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Updated: Aug 20, 2026
A Morphometric and Cellular Analysis Method for the Murine Mandibular Condyle
Published on: January 11, 2018
Localization of CD44 (hyaluronan receptor) and hyaluronan in rat mandibular condyle
Hiroaki Nakamura1, Ryoko Kato, Azumi Hirata
1Division of Hard Tissue Research, Institute for Oral Science, Matsumoto Dental University, 1780 Hirooka-Gohara, Shiojiri 399-0781, Japan. nakam@po.mdu.ac.jp
Insights
Chondrocytes in mandibular condylar cartilage express CD44, unlike those in growth plate and articular cartilage. This suggests a unique role for CD44 and hyaluronan (HA) in mandibular chondrocyte proliferation.
Area of Science:
- Biochemistry
- Cell Biology
- Orthodontics
Background:
- CD44 is a cell surface receptor involved in cell adhesion and matrix interactions.
- Hyaluronan (HA) is a major component of the extracellular matrix, crucial for cartilage homeostasis.
- Understanding chondrocyte heterogeneity is vital for regenerative medicine and understanding craniofacial development.
Purpose of the Study:
- To investigate the differential expression and localization of CD44 and HA in mandibular condylar cartilage.
- To compare CD44 and HA distribution in mandibular condylar cartilage with tibial growth plate and articular cartilage.
- To elucidate the potential role of CD44-HA interactions in mandibular chondrocyte function.
Main Methods:
- Immunohistochemical analysis of CD44 and HA localization in cartilage tissues.
- Western blotting to determine the molecular weight of CD44 in mandibular condyle lysates.
- Comparative analysis across mandibular condyle, growth plate, and articular cartilage.
Main Results:
- CD44-positive cells were identified in the superficial and proliferative zones of the mandibular condyle.
- Hyaluronan (HA) showed intense reactivity on the condyle surface and hypertrophic chondrocytes, with moderate and weak labeling in other zones.
- Unlike mandibular condylar chondrocytes, those in the tibial growth plate and articular cartilage did not exhibit CD44 reactivity.
Conclusions:
- Mandibular condylar chondrocytes display distinct CD44 expression patterns compared to other cartilage types.
- The interaction between CD44 and HA in the mandibular condyle may be critical for chondrocyte proliferation.
- These findings highlight unique cellular mechanisms governing mandibular cartilage development and homeostasis.
Abstract:
CD44 is a multifunctional adhesion molecule that binds to hyaluronan (HA), type I collagen, and fibronectin. We investigated localization of CD44 and HA in mandibular condylar cartilage compared with the growth plate and the articular cartilage, to clarify the characteristics of chondrocytes. We also performed Western blotting using a lysate of mandibular condyle. In mandibular condyle, CD44-positive cells were seen in the surface region of the fibrous cell layer and in the proliferative cell layer. Western blotting revealed that the molecular weight of CD44 in condyle was 78 to 86 kD. Intense reactivity for HA was detected on the surface of the condyle and the lacunae of the hypertrophic cell layer. Moderate labeling was seen in cartilage matrix of the proliferative and maturative layer. Weak labeling was also seen in the fibrous cell layer. In growth plate and articular cartilage, HA was detected in all cell layers. However, chondrocytes of these cartilages did not exhibit reactivity for CD44. These results suggest that chondrocytes in the mandibular condylar cartilage differ in expression of CD44 from those in tibial growth plate and articular cartilage. Cell-matrix interaction between CD44 and HA may play an important role in the proliferation of chondrocytes in the mandibular condyle.
