Insulin-like growth factors and pancreas beta cells.
Abstract Insulin-like growth factors (IGFs) have been implicated in normal growth, and especially foetal pancreas beta-cell development. As low birth weight has been implicated in the development of obesity and type 2 diabetes, much research has evolved into the importance of IGF and their signalling pathways for pancreas beta-cell development, and for type 2 diabetes. Insulin-like growth factor-I signalling has a lot in common with insulin signalling, and is involved in diverse cellular effects such as antiapoptosis, protein synthesis, cell growth and mitogenesis. Insulin-like growth factor-II can be bound by the insulin receptor A subtype and the IGF-1 receptor, which may explain its antiapoptotic effect. Various knock-out model studies indicate that absence of IGF-I or the IGF-1 receptor is critical for foetal and postnatal growth. Similarly, knock-out models of post-receptor molecules (such as IRS-2) point to the physiological role of IGFs for pancreas beta-cell development. A beta-cell-specific IGF-1 receptor knock out model indicates the importance of IGF-I for beta-cell function. The Goto-Kakizaki (GK) rat, a model for diabetes, has insufficient beta-cell development, which may be related to its defective IGF-II synthesis. As normal pancreas beta cells adapt to the prevailing insulin resistance with increasing beta-cell function, it is possible that insulin resistance interacts with IGF signalling in pancreas beta cells.
van Haeften
T W
TW
Twickler
Th B
TB
D000818:Animals; D003924:Diabetes Mellitus, Type 2 / Q000503:physiopathology; D006801:Humans; D007328:Insulin / Q000378:metabolism; D007333:Insulin Resistance / Q000502:physiology; D007334:Insulin-Like Growth Factor I / Q000502:physiology; D007335:Insulin-Like Growth Factor II / Q000502:physiology; D007515:Islets of Langerhans / Q000254:growth & development* / Q000503:physiopathology; D051381:Rats; D015398:Signal Transduction / Q000502:physiology; D013002:Somatomedins / Q000502:physiology*
D007328:Insulin; D013002:Somatomedins; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II