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, a metabolic illness afflicting an estimated 26 million Americans. The researchers believe that the hormone might also have a role in treating type 1, or juvenile, diabetes.
The work was published today by the journal Cell as an early online release. It is scheduled for the May 9 print edition of the journal.
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, the leading medical cause of amputations and non-genetic loss of vision.
The researchers who discovered betatrophin, HSCI co-director Doug Meltonand postdoctoral fellow Peng Yi, caution that much work remains to be done before it could be used as a treatment in humans. But the results of their work, which was supported in large part by a federal research grant, already have attracted 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.”
Type 2 diabetes, a disease associated with the national obesity epidemic, is usually caused by a combination of excess weight and lack of exercise. It causes patients to slowly lose beta cells and the ability to produce adequate insulin. One recent study has estimated that diabetes treatment and complications cost the United States $218 billion annually, or about 10 percent of the nation’s entire health bill.
“Our idea here is relatively simple,” Melton said. “We would provide this hormone, the type 2 diabetic 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.”
Though Melton sees betatrophin primarily as a treatment for type 2 diabetes, he believes it might play a role in the treatment of type 1 diabetes as well, perhaps boosting the number of beta cells and slowing the progression of that autoimmune disease when it’s first diagnosed.
“We’ve done the work in mice,” Melton said, “but of course we’re not interested in curing mice of diabetes, and we now know the gene is a human gene. We’ve cloned the human gene and, moreover, we know that the hormone exists in human plasma; betatrophin definitely exists in humans.”