Scientists make old muscles young again in attempt to combat ageing

Researchers at King's College London, Harvard University and Massachusetts General Hospital have identified for the first time a key factor responsible for declining muscle repair during ageing, and discovered how to halt the process in mice with a common drug. Although an early study, the finding provides clues as to how muscles lose mass with age, which can result in weakness that affects mobility and may cause falls. Published today in the journal Nature , and funded by the Biotechnology, and Biological Sciences Research Council, Harvard Stem Cell Institute and National Institutes of Health (US), the study looked at stem cells found inside muscle - which are responsible for repairing injury - to find out why the ability of muscles to regenerate declines with age. A dormant reservoir of stem cells is present inside every muscle, ready to be activated by exercise and injury to repair any damage. When needed, these cells divide into hundreds of new muscle fibres that repair the muscle. At the end of the repairing process some of these cells also replenish the pool of dormant stem cells so that the muscle retains the ability to repair itself again and again. The researchers carried out a study on old mice and found the number of dormant stem cells present in the pool reduces with age, which could explain the decline in the muscle's ability to repair and regenerate as it gets older.