Insulin-producing Gene Discovered in Diabetic Mice

Researchers have discovered that neurogenin3 is the gene crucial to inducing the production of insulin in the liver.

Dr. Lawrence C.B. Chan and his colleagues at the Baylor College of Medicine originally cured Type I diabetes in mice more than five years ago by inducing the production of insulin in the liver cells.

Now, they have used a disarmed virus to inject neurogenin3 into the livers of diabetic mice, which dropped the level of the mice’s blood sugar immediately. The mice’s blood sugar level stayed at a normal rate for the rest of their “normal lives,” according to their press release.

The discovery involved a two-step process. Neurogenin3 first traveled into the mature liver cells and produced small quantities of insulin that were still significant enough to return blood sugar to normal. Other cells that made larger amounts of insulin were produced later, around the portal veins, in a cluster of adult stem cells.

Neurogenin3 changed the direction of these stem cells from a safety net for liver injuries to insulin-producing islet cells.

According to Vijay Yechoor, MD, assistant professor of medicine-endocrinology and lead author of the study, published in the March issue of Developmental Cell, the islet cells look similar to the cells made by the pancreas after an injury.

Neurogenin3 was the crucial component in the success of this experiment, added Yechoor, because the fate of the mature liver cells seems unchangeable before the induction of the gene.

Chan said that this discovery is significant, even though much more research needs to be done before they are eventually able to treat people with diabetes.

"The concept is important because we can induce normal adult stem cells to acquire a new cell fate,” Chan said. “It might even be applicable to regenerating other organs or tissues using a different gene from other types of adult stem cells.”