UBC lab accomplishes diabetes breakthrough

Researchers at UBC have discovered how to cure Type 1 diabetes in laboratory mice. The lead researcher, UBC medical professor Timothy Kieffer, told the Georgia Straight in a phone interview that researchers in his lab have figured out how to genetically engineer cells in the animal’s gut to produce insulin at meal times.

Normally, insulin is produced by beta cells in the pancreas. However, in people with Type 1 diabetes, the immune system attacks the beta cells, which makes it impossible for them to produce their own insulin.

Kieffer said that the UBC researchers focused on K cells in the gut that produce a hormone, glucose-dependent insulinotropic polypeptide. This hormone, known as GIP, sends messages through the bloodstream to produce insulin when food is in the digestive tract. Using genetic engineering on mice with Type 1 diabetes, the researchers altered these cells so that instead of producing GIP, they produced insulin.

This insulin from the gut was able to absorb blood sugar in the mice with Type 1 diabetes, according to Kieffer. And for some reason, the animal’s immune system did not wipe out these insulin-producing K cells in the gut.

“What we find is that when the immune system in those animals attacks the beta cells, it doesn’t kill the insulin-producing K cells in the intestine, and those cells are thereby able to protect the animals from developing Type 1 diabetes,” Kieffer said. “We’re really excited.”

Insulin is essential to absorbing blood sugars in the bloodstream. Sustained high blood-sugar levels eventually wreak havoc on internal organs, causing heart disease, kidney damage, blindness, and other complications, including amputations.

The Kieffer lab’s research is funded by the Juvenile Diabetes Research Foundation, which is holding the Vancouver edition of its 2008 BC Telus Walk to Cure Diabetes on Sunday (May 25) at Swangard Stadium in Burnaby. (For more information, call 604-320-1937 or e-mail walkinfobc@jdrf.ca.)

Kieffer explained that funding from the JDRF was “critical” in making this discovery, which hasn’t yet been published in a peer-reviewed journal. He said his team will send the results out this summer for review. Kieffer added that the JDRF, which was formed by parents of children with Type 1 diabetes, recently awarded his lab another grant to engineer pig cells in the intestine to produce insulin.

“Hopefully, in the not-too-distant future, we’ll be able to find out if this idea works in humans,” he said.

In the past, Kieffer worked on teams that transplanted insulin-producing beta cells into pancreases of people with Type 1 diabetes. Although this procedure reduces the patients’ dependence on insulin for a while, their immune system eventually goes on the attack against these cells in the pancreas. As a result, the patients require immunosuppressive drugs.

The advantage of genetically engineering K cells in the gut is that it creates the possibility of using the body’s own cells to produce insulin, which may eliminate the need for immunosuppressive therapy. “Insulin injections are a very crude way to deliver insulin,” Kieffer said. “We think the answer is to put it back in the body and to have automatic meal-dependent insulin that’s in tune with nutrient intake. That’s what’s motivating us to come up with the gene-cell therapy approach.”