New research from the UK suggests that tendons break down with age because they lose the ability to repair themselves effectively, allowing protein fragments to accumulate over time. The researchers, from Queen Mary University of London and the University of Liverpool, hope their findings will offer targets for treatments to prevent breakdown of tendon tissue.
Dr. Hazel Screen, a reader in biomedical engineering at the School of Engineering and Materials Science at Queen Mary University of London (QMUL), and colleagues describe their work in a study paper published in the Journal of Biological Chemistry.
It is not just athletes who need well-functioning tendons such as the Achilles, an important one for storing energy and also prone to injury; they are also important for ordinary people to be able to go about their everyday activities.
Molecular mechanisms of tendon injury and aging not well understood
However, while we know that risk of injury to tendons increases with age, the underlying cellular and molecular mechanisms are not well understood, although scientists believe it has something to do with changes to the way tissue is renewed and repaired.
For the study, Dr. Screen and colleagues analyzed proteins and protein fragments from injured and uninjured tendon tissue in horses of all ages. Horses and humans have similar tendon tissue structure that breaks down in a similar way following injury.
The analysis showed that young and old tendons have distinct protein profiles, with differences in levels of proteins involved in organizing the tissue structure and regulating cell tension.
The researchers also found several new protein fragments in aged healthy tendons, suggesting there are specific ways that the proteins break down in older tendons.
They found young and old injured tendons also have distinct protein profiles - plus there was evidence of greater protein breakdown in young injured tendons.
Study suggests tendon tissue's ability to self-repair wanes as it gets older
The study concludes that the findings give new information about the molecular events surrounding tendon aging, and suggest maintenance and repair of tendon tissue may reduce with age. They may also explain why risk of tendon injury increases with age.
The team also hopes the new information, which represents an important first step in understanding how our tissues break down as we age, will help find ways to prevent it occurring.
Meanwhile, in November 2013, Medical News Today reported on a study that demonstrated how researchers are working on an improved way of repairing tendons using a new technique for suturing tissue-engineered collagen graft.