Toronto, Sep 8 (IANS): In what could lead to the discovery of drugs to treat muscle weakening diseases such as muscular dystrophy, researchers have discovered a signalling pathway responsible for reducing aged stem cells' ability to repair muscle.

As people age, stem cells gradually lose their capacity to repair damage, even from normal wear and tear.

As muscle stem cells age, their reduced function is a result of a progressive increase in the activation of a specific signalling pathway that transmits information to a cell from the surrounding tissue.

The particular culprit identified by the researchers is called the JAK/STAT signalling pathway.

"What is really exciting to our team is that when we used specific drugs to inhibit the JAK/STAT pathway, the muscle stem cells in old animals behaved the same as those found in young animals," said Michael Rudnicki, a professor from the University of Ottawa in Canada.

"These inhibitors increased the older animals' ability to repair injured muscle and to build new tissue," Rudnicki added.

With this discovery, the researchers are exploring the therapeutic possibilities of drugs to treat muscular dystrophy and such other muscle weakening diseases.

The drugs used in this study are commonly used for chemotherapy and the team is now looking for less toxic molecules that would have the same effect.

The findings appeared online in the journal Nature Medicine.