A protein famous for slowing aging and increasing life span also acts as a metronome, helping coordinate metabolism and the body’s daily rhythms.
SIRT1, one of a group of proteins called sirtuins, plays roles in many cellular processes, including aging. Researchers hope that activating the protein with drugs such as resveratrol can extend life span and improve health for people, as it does in animal studies.
Now, researchers at MIT have evidence that SIRT1 may not only help determine long-term health and longevity, but it also has a hand in setting the body’s daily or “circadian” clock. The finding, reported May 31 at the Metabolism, Diet and Disease meeting, could be important for understanding how metabolism and life span are linked.
Studies of cells in laboratory dishes had suggested that SIRT1 might work with certain gears of the circadian clock in liver cells. But until now no one has shown that the protein could influence the body’s master clock in the brain, says Raul Mostoslavsky, a molecular biologist at Harvard Medical School.
In the new study, scientists led by Leonard Guarente of MIT monitored the natural activity patterns of mice. Normally, mice’s circadian clocks run just shy of a 24-hour day, at about 23.5 hours. Mice that lack SIRT1 in their brains have a longer internal day, closer to 24 hours, Guarente said. And mice that made twice as much SIRT1 as normal in their brains had a shorter-than-usual day. Mice making five times as much SIRT1 as normal had even shorter natural days.