Research reveals role of protein complex in muscle weaknesses
1st May 2013
This news article is from Handicare UK. Articles that appear on this website are for information purposes only.
Scientists from Switzerland believe that they have been able to describe the exact biological mechanism which results in many of us choosing to use stairlifts as we get older. Their findings were recently published in the respected scientific journal Cell Metabolism, and pointed towards unclean cells resulting in weak muscles.
The study was undertaken by a team of scientists from the Biozentrum of the University of Basel and from the Department of Biomedicine, who were led by Professor Markus Rüegg. Together, they looked into how a cell remains healthy and what processes are involved in making this so. In summary, the protein complex mTORC1 promotes muscle growth, but if it remains constantly active then myopathy is caused, which can be attributed to impaired autophagy; the ability for cells to clean themselves.
Just as the individual parts of a machine wear out with time, malfunctioning parts of a cell or parts that are waste products need to be regularly recycled or disposed of in a cellular self-cleaning process. As we age, our body's capacity for self-renewal decreases and our muscles get weaker; the exact role of growth regulator mTORC1 in this process has been discovered in this study.
mTORC1 is a protein complex which exists in the skeletal muscle and it was previously believed that it plays an important role in growth regulation, but not in the process of autophagy that is key to keeping our cells clean. The recent study undertaken by Professor Markus Rüegg and his team revealed that mTORC1 is actually very important to the cell self-cleaning process; mice which had the protein complex permanently activated had progressive myopathy, which links to impaired autophagy. Understandably, the effects of muscle weakness were particularly observable in older mice.
After this discovery, the scientists then went on to see if they could reverse the symptoms. They found that administering rapamycin to the mice returned the strength of their muscles to normal; rapamycin is known to inhibit mTORC1. Not only does this add further weight to the importance of mTORC1 to the process of autophagy, it also provides the basis for further investigations into how to regain muscle strength.
Professor Markus Rüegg and his team believe that an overactive mTORC1 complex could also be linked to muscle weakness in humans as well as in mice, and further investigations are expected to come from this. It is hoped that new therapeutic approaches for counteracting muscle weakness as we age could then stem from this, helping those with muscle weakness use walk in baths more independently.
Image Credit: SashaW (flickr.com)