Someday, men with Type 1 diabetes may be cured using stem cells from their own testes, if a current line of research pans out.
Researchers have taken the stem cells that would differentiate into sperm from adult men and, after a five-week process, transformed them into cells that secrete insulin, just like the beta islet cells in the pancreas, which Type 1 diabetes destroys. The researchers will present their findings today (Dec. 12) at the American Society of Cell Biology 50th annual meeting in Philadelphia.
In Type 1 diabetes, the immune system attacks and destroys the beta-islet cells of the pancreas, so the body can no longer process glucose using insulin, the hormone they produce.
The technique is promising, but there's still work to do.
"We need to get the amount of insulin up to the point [of] being secreted from each cell that it will be enough to cure diabetes in humans," said G. Ian Gallicano, a developmental and stem cell biologist at Georgetown University Medical Center. "If you are a mouse and you have diabetes, you are in luck, we can help you."
Gallicano is collaborating with Stephen Clement, director of the Georgetown Diabetes Center, on this technique.
Scientists have tried a number of means to cure Type 1 diabetes by giving patients with the disease new insulin-producing cells. These have included transplanting both fetal and adult cells, and coaxing embryonic stem cells to become beta-islet cells, according to the National Institutes of Health. Stem cells from embryonic tissue can differentiate to become many different types of specialized tissue. Adults have stem cells, too, but their potential is much more limited. [Embryonic Stem Cells: 5 Misconceptions]
Embryonic stem cell research has also been a politically sensitive topic, because it involves the destruction of a human embryo. Because of this, researchers have experimented with other techniques, such as this one, to turn adult cells into beta-islet cells. One involves coaxing adult cells back to an embryonic-like state by introducing new genes into them — however, these produce cancer, according to Gallicano.
The spermatogonial stem cells, as those from the testes are called, naturally differentiate into sperm cells, or they create more of themselves. They can be coaxed into an embryonic-like state without any additional genes, and after becoming insulin-producing cells, they produce less cancer than other methods, according to Gallicano.
The researchers used cells from the testes of donors from the ages 16 through 57 and coaxed them back to an embryonic-like state, a two-week process. To convince the cells to become insulin producers, they exposed them to chemicals that stimulate differentiation at specific times over the course of about three weeks.
"What we are doing is trying to get these cells to think they are in an embryo and they are supposed to make islet cells," Gallicano told LiveScience.
The fact that the new insulin-producing cells come from the patient himself means his immune system won't fight them as foreign intruders. However, it's not yet clear if the self-destructive nature of Type 1 diabetes will be a problem.
"We don't know yet if the immune system will destroy the cells because they have become islet-like cells," he said.
A former high school student, Anirudh Saraswathula contributed to this research while working with Gallicano. Saraswathula, then a student at Thomas Jefferson High School for Science and Technology in Virginia, was the first person to duplicate the results of the protocol Gallicano developed, he said. In May, Saraswathula's work placed third in a international science competition held in Chicago.