Turning white into brown
Why does sport burn fat?
Kirill Stasevich, CompulentaThose who want to lose weight are advised to go in for sports: physical exercises help burn excess calories.
Exercises work primarily on the muscles, but from the muscles the effect of the load spreads throughout the body. An important role here is played by the PGC-1alfa protein – a transcription regulator that stimulates the activity of genes, which, in turn, provide a high level of energy metabolism.
But the mystery of this protein is that, without leaving the muscles, it somehow still controls fat cells, including genes in white fat cells that turn them into brown fat cells.
Enough is already known about white and brown fat: the first accumulates fat reserves, the second burns them, and just the management of brown fat, according to many, helps to cope with overweight and obesity. PGC-1alfa could also act as such an "influence agent" if it were possible to find out through what it affects fat cells.
Robert Gerszten and his colleagues from Harvard Medical School (USA) managed to find the mysterious intermediary. Scientists have found a link between the PGC-1alfa protein and beta-aminoisobutyric acid (BAIBA – beta-aminoisobutyric acid). As they write in Cell Metabolism, this compound directly acted on white fat cells, causing them to "burn". In addition, BAIBA also influenced other cell types, activating, for example, fat burning in the liver. Beta-aminoisobutyric acid itself comes from muscle cells: it was isolated by muscles under the influence of PGC-1alfa.
Experiments with mice showed that animals who were watered with BAIBA water lost weight, and in general their metabolism became healthier. But is it possible to extend this data to a person? The authors of the study tested the level of BAIBA in more than 2,000 people and found that low levels of beta-aminoisobutyric acid accompany a number of diseases, from diabetes to cardiovascular disorders. At the same time, a person who led a sedentary lifestyle, but then began to play sports, the level of BAIBA in the blood rose by as much as 17%.
The following picture emerges: physical exercises increase the activity of the PGC-1alfa protein, and due to its increased activity, muscles secrete BAIBA, which becomes an "agent of influence" of muscles in adipose tissue, forcing it to burn fat reserves.
A diagram from an article in Cell Metabolism – VM.
It is too early to say whether it is possible to make a cure for obesity from beta-aminoisobutyric acid: this will require a lot of clinical and preclinical tests. However, do not think that the light has come together with a wedge on it: there may be several intermediary molecules capable of regulating metabolism in response to physical activity, and the year before last, for example, we reported something similar, talking about the hormone irisin. In short, if an obesity pill is created, it will most likely include a whole cocktail of molecular metabolic stimulants, many of which probably have yet to be discovered.
Prepared by ScienceNOW: Muscle Molecule Spurs Fat Cells to Slim DownPortal "Eternal youth" http://vechnayamolodost.ru