RESEARCHERS at the Harvard Stem Cell Institute (HSCI) have discovered a hormone that holds promise for a dramatically more effective treatment of type 2 diabetes. The researchers believe that the hormone might also have a role in treating type 1, or juvenile, diabetes. The work was published on April 24 by the on-line version of the journal Cell.

The hormone, called betatrophin, causes mice to produce insulin-secreting pancreatic beta cells at up to 30 times the normal rate. The new beta cells only produce insulin when called for by the body, offering the potential for the natural regulation of insulin and a great reduction in the complications associated with diabetes. HSCI co-director Doug Melton and postdoctoral fellow Peng Yi, who made the discovery, caution that much work remains to be done before it can be used as a treatment in humans. But their work has already drawn the attention of drug manufacturers.

“If this could be used in people,” said Melton, Harvard’s Xander University Professor and co-chair of the University’s Department of Stem Cell and Regenerative Biology, “it could eventually mean that instead of taking insulin injections three times a day, you might take an injection of this hormone once a week or once a month, or in the best case maybe even once a year.” “Our idea here is relatively simple,” he said. “We would provide this hormone, type 2 diabetics will make more of their own insulin-producing cells, and this will slow down, if not stop, the progression of their diabetes. I’ve never seen any treatment that causes such an enormous leap in beta cell replication.”

According to Melton, betatrophin could be in human clinical trials within three to five years. Most of Melton’s work has involved using stem cells but stem cells played no direct role in the discovery of betatrophin. “We were just wondering what happens when an animal doesn’t have enough insulin. We were lucky to find this new gene that had largely gone unnoticed before.

“Another hint came from studying something that people know about but don’t think much about, which is: What happens during pregnancy?” he said, “When a woman gets pregnant, her carbohydrate load, her call for insulin, can increase an enormous amount because of the weight and nutrition needs of the foetus... and it turns out that this hormone goes up during pregnancy. We looked in pregnant mice and found that this hormone is turned on to make more beta cells.”