A Replacement for Exercise?

A protein called Sestrin might be responsible for many of the benefits of a good workout.

8:51 AM

Author | Kelly Malcom

Exercise gear in a bottle

 

Whether it be a brisk walk around the park or high intensity training at the gym, exercise does a body good. But what if you could harness the benefits of a good workout without ever moving a muscle? Michigan Medicine researchers studying a class of naturally occurring protein called Sestrin have found that it can mimic many of exercise's effects in flies and mice. The findings could eventually help scientists combat muscle wasting due to aging and other causes.

"Researchers have previously observed that Sestrin accumulates in muscle following exercise," said Myungjin Kim, Ph.D., a research assistant professor in the Department of Molecular & Integrative Physiology. Kim, working with professor Jun Hee Lee, Ph.D. and a team of researchers wanted to know more about the protein's apparent link to exercise. Their first step was to encourage a bunch of flies to work out.

Taking advantage of Drosophila flies' normal instinct to climb up and out of a test tube, their collaborators Robert Wessells, Ph.D. and Alyson Sujkowski of Wayne State University in Detroit developed a type of fly treadmill. Using it, the team trained 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. "Flies can usually run around four to six hours at this point and the normal flies' abilities improved over that period," says Lee. "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. In fact, flies with overexpressed Sestrin didn't develop more endurance when exercised.

The beneficial effects of Sestrin include more than just improved endurance. Mice without Sestrin lacked the improved aerobic capacity, improved respiration and fat burning typically associated with exercise.

LISTEN UP: Add the new Michigan Medicine News Break to your Alexa-enabled device, or subscribe to our daily updates on iTunesGoogle Play and Stitcher.

"We propose that Sestrin can coordinate these biological activities by turning on or off different metabolic pathways," says Lee. "This kind of combined effect is important for producing exercise's effects."

Lee also helped another collaborator, Pura Muñoz-Cánoves, Ph.D., of Pompeu Fabra University in Spain, to demonstrate that muscle-specific Sestrin can also help prevent atrophy in a muscle that's immobilized, such as the type that occurs when a limb is in a cast for a long period of time. "This independent study again highlights that Sestrin alone is sufficient to produce many benefits of physical movement and exercise," says Lee.

Could Sestrin supplements be on the horizon? Not quite, says Lee. "Sestrins are not small molecules, but we are working to find small molecule modulators of Sestrin."

Additionally, adds Kim, scientists still don't know how exercise produces Sestrin in the body. "This is very critical for future study and could lead to a treatment for people who cannot exercise."

MORE FROM THE LAB: Subscribe to our weekly newsletter

The work appears in the journal Nature Communications.


More Articles About: Lab Report All Research Topics Sports Training Fitness Training Sports Medicine & Fitness
Health Lab word mark overlaying blue cells
Health Lab

Explore a variety of health care news & stories by visiting the Health Lab home page for more articles.

Media Contact Public Relations

Department of Communication at Michigan Medicine

[email protected]

734-764-2220

Stay Informed

Want top health & research news weekly? Sign up for Health Lab’s newsletters today!

Subscribe
Featured News & Stories balancing scale of food and hand reaching purple background yellow scale
Health Lab
All FODMAPs aren’t created equal: working toward alternative diets to manage IBS
Two studies from Michigan Medicine may provide hope for patients with irritable bowel syndrome (IBS) struggling to implement the traditional low-FODMAP diet.
woman sitting at table in stripe shirt stressed seeming white background window
Health Lab
An unequal toll of financial stress
Inflation rates may have cooled off recently, but a poll shows many older adults are experiencing financial stress – especially those who say they’re in fair or poor physical health or mental health
sunscreen blue people outside
Health Lab
Sunscreen dispensers make skin cancer prevention easier
Medical students have worked to place dispensers at parks, pools and golf courses around Washtenaw County to give people easy access to sunscreen.
woman laying down and sheet over going into surgery
Health Lab
Older women more likely to receive heart surgery, die at low quality hospitals
Women over the age of 65 who require complex heart surgery are more likely than men to receive care at low quality hospitals — where they also die in greater numbers following the procedure, a Michigan Medicine study finds.
Cancer cell microscopic, colored yellow
Health Lab
Researchers find common immune system mechanism between pregnancy, cancer
Researchers find common immune system mechanism between pregnancy, cancer
food photo
Health Lab
Nanoparticles reprogram mouse immune systems to cope with allergens
Two doses of allergen-encapsulating nanoparticles delivered intravenously prevented anaphylaxis during a food allergy test in mice, according to new research.