Expression of Ten-m/Odz3 in the fibrous layer of mandibular condylar cartilage and the early stage of chondrogenic differentiation of ATDC5 cells

Temporomandibular joint is essential for normal development and function of jaw. Mandibular condylar cartilage histologically consists of fibrous and cartilage layers. It has been speculated that fibroblast-like cells in the fibrous layer differentiate into chondrocytes in the process of condylar development. However, molecular mechanisms regulating the process have not been cleared. We revealed that Ten-m/Odz3 was highly expressed in the fibrous layer compared with the cartilage layer. Ten-m/Odz3 was strongly expressed in fibrous and proliferating chondrocyte layers in mandibular condylar cartilage and in perichondrium and proliferating chondrocyte layer in femoral cartilage during the early stage of development. Furthermore, Ten-m/Odz3 was expressed during the early stage of the chondrogenic differentiation of ATDC5 cells. These findings suggest that Ten-m/Odz3 acts as a regulator during the early development of cartilage and may modulate the differentiation of fibroblast-like cells into chondrocytes in the mandibular condyle.