Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mouse, stripped of a key gene, resists diabetes

03.09.2003


An engineered mouse, already known to be immune to the weight gain ramifications of a high-calorie, high-fat diet, now seems able to resist the onset of diabetes.


Professor of biochemistry and nutritional sciences James Ntambi holds two mice in his research lab and points to the mouse that is missing a SCD-1 gene and is significantly thinner than the normal mouse at right. Ntambi recently found that subracting a single gene, SCD-1, from the genome of a mouse creates an animal that can eat a rich, high-fat diet without gaining weight or risking the complications of diabetes.
Photo by: Jeff Miller
Date: August 2002



The mouse, stripped of a gene known as SCD-1, is apparently impervious to the negative effects of the type of diet that, for many people, has significant health and social consequences.

"We think this animal model may be protected against diabetes," says James Ntambi, a University of Wisconsin-Madison professor of biochemistry and Steenbock professor of nutrition, and the senior author of a report describing the remarkable mouse in this week’s (Sept. 1) online editions of the Proceedings of the National Academy of Sciences (PNAS).


The new finding is important because it provides critical genetic and biochemical clues to diet, obesity and the onset of a disease that affects as much as 6 percent of the U.S. population.

Type II diabetes, which accounts for about 90 percent of the incidence of diabetes in the United States, is a chronic disease caused by a problem in the way the body makes or uses insulin. Insulin is a hormone secreted by the pancreas that, under healthy circumstances, plays an essential role in moving glucose from blood to cells where the sugar’s energy is expended.

In many instances, obesity and diabetes go hand in hand. Between 75 and 80 percent of people with type II diabetes are obese, although the disease can also develop in lean people, especially the elderly.

The discovery of a gene that seems to exercise significant influence over both weight gain and glucose regulation promises a potentially significant window into both conditions and their relationship. The gene makes an enzyme called SCD. It affects the production of fatty acids, and because humans have SCD-1 equivalents, the new finding helps explain why some people, who may lack the gene, remain lean and diabetes free, despite a rich, fatty diet.

"We are beginning to suspect that obese individuals have increased expression of this enzyme," says Ntambi. "If you reduce expression of this enzyme, you reduce fat expression in muscle."

This new insight into the gene and its influence could herald the development of new drugs to prevent both diabetes and obesity as it may help scientists zero in on the underlying problems that lead to both conditions.

In the engineered mice, the Wisconsin team observed that muscle cells were more sensitive to insulin, enabling the cells to absorb glucose and avoid hyperglycemia. Elevated levels of glucose in the blood prompt the pancreas to produce more insulin, which tends to make cells even more resistant to the critical hormone.

"In this animal, there is increased insulin signaling or sensitivity," Ntambi explains. "When insulin binds to the cell’s insulin receptor, it triggers a cascade of events " that enables the animal to successfully regulate levels of blood sugar.

"There are lots of steps involved in the process, and in the case of type II diabetes things go wrong in some of those events," Ntambi says. "What we found in these animals is that the insulin signaling steps in muscle are all enhanced, despite low levels of insulin in plasma. We don’t see a defect yet."


The work by the Wisconsin team was funded primarily by the National Institutes of Health and in part by a grant from Xenon Genetics, Inc.

In addition to Ntambi, co-authors of the PNAS report include Shaikh Mizanoor Rahman, Agnieszka Dobrzyn, Pawel Dobrzyn, Seong-Ho Lee and Makoto Miyazaki.

- Terry Devitt (608) 262-8282, trdevitt@wisc.edu

James Ntambi | EurekAlert!
Further information:
http://www.wisc.edu/

More articles from Health and Medicine:

nachricht A whole-body approach to understanding chemosensory cells
13.12.2017 | Tokyo Institute of Technology

nachricht Research reveals how diabetes in pregnancy affects baby's heart
13.12.2017 | University of California - Los Angeles Health Sciences

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

A whole-body approach to understanding chemosensory cells

13.12.2017 | Health and Medicine

Water without windows: Capturing water vapor inside an electron microscope

13.12.2017 | Physics and Astronomy

Cellular Self-Digestion Process Triggers Autoimmune Disease

13.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>