White fat was turned beige and made to burn calories
Scientists from the USA have managed to make beige cells of white fat, which stores calories. Beige adipose tissue in the human body is responsible for the reverse process - burning calories.
Previous studies have shown that a person's weight and health may be affected by changes in the type of fat tissue. For example, if beige fat turns into white fat, body weight subsequently increases.
Researchers from the University of California, San Francisco (USA) studied the reverse mechanism - the transformation of white fat into beige fat. This process is considered a positive change in the body, as it leads to weight loss rather than weight gain. The fact is that white fat cells are responsible for the accumulation of calories, and beige - on the contrary, for burning. A scientific article describing the mechanism of transformation was published by The Journal of Clinical Investigation.
Many mammals have three types of fat cells: white, brown and beige. White cells store energy for the body, while brown cells burn it to maintain body temperature. Beige cells are also able to burn energy, but are "embedded" in white fat deposits.
The conversion of white fat to beige fat can occur naturally - as a response to diet or cold. It was thought that in order to mimic this process, it was necessary to work with stem cells. It was them that scientists tried to turn into beige fat, but wanted to find some kind of "switch" capable of transforming directly white fat cells.
The authors of the new paper managed to turn white fat into beige fat by restricting the production of the KLF-15 protein, which plays an important role in metabolism. When mice were planted with white cells without the KLF-15 protein, they turned into beige cells.
To better understand the discovered mechanism, scientists cultured human fat cells. It turned out that the KLF-15 protein controls the content of the Adrb1 receptor, which helps maintain energy balance. It was previously known that stimulation of this receptor leads to weight loss, but drugs whose action is based on this mechanism did not work and could not pass clinical trials.
Scientists believe that the results of the new work will make it possible to develop more effective drugs for weight loss and improve existing schemes of obesity therapy. Among other things, they believe it will be possible to get rid of side effects like nausea, because the drug will affect only fat cells without affecting the brain:
"We are certainly not at the finish line, but we are close enough to demonstrate that these discoveries could revolutionise the treatment of obesity."