In a world’s first, University of B.C. scientists used human embryonic stem cell transplants to reverse diabetes in mice with the disease.
A 13-member team whose work is published in the journal, Diabetes, show that as the stem cells matured into insulin-secreting cells (beta-cells in the pancreas), a few dozen diabetic mice were gradually weaned off insulin over a period of months.
“It took about four to five months for the (stem) cells to become functional in our experiments and the mice were able to maintain good blood glucose levels even when fed a high glucose diet,” said lead author Timothy Kieffer, a UBC professor in the department of cellular and physiological sciences.
Type 1 (otherwise known as juvenile diabetes) is an autoimmune disease in which a patient’s immune system kills off insulin producing cells in the pancreas. Typically, patients must inject themselves with insulin or use insulin pumps to control their blood glucose levels.
While pancreatic islet cell transplantation — pioneered at the University of Alberta several years ago — has been shown to be an effective way of reducing dependence on insulin injections, such treatment is costly and cumbersome since it requires cadaveric donor cells which are always in short supply. As well, islet cell transplant patients must forever take anti-rejection drugs that can cause organ damage.
To conduct the new study, mice were anesthetized and then infused with millions of cells derived from stem cells which were then placed under the left kidney area. Although the research showed that stem cells are full of potential as a diabetes cure one day, it also revealed there are still a few pitfalls to overcome before agencies like the Food and Drug Administration in the United States or Health Canada approve such a therapy.
For one, some mice developed bone or cartilage in areas where the cells were inserted, an unacceptable side-effect that future experiments must resolve.
Another obstacle is that the mice used in the study weren’t typical; they were a special strain, bred to be immuno-compromised so they wouldn’t reject the human cells as foreign invaders. Studies are continuing at UBC, in many more mice, to determine the feasibility of a method to encapsulate stem cells in a membrane material that won’t be recognized as a foreign body and rejected. Kieffer said he’s extremely encouraged by the fact that mice were not only weaned off their need for insulin but they also lived well and long, even though they were bred to be immune deficient. Still, research must carry on to investigate ways to fine tune the approach so that cells don’t evolve into something other than what’s desired. In the early stages of the experiment, some mice developed fluid-filled cysts, a problem that was rectified in the laboratory with a cell culture medium change.
“The fact that we saw cartilage-like cells means that we failed to restrict for only desirable cells and that proves the potential risks of this approach. We need to ensure that we’re getting only what we want (insulin-producing cells) and that may be done by improving the cultivation and the recipe or by purifying the cells,” Kieffer said, referring to ongoing studies
Health-e-Solutions comment: I don’t find this work particularly exciting inits current form. It has a long way to go before it could be feasible to try in humans. Even then, there is no guarantee it would work the same way it did in mice. The trick is always to find a way to suppress only the unwanted autoimmune response without effecting the rest. Until something better comes along, we will live the Health-e-Solutions lifestyle and enjoy the almost cure-like benefits it has provided or two boys with type 1 diabetes.