, and the age of faulting in southernmost Africa ...

Recommended for you

Mutation disables innate immune system

7 hours ago

A Ludwig Maximilian University of Munich team has shown that defects in the JAGN1 gene inhibit the function of a specific type of white blood cells, and account for a rare congenital immune deficiency that ...

Study identifies genetic change in autism-related gene

Aug 28, 2014

A new study from Bradley Hospital has identified a genetic change in a recently identified autism-associated gene, which may provide further insight into the causes of autism. The study, now published online in the Journal of ...

NIH issues finalized policy on genomic data sharing

Aug 27, 2014

The National Institutes of Health has issued a final NIH Genomic Data Sharing (GDS) policy to promote data sharing as a way to speed the translation of data into knowledge, products and procedures that improve health while ...

The genes behind the guardians of the airways

Aug 27, 2014

Dysfunctions in cilia, tiny hair-like structures that protrude from the surface of cells, are responsible for a number of human diseases. However the genes involved in making cilia have remained largely elusive. ...

User comments : 0