Exercise is among the best intercessions for age-related mobility decline and metabolic dysregulation. Albeit long term endurance exercise promotes insulin sensitivity and extends respiratory capacity, genetic components, and pathways intervening the metabolic advantages of exercise have remained elusive.
Now, scientists have identified a protein that may be responsible for many of the benefits of a good workout. The study could lead to advancements that could eventually help combat muscle wasting due to aging and other causes.
Called ‘Sestrin,’ the protein mimics both molecular and physiological effects of exercise, suggesting that it could be a significant effector of exercise metabolism.
In both fly and mouse models, scientists observed that the genetic ablation of Sestrins prevents organisms from acquiring metabolic benefits of exercise.
Myungjin Kim, a research assistant professor at the University of Michigan in the US, said, “Researchers have previously observed that Sestrin accumulates in muscle following exercise.”
Scientists were keen to determine the association between protein and exercise. They thus took advantage of Drosophila flies’ healthy instinct to climb up and out of a test tube.
Their collaborators from Wayne State University in Detroit developed a kind of fly treadmill. Using it, the group prepared the flies for three weeks and compared the running and flying ability of normal flies with that of flies bred to lack the ability to make ‘Sestrin.’
Lee said, “Flies can usually run around four to six hours at this point, and the normal flies’ abilities improved over that period. The flies without Sestrin did not improve with exercise.”
What’s more, when they overexpressed Sestrin in the muscles of normal flies, essentially maxing out their Sestrin levels, they found those flies had abilities above and beyond the trained flies, even without exercise. Flies with overexpressed Sestrin didn’t develop more endurance when exercised.
When tested in mice, scientists found that mice without Sestrin lacked the improved aerobic capacity, improved respiration, and fat burning typically associated with exercise.
Lee said, “We propose that Sestrin can coordinate these biological activities by turning on or off different metabolic pathways. This kind of combined effect is important for producing exercise’s effects.”
“This independent study again highlights that Sestrin alone is sufficient to produce many benefits of physical movement and exercise. But that does not mean that Sestrin supplements are on the horizon.”
The study is published in the journal Nature Communications.