Georgetown University Medical Center researchers have shown results that suggest men may be able to make their own new insulin-secreting cells, potentially providing their own transplants for treatment of Type I (juvenile) diabetes. Why just men? Because the scientists took the stem cells from testicular tissue. In particular, the scientists isolated spermatogonial stem cells (SSCs) extracted from testicular tissue, and found that in culture the cells can morph into insulin-secreting beta islet cells normally found in the pancreas. They tested the cells by transplanting some into the backs of immune deficient diabetic mice, and found they were able to decrease glucose levels in the mice, demonstrating the cells were producing enough insulin to reduce hyperglycemia.

The results, so far unpublished, were presented at the American Society of Cell Biology annual meeting in Philadelphia.

The lead investigator, G. Ian Gallicano, says:

"These are male germ cells as well as adult stem cells. We found that once you take these cells out of the testes niche, they get confused, and will form all three germ layers within several weeks. These are true, pluripotent stem cells."

This is not the first report of pluripotent stem cells derived from testicular tissue. Previous reports were published in 2004, in 2006, in 2007, and in 2009 by an international collaboration and a German group. But the Georgetown report appears to be the first using human tissue to show production of insulin-secreting cells.