Stem cells aid muscle repair and strengthening after resistance exercise

University of Illinois kinesiology and community health professor Marni Boppart studies the mechanisms that enable muscles to recover and grow stronger after exercise. Credit: L. Brian Stauffer

A new study in mice reveals that mesenchymal (mezz-EN-chem-uhl) stem cells (MSCs) help rejuvenate skeletal muscle after resistance exercise.

By injecting MSCs into mouse leg muscles prior to several bouts of eccentric exercise (similar to the lengthening contractions performed during resistance training in humans that result in mild muscle damage), researchers were able to increase the rate of repair and enhance the growth and strength of those muscles in the exercising mice.

The findings, described in the journal Medicine and Science in Sports and Exercise, may one day lead to new interventions to combat age-related declines in and function, said University of Illinois kinesiology and community health professor Marni Boppart, who led the research.

"We have an interest in understanding how muscle responds to exercise, and which cellular components contribute to the increase in repair and growth with exercise," she said. "But the primary goal of our lab really is to have some understanding of how we can rejuvenate the aged muscle to prevent the physical disability that occurs with age, and to increase quality of life in general as well."

MSCs occur naturally in the body and may differentiate into several different cell types. They form part of the stroma, the connective tissue that supports organs and other tissues.

MSCs also excrete growth factors and, according to the new study, stimulate , called satellite cells, to expand inside the tissue and contribute to repair following injury. Once present and activated, actually fuse to the damaged and form new fibers to reconstruct the muscle and enhance strength.

"Satellite cells are a primary target for the rejuvenation of aged muscle, since activation becomes increasingly impaired and recovery from injury is delayed over the lifespan," Boppart said. "MSC transplantation may provide a viable solution to reawaken the aged satellite cell."

Satellite cells themselves will likely never be used therapeutically to enhance repair or strength in young or aged muscle "because they cause an immune response and rejection within the tissue," Boppart said. But MSCs are "immunoprivileged," meaning that they can be transplanted from one individual to another without sparking an immune response.

"Skeletal muscle is a very complex organ that is highly innervated and vascularized, and unfortunately all of these different tissues become dysfunctional with age," Boppart said. "Therefore, development of an intervention that can heal multiple tissues is ideally required to reverse age-related declines in mass and function. MSCs, because of their ability to repair a variety of different tissue types, are perfectly suited for this task."

More information: The paper, "Mesenchymal stem cells augment the adaptive response to eccentric exercise," is in press and is available online.

add to favorites email to friend print save as pdf

Related Stories

Exercise triggers stem cells in muscle

Feb 06, 2012

University of Illinois researchers determined that an adult stem cell present in muscle is responsive to exercise, a discovery that may provide a link between exercise and muscle health. The findings could lead to new therapeutic ...

Recommended for you

Growing a blood vessel in a week

18 hours ago

The technology for creating new tissues from stem cells has taken a giant leap forward. Three tablespoons of blood are all that is needed to grow a brand new blood vessel in just seven days. This is shown ...

Testing time for stem cells

21 hours ago

DefiniGEN is one of the first commercial opportunities to arise from Cambridge's expertise in stem cell research. Here, we look at some of the fundamental research that enables it to supply liver and pancreatic ...

Team finds key signaling pathway in cause of preeclampsia

Oct 23, 2014

A team of researchers led by a Wayne State University School of Medicine associate professor of obstetrics and gynecology has published findings that provide novel insight into the cause of preeclampsia, the leading cause ...

Rapid test to diagnose severe sepsis

Oct 23, 2014

A new test, developed by University of British Columbia researchers, could help physicians predict within an hour if a patient will develop severe sepsis so they can begin treatment immediately.

User comments