By “reprogramming” adult exocrine cells in mice pancreases to function as beta-like insulin producers, Harvard biologists have taken a giant step toward the use of cell regeneration therapy in the treatment of type 1 diabetes.
Building on a technique developed by Japanese biologist Shinya Yamanaka, Harvard researchers led by Qiao Zhou and Douglas A. Melton were able to return adult cells to an embryonic state in which they could be coaxed to take on a different function.
Yamanaka’s technique involved inserting proteins called transcription factors into the adult cells. Transcription factors control which genes are active in a cell and, therefore, its function.
The Harvard team identified three transcription factors that are active in the insulin-producing cells of the pancreas. They “hitched” the genes for these three factors to a virus that is known to infect exocrine cells in the pancreas.
Exocrine cells infected by the virus began taking on beta cell-like functions, including the production of insulin. The altered cells, however, did not cluster together in islets the way that genuine original beta cells do.
The Harvard findings are a boon to researchers because they confirm that adult cells are “pliable” enough to be manipulated to a degree greater than previously thought possible. Research with embryonic cells has taken longer than expected to produce the same kinds of results scientists are now enjoying with adult cells.
However, there are some cautions involved. For one thing, the FDA currently forbids the injection of viruses into human subjects for research. For another, although laboratory mice are analogous to human beings in many ways, there will have to be more research into whether human exocrine cells can be altered as readily as those in mice.