Dr. Helal Endisha, researcher at the Schroeder Arthritis Institute at UHN
A recent discovery at the Schroeder Arthritis Institute has overturned conventional thinking about the link between obesity and osteoarthritis.
It has always been thought that increased weight puts strain on joints and that is what causes osteoarthritis. Now arthritis scientists have discovered a surprising new molecular link between obesity, diet and osteoarthritis.
“We have identified a small molecule that is increased in the blood and joint tissues of osteoarthritis patients, especially those who are obese,” says Dr. Helal Endisha, first author of the study and researcher at the Schroeder Arthritis Institute at UHN.
In a study published in the March 2021 issue of Arthritis and Rheumatology, the research team led by Dr. Mohit Kapoor, Co-Director of the Schroeder Arthritis Institute and the Tony and Shari Fell Platinum Chair in Arthritis Research, found that when cells from the joints of osteoarthritis patients were treated with increased levels of the small molecule (called microRNA 34a-5p), the cells produced harmful factors associated with joint destruction and inflammation. On the other hand, patient joint cells treated with a blocker against this molecule produced more of the building blocks required for healthy joint tissues.
Overall, this study has identified a molecule that is elevated in joint tissues as well as blood of osteoarthritis patients, especially patients who are obese. “This is a population of patients who are at-risk of not only of developing osteoarthritis at an earlier age, but also a more severe and rapidly progressing form of the disease,” says Dr. Rajiv Gandhi, an orthopedic surgeon within the Division of Orthopedics at the Schroeder Arthritis Institute. Using patient cells and pre-clinical models of obesity and osteoarthritis, the study shows that blocking this molecule is able to reduce the severity of joint damage in obese animals.
“The next step is to develop a targeted therapy for obese patients that will halt the rapid progression of osteoarthritis,” says Dr. Kapoor.