Stem cell manipulation shows promise for cartilage renewal and joint repair
For people with a type of jaw joint disorder that results from loss of cartilage, the only treatments available address symptoms but do not repair the damaged tissue. Now, a new study of mice suggests stem cells already present in the jaw joint could be manipulated to repair it.
The study, led by Columbia University Medical Center in New York, NY, is published in the journal Nature Communications. The authors describe how manipulating stem cells in the temporomandibular joint (TMJ) of mice with TMJ degeneration led the cells to repair cartilage in the joint.
The researchers also found that transplanting just a single TMJ stem cell into a mouse spontaneously generated cartilage and bone and even began to form a bone marrow niche.
In their study, Prof. Embree and colleagues – including Jeremy Mao, the Edwin S. Robinson Professor of Dentistry (in Orthopedic Surgery) at Columbia - show for the first time that the “fibrous superficial zone” in the TMJ of mice harbors fibrocartilage stem cells (FCSCs).
They also discovered that a single FCSC transplanted into a live mouse is capable of not only generating cartilage and bone, but also of organizing the microenvironment to support the process – rather like specialized niches in bone marrow.
Moreover, the researchers showed that they could manipulate FCSCs to differentiate into the required cell types by suppressing a type of cell signal called Wnt. They found that overactive Wnt signals disrupt the stability of fibrocartilage and promote degeneration by depleting FCSCs.