In the hope of treating millions of people suffering from muscle diseases, US researchers have developed a novel technique to promote tissue repair in damaged muscles.
The technique also creates a sustainable pool of muscle stem cells needed to support multiple rounds of muscle repair.
"We found that by introducing an inhibitor of the STAT3 protein in repeated cycles, we could alternately replenish the pool of satellite cells and promote their differentiation into muscle fibres," explained Alessandra Sacco, an assistant professor from the Sanford-Burnham Medical Research Institute in La Jolla, California.
The results are important because the process works in mice and in human muscle cells, Sacco added.
STAT3 is a protein that activates the transcription of genes in response to IL-6, a signaling protein released by cells in response to injury and inflammation.
The team first used mice suffering from a form of muscular dystrophy that resembles the human disease.
They found that the inhibitor initially promoted satellite cell replication, followed by differentiation of the satellite cells into muscle fibres.
When they injected the STAT3 inhibitor every seven days for 28 days, they found an overall improvement in skeletal-muscle repair, and an increase in the size of muscle fibres.
"We were pleased to find that we achieved similar results when we performed the experiments in human muscle cells," Sacco announced.
By timing the inhibition of STAT3, we can transiently expand the satellite cell population followed by their differentiation into muscle cells, the researchers concluded.
The study appeared in the journal Nature Medicine.
