Brown fat fingers a new target for metabolic disorders, including diabetes

Brown fat is once again providing clues in how to treat metabolic disorders like diabetes. A group of investigators at the University of Michigan followed up on earlier studies that have examined the role of brown fat in burning calories. Their work led them to NRG4, a hormone secreted by brown fat that may play a role as a messenger with the liver in regulating the conversion of sugar into fat, according to the university.

In mouse models developed to exclude NRG4, the rodents became fat and subject to diseases like diabetes and fatty liver disease--two of the hottest targets in biopharma. Mice with elevated levels of NRG4, though, appeared to be protected from metabolic diseases even when fed a diet with a high sugar content.

The trigger here is in fat conversion, as NRG4 prevents sugar from being converted into fat. Without that interference from NRG4, the liver becomes more active in converting sugar to fat, and the theory is that promotes the disease cycle.

"We think obesity is a state of NRG4 deficiency," noted Jiandie Lin of the university's Life Sciences Institute. And that makes it a target for drug development. But it's early days.

"Realistically, there are still many challenges to figuring out how it acts in the body and might be used as a drug," Lin said. "But in general, we know that NRG4 is beneficial for body metabolism and are excited about its potential."

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