The researchers were thus able to gain a deep insight into the function of the gene. Further clarification of its function would provide a basis for developing new approaches for prevention and treatment, as this gene could also be linked to obesity and diabetes in humans.
The researchers published their data today in the scientific journal Nature Genetics (Chadt, A. et al.; 2008).
The mutation that knocks out the Tbc1d1 gene causes increased fat uptake in skeletal muscle and, at the same time, boosts fat oxidation. On the other hand, glucose uptake of muscles is reduced. “This shows that the normal Tbc1d1 gene has a very important function in fat and glucose metabolism and therefore plays an essential role in regulation of energy metabolism“, explains Hadi Al-Hasani.
“Not only how much food we eat but also how our body uses it is decisive for development of obesity and diabetes“, says Hans-Georg Joost, Scientific Director of DIfE. When the relation between glucose and fat oxidation shifts so that the muscles use more fat and less glucose as a source of energy, this is energetically less efficient. As a result, the body stores less fat. This lowers the risk for obesity and consequently also for diabetes.
In Germany, 66 percent of the men and 50.6 percent of the women are already overweight or obese. In the USA, even three-fourths of adults “break the bathroom scales“, according to the latest reports. Overweight increases significantly the risk of heart attack, stroke, intestinal cancer, and type-2 diabetes. At present, more then seven percent of Germans are diabetic and this number will increase even more due to the growing number of overweight persons.
Studies in animals and humans have shown that there is a relation between overweight, type-2 diabetes, diet, and genes. Researchers suspect that natural variants of at least 50 genes are involved in the development of overweight. As for diabetes, probably more than 100 genes are involved. Only very few of these genes and variants are known to date. In addition, they form a functional, interacting network with environmental variables that is incompletely understood.
Since humans and mice are genetically very similar, the researchers of DIfE use the mouse model to identify genes involved in the development of overweight and diabetes. If an “overweight gene“ has been discovered which plays a role in both species, then the researchers can investigate its function and the basic molecular mechanisms in animal models under controlled conditions. Such studies often cannot be carried out in humans for ethical as well as practical reasons. The results from the animal model studies can then be used to develop new medications for treatment of obesity and diabetes.
About the study: The researchers identified the mutation on the Tbc1d1-gene by means of back-crossing experiments. Then the genetic makeup of two very different mouse strains was compared. The New Zealand obese mouse gains weight rapidly under a high-fat diet (60 percent fat) and develops obesity, whereby the proportion of body fat can increase to over 40 percent. Despite a very high fat diet, the mice of the Swiss Jim Lambert strain did not gain weight but stayed lean, due to their genetic makeup.
Seven base pairs are missing in the mutated Tbc1d1 gene of the Swiss Jim Lambert strain. These changes lead to the synthesis of a shortened Tbc1d1 protein molecule and, most likely, loss of enzyme activity. The Tbc1d1 protein molecule is located mainly in skeletal muscle. Researchers have found smaller amounts in heart, pancreas, intestine, kidney, and hypothalamus. It is not found in fatty tissue or liver.
Gisela Olias | alfa
Complementing conventional antibiotics
24.05.2018 | Goethe-Universität Frankfurt am Main
Building a brain, cell by cell: Researchers make a mini neuron network (of two)
23.05.2018 | Institute of Industrial Science, The University of Tokyo
A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.
The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
24.05.2018 | Ecology, The Environment and Conservation
24.05.2018 | Medical Engineering
24.05.2018 | Physics and Astronomy