IGF-1 and Insulin-Receptor Signalling in Insulin-Secreting Cells: From Function to Survival 23

Insulin and insulin-like growth factor 1 (IGF-1) receptors are ubiquitously expressed and regulate cell growth, survival, and function. In insulin-secreting cells, they contribute to proper insulin synthesis and secretion, as well as to overall pancreatic β-cell survival. The most convincing proof of the importance of these signalling pathways came from mice deficient in insulin receptors, IGF-1 receptors, or insulin receptor substrate-2 (IRS-2). Knockout of the insulin