Stem Cell Treatments for Diabetes
For people with type 1 diabetes, life is a delicate balance of carbohydrate intake, insulin intake, and exercise. For most people, there is no permanent solution that eliminates the need to constantly balance carbs in and carbs out. In medical science, much of the research into treatments for type 1 diabetes centers on the transplantation of insulin-producing islet cells from a donor into a type 1 diabetic recipient.
Transplants are problematic, however, as the immune system does not take kindly to strangers. Even if donor cells are human, they are still sufficiently unlike the recipients that an immune reaction against the donor cells is triggered, resulting in rejection of the offending cells. To combat this problem the recipient must take immunosuppressive drugs that prevent rejection – and they must also deal with the fact that these drugs make them highly susceptible to infection.
Another potential solution is the generation of stem cells which can differentiate into insulin-producing islet cells. This approach could allow for the generation of self-cells which don’t trigger a rejection response when implanted into a diabetic recipient. (Note, however, that there is still the problem of preventing the destruction of the cells – because type 1 diabetes is an autoimmune disease caused by immune-mediated destruction of insulin-producing cells).
A group of researchers based in Singapore recently announced that they had been able to coax stem cells into differentiating into insulin-producing cells which, when implanted into diabetic mice, could reduce their blood sugar to normal levels.
Two important factors make this a potentially significant breakthrough in stem cell treatments for diabetes: first, the cells were able to continue sensing glucose levels and producing insulin over time, an important factor if any therapeutic potential is to be realized. Second, the cells did not form teratomas – a type of tumor which is associated with embryonic stem cells, and which would severely limit the therapeutic potential of any human treatment using the insulin-producing cells.
Another benefit of the work, apart from the therapeutic potential, is the development of a protocol which allows large quantities of insulin-producing cells to be generated in the laboratory. The fact that such cells have previously been available in limited supply has prevented in-depth study which could prove of benefit to medical science.
GuoDong Lia, Ruihua Luoa, Jiping Zhanga, Keng Suan Yeob, Qizhou Liana, Fei Xiea, Eileen Khia Way Tanb, Dorothée Caillec, Oi Lian Kond, Manuel Salto-Telleze, Paolo Medac and Sai Kiang Lim. Generating mESC-derived insulin-producing cell lines through an intermediate lineage-restricted progenitor line. Stem Cell Research. Volume 2, Issue 1, January 2009, Pages 41-55.
Guo Dong Lia, Ruihua Luoa, Jiping Zhanga, Keng Suan Yeob, Fei Xiea, Eileen Khia Way Tanb, Dorothée Caillec, Jianwen Qued, Oi Lian Kone, Manuel Salto-Tellezf, Paolo Medac and Sai Kiang Lim. Derivation of functional insulinnext term-producing cell lines from primary mouse embryo culture. Stem Cell Research. Volume 2, Issue 1, January 2009, Pages 29-40.