>Reports this week from Nature Biotechnology (sorry, full access is subscription only) give hope for future stem cell treatments for insulin dependent diabetes by the production of beta islet cells found in the pancreas. Both concern the production of endoderm, the cell line layer in the embryo which develops into visceral organs and tissues such as the thymus, the lining of the intestines and lungs, and both the tissues found in the pancreas which produce digestive enzymes and the Islets of Langerhans, which regulate glucose.
The first article details the dedifferentiation and immortalization of human adult beta islet cells to stem cells that then can be induced to develop into functional human beta islet cells. The second article describes a protocol for the development of a line of “definitive” endoderm human embryonic stem cells (hESC) after identifying necessary triggers and markers.
Both articles are highly technical and name all sorts of enzymes and cultural requirements and proofs that the cells are what the experimenters say they are. Neither group produced cells that would be fit for implantation into human subjects. The first involves retroviruses and telomerase, the second. However, the first group of scientists was able to produce cells suitable for implantation into immune deficient diabetic mice. The mice were cured of their diabetes by the cells and the diabetes returned after the cells were removed. In contrast, the second group produced cells that remained immature and non-functional when implanted in mice.
Another big difference is that the second article received more notice in the press. I found only two articles on the mass production of beta islet cells by the ethical method, but there were at least 15 stories about the results of the hESC research. Could it be the opportunity to call for more embryo destruction that made the difference?
As I’ve said before, I’m convinced that the ultimate result will be regeneration at the site – with the stimulation of growth factors or some enzyme, not transplantation and certainly not the destruction of at least one embryo per cure.
In the meantime, let’s continue to limit the number of embryos we create and kill, okay?