A molecular mechanism that links diet, obesity and diabetes involves depletion of specialized ‘transporter proteins’, a Japanese–American team has found1. Transporter proteins deliver glucose to so-called ‘beta cells’ of the pancreas, which produce the hormone insulin to help the body regulate its sugar levels. The work opens the way to new treatments for diabetes since ensuring sufficient numbers of glucose transporter (Glut) proteins on their outer surface could improve beta cell function.
In both humans and animals, there is a widespread and accepted connection between high-fat diets, obesity and susceptibility to type 2 (or adult onset) diabetes (Fig. 1). Until now, however, the causal links were not clear, particularly at a molecular level, explains team member Kazuaki Ohtsubo from the RIKEN Advanced Science Institute in Wako.
A hallmark of the condition is a drop in the effectiveness of insulin in lowering blood sugar levels, known as insulin resistance. Previous work by other researchers had determined that type 2 diabetes is accompanied by a loss of sensitivity of beta cells to increasing glucose levels. Rising levels of glucose normally trigger secretion of insulin and are detected by greater amounts of sugar moving into beta cells. A decrease in Glut proteins, hence a lower capacity for glucose transport, could therefore explain defective insulin secretion. Interestingly, mice that lack the enzyme GnT-4a, which catalyzes the linkage of Glut proteins to the cell surface, develop type 2 diabetes. In earlier work2, Ohtsubo also showed that a high-fat diet can induce a deficiency of GnT-4a.
To investigate these earlier findings in detail, Ohtsubo and his colleagues from the University of California, USA, investigated the sequence of molecular events in pancreatic beta cells of mice and humans. They found that high levels of fatty acids led to nuclear exclusion of the proteins that facilitate transcription of the genes for GnT-4a and Glut. The resulting deficiency of the GnT-4a enzyme led to many of the symptoms of diabetes. This could be alleviated in mice by adding the human gene for GnT-4a. The researchers also observed that the molecular pathways activated in the mice that developed type 2 diabetes were similar to those that were active in human type 2 diabetes.
“We are already searching for small chemical compounds which activate the expression of GnT-4a in pancreatic beta cells under high-free fatty acids conditions,” says Ohtsubo. “These compounds could improve beta cell function and should be good candidates for new types of drugs for diabetes.”
The corresponding author for this highlight is based at the Disease Glycomics Team, RIKEN Advanced Science Institute
Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt
Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton University
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.
The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...
UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration
"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...
Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.
Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
16.01.2017 | Trade Fair News
16.01.2017 | Automotive Engineering
16.01.2017 | Life Sciences