Scientists from the Baylor College of Medicine in Houston, Texas, have come up with a new gene therapy that could protect against osteoarthritis (OA), potentially bringing relief to the millions of people suffering from this painful and debilitating condition.
The new study, published in the journal Science Translational Medicine, has uncovered a naturally-occurring protein called lubricin, or Proteoglycans 4 (PRG4), which acts as a lubricant between bones in the joint, thus protecting the joints from wear and tear.
The researchers found that mice that produced higher levels of lubricin in cartilage did not develop OA when they had a knee injury. As mice grew older, their cartilage looked much like that of young mice.
The researchers then tried a gene therapy on mice without the extra protein, using a specially-developed virus to inject the PRG4 gene into their joints.
The lubricin protein was expressed for the life of the mouse after a single injection into the joint, said Brendan Lee, professor of molecular and human genetics. While gene therapy does not regenerate cartilage that is already lost, the US researchers claim this new technique could one day prevent or delay the onset of the disease.
They now intend to test the gene therapy on larger animals like horses. The team says the gene therapy´s most immediate use in humans will be to treat OA that occurs after sports or work-related injuries.
Commenting on the study, Professor Alan Silman, medical director of Arthritis Research UK, said there are some signs that gene therapies could lead to new treatments of OA but further research is needed to see if the positive results in mice could be translated into an effective treatment for humans.
Osteoarthritis affects over 8.5 million people in the UK, causing pain in the knee, hip, spine and hands as degeneration of the cartilage leads to bones rubbing against one another.