One of the primary challenges in curing type 1 diabetes is finding the best source of new insulin producing beta cells to replace the ones that have been destroyed by the body’s autoimmune response.  Researchers are investigating numerous potential sources of insulin producing cells. Currently, these sources include pancreatic islets transplanted from organ donors, adult stem cells, embryonic stem cells, induced pluripotent stem cells (iPS), cells transplanted from other species (xenotransplantation), and beta cells regenerated from within the body.

Last week, a researcher from Georgetown University announced a new cell type that may be a potential source to generate beta cells: human sperm stem cells.  The study, whose results were reported in an abstract at the American Society of Cell Biology annual meeting, involved the extraction of spermatogonial stem cells (SSCs) from the testicles of organ donors.  According to the abstract, the extracted cells acted as pluripotent stem cells, meaning they had the potential to develop into any type of cell in the body.  When transplanted into diabetic mice, the cells developed into insulin-producing cells that regulated the rodents’ blood sugar levels for a week.

While the development of a novel pluripotent stem cell source is certainly welcome, this particular study using SSCs raises a number of issues that need to be addressed before assessing its impact.  At present, the full results of this study have not been published in a journal, so we don’t yet know important details, such as what was done to the pluripotent stem cells to make them secrete insulin in the mice, and how their insulin secretion was assessed.  Also, we don’t know whether a similar approach in humans would overcome the body’s autoimmune response that causes type 1 diabetes in the first place.

JDRF is currently focused on developing new sources of insulin producing cells through beta cell therapies, including both replacement and regeneration methods described above.  Research involving stem cells is a chief component of this strategy.  Rather than focusing on discovering novel sources of stem cells, such as SSCs, JDRF’s priority is understanding how they differentiate into insulin producing beta cells, and putting this knowledge into practice.

Recently, two JDRF scientific staffers, Drs. Adrianne Wong and Concepcion Nierras, collaborated on an editorial for the journal Future Medicine on how beta cells derived from stem cells might be a commercially viable treatment and/or cure for type 1 diabetes.  The editorial includes a comprehensive discussion of the specific issues that need to be addressed and cites the steps necessary for success.   First, we need to further understand more about the biology of the insulin producing cells, and then we need to take what we’ve learned and apply it to the new cell source.  The beta cell or surrogate beta cell produced from the new source must be safe, and must secrete insulin in response to glucose.