Betting on Beta Cells
Posted on February 2, 2019
Scientists working to find better treatments and potential cures for diabetes are turning more readily to stem cells.
Stem cells are a regenerative class of cells with the ability to develop into different types of tissues and organs. Stem cells can also regenerate without limit, which is useful for repairing tissue damaged by illness or injury.
These two benefits are precisely why researchers at Washington University School of Medicine in St. Louis are working to integrate stem cells into their diabetes research.
Stem Cells and Diabetes
Earlier projects have shown the benefit of stem cells for treating diabetes; stem cells can be transformed into islets, the cells that produce insulin. Insulin is the hormone the body needs to control blood sugar.
But, while these previous studies have proven the cells’ ability to develop additional islets, regulating the amount of insulin produced by these newly created cells has been difficult to control.
The WU researchers may have a fix.
The researchers were able to coax human stem cells into insulin-secreting beta cells that are more responsive to changing levels of glucose in the blood. In turn, the cells then produce the right amount of insulin.
“Individuals who are living with type 1 diabetes produce little or no insulin,” said Dr. Joel Singer, a New York physician.
Without insulin, blood glucose levels run rampant. Uncontrolled levels of glucose can wreak havoc on the entire body and cause damage to the kidneys, heart, eyes and peripheral nerves.
Keeping Blood Sugar Under Control
The WU researchers implanted the beta cells into mice that could not produce insulin. After a few days, they observed that the cells were creating insulin.
Over the next few months, the researchers tested the mice and found their blood sugar was being controlled.
The beta cells were more responsive than cells created in the previous study; they were able to react more quickly and adjust in the presence of glucose.
The St. Louis scientists believe their approach could help control blood sugar and mean new treatments for diabetes.
The research team is not new to diabetes and stem cell research; in 2014 some of the researchers worked on a Harvard study that used skin cells converted into stem cells to create insulin-creating beta cells. While coaxing the skin cells into beta cells was successful, the beta cells did not respond and adjust to blood glucose levels.
Instead, the cells were producing no glucose or way more glucose than was needed. The researchers believe their new beta cells will be more beneficial because of their responsiveness.
‘Recipe’ for Greatness
This round of beta cells was grown from human stem cells, but how the researchers produced the insulin-producing beta cells depended on adding in different factors at different times during growth.
This “recipe” helped the cells grow and mature into a functioning and responsive beta cell.
Once the beta cells were created, they were transplanted into diabetic mice that had been treated to prevent rejection of the cells. The transplanted beta cells began producing insulin at levels that effectively controlled blood sugar in the mice.
The researchers believe the next step for their beta cells is human trials, either using a gel to encapsulate the cells for delivery or using gene-editing tools to modify the genes of created cells to “hide” them from the immune system.
“The immune system is trained to attack foreign tissue,” Singer said.
Potential new treatments for diabetes are critical as the number of diagnosed cases continues to grow.
According to the American Diabetes Association, 1.25 million Americans have type 1 diabetes. The ADA estimates that the number is actually much higher, as many people go undiagnosed.
There are 40,000 cases of type 1 diabetes diagnosed each year in the United States.
Washington University School of Medicine. “New hope for stem cell approach to treating diabetes: Insulin-producing cells more responsive to fluctuating glucose levels.” ScienceDaily. ScienceDaily, 17 January 2019.