Diabetes and the Stem Cell Promise
The search for a cure, or even a less-complicated treatment, is still on a long road to its goal.
Ever since scientists started talking about the medical potential of embryonic stem cells, curing Type 1 diabetes has been one of the dearest dreams.
Years later, scientists are still studying how embryonic stem cells, which can develop into any type of cell in the body, can be coaxed to become cells that make insulin at just the right time, in just the right amounts, and that can be transplanted into patients to cure diabetes. Getting the cells to develop properly and figuring out how to administer them safely has been challenging.
"It's maddeningly simple as a concept," says Dr. Gordon C. Weir, a longtime diabetes researcher at the Joslin Diabetes Center in Boston. "It's been incredibly frustrating that we can't bring this to the clinic more quickly."
Healthy people have about a million functioning islets in the pancreas, each comprised of about 1,000 beta cells. In Type 1 diabetes, those islets are destroyed. Restoring the islet cells would cure the disease — and researchers already know that they can do that. Scientists made the first successful islet cell transplant in 1989, placing beta cells from a cadaver into a diabetic patient.
If there were enough cadaver pancreases to go around, a better diabetes treatment would already be available. But there aren't. But if scientists can figure out how to turn embryonic cells (or adult cells that have been transformed back to a versatile, embryonic state) into functioning beta cells, they'll have access to a possibly endless supply for transplantation.
But fine-tuning the cells to make them safe and effective for human use will take time. For example, beta cells respond to body cues to produce just the right amount of insulin when it's needed and thus regulate glucose levels with great precision. If you make beta cells that produce too much insulin, the level of glucose can drop dangerously low — and people can pass out, lapse into a coma or even die.
"We have not regenerated the intricate mechanisms that regulate the levels of secretions," says Matthias Hebrok, director of the UC San Francisco Diabetes Center. "Beta cells are like a Porsche — an amazing, calibrated machine. What we've made is more like a Volkswagen Beetle."
Another major problem facing a cure in humans is the issue of autoimmunity — the problem that causes Type 1 diabetes in the first place. "Even if we are able to generate beta cells from stem cells, if you put them into a patient with Type 1 diabetes, they'll be eliminated, because the immune system is primed to destroy those cells," Hebrok says.
Currently, physicians combat autoimmune responses with anti-rejection drugs. In the future, immunologists hope to figure out ways to specifically interfere with the interaction of the immune system and beta cells.
Researchers all say they can't predict when stem cell therapies for diabetes might become available. The pace of progress can seem unbearably slow to some.
"There was too much hype for this type of technology. There are no shortcuts in this kind of research," says Dr. Camillo Ricordi, an islet cell transplantation expert at the University of Miami Diabetes Research Institute. "Next century, when you look back at it, two decades won't seem like much. But for those affected right now, every month is too long."
Health-e-Solutions Comment: Islet cell transplant, touted as a “better diabetes treatment” in the above article, is not better for a number of reasons. Recipients must take anti-rejection drugs, which can lead to infection and organ damage, to prevent the body from attacking the foreign cells. Also, because of autoimmunity, their new beta cells peter out or are destroyed and a new transplant is needed. I do not think this constitutes a “better” treatment for the vast majority of people with diabetes. Autologous stem cell transplant hold much more promise and is far less invasive. Still, the problem of autoimmunity remains.
Of course I am persuaded that, when available, natural remedies are always better than man-made interventions. I would rather live a healthy, natural, healing lifestyle than put my hope in this type of transplant. If a cure for type one diabetes comes along with few or no major side effects, I will rejoice! But for now, I am grateful for the freedom provided by the diabetic-alkaline lifestyle.