Cells That Increase Fat Burning Found in Humans

The find is crucial for fat research and future treatment of obesity….

Researchers from Sweden are the first in the world to demonstrate that brown cells as well as ‘brite’ cells exist in the neck region in adult humans.

Previous knowledge was that the brown fatty tissue in the neck region of adults was only composed of brite fat cells, which do not convert anywhere near as much energy as the classical brown fat cells. However, now researchers from Rigshospitalet have discovered that adults also have the classical brown fat cells, which if activated can burn fat and sugar and thereby help weight loss.

Camilla Scheele, post-doc from the Centre of Inflammation and Metabolism at Rigshospitalet in an interview stated that, "We are the first researchers to have been able to demonstrate that at least two types of brown fat cells, the classical brown and the brite, exist in the fatty tissue in the neck region of adults. In contrast to normal white fat cells, the brown fat cells actually consume large amounts of fat and sugar instead of storing it. That is, brown fat itself burns fat when it is activated. Brite fat cells act in the same way as the classical brown cells, but they are nowhere near as potent. Therefore this is very good news. Now we’ve also found the classical brown fat cells in adults and this is crucial for how we will research into fat and treat obesity in the future. If we can find out how to activate the brown fat in overweight people, we will be able to promote weight loss and hopefully prevent a large number of diseases such as diabetes."

Brown fat is common in newborns, but in several previous attempts researchers have failed to find it in adults. On closer examination, what researchers thought were brown fat cells turned out to be brite fat cells, which are less effective at burning fat.

In this experiment it has also been possible for researchers to isolate brown fat stem cells from the neck region, which can be cultivated and studied more closely. 

"Isolating the cells such that they retain their properties means that we can use them as a model. We can then test how we can activate them so that they use their energy. We know, for example, that they are activated at cold temperatures, when the brain signals that they must start creating heat by burning fat and sugar. In practice, however, it is not particularly nice to have to be freezing cold in order to lose weight, so now we’re testing how the brown fat cells react to different hormones, which perhaps can activate them to burn," said Camilla Scheele.

The researchers wrote, "Human brown adipose tissue (BAT) has been detected in adults but was recently suggested to be of brite/beige origin. We collected BAT from the supraclavicular region in 21 patients undergoing surgery for suspected cancer in the neck area and assessed the gene expression of established murine markers for brown, brite/beige, and white adipocytes. We demonstrate that a classical brown expression signature, including upregulation of miR-206, miR-133b, LHX8, and ZIC1 and downregulation of HOXC8 and HOXC9, coexists with an upregulation of two newly established brite/beige markers, TBX1 and TMEM26. A similar mRNA expression profile was observed when comparing isolated human adipocytes from BAT and white adipose tissue (WAT) depots, differentiated in vitro. In conclusion, our data suggest that human BAT might consist of both classical brown and recruitable brite adipocytes, an observation important for future considerations on how to induce human BAT."