New link between obesity and diabetes discovered
Obesity increases the risk of diabetes, but no one knows in detail why this is so. Now scientists at Sahlgrenska Academy, Göteborg University, have identified a protein that may be the cause. The discovery may eventually lead to new ways of preventing type 2 diabetes.
Diabetes is a metabolic disease in which the body fails to produce sufficient insulin or the insulin does not have sufficient effect. Type 2 diabetes is the most common form of the disease. Most people who develop type 2 diabetes are overweight.Defective storage of fat in the body´s muscle cells impairs the insulin signal for increased sugar uptake.
"The fat is stored in the cell in fat particles, and by studying in detail how these are formed and grow we have been able to clarify how the insulin signal is impaired," says Professor Sven-Olof Olofsson, who heads the Wallenberg Laboratory at Sahlgrenska Academy.
The study showed that the lipid droplets aggregated in the cell by using a protein called SNAP23. This protein also has a completely different function: to pass on the insulin signal in the cell.
"It looks as though SNAP23 is 'stolen' from the insulin signal when the cell starts to pack fat and consequently creates the defect that then leads diabetes. If we can find out more about how this happens we might perhaps be able to influence the process and in the future protect patients against the development of diabetes," says Pontus Boström, a doctoral student at Sahlgrenska Academy.
Further studies are required before it will be possible to test the results on patients.
The results will be published in the next issue of the scientific journal Nature Cell Biology.
Title of article: SNARE proteins mediate fusion between cytosolic lipid droplets with implications for insulin sensitivity
Authors: Pontus Boström, Linda Andersson, Mikale Rutberg, Jeanna Perman, Ulf Lidberg, Bengt R. Johansson, Julia Fernandez-Rodriguez, Tommy Nilsson, Jan Borén and Sven-Olof Olofsson.
