Link between sirtuins and life extension strengthened

Link between sirtuins and life extension strengthened

ScienceDaily (Dec. 15, 2009) — A new paper from MIT biology professor Leonard Guarente strengthens the link between longevity proteins called sirtuins and the lifespan-extending effects of calorie restriction...sirtuins bring about the effects of calorie restriction on a brain system, known as the somatotropic signaling axis, that controls growth and influences lifespan length..."This puts SIRT1 at a nexus connecting the effects of diet and the somatropic signaling axis," says Guarente. "This is a major shot across the bow that says sirtuins really are involved in fundamental aspects of calorie restriction."...The researchers genetically engineered mice whose ability to produce the major mammalian sirtuin SIRT1 in the brain was greatly reduced. Those mice and normal mice were placed on a calorie-restricted diet. The normal mice showed much lower levels of circulating growth hormones, demonstrating that their somatotropic signaling system was impaired, but calorie restriction had no effect on hormone levels of mice that could not produce SIRT1..."