obesity It has been revealed that mice have similar brown fat deposits to the largest depot found in people, and could potentially lead to new ways of using brown fat to treat metabolic conditions such as obesity and type 2 diabetes in the future.

The study was carried out by collaborators from several institutions, including Baylor College of Medicine, reports GEN. They discovered brown adipose tissue (BAT) depots that are located in a region analogous to that of human supraclavicular BAT (scBAT).

“The mouse scBAT depot has morphological characteristics of classical BAT, possesses the potential for high thermogenic activity, and expresses a gene signature that is similar to that of human scBAT. Taken together, our studies reveal a mouse BAT depot that represents human BAT and provides a unique tool for developing new translatable approaches for utilizing human scBAT,” explains the investigators.

Senior author Miao-Hsueh Chen, Ph.D., assistant professor of pediatrics and nutrition at Baylor College of Medicine and the U.S. Department of Agriculture/Agricultural Research Center (USDA/ARS) Children’s Nutrition Research Center at Baylor and Texas Children’s Hospital, added, “In addition to white adipose tissue, or white fat, people have brown fat, an important contributor to the body’s energy balance via the generation of body heat and the participation in metabolic processes.”

Brown fat contains adipocytes, which use fat and glucose as sources of energy. In mice, brown fat activated to produce heat markedly affects the energy balance. Studies have indicated that most brown fat in mice is on the back, between the shoulder blades. In people, however, the main depots of brown fat are located above the collar bones and deep in the neck. Scientists think that what they learn by studying mouse brown fat might not be applicable to people because mouse and human brown fat are at different locations. 

In the search for a better mouse model, Dr. Chen and her colleagues analysed mouse embryos and found brown fat surrounded by muscles in the neck, including a brown fat depot located above the collar bones, the same location of main human brown fat that had not been described before.

“Further studies showed that adult mice also have brown fat above the collar bones,” commented Dr. Chen.”This is important because studies will be carried out mostly in adults. In addition, mouse brown fat in the collar bone is morphologically similar to human brown fat in the same location, produces compounds involved in the production of heat, and expresses genes similar to those expressed by human brown fat.” 

In collaboration with Kristin Stanford, Ph.D., assistant professor of physiology and cell biology at Ohio State University Wexner Medical Center, the research team carried out brown fat transplantation experiments in mice.

“For several years, I’ve been interested in how to combat obesity and improve metabolic health,” concluded Dr. Stanford. “A few years ago, my lab developed a transplantation model looking at the effects of increasing brown fat above the shoulder blade in mice, and we saw a dramatic improvement in metabolic health. When Dr. Chen showed me her data identifying brown fat above the collar bone in mice, I was excited to collaborate and apply our transplantation model.”