It turns out that scientists who are striving to create more effective treatments for diabetes are turning towards stem cells.
Stem cells can be transformed into cells that produce insulin, the hormone that controls sugar.
However, the amount of insulin produced by these cells is difficult to control.
By tweaking the recipe for coaxing human stem cells into insulin-secreting beta cells, a team of researchers at Washington University School of Medicine in St. Louis has shown that the resulting cells are more responsive to fluctuating glucose levels in the blood.
The scientists found that when they transplanted the beta cells into mice that were unable to make insulin, the new cells began secreting insulin within a few days. They continued to control blood sugar in the animals for months.
The study was published in the journal Stem Cell Reports.
Speaking about the study, principal investigator Jeffrey R. Millman said, “We’ve been able to overcome a major weakness in the way these cells previously had been developed. The new insulin-producing cells react more quickly and appropriately when they encounter glucose.”
Millman, PhD, an assistant professor of medicine and of biomedical engineering added, “The cells behave much more like beta cells in people who don’t have diabetes.”
The researchers believe that it may be time to evaluate whether the same stem-cell approach could produce insulin and effectively control blood sugar in people.
Millman was earlier part of a research team at Harvard that, in 2014, converted skin cells into stem cells, and, in 2016, did the same thing with skin cells from a patient with diabetes. Each time, the stem cells were then treated with various growth factors to coax them into insulin-secreting beta cells. The beta cells, however, didn’t work as well as the researchers had hoped.
However, for the new study, Millman’s laboratory still grew beta cells from human stem cells, but they made numerous changes to the “recipe” for producing insulin-producing beta cells, treating the cells with different factors at different times as they grew and developed to help the cells mature and function more effectively.
Once complete, the researchers transplanted the beta cells into diabetic mice with suppressed immune systems so that they wouldn’t reject the human cells. Those transplanted cells produced insulin at levels that effectively controlled blood sugar in the mice, functionally curing their diabetes for several months, which, for most of the mice in the study, was about the length of their lives.
As laboratory researcher rather than a clinician, Millman said he can’t predict exactly when such cells may be ready for human trials but believes there are at least two ways that stem cell-derived beta cells could be tested in human patients.
The first, he says, would be to encapsulate the cells in something like a gel, with pores small enough to prevent immune cells from getting in but large enough to allow insulin to get out. He added, “Another idea would be to use gene-editing tools to alter the genes of beta cells in ways that would allow them to ‘hide’ from the immune system after implantation.”
According to Millman, if stem cell-derived beta cells are proven safe and effective for people with diabetes, his method of manufacturing the cells could be increased up to an industrial scale.