By inducing specific molecular processes occurring during embryonic cartilage formation, stable joint cartilage can be produced from adult stem cells originating from bone marrow, suggests new study. The study conducted by a research team from the University and University Hospital of Basel is published in the journal PNAS.
Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem cells usually develop into cartilage tissue which later naturally remodels into bone tissue. Even if the stem cells are induced to differentiate into cartilage cells, they spontaneously mature into a so-called "hypertrophic" state, ultimately leading to the formation of bone tissue; this is similar to the cartilaginous tissue temporarily formed after a fracture.
Inhibiting signaling pathways
Specifically, the scientists investigated two highly specific BMP receptor inhibitors in a special device (microfluid platform) developed in cooperation with Politecnico di Milano. With the use of this new technology, they were able to show that the temporary blocking of specific BMP receptors Ž- even if only for a limited time - is sufficient to maintain stable cartilage tissue, both in the laboratory and in a mouse model.
Embryonic cartilage formation as a model
These results open new perspectives in the regeneration of articular cartilage as well as in the establishment of stem cell-based models of cartilage development, physiology, and possibly pathology. "Importantly, we have achieved our insights by mimicking molecular processes occurring during embryonic cartilage formation," says Ivan Martin. This confirms the vital role of "developmental engineering," in which natural processes are mimicked to control the development and specification of adult stem and progenitor cells.