Scientists have shown they can make animals burn more fat by inserting a molecular shunt into the livers of mice. The shunt consists of two metabolic enzymes not normally found in mammals, but common in bacteria and plants, according to the article in the June issue of the journal Cell Metabolism. In this case, the enzymes were taken from E. coli bacteria.
The shunt is "an additional channel for burning fat to control obesity," said James Liao of the University of California, Los Angeles, in a press release announcing the findings. His UCLA colleague Katrina Dipple put it this way: "It's like putting in a toll road."
The researchers didn't know what would happen when the E. coli enzymes were inserted into mammalian cells. "There was no guarantee it would work," Liao said. "But we were brave enough to try."
Surprisingly, they found that human liver cells expressing the enzymes burn larger quantities of fat. Similarly, mice on a high-fat diet with the shunt can resist becoming obese — effects attributable to lower levels of a fat metabolite and the additional fat oxidation channel.
However, although the delivery of these genes into humans might one day be an option, the researchers emphasized it is not their intent to target human obesity in this way, but rather to learn more about metabolic mechanisms.
"Usually, we study metabolism by knocking out a gene or replenishing one that is missing," Liao said. "In this case, we introduced a new pathway to see the response."
Are you on Facebook? Become our fan.
Follow us on Twitter.