Migration of Local Progenitor Cells as Therapeutic Target in Knee Osteoarthritis

The identification of mesenchymal progenitor cells in bone marrow and various joint related tissues like cartilage or synovial tissue renders the cell-biologic systems on which the pathogenetic concepts of osteoarthritis have been developed more complicated by introducing a novel cellular player. The progenitor cells could have different implications in the osteoarthritic process but their precise role is not known so far. For bone marrow derived mesenchymal stromal cells (MSC) the capacity to migrate in response to various chemoattractive factors and to differentiate into the chondrogenic phenotype has been shown. Their potential role in tissue repair may further include the secretion of trophic factors and a certain immunomodulatory function. Migration activity of cartilage-derived cells has also been shown by different approaches. The emerging concept of motile chondroprogenitor cells present within synovial joints might lead to novel therapeutic strategies. Therefore, local mesenchymal progenitor cells may become a future therapeutic target in patients with early stage degenerative joint disease.