Using a cocktail of proteins inserted directly into the bodies of diabetic mice, researchers have converted normal pancreas cells into insulin-producing cells using a procedure that could pave the way for treating intractable diseases and injuries using the patient’s own abundant store of healthy tissue.

The Harvard University scientists activated a trio of dormant genes that commanded the cells to transform themselves, much like loading a computer operating system to change a PC into a Mac.

Within 10 days, the pancreas cells ceased their normal function – making gut enzymes to digest food – and instead produced insulin to regulate blood sugar, according to a study published online Wednesday in the journal Nature.

Doug Melton, co-director of the Harvard Stem Cell Institute and the study’s senior author, said the same approach could be used to generate motor neurons for patients with amyotrophic lateral sclerosis, make cardiac muscle cells for heart attack victims or create other cells that can repair damage wrought by a range of illnesses.

The method only has been tested in mice and is at least two to five years away from being tried in humans, he said.