Brain "switch" that regulates energy expenditure and fat production uncovered
In recent years our understanding ofthe body's metabolic processes has progressed at an incredible pace.With rapidly increasing global rates of obesity, the race has been onto unlock the mysteries of how to manipulate the body's fat burningmechanisms. A team at Monash University recently made a majordiscovery, identifying the "switch" in the brain that controls howthe body converts food into energy.
The majority of research around obesityhas examined the way the body alternates production of its two major fatcells – white and brown. The production of these fat cells, calledadipocytes, are directed by signals from the brain, with white fat cells produced to store energy, while brown fat cells are produced toexpend energy.
Research has shown these adipocytes aredynamic and can change from brown to white depending on directionfrom the brain. The team from Monash discovered in 2015 how the bodyexecuted this fat cell change, but the underlying mechanism thatcontrolled the process was still a mystery.
The new study shows that after a meal,the brain senses the body's insulin levels and sends signals to generate either brown or white adipocytes. This on/off energyexpenditure switch is coordinated by the hypothalamus through changesin the levels of a type of protein called T-Cell Protein TyrosinePhosphatase (TCPTP).
The research found that, if the bodyis working properly, TCPTP is repressed when one consumes a meal. WhenTCPTP is inhibited the brain begins increasing its energy expenditureprotocols, ultimately signaling production of brown fat. But thisfeeding-induced repression of hypothalamic TCPTP was found to bedefective in the obese.
Across mouse studies it was found thatmice lacking in hypothalamic TCPTP were resistant to diet-inducedobesity, and when obese mice had hypothalamic TCPTPdeleted from their system, they exhibited increased energyexpenditure and feeding-induced brown fat conversion was restored.
This key mechanism may unlock themystery of why some people struggle with obesity regardless of diet,while others seem to be able to eat anything and not gain significantweight.
"What happens in the context ofobesity is that the switch stays on all the time – it doesn'tturn on off during feeding," says lead researcher Professor TonyTiganis. "Potentially we may be able to rewire this mechanism topromote energy expenditure and weight loss in obese individuals."
Of course, the researchers point outthat this exciting prospect is still some time off. It is one thingto discover such as key mechanism as this, but actually finding asafe and effective way to manipulate it will take years of work.
However, this increased understanding into howthe brain directs overall energy expenditure is still a major revelation forscientists and hopefully puts us on a path to overcoming the obesityepidemic.
The research was published in thejournal Cell Metabolism.
Source: Monash University