Stem Cells Turned Into Insulin Producers Offer Promise for Diabetics
April 26, 2001 -- Undeveloped cells derived from mouse embryos can be coaxed in the lab into becoming a specialized type of insulin-producing cell. If the technique works in humans, it could represent a major breakthrough in the treatment of diabetes and could even replace injected insulin, report researchers in the April 26 issue of the journal Science.
But because the newly minted insulin-secreting cells are derived from a type of stem cell found only in the earliest stages of embryonic development, a human version of the treatment would face stiff opposition from the political and religious right, who oppose any medical research using cells from human embryos -- even when embryos created for the purpose of in vitro fertilization go unused and are slated for disposal.
"It's so short-sighted to try to deprive the world of a very promising intervention like this," stem cell researcher Evan Snyder, MD, PhD, tells WebMD. Snyder was not involved in the study.
If you'd like to share your opinion on the controversy, or just have a question about diabetes, go WebMD's Diabetes board, moderated by Gloria Yee, RN, CDE.
Type 1 diabetes is caused when the immune system turns on itself and begins to destroy its reservoir of beta-islet cells of the pancreas, the only cells in the body that produce the hormone insulin. Insulin is essential for the storage and efficient use by the body of energy obtained from food. People with type 1 diabetes must take multiple daily injections of insulin to replace the hormone that the missing beta cells would otherwise produce. In type 2 diabetes, the body still produces insulin, but the cells lose their ability to respond to it.
As Ron McKay, PhD, and colleagues from the National Institute for Neurologic Disease and Stroke report, it is possible to nudge stem cells from mouse embryos into becoming mature cells with all of the hallmarks of beta-islet cells, including their ability to release insulin in the presence of blood sugar.
When the cells were injected into mice with a form of drug-induced diabetes, the cells took on all the characteristics of insulin-secreting cells, and the mice maintained their weight and survived longer than similar, untreated animals. The injected cells did not fully restore blood sugar levels in the treated mice to normal, but this may have been due to the fact they are much less efficient at producing insulin than native beta cells, or because they were injected under the skin rather than directly into the pancreas.
McKay and colleagues built on earlier research showing that cells that grow up into brain and nerves are strikingly similar in early embryonic development to cells that go on to become part of the endocrine system, which controls hormones such as insulin.
"There has always been a belief that endocrine cells and neural cells have a kind of common history, way back early in development, and there are a lot of similarities between them, particularly beta cells of the pancreas," says Snyder, assistant professor of neurology at Harvard Medical School. "This work would support the common heritage that the two cell types have, and it would make some sense, in fact, that you could use selection techniques for neural cells to then derive endocrine cells, even from cells that seem to have the broad range of potential as embryonic stem cells do."