Scientists at the University Hospital of Basel have produced joint cartilage from bone marrow stem cells by preventing them from becoming bone tissue.
Under normal conditions the mesenchymal stem/stromal cells from the bone marrow of adults develop into cartilage tissue which then remodels into bone tissue. This is similar to what happens after a fracture, for example.
However, the researchers found they could prevent embryonic cartilage from becoming bone tissue by inhibiting the signaling pathway of a specific protein called Bone Morphogenetic Protein (BMP). By temporarily blocking specific BMP receptors they were able to maintain stable cartilage tissue in the lab and in mice.
“Importantly, we have achieved our insights by mimicking molecular processes occurring during embryonic cartilage formation,” said study leader Ivan Martin.
The findings confirm the importance of the field of “developmental engineering” where natural processes are replicated to control the development of adult stem and progenitor cells. The Basel researchers worked with the Novartis Institutes for Biomedical Research, which produced and supplied the inhibitors. The results were publishedexternal link in the US Proceedings of the National Academy of Sciences (PNAS) journal this Monday.
According to Martin, the “cultivated cartilage” could potentially be used to treat cartilage injuries and degeneration by manufacturing engineered cartilage grafts, combining it with existing procedures, or releasing it directly into joints. Transforming this discovery into clinical use is still a long time away though, he cautions.