Men with Type 1 diabetes may eventually have a way to provide tissues for their own beta-cell transplants, reseachers have found. Stem cells that normally grow into sperm can be prodded to change into insulin-producing beta-cells instead, researchers from the Georgetown University Medical Center in Washington reported at the recent Philadelphia meeting of the American Society of Cell Biology.
If the technology can be scaled up and improved, it could eliminate many of the problems now associated with the use of stem cell technology and pancreas transplants. Transplants of whole pancreases or of isolated beta cells have a strong tendency to be rejected, so researchers must use powerful immune-suppressive drugs.
Furthermore, donor tissues are in short supply. Techniques used to convert adult tissues to so-called pluripotent stem cells occasionally produce problems, such as triggering tumors. Because the sperm cells would come from the man himself, rejection would not be a problem and because they are already stem cells, the induction of cancer is unlikely.
Biochemist G. Ian Gallicano of Georgetown and his colleagues obtained tissue from human testes from recently deceased donors and placed them in a special growth medium in the laboratory, where they began producing insulin. "These are true pluripotent stem cells," he said in a statement. When transplanted into the backs of immune-deficient mice, the cells cured diabetes for about a week before dying. More recent results, Gallicano said, show that the researchers are able to produce more insulin-producing cells and keep them alive longer. The challenge, he noted, is to make them survive for very long periods of time in the recipient.