Researchers at Queen Mary University of London (QMUL) have identified a potential new way of treating joints affected by arthritis.
Their study indicates that arthritic cartilage, previously thought impenetrable to therapies, could be treated by a patient´s own ‘microvesicles´ that are able to travel into cartilage cells and deliver therapeutic agents.
Fluid in human joints is rich in cartilage-protecting microvesicles, the researchers said. These are very small subcellular structures (0.05 to 1 micrometer in diameter) that consist of fluid enclosed by a membrane. They are released by cells to transfer lipids and proteins to target cells.
Some white blood cells´ microvesicles tend to accumulate in large numbers in the joints of rheumatoid arthritis patients. According to a report on the research by QMUL, the biological impact of these microvesicles has been intriguing to researchers because they are known to contain over 300 types of protein that vary in different situations.
Lead author Professor Mauro Perretti from QMUL´s William Harvey Research Institute said: “Cartilage has long been thought to be impenetrable to cells and other small structures, leading to strong limitations in our abilities to deliver therapies for arthritis. To our surprise, we´ve now discovered that vesicles released from white blood cells can ‘travel´ into the cartilage and deliver their cargo, and that they also have a protective effect on cartilage affected by arthritis.
“Our study indicates that these vesicles could be a novel form of therapeutic strategy for patients suffering from cartilage damage due to a range of diseases, including osteoarthritis, rheumatoid arthritis and trauma. Treating patients with their own vesicles may only require a day in hospital, and the vesicles could even be ‘fortified´ with other therapeutic agents, for example, omega-3 fatty acids or other small molecules.”
The researchers also found that one particular cellular receptor played a role in protecting cartilage tissue. As such, it could be targeted by new small molecules for the treatment of cartilage erosive diseases.
The findings of the study have been published in Science Translational Medicine.