Expression of chondromodulin-1 in the temporomandibular joint condylar cartilage and disc

Abstract

BACKGROUND: The temporomandibular joint (TMJ)
cartilage consists of condylar cartilage and disc and
undergoes continuous remodeling throughout post-natal
life. To maintain the integrity of the TMJ cartilage,
anti-angiogenic factors play an important role during the
remodeling process. In this study, we investigated
the expression of the anti-angiogenic factor, chondromodulin-
1 (ChM-1), in TMJ cartilage and evaluate its
potential role in TMJ remodeling.
METHODS: Eight TMJ specimens were collected from
six 4-month-old Japanese white rabbits. Safranin-O
staining was performed to determine proteoglycan
content. ChM-1 expression in TMJ condylar cartilage and
disc was determined by immunohistochemistry. Three
human perforated disc tissue samples were collected for
investigation of ChM-1 and vascular endothelial growth
factor (VEGF) distribution in perforated TMJ disc.
RESULTS: Safranin-O stained weakly in TMJ compared
with tibial articular and epiphyseal cartilage. In TMJ,
ChM-1 was expressed in the proliferative and hypertrophic
zone of condylar cartilage and chondrocyte-like
cells in the disc. No expression of ChM-1 was observed in
osteoblasts and subchondral bone. ChM-1 and VEGF
were both similarly expressed in perforated disc tissues.
CONCLUSIONS: ChM-1 may play a role in the regulation
of TMJ remodeling by preventing blood vessel invasion
of the cartilage, thereby maintaining condylar
cartilage and disc integrity.