Researchers at the Perelman School of Medicine at the University of Pennsylvania have found that TRF2, a protective chromosomal protein, performs a hidden function: preserving the identity of muscle stem cells. It was previously known mainly for its role in protecting the ends of chromosomes, but it now turns out to be critical for regenerating muscle tissue, infohub.kz reports.
The results of the work, led by Foteini Mourkioti, were published in the journal Science Advances. Experiments in mice showed that without this protein, muscle stem cells lose their specialization, and damaged tissue is filled with fat and scar tissue. The science portal ScienceDaily reports this.
Previously, specialists studied TRF2 as an element that protects telomeres from destruction. New laboratory experiments revealed its ability to bind to regulatory regions of the genome containing secondary DNA structures — G-quadruplexes. By interacting with them, the protein supports the genetic program that allows muscle stem cells to remain in reserve, activate upon injury and restore fibers throughout life.
When the researchers removed TRF2 from the muscle stem cells of mice, the cells did not die but lost the ability to perform their restorative function. In animals with a model of Duchenne muscular dystrophy, the disease began to progress significantly faster.
According to Foteini Mourkioti, the discovery not only outlines new approaches to treating dystrophy but will also help explain why skeletal muscles regenerate actively without an increased risk of cancer.