When levels of the protein were increased in a group of fruit flies they lived longer, it shielded the flies from the effects of a protein-rich diet and helped maintain stem cells located in the fruit flies’ guts; an excessive amount of protein appears to have a link to a shorter lifespan.
Research has revealed that the benefits of dietary restriction aren’t so much tied to ingesting fewer calories overall but it is more so connected to the restriction of certain kinds of foods, specifically limiting the intake of proteins in general and their specific amino acids as being most important when it comes to the tangible benefits from dietary restriction.
According to the researchers, this study focused on using Sestrin’s impact on the TOR signalling pathway which is known to play an important role in longevity and lifespan. Their findings indicate that Sestrin could work as a novel potential anti-aging factor.
“We wanted to know which factor is responsible for measuring nutrients in the cell, especially amino acids, and how this factor affects the TOR pathway”, explains researcher Jiongming Lu. “We focused on a protein called Sestrin, which was suggested to sense amino acids. However, no one has ever demonstrated amino acid sensing function of Sestrin in a living being.”
“Our results in flies revealed Sestrin as a novel potential anti-aging factor”, says Linda Partridge, head of the research team.
“We could show that the Sestrin protein binds certain amino acids. When we inhibited this binding, the TOR signaling pathway in the flies was less active and the flies lived longer,” Lu continues. “Flies with a mutated Sestrin protein unable to bind amino acids showed improved health in the presence of a protein-rich diet.”
The study published in Nature Aging describes how when the Sestrin levels were increased in some of the fruit flies’ stomachs those flies lived 10% longer than the control flies, and more Sestrin in the gut helped to protect the flies against the adverse effects of too much protein.
“We are curious whether the function of Sestrin in humans is similar as in flies. Experiments with mice already showed that Sestrin is required for the beneficial effects of exercise on the health of the animal. A drug that increases the activity of the Sestrin protein might therefore be in future a novel approach to slow down the aging process,” Lu concludes.
