Custom-made fat tissue that burns calories
In research that might lead to a new obesity and diabetes treatment approach, scientists developed a novel technique in mice for directing stem cells from body fat to grow in special gels and form fat tissue that burns—rather than stores—calories. Based on earlier findings that some types of body fat, called brown and beige fat, can generate heat by burning stored calories, researchers have proposed various strategies for creating more of these types of tissues to reduce excess weight and boost metabolism. Pursuing one such strategy, a multidisciplinary research team sought to grow beige fat tissue in the lab and test whether it would improve weight and health in mice.
They began by extracting stem cells from white fat tissue, the more abundant type of fat best known for storing calories. Next, they devised a way to coax these cells into becoming beige fat, taking into account the importance of a cell’s surrounding environment in determining its fate. In the body, critical signals come not only from molecules that enter into cells, but also from the biological structures on which cells sit, including the proteins on these structures. Thus, to grow the stem cells, the researchers developed a special gel matrix that included fragments of proteins they had carefully selected to help guide stem cell maturation into beige fat. After immersing the stem cells in chemicals known to induce beige fat characteristics, the researchers mixed the cells with the gel components to help seal their fate, and transplanted the mixture into male mice. The technology worked. Cells grown in the special gel turned on a key beige fat gene, UCP1, used for generating heat from calorie burning, and did so more effectively than cells grown in other ways. Mice transplanted with this new beige fat gained less weight than other mice on a high-fat diet. They also had less fat in their bloodstream; higher body temperatures after exposure to cold; and improved blood sugar levels, a sign of reduced risk for diabetes.
In the future, scientists could test this new technology to see whether it works with human cells. If it does, a person’s own excess fat tissue might one day be used as a source of stem cells for generating beige fat—turning a problem into a potential solution.