Stem cell research is heralding a new age of possiblemedical treatments as scientists use them to grow transplantable cells andorgans.
Now, it appears those new treatments might include one fortype 2 diabetes.
Existing research has already found avenues to treat type 1diabetes. This less-common, early-onset form of diabetes occurs when the body’simmune 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 pancreashas lost.
However, type 2 diabetes – which makes up 90 percent ofdiabetes cases worldwide – is harder to treat. It typically occurs in adults asa result of excess weight or hormonal imbalances.
While people with type 2 diabetes do lose some of theirinsulin-producing cells, their primary problem is elsewhere. Their cells havebecome resistant to insulin. Although insulin is present in the body, the cellscan no longer use insulin to keep blood sugar levels in check. Simply regrowingthe missing insulin-producing cells is not enough to solve the problem.
Now, in new research published in StemCell Reports, scientists may have found a way.
A Two-Pronged Approach
To create a mouse model of type 2 diabetes, the researchersput mice on a high-fat, high-carb diet. The symptoms of type 2 diabetes soonfollowed. The mice became overweight, intolerant to glucose (blood sugar), andresistant 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 besafely implanted into the diabetic mice.
Once transplanted, the stem cells slowly matured intoinsulin-producing cells over the course of a few months. By three months, themice began to see beneficial effects. Among other improvements, they were gettingbetter at regulating their glucose levels. By the six-month mark, theimprovements were substantial.
However, while stem cells alone helped the mice, theyweren’t enough to fully reverse the diabetic state. So, the team added a secondangle 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 bloodsugar.
The combination of stem cell transplants and theantidiabetic drugs substantially improved the mice’s ability to processglucose. The sitagliptin produced the best results. Diabetic mice given stemcells and sitagliptin showed the same responses to eating sugar as thenon-diabetic mice on the low-fat diet.
The diabetic mice given drugs also lost much of their gainedbody weight, unlike those given stem cells but no antidiabetic drugs.
“Further testing is required, but our studies raise thepossibility that in addition to the potential for a stem-cell based therapy fortype 1 diabetes, this approach may also prove beneficial for treating the muchmore common form, type 2 diabetes,” said Timothy J. Kieffer, professor at theUniversity of British Columbia and supervisor of the research, in an interviewwith Healthline
A Global Epidemic
Diabetes affects 387 millionpeople worldwide and at least 21million people in the United States. In the U.S., diabetes treatment costshealthcare systems at least $612 billion, or 11percent of all medical spending on adults.
Without proper management and treatment, diabetes can causekidney failure, blindness, and gangrene leading to limb amputation. The WorldHealth Organization predicts that diabetes will be the 7th leading cause ofdeath by 2030.
This makes finding simple, effective, and streamlined curesfor diabetes a major healthcare priority. While currently expensive anddifficult to manage, stem cells may someday offer an affordable avenue oftreatment. The source of the stem cells also remains in question.
Kieffer’s research used human embryonic stem cells. Theseare better understood and therefore easier to transform into insulin-producingcells than the newer induced pluripotent stem cells (iPSCs), which can becreated from a person’s own adult cells. In the future, though, human embryosshouldn’t be necessary.
“We anticipate that with some protocol refinements, the sameresults could be obtained with pluripotent stem cells,” Kieffer said.
Kieffer isn’t sure if his findings will present a permanentcure, but they’re a solid step in the right direction.
“It is likely that empirical testing in patients will berequired to determine how long the cell therapy ultimately works,” heconcluded.
This work was performed as a collaboration between theUniversity of British Columba and BetaLogics, which is part of Janssen Research& Development.
The Canadian Institutes of Health Research RegenerativeMedicine and Nanomedicine Initiative, the Stem Cell Network, JDRF, and StemCell Technologies supported the research.