UI researchers tout diabetes development

University of Iowa researchers say they've retrained human skin cells to produce insulin in mice, a discovery that they hope could someday help reverse the effects of diabetes in people.

The researchers are working toward a day when people with diabetes could avoid the need for insulin shots or pancreas transplants.

In a paper published online Wednesday by the Public Library of Science, the researchers explained that they took skin cells from adult humans and retrained them to act as if they were pancreas cells. The pancreas is the organ whose failure causes diabetes, a dangerous condition that leaves the body unable to process sugar.

The American Diabetes Association's top national expert called the Iowa research "a cutting-edge approach."

In the experiment, the transplanted cells essentially grew into a new pancreas near each mouse's kidney, said Dr. Nicholas Zavazava, a UI internal medicine professor who helped lead the study.

Zavazava said it would be at least several years before the approach could be tried in humans. But he expressed optimism about the project, which began in 2005. "We are no longer in the wilderness, like we were 10 years ago," he said.

Zavazava said stem cells from human embryos can be used to do the same thing. That method is controversial, however, because it involves the question of whether it's ethical to use embryonic tissue to treat diseases.

The new UI approach took skin cells from adult humans and transformed them into a version of stem cells. The cells then were treated with special proteins that encouraged them to act like pancreas cells. Then they were transplanted near the kidneys of the mice, which had been previously treated to have diabetes, the paper said. The cells grew into what amounted to new pancreases. Over time, most of the mice with the transplanted cells processed sugar better than similar mice that didn't get the transplants.

Dr. Samuel Dagogo-Jack, president of medicine and science for the American Diabetes Association, said several teams around the world are working on similar ideas. The Iowa team's results are some of the most successful so far, he said. "They're pushing the envelope in a very promising direction," said Dagogo-Jack, a diabetes specialist at the University of Tennessee Health Science Center and is not directly involved in the Iowa research.

Dagogo-Jack said experts were excited several years ago about the potential of transplanting insulin-producing cells from people who had died into people with diabetes. But there haven't been enough of those cells to make as much of a difference as hoped, he said. Dagogo-Jack said the type of method being tried in Iowa City could grow cells derived from patients' own systems. "If the body could be tweaked or cajoled into making its own insulin, basically we could solve the diabetes problem," he said.

Of course, just because something works in mice does not mean it would work in humans. One concern would be that the transplanted cells could grow out of control and become cancer. Zavazava said he believes that problem could be prevented. Also, he said, before the approach could be a practical treatment in people, researchers would have to find ways to grow larger volumes of the new cells than they're now producing in the lab. The Iowa doctor said his team is already working on that.

Zavazava said a California team is already conducting a human trial using embryonic stem cells, so it should be possible to gain approval for a human trial of his team's approach.

The UI project has been financed so far with a $650,000 grant from the Department of Veterans Affairs, for which Zavazava also works. He estimated that to move ahead with a human trial, the team would need $5 million to $10 million. They plan to seek money from the National Institutes of Health, but Zavazava noted that the federal agency's grants have been tougher to come by in recent years. He also said the team also could seek donations from private sources.