Immunohistochemical localization of matrix metalloproteinase 13 (MMP-13) in mouse mandibular condylar cartilage.
MMP-13 appears to be one of the most important MMPs in cartilage remodeling and mineralization, because it exhibits a substrate preference for the cartilage-specific type II collagen. The condylar process is constructed by rapid accumulation of hypertrophic chondrocytes during development, but its mechanism is still unclear. To investigate the role of MMP-13 in developing condylar cartilage, we immunohistochemically examined the localization of MMP-13 in the endochondral ossification of the mandibular condyle and tibiae of newborn mice. In the tibiae, the MMP-13 expression was detected only in the deepest layer of the terminal hypertrophic chondrocytes through every examined stage (day 1 to day 10 after birth). On the other hand, in the condylar cartilage at days 1 and 5, MMP-13 was expressed throughout the proliferating and the hypertrophic chondrocytes, and at day 10, MMP-13 was mainly localized in the deepest edge of the hypertrophic layer. A zymographical study showed that the activity of MMP-13 in the condyle was observed at day 1, earlier than in the tibia, and increased until day 7. The time-dependent and cell-specific expression of MMP-13 and its enzymatic property suggest that in the mandibular condylar cartilage, MMP-13 plays a role in making the space for cell enlargement by degradation of the cartilage matrix and in onset of mineralization during the early stage of development.
Ohkubo
Kazumi
K
Maxillofacial Orthognathics, Department of Maxillofacial Reconstitution and Function, Division of Maxillofacial/Neck Reconstitution, Graduate School, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo 113-8549, Japan. k-ohkubo.mort@tmd.ac.jp
Shimokawa
Hitoyata
H
Ogawa
Takuya
T
Suzuki
Shoichi
S
Fukada
Kenji
K
Ohya
Keiichi
K
Ohyama
Kimie
K
D000818:Animals; D000831:Animals, Newborn; D002356:Cartilage / Q000201:enzymology* / Q000254:growth & development; D002455:Cell Division; D019902:Chondrocytes / Q000201:enzymology; D020219:Chondrogenesis; D017364:Collagenases / Q000032:analysis*; D018483:Diaphyses / Q000201:enzymology / Q000254:growth & development; D004838:Epiphyses / Q000201:enzymology / Q000254:growth & development; D006132:Growth Plate / Q000201:enzymology; D006984:Hypertrophy; D007150:Immunohistochemistry; D008335:Mandibular Condyle / Q000201:enzymology* / Q000254:growth & development; D053509:Matrix Metalloproteinase 13; D051379:Mice; D010012:Osteogenesis; D013977:Tibia / Q000201:enzymology / Q000254:growth & development
D017364:Collagenases; D053509:Matrix Metalloproteinase 13; C507081:Mmp13 protein, mouse