Adult vs. Embryonic Insulin Stem Cells

A friend asked me about the report in Nature Medicine on the development of human embryonic stem cells that produce the hormons found in the pancreas. These cells were grown in cultures (in dishes, not animals and certainly not in humans) and don't appear to be able to respond to the levels of glucose. So they just sit there and make the insulin and other enzymes whether they're needed or not and can't make more when that's needed. The only advance over previous research is that these scientists are convince that the cells are actually making insulin and the other hormones because the cells have more insulin that the surrounding medium. Here's a more detailed review on the report.

The problem, as in all embryonic stem cells is finding a way to control the growth and development of the embryonic stem cells to prevent the formation of tumors and to achieve the cells that are needed.

Another group of scientists believe that they have discovered a way to prevent tumors by wrapping the embryonic stem cells in seaweed. I would think that this will add more than a couple of brand new variables and possible complications and hurdles to overcome before this will be helpful.

On the other hand, adult "mesenchymal stem cells" or "stromal cells" from the bone marrow can stimulate the Type II diabetics' own pancreas to make insulin on demand and also repair kidney damage from diabetes.

While there is not much popular press coverage, The best non-scientific report is at CBC.CA:


Scientific American gives more detail:

Before transplantation, the mice had severe hyperglycemia (high blood sugar) and a loss of function in B and T cells. Lower blood glucose levels were seen in treated mice by day 32 but not in untreated control mice. On days 17 and 32, human DNA sequences were found only in the pancreas and kidneys of treated mice.

Treated animals had an increase in pancreatic islets and beta cells that produced mouse insulin.

"In the (mouse) pancreas, the human cells promoted the regeneration of mouse cells that produce mouse insulin," Prockop told Reuters Health. "In the kidney, the human cells probably helped repair the damage that diabetes does to the kidneys. The cells were there after a month and we think they can probably last much longer."

From a press release at PRWeb.com:

Tulane University Researcher Darwin Prockop said of the tests: "We are not certain whether the kidneys improved because the blood sugar was lower or because the human cells were helping to repair the kidneys. But we suspect the human cells were repairing the kidneys in much the same way they were repairing the insulin-producing cells in the pancreas."

LifeEthics reported on these adult stem cells last February (even if the mainstream press did not), about Argentinean scientists who reported curing 85% of Type II diabetics with their own bone marrow stem cells. The the latest news covers a controlled experiment in mice to discover what the scientists have found since about what is actually happening in the patients.

In fact, Baylor College of Medicine (in Houston, Texas) reported finding insulin-producing stem cells in fat, bone and liver tissue of diabetic mice back in 2004. I imagine that that research is continuing.