Stem cell research is heralding a new age of possible medical treatments as scientists use them to grow transplantable cells and organs.
Now, it appears those new treatments might include one for type 2 diabetes.
Existing research has already found avenues to treat type 1 diabetes. This less-common, early-onset form of diabetes occurs when the body’s immune system attacks and destroys insulin-producing cells in the pancreas, often while fighting an infection elsewhere in the body. By using stem cells, doctors can grow new insulin-producing cells to replace those that the pancreas has lost.
However, type 2 diabetes – which makes up 90 percent of diabetes cases worldwide – is harder to treat. It typically occurs in adults as a result of excess weight or hormonal imbalances.
While people with type 2 diabetes do lose some of their insulin-producing cells, their primary problem is elsewhere. Their cells have become resistant to insulin. Although insulin is present in the body, the cells can no longer use insulin to keep blood sugar levels in check. Simply regrowing the missing insulin-producing cells is not enough to solve the problem.
Now, in new research published in Stem Cell Reports, scientists may have found a way.
A Two-Pronged Approach
To create a mouse model of type 2 diabetes, the researchers put mice on a high-fat, high-carb diet. The symptoms of type 2 diabetes soon followed. The mice became overweight, intolerant to glucose (blood sugar), and resistant to insulin. Their blood sugar levels skyrocketed.
Next came the attempt to reverse the induced diabetic state. The research team cultured human embryonic stem cells and prepared them to be safely implanted into the diabetic mice.
Once transplanted, the stem cells slowly matured into insulin-producing cells over the course of a few months. By three months, the mice began to see beneficial effects. Among other improvements, they were getting better at regulating their glucose levels. By the six-month mark, the improvements were substantial.
However, while stem cells alone helped the mice, they weren’t enough to fully reverse the diabetic state. So, the team added a second angle of attack. They also treated the mice with antidiabetic drugs.
Two drugs in particular showed promise: metformin (Glucophage), which reduces the rate at which the liver manufactures glucose, and sitagliptin (Januvia), which boosts insulin production and regulates blood sugar.
The combination of stem cell transplants and the antidiabetic drugs substantially improved the mice’s ability to process glucose. The sitagliptin produced the best results. Diabetic mice given stem cells and sitagliptin showed the same responses to eating sugar as the non-diabetic mice on the low-fat diet.
The diabetic mice given drugs also lost much of their gained body weight, unlike those given stem cells but no antidiabetic drugs.
“Further testing is required, but our studies raise the possibility that in addition to the potential for a stem-cell based therapy for type 1 diabetes, this approach may also prove beneficial for treating the much more common form, type 2 diabetes,” said Timothy J. Kieffer, professor at the University of British Columbia and supervisor of the research, in an interview with Healthline
A Global Epidemic
Diabetes affects 387 million people worldwide and at least 21 million people in the United States. In the U.S., diabetes treatment costs healthcare systems at least $612 billion, or 11 percent of all medical spending on adults.
Without proper management and treatment, diabetes can cause kidney failure, blindness, and gangrene leading to limb amputation. The World Health Organization predicts that diabetes will be the 7th leading cause of death by 2030.
This makes finding simple, effective, and streamlined cures for diabetes a major healthcare priority. While currently expensive and difficult to manage, stem cells may someday offer an affordable avenue of treatment. The source of the stem cells also remains in question.
Kieffer’s research used human embryonic stem cells. These are better understood and therefore easier to transform into insulin-producing cells than the newer induced pluripotent stem cells (iPSCs), which can be created from a person’s own adult cells. In the future, though, human embryos shouldn’t be necessary.
“We anticipate that with some protocol refinements, the same results could be obtained with pluripotent stem cells,” Kieffer said.
Kieffer isn’t sure if his findings will present a permanent cure, but they’re a solid step in the right direction.
“It is likely that empirical testing in patients will be required to determine how long the cell therapy ultimately works,” he concluded.
This work was performed as a collaboration between the University of British Columba and BetaLogics, which is part of Janssen Research & Development.
The Canadian Institutes of Health Research Regenerative Medicine and Nanomedicine Initiative, the Stem Cell Network, JDRF, and Stem Cell Technologies supported the research.