Most fat cells in the body store energy, but a small subset of brown fat cells do the opposite by burning energy and generating heat. The molecule ERRy gives brown fat its energy expending identity, making those cells ready to warm up the body, and a potential therapeutic target for obesity and related diseases.
Brown fat cells express ERRy genes all the time, not just when cold, white fat cells do not express ERRy at all. Studying mice lacking in ERRy it was observed that all brown cells resembles white cells in these mice. When the mice were exposed to cold they were unable to maintain body temperature, 80% of normal mice can handle a temperature drop, mice lacking in ERRy did not tolerate the cold, no difference was found in metabolism or weight between the mice. Findings show that ERRy is important to helping brown fat to maintain identity and respond to cold.
ERRy gene codes for a protein that is able to travel into the cell nucleus and directly control expression of other genes. Researchers investigated which genes ERRy mediated in brown fat cells, and pinpointed a number of genes which were already known to be important to brown fat but had not yet be linked to ERRy specifically previously.
Future studies are planned to investigate the effect of activating ERRy in white fat cells which may possibly help treat obesity and diabetes; and also to investigate whether ERRy plays the same role in human brown fat as was observed in mice.
