Understanding Brown Versus White Fat with Proteomics

Many studies have focused on the relationship between white body fat and its relationship to health and diseases, but researchers are increasingly focusing on the health benefits of brown fat. In a study published yesterday in Cell Metabolism, University of Copenhagen researchers used mass spectrometry to map all the proteins that are secreted from adult human white and brown fat cells. What they discovered is that the two types of fat tissue send very different signals to the rest of the body.

Most body fat is white fat that sits on your stomach, hips and thighs. It’s an energy storage that the body can use when food is scarce, and it also produces and receives signals from a variety of different hormones. Brown fat, on the other hand, sits close to the nervous system, up the spine, around the throat, and near the kidneys. Its role is completely different: it produces heat. Additionally, brown fat can help to burn energy.

In the study, the researchers discovered that brown fat secretes more than 100 proteins that are not secreted by white fat. The researchers categorized the proteins and were able to form a general picture about the differences between the fat types. For example, brown fat is better at regulating the cellular immune system, while white fat secretes proteins that allow greater tissue plasticity.

“One of the great mysteries about brown fat is that we are not sure how it is formed,” says senior author Camilla Schéele. “But we have found an interesting clue. One of the proteins that brown fat secretes plays an important role in developing and maturing new brown fat cells to prepare them for producing heat and energy.”

The researchers are now studying the proteins in more detail to better understand how they communicate with the rest of the body, especially the signals that they send to the brain.