Wadhwa S, Embree MC, Kilts T, Young MF, Ameye LG. Accelerated osteoarthritis in the temporomandibular joint of biglycan/fibromodulin double-deficient mice.
Osteoarthritis Cartilage 2005;
13:817-27. [PMID:
16006154 DOI:
10.1016/j.joca.2005.04.016]
[Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2004] [Accepted: 04/18/2005] [Indexed: 02/02/2023]
Abstract
OBJECTIVE
To investigate whether the absence of biglycan and fibromodulin, two proteoglycans expressed in cartilage, bone and tendon, resulted in accelerated osteoarthritis in the temporomandibular joint (TMJ).
METHODS
Histological sections of TMJ from 3-, 6-, 9- and 18-month-old wild-type (WT) and biglycan/fibromodulin double-deficient (DKO) mice were compared. Immuno-stainings for biglycan, fibromodulin and proliferating cell nuclear antigen (PCNA) were performed.
RESULTS
Biglycan and fibromodulin were highly expressed in the disc and articular cartilage of the TMJ. At 3 months of age, both WT and DKO presented early signs of cartilage degeneration visible as small acellular areas under the articular surfaces and superficial waving. From 6 months of age, DKOs developed accelerated osteoarthritis compared to WT. At 6 months, small vertical clefts in the condylar cartilage and partial disruption of the disk were visible in the DKO. In addition, chondrocytes had lost their regular columnar organization to form clusters. At 9 months, these differences were even more pronounced. At 18 months, extended cartilage erosion was visible in DKOs when by comparison the thickness of the articular cartilage in WT controls was basically intact. PCNA staining was stronger in 3-month-old WT TMJ fibrocartilage than in 3-month-old DKO TMJ fibrocartilage suggesting that chondrocyte proliferation might be impaired in DKOs.
CONCLUSION
The biglycan/fibromodulin double knock-out mouse constitutes a useful animal model to decipher the pathobiology of osteoarthritis in the TMJ.
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