Scientists Get Closer to Generating Cells Lost to Diabetes
People with diabetes often don't have enough insulin-producing beta cells to control their blood sugar, but a combination of two novel drugs may coax the body into making more of these vital cells, an early study finds.
Together, the drugs caused beta cells to reproduce at a rate of about 5 percent to 8 percent a day, according to the researchers. Work has only been done in the lab and in rodents, and a major hurdle remains before this treatment could be tried in humans: researchers need to develop a targeted delivery system.
"We're at a stage where we have nuclear warheads but no guided missiles. We can't just release the treatment because we don't want to affect other cells," explained study senior author Dr. Andrew Stewart. He's the director of the Mount Sinai Diabetes, Obesity and Metabolism Institute in New York City.
Stewart said researchers are now working on ways to deliver the medication only to beta cells, and he's hopeful that they'll make progress on that front.
"While it might not seem fast for people with diabetes, the rate of progress in beta cell regeneration has been astonishingly fast on the scientific side. Ten years or so ago, there were no drugs that could regenerate beta cells. Now we have those drugs," he said.
Beta cells are found in the pancreas and they produce the hormone insulin. This hormone ushers the sugar from foods into the body's cells to be used as energy.
People with type 2 diabetes are resistant to the effects of insulin, and may not make enough insulin. About 30 million people in the United States have type 2 diabetes, according to the American Diabetes Association (ADA). Type 2 diabetes is associated with obesity and a sedentary lifestyle.
Type 1 diabetes is an autoimmune disease that causes the body to mistakenly destroy beta cells. People with type 1 diabetes make little to no insulin, and must replace that lost insulin through injections or an insulin pump. Approximately 1.25 million Americans have type 1 diabetes, the ADA says.
The current research builds off previous work done by Stewart's group. The researchers found that a drug called harmine could prompt beta cell regeneration in the lab and in mice. But harmine could only regenerate about 2 percent of beta cells a day, which isn't sufficient, according to Stewart.
That led the researchers to look for another drug to use with harmine. They found one that boosted the beta cells' ability to reproduce by as much as 18 percent when combined with harmine (the average was 5 to 8 percent a day).
Andrew Rakeman is assistant vice president of research for JDRF (formerly the Juvenile Diabetes Research Foundation). He said, "These findings are really exciting. If we go back 10 or 12 years ago, the idea that you could even get beta cells to regrow or regenerate was controversial. Now we know not only is it possible, but it could be impactful."
He did add a caveat, however. "There are still some challenges ahead," Rakeman said.
One is developing a drug delivery system. Another is the concern that in people with type 1 diabetes, it's possible the immune system might destroy any newly made beta cells. And it isn't clear if the drug combination would be able to reproduce the cells quickly enough to make a difference if the immune system was attacking the new cells.
There's also a concern that a drug designed to make beta cells reproduce could induce other cells in the body to reproduce and cause unwanted side effects.
"There's still work to do before testing in people. But this study highlights what the next steps need to be," Rakeman said.
The findings were published Dec. 20 in the journal Cell Metabolism.
Learn more about diabetes from the American Diabetes Association.
SOURCES: Andrew Stewart, M.D., director, Mount Sinai Diabetes, Obesity and Metabolism Institute, New York City; Andrew Rakeman, Ph.D., assistant vice president, research, JDRF; Dec. 20, 2018, Cell Metabolism