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 New malaria analysis method reveals disease severity in minutes
14.08.2017 | University of British Columbia

nachricht New type of blood cells work as indicators of autoimmunity
14.08.2017 | Instituto de Medicina Molecular

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: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

Im Focus: Scientists improve forecast of increasing hazard on Ecuadorian volcano

Researchers from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science, the Italian Space Agency (ASI), and the Instituto Geofisico--Escuela Politecnica Nacional (IGEPN) of Ecuador, showed an increasing volcanic danger on Cotopaxi in Ecuador using a powerful technique known as Interferometric Synthetic Aperture Radar (InSAR).

The Andes region in which Cotopaxi volcano is located is known to contain some of the world's most serious volcanic hazard. A mid- to large-size eruption has...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

New thruster design increases efficiency for future spaceflight

16.08.2017 | Physics and Astronomy

Transporting spin: A graphene and boron nitride heterostructure creates large spin signals

16.08.2017 | Materials Sciences

A new method for the 3-D printing of living tissues

16.08.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>