A newly discovered molecule has the potential to play a role in treating osteoarthritis, after researchers found it provided long-lasting regeneration of bone and cartilage defects in animals.
Osteoarthritis is a condition that causes joints to become painful and stiff and is the most common type of arthritis in the UK, affecting nearly 9 million people.
Cartilage, which overlies bones to enable frictionless movement in joints, often fails to repair after injury which leads to further cartilage loss and osteoarthritis.
There is no cure for arthritis, with treatments only helping to slow it down.
A team of researchers, led by Queen Mary University of London in England, studied the effects of a molecule called agrin on animals and discovered that it repairs cartilage by recruiting and activating adult stem cells present in the joint.
Scientists explained that these mechanisms were the same as those used by a body first developing a skeleton in the embryo.
Their study, published in Science Translational Medicine journal, suggests that supporting such mechanisms is an effective way to help heal injuries that are too big to heal in normal conditions.
Researchers injected mice with a gel containing agrin into “joint surface defects” and after eight weeks found it caused long-lasting regeneration of bone and cartilage – more than a control group that received the gel without agrin.
Testing the agrin-containing gel on sheep also found cartilage and bone repair was better after six months, when compared to a control group.
Researchers said the sheep spent more time playing and less time resting during the study, suggesting the repair improvement was associated with improved function.
Dr Suzanne Eldridge, from Queen Mary University of London, said osteoarthritis costs the UK £13 billion a year when factoring in indirect costs such as carers and being out of employment.
She explained the condition “leaves people severely disabled and there is no cure”.
“Many are unable to do basic things, including bathing, getting dressed, cooking or shopping,” she said.
Dr Eldridge added: “If we could intervene at an early stage once an injury has occurred, and repair the damage, the likelihood of patients going on to develop osteoarthritis is much slimmer.
“Our ultimate aim is to transform osteoarthritis from a disease that requires surgery, to one that just requires an injection.”
Professor Francesco Dell’Accio, also from Queen Mary University of London, said: “We’ve shown that it’s possible to repair joint defects, for the moment at least in animals, not just in the bone but also in the cartilage.
“One single administration of this molecule is sufficient to trigger a cascade of events in the joints, which, once started, are then self-maintained.
“Not only does it achieve structural repair, but we’ve shown that it gives symptomatic relief in animals extremely rapidly.”
Researchers are now working towards applying their findings safely in humans but predict clinical trials are several years away.
The study was funded by the Medical Research Council, charity Versus Arthritis, Reumafond, a Dutch arthritis foundation, and private medical research charity The Rosetrees Trust.
It also involved researchers from Scotland's University of Aberdeen and England's University of Cambridge.