Thermograph of brown-like fat implanted in anesthetized animal at room temperature. The implant, shown in area A, is significantly warmer (30.86 degrees Celsius maximum) compared with the control region in area B (29.43 degrees Celsius maximum). (Photo by Kevin Tharp and Andreas Stahl)
Scientists at UC Berkeley wanted to see whether they can grow a chunk of engineered brown fat-like tissue inside adult mice, and what it can do. Brown fat is known to burn calories via heat production in hibernating animals and human babies, since they don’t shiver. The team used stem cells isolated from white fat that were encapsulated inside a specially fabricated hydrogel scaffold and pushed to differentiate into beige fat, a brown fat that turns lighter after exposure to cold temperatures.
Appearance of implant, less than a centimeter long, removed after two weeks. Notably, the fat shows the development of blood vessels and a marked brown hue. (Photo by Kevin Tharp and Andreas Stahl)
Inside the hydrogel scaffold there was also water, hyaluronic acid, and proteins related to brown fat. The acid stiffens the water, helping to promote proper differentiation because it’s been shown that pressure on stem cells can steer them to produce different types of cells. The stem cells themselves were genetically engineered to produce the firefly enzyme that makes them glow, allowing researchers to track the new tissue.
The compound was injected into identical mice and the growth of the new tissue monitored, the animals compared against a control group. The researchers showed that the mice with the new implants had a higher body temperature than the controls and so burned more calories in the process. Moreover, the levels of blood glucose and fatty acid content were lower in these mice.
The researchers envision that this approach may turn into a way of helping obese and diabetic people control their weight and blood sugar.
Study in journal Diabetes: Matrix assisted transplantation of functional beige adipose tissue…
Source: UC Berkeley…