Researchers at Western University have identified a specific gene that plays a key role in the degradation of cartilage in osteoarthritis (OA). The study, published online in the journal Arthritis & Rheumatology showed that when the gene, PPARdelta, was removed from cartilage the progression of post-traumatic osteoarthritis was considerably slowed.
Study co-author Frank Beier, PhD, a professor in the Department of Physiology and Pharmacology at Western's Schulich School of Medicine & Dentistry, says this promising new research may be the first step to identifying new treatments.
"What this tells us is that this gene is an important player in the pathogenesis of the disease and therefore might be a potential therapeutic target," Beier said.
According to a report by the Arthritis Alliance of Canada, more than 4.5 million adult Canadians currently live with OA, and it is estimated that it drives $10 billion in direct health care costs. Post-traumatic osteoarthritis, which is triggered by a specific injury, makes up 10 to 15 per cent of all cases of the disease and affects a younger, more active portion of the population.
"The current thinking is that what happens in those first hours after injury can have long-term impact," Beier said. "This research shows that we might have a window that we could give these drugs right after the injury happens and maybe slow the onset of the cartilage degradation associated with osteoarthritis."
These research findings may also help to explain the link between obesity and OA. It has long been known that obesity is one of the major risk factors for OA, and the conventional thinking was that the link was associated with the increased load on the joints. However, recent evidence suggests that chemical signals circulating in the body contribute to osteoarthritis risk in obese patients. Beier says that because PPARdelta is activated by fatty molecules, lipids from a high-fat diet could directly activate the pathway that allows PPARdelta to break down cartilage in the animal model.
"This also suggests that in the future, modulation of PPARdelta through diet changes, as opposed to drugs, could also be a strategy to prevent Osteoarthritis," Beier said.
The study's lead author, PhD Candidate Anusha Ratneswaran, is currently on a three month exchange in Australia with funding from an Osteoarthritis Research International Collaborative Scholarship.