University of Florida adult stem cell experts have restored normal blood sugar levels in diabetic mice for three months by chemically coaxing bone marrow cells to produce insulin, a hormone normally made in the pancreas.
The findings demonstrate the continued importance of adult stem cell research and may one day help doctors combat a form of diabetes in people, said senior author Bryon Petersen, an assistant professor of pathology, immunology and laboratory medicine at UF’s College of Medicine. But crucial questions about the treatment’s potential may take another decade to answer.
“This is a preliminary study conducted in animals with diabetes,” Petersen said. “But I think it’s a very profound study, since it shows that adult stem cell plasticity still exists and that if we understand how we can get a cell to differentiate, we can actually teach an old dog some new tricks.”
The study was funded by grants from the National Institutes of Health and other sources totaling $2 million.
Stem cells change into other types of cells, a process called differentiation, Petersen said. Human embryos contain large quantities of embryonic stem cells needed for tissue development. After birth, another type called adult stem cells are produced that act to repair the body. Experts disagree about the potential medical value of adult stem cells.
“There are still a lot of questions that we need to answer in the different facets of stem cell research,” Petersen said. “Everybody tends to give the pat answer that clinical applications of stem cell technology are at least 10 years down the road. The way the field is moving, it may be 10 years, it may be sooner.”
UF researchers conducted the study on bone marrow stem cells obtained from adult rats, he said. Using a unique chemical process, the reseachers induced laboratory cultures of cells to form clusters that produced insulin and three other hormones usually made only in the pancreas by structures called the islets of Langerhans. When the clusters were implanted in nine diabetic mice, the animals’ blood sugar levels dropped from about 550 milligrams per deciliter to 200 milligrams per deciliter and remained stable for three months. The mice were fed the same diet throughout the study.
“Whether or not these (clusters) are full, mature islets remains to be seen,” said Petersen, who also is associated with the UF College of Medicine’s Program in Stem Cell Biology and Regenerative Medicine. “But they are (similar) enough that they will play by the same rules as a normal islet would in the pancreas.”
Petersen and lead investigator Seh-Hoon Oh, a UF research associate, hope to get similar results in a future study using laboratory cultures of human bone marrow stem cells or umbilical cord blood cells, Petersen said. Eventually, the treatment could be useful against type 1 diabetes, a disease in which the immune system attacks the islets of Langerhans and destroys them, reducing the body’s supply of insulin. The hormone is needed to convert sugar and starch into energy.
Type 1 diabetes accounts for 5 percent to 10 percent of America’s 12 million diagnosed diabetes cases, according to the American Diabetes Association. Its cause is unknown but both genetics and environmental factors may play a role. The disease, usually diagnosed in children and young adults, almost always must be controlled with daily shots of insulin. Complications can include heart disease, blindness, nerve damage and kidney damage.
The UF study suggests that eventually it may be possible to take bone marrow from a person, put it in culture, turn it into islet cells and then return it to the same person as an islet cell transplant, said Dr. Neil Theise, an attending physician in the departments of pathology and medicine at Beth Israel Hospital in New York who is considered an expert on adult stem cells.