Muscle regeneration compromises stability in muscular dystrophy

March 1, 2018, American Physiological Society

A new study finds that muscle fibers in Duchenne muscular dystrophy (DMD) split during regeneration to such an extreme that the muscle is weakened beyond repair. The article is published ahead of print in the American Journal of Physiology—Cell Physiology.

DMD is a genetic degenerative disorder that affects mostly boys. People with DMD do not make dystrophin, a protein that helps keep the muscles intact. Without dystrophin, muscles constantly break down and regenerate. Muscle regeneration, even in healthy people, causes some of the fibers to split into multiple strands called branches. Branching typically helps the new become bigger, stiffer and overall stronger. Researchers from Australia found that this may not be the case in DMD.

The research team studied in two mouse models of DMD. One group of mice was younger than the other. The researchers found extensive branching in the older group. Some muscle fibers in DMD can have as many as 10 separate branches, explained Stewart Head, Ph.D., one of the study's authors. Muscle contraction tests caused the branched fibers to rupture, or tear apart, in the older mice. The younger mice had fewer and less complex branched fibers and did not experience rupturing, showing that "a moderate amount of simple branching does not compromise the mechanical stability of the muscle," Head said.

"This evidence supports our concept of 'tipping point' where the number and extent of fiber branching reaches a level where the branching itself terminally compromises , irrespective of the absence of dystrophin," the researchers wrote.

The full article, "Branched fibers from old fast-twitch dystrophic muscles are the sites of terminal damage in muscular dystrophy," is published in the American Journal of Physiology—Cell Physiology.

Explore further: Researchers create skeletal muscle from stem cells

More information: Leonit Kiriaev et al. BRANCHED FIBERS FROM OLD FAST-TWITCH DYSTROPHIC MUSCLES ARE THE SITES OF TERMINAL DAMAGE IN MUSCULAR DYSTROPHY, American Journal of Physiology-Cell Physiology (2018). DOI: 10.1152/ajpcell.00161.2017

Related Stories

Researchers create skeletal muscle from stem cells

December 18, 2017
UCLA scientists have developed a new strategy to efficiently isolate, mature and transplant skeletal muscle cells created from human pluripotent stem cells, which can produce all cell types of the body. The findings are a ...

Do elite athletes have an anti-aging secret in their muscles?

December 22, 2015
Elite runners do not experience the muscle weakening associated with aging as non-athletes do. A new study published in American Journal of Physiology—Cell Physiology examines if their superb fitness is because their muscles ...

Restoring breathing capacity in Duchenne muscular dystrophy by activating the brain

September 27, 2017
New research published in The Journal of Physiology today suggests that enhancing breathing via the brain may limit deficiencies in respiratory capacity in Duchenne muscular dystrophy (DMD) patients.

Scientists reveal how osteopontin ablation ameliorates muscular dystrophy

April 18, 2016
Removing an immunomodulatory protein called osteopontin improves the symptoms of mice with muscular dystrophy by changing the type of macrophages acting on damaged muscle tissue, according to a paper published in The Journal ...

Promoting muscle regeneration in a mouse model of muscular dystrophy

April 1, 2013
Duchenne muscular dystrophy (DMD) is a degenerative skeletal muscle disease caused by mutations in the protein dystrophin. Dystrophin functions to protect muscle cells from injury and loss of functional dystrophin results ...

Gene transfer corrects severe muscle defects in mice with Duchenne muscular dystrophy

July 27, 2017
Duchenne muscular dystrophy is a rapidly progressive disease that causes whole-body muscle weakness and atrophy due to deficiency in a protein called dystrophin. Researchers at the University of Missouri, National Center ...

Recommended for you

Breakthrough article on mechanistic features of microRNA targeting and activity

March 23, 2018
Giovanna Brancati and Helge Grosshans from the FMI have described target specialization of miRNAs of the let-7 family. They identified target site features that determine specificity, and revealed that specificity can be ...

Boosting enzyme may help improve blood flow, fitness in elderly

March 22, 2018
As people age, their blood-vessel density and blood flow decrease, which is why it's harder to maintain muscle mass after 40 and endurance in the later decades, even with exercise. This vascular decline is also one of the ...

Scientists pinpoint cause of vascular aging in mice

March 22, 2018
We are as old as our arteries, the adage goes, so could reversing the aging of blood vessels hold the key to restoring youthful vitality?

Sulfur amino acid restriction diet triggers new blood vessel formation in mice

March 22, 2018
Putting mice on a diet containing low amounts of the essential amino acid methionine triggered the formation of new blood vessels in skeletal muscle, according to a new study from Harvard T.H. Chan School of Public Health. ...

Cold can activate body's 'good' fat at a cellular level, study finds

March 21, 2018
Lower temperatures can activate the body's 'good' fat formation at a cellular level, a new study led by academics at The University of Nottingham has found.

Gradual release of immunotherapy at site of tumor surgery prevents tumors from returning

March 21, 2018
A new study by Dana-Farber Cancer Institute scientists suggests it may be possible to prevent tumors from recurring and to eradicate metastatic growths by implanting a gel containing immunotherapy during surgical removal ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.