A new study in Switzerland demonstrated that mice can regenerate beta cells in the pancreas after all of the original cells have been destroyed, giving some hope to those with type I diabetes. They were formed from alpha cells also present in the pancreas.
Alpha and beta cells are two types of cells that form islets of Langerhans, areas in the pancreas that secrete hormones. Alpha cells secrete the hormone glucagon, which is released when we need to raise our blood glucose levels. Beta cells release insulin, which decreases glucose. In type I diabetes, the body attacks beta cells so that insulin is no longer produced in response to high glucose levels. Chronically high blood glucose is toxic to many cells in the body, and diabetics can and often do have a number of problems such as kidney disease and ocular problems.
Interestingly when mice with an adult pancreas were given insulin, the alpha cells were able to spontaneously become beta cells even when more than 99% of them were destroyed. These beta cells functioned normally and when a sufficient number were present, the mice no longer needed insulin.
Although this is very exciting in terms of treating people with type I diabetes, one major issue remains. Type I diabetes is an autoimmune disease in which the body sees the beta cells as foreign and attacks them. Even when doctors have transplanted beta cells into people, they are eventually destroyed by the immune system and they need to start taking insulin again.
Alpha cells are not attacked by the immune system under normal circumstances, but if they could be programmed to become beta cells, the immune system would most likely destroy the newly generated cells.
Unfortunately, observations in mice do not always mean that the same thing can be done in humans, but it does provide us with a greater understanding of biological mechanisms. This study does suggest that insulin therapy alone could regenerate beta cells in humans with type I diabetes if scientists can figure out how to prevent the immune system from attacking them.
In addition to learning more about the process alpha cells undergo to become beta cells, hopefully this study prompts more research into why the immune system attacks beta cells in the pancreas. It is likely that both approaches will have to be understood and managed to treat and possibly cure type I diabetes. [Yahoo! Health Day]