Researchers have long debated the presence of stem cells in the pancreas that generate insulin-producing beta cells. Now researchers have shown that beta cells are indeed produced in the adult mouse pancreas, which means the tissue must contain stem cells.

The paper, published today (January 24) in Cell, "reconciles some conflicting observations that have been around for a while in regards to these special progenitors," Jake Kushner, from the University of Pennsylvania, who was not involved in the study, told The Scientist. For a long time there was conflicting data on whether or not beta cell progenitor cells existed in the pancreas, he added; in particular, the expression of Neurogenin 3(Ngn3), the earliest islet beta cell transcription factor in embryonic development, had been seen in low amounts by some researchers, in high amounts by others.

The researchers, led by Harry Heimberg, at Vrije Universiteit Brussel in Belgium, purified tissue sections from the pancreas of adult mice. They used an injury model to induce rapid cell turnover in the pancreas. They cultured the cells and found that the injured tissue does indeed express Ngn3, at double the amount of normal pancreatic cells -- implying that the tissue must contain the progenitor cells. Whether this injury model reveals a pathway for Ngn3 expression is still not clear, said Kushner. "But it opens a whole new window into the field."