Healthy, insulin-producing beta cells in the pancreas have a relatively long life and typically do not replicate under normal conditions. Any loss of beta cells, therefore, is usually permanent. In the case of type 1 diabetes, for example, the destruction of beta cells by the body's own immune system is permanent.

Using a mouse model of type 1 diabetes, researchers found that alpha cells in the pancreas can actually regenerate into insulin-producing beta cells.  After all beta cells were destroyed using a special toxin to induce an animal model of type 1 diabetes, the remaining alpha cells in the pancreas that were not destroyed by the toxin converted to beta cells over time. The conversion was tracked by using a special marker placed in the alpha cells after the beta cells were destroyed.

Pedro Herrera and colleagues at the University of Geneva Medical School in Switzerland carried out the research.  The study was published April 4 in the online edition of the journal Nature.

The study is the first to show that a conversion from alpha cells to beta cells can happen spontaneously, without genetic manipulation.

Alpha cells in the pancreas normally produce glucagon, while beta cells are responsible for producing insulin.  Because insulin is necessary for survival, animals in the study were given insulin after destruction of the beta cells.  Slowly, as alpha cells converted to beta cells, less insulin was needed until it was no longer necessary.

One caveat to this finding is that the immune response to beta cells in type 1 diabetes continues regardless of where the beta cells came from.  Transplanted beta cells, for example, succumb to the immune system after a while and are destroyed.

The process by which alpha cells are converted is now under investigation in the lab and can be evaluated as a potential method of producing new beta cells for diabetes therapies. This research could be conducted either in differentiation settings in a lab dish or in induced regeneration in an animal.  A different program of alleviating the destruction by immune cells would have to coincide with this research to protect the newly formed beta cells.  

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Sources:

http://www.nlm.nih.gov/medlineplus/news/fullstory_97203.html

Nature abstract