It remains a great challenge to enhance the regeneration potential of hyaline cartilage tissue. Tissue degeneration activities initiated after major injury or due to age-related processes override the generally limited self-renewal capacity of this tissue. Numerous catalytic enzymes lead to chondrocyte apoptosis and extracellular matrix deterioration. During early embryonic development, some of the embryonic stem cells of the inner cell mass of the blastocyst will turn into the mesoderm. This will be the founder of the mesenchymal cells in connective tissues of adult life, such as bone, tendon, muscle, and cartilage. Some of these embryonic mesenchymal cells are believed not to differentiate, but to reside in each of the tissues. These are now collectively described as adult mesenchymal stem cells, which are thought to be capable of repairing injured tissue. To date, various populations of bone marrow stroma cells, one of the various populations of adult stem cells, have been described and have been experimentally differentiated into cartilage tissue in vivo and in vitro. In this review, we will briefly summarize the current knowledge about stem cell related cells in cartilage tissue that are potentially involved in regeneration processes in osteoarthritis. Our unpublished results indicate that a cell population already present in the diseased cartilage tissue might be a starting point for a regenerative therapy for osteoarthritis.
Keywords: Osteoarthritis, Progenitor Cells, chondrocyte apoptosis, embryonic stem cells, mesenchymal cells, tendon, cartilage