Researchers at the University of Aberdeen in the United Kingdom have identified the stem cells that play a key role in repairing the knee joints. The findings of the team from the Center for Arthritis and Musculoskeletal Health were published in Nature Communications.
Stem Cells with Key Role in Knee Joint Repair Identified
The connective tissue surrounding the knee joint is known as the synovium. Conditions such as injury or arthritis are associated with an inflammation of this thin membrane, causing it to become thick with increased synovial fluid, leading to pain and swelling.
The team has identified the stem cells that are present in the synovium and have the ability to regenerate and repair damaged knee cartilage. A key protein called Yap has also been identified. This protein regulates stem-cell-mediated cartilage repair. The researchers discovered that there is an increased amount of Yap in the stem cells in arthritic or injured joints with enlarged synovial membranes.
Stem Cell Experiments in Arthritic Knees
When Yap was removed from the stem cells of injured and arthritic joints, the researchers found that the synovial membrane did not expand in size. In addition, the cells from which Yap had been removed had reduced capacity for cartilage repair.
The stem cells involved in knee joint repair are the same stem cells from which the knee joint is created during embryonic development. It would appear that these stem cells maintain a memory of forming the joint even in adults. This would suggest that these specific stem cells are the ideal candidates to repair damaged joints in adults.
Targeted Therapy for Knee Arthritis
The ultimate goal is to prevent irreversible damage and treat knee arthritis before the disease advances. The challenge is to encourage stem cells in the joint to remain functional. Arthritis of the knees affects millions of people worldwide. The team hopes to better understand the pathophysiology of the disease and come one step closer to preventing and treating it with novel therapies.