The mice continued to eat a high-fat diet for another 80 days. The mice receiving no treatment continued to gain weight in those 80 days, while the mice receiving thermogenic cells lost weight for 23 days and then began to gain it back, eventually maintaining a steady weight even after continuing to eat excessive saturated fat. Mice receiving empty capsules also lost some weight, but the researchers determined in a separate pilot study that the sham injections did not reduce visceral fat.
The researchers examined visceral fat pads from the mice and determined that overall, lipid content was at least 20 percent lower in mice treated with active capsules compared to the placebo injection group of mice.
A closer look at exactly what was going on in the animals' cells showed that the injected cells produced high levels of a protein called Ucp1, which burns fat, suggesting that this protein assisted in the visceral fat reduction.
By tagging the injected cells with a fluorescent protein, the scientists could use imaging technology to track the cells in the body; this not only benefited the research, but also provides a way to safely remove these capsules if needed, Ziouzenkova noted.
"The injected cells were perfectly inversely correlated with lipids so the more injected cells we have capable of burning fat, the more fat gets burned," she said. "These injected cells worked almost like missionaries, starting to convert host cells and turning them into thermogenic cells."
Because that creation of heat could be uncomfortable inside a human body, the researchers analyzed the treated mice further to see if the thermogenesis in the belly would produce effects similar to hot flashes.
|Contact: Ouliana Ziouzenkova|
Ohio State University