Transplanted pancreatic cells, including β cells, have been shown to re-establish the production of insulin in the pancreas but unfortunately, the demand for β cells far outweighs the supply. In October Nature Medicine, Robyn Tuttle and colleagues from University of Pennsylvania School of Medicine, Philadelphia, showed overexpression of active protein enzyme Akt1 caused murine β cells to grow larger and produce more insulin — an effect which may have the potential to enlarge the pool of β cells for transplants.

The 3-phosphoinositide–dependent protein kinase Akt is a signaling molecule that mediates the actions of insulin and insulin-like growth factor 1. Tuttle et al. created transgenic mice in which a constitutively active form of Akt1 was overexpressed in pancreatic β cells. In these mice they found a significant increase in both β cell size and total islet mass, accompanied by improved glucose tolerance and complete resistance to experimental...