Strategic Communications and Marketing News Bureau

Researchers find protein that suppresses muscle repair in mice

CHAMPAIGN, Ill. — Researchers report that a protein known to be important to protein synthesis also influences muscle regeneration and regrowth in an unexpected manner. The discovery, reported in the Journal of Clinical Investigation, could one day lead to new methods for treating disorders that result in muscle weakness and loss of muscle mass, the researchers said.

Scientists have long studied leucine tRNA-synthetases, or LRS, for its role in protein synthesis, said University of Illinois cell and developmental biology professor Jie Chen, who led the research.

“In the last 5-10 years, scientists have begun to realize that LRS and other proteins like it have functions independent of protein synthesis,” Chen said. “Previously, my lab and other labs discovered that one of such functions of LRS is that it can regulate cell growth. Our new study is the first report of its function in muscle regeneration.”

Chen and her colleagues used mammalian cell cultures and mice in the new study. They compared the speed of muscle repair in mice with normal and lower-than-normal LRS levels. They discovered that mice with lower levels of LRS in their tissues recovered from muscle injury much more quickly than their counterparts with normal LRS levels.

A 70% reduction of LRS proteins in the cell does not affect protein synthesis, Chen said.

“But lower levels do positively influence muscle regeneration,” she said. “We saw that, seven days after injury, the repaired muscle cells are bigger when LRS is lower.”

While it is not possible to lower LRS in human subjects, the researchers sought another method to block its effects.

Chen and her colleagues further unraveled the exact molecular mechanism by which LRS influences muscle regeneration. This led them to hypothesize that a nontoxic inhibitor that their collaborators in South Korea previously developed would block the effect of LRS on muscle cells without interfering with its role in protein synthesis.

“We showed that this inhibitor works both in mammalian cells and in mice,” Chen said. Muscle repair occurred more rapidly – and the regenerated muscles were stronger – when the inhibitor was present.

As the science progresses, researchers are gaining greater insights into the multifunctionality of proteins once thought to have only a single role in cells, Chen said.

“We now understand that ‘protein moonlighting,’ where one protein does many different things in the cell, is the norm,” she said.

Chen and her colleagues are investigating the effect of LRS on older mice, which tend to rebuild their muscles more slowly and have less muscle tone than younger mice.

The National Institutes of Health and the Keck Foundation supported this research.

Editor’s notes:
To reach Jie Chen, call 217-265-0674; email jiechen@illinois.edu.   
The paper “Nontranslational function of leucyl-tRNA synthetase regulates myogenic differentiation and skeletal muscle regeneration” is available online and from the U. of I. News Bureau.
DOI: 10.1172/JCI122560

Read Next

Humanities Diptych image with book cover of "The New Internationals" and a headshot of English professor David Wright Faladé

English professor’s novel tells of love triangle in post-WWII Paris, based on his family history

CHAMPAIGN, Ill. — A new novel by University of Illinois Urbana-Champaign English professor David Wright Faladé tells the story of three people in a love triangle in post-World War II Paris. The characters in “The New Internationals” — a young French woman who has survived the Holocaust, a university student from West Africa and a […]

Life sciences Portrait of the research team posing together.

Minecraft players can now explore whole cells and their contents

CHAMPAIGN, Ill. — Scientists have translated nanoscale experimental and computational data into precise 3D representations of bacteria, yeast and human epithelial, breast and breast cancer cells in Minecraft, a video game that allows players to explore, build and manipulate structures in three dimensions. The innovation will allow researchers and students of all ages to navigate […]

Arts Photo of seven dancers onstage wearing blue tops and orange or yellow flowing skirts. The backdrop is a Persian design.

February Dance includes works experimenting with live music, technology and a ‘sneaker ballet’

CHAMPAIGN, Ill. — The dance department at the University of Illinois Urbana-Champaign will present February Dance 2025: Fast Forward this week at Krannert Center for the Performing Arts. February Dance will be one of the first performances in the newly renovated Colwell Playhouse Theatre since its reopening. The performances are Jan. 30-Feb. 1. Dance professor […]

Strategic Communications and Marketing News Bureau

507 E. Green St
MC-426
Champaign, IL 61820

Email: stratcom@illinois.edu

Phone (217) 333-5010