Abstract |
Vascular endothelial growth factor ( Vegf) was previously shown to be expressed specifically in the condylar cartilage of temporomandibular joint- osteoarthritis (TMJ-OA) model rats. Here we demonstrate for the first time that hypoxia-inducible factor-1alpha (Hif-1alpha) is activated in mature chondrocytes of temporomandibular joint- osteoarthritis (TMJ-OA) model rat by mechanical overload, and that activated Hif-1 in chondrocytes can induce osteoclastogenesis via repression of osteoprotegerin (Opg) expression. In rat TMJs, degeneration of the condylar cartilage became prominent in proportion to the duration of overloading. Hif-1alpha expression was observed specifically in mature and hypertrophic chondrocytes, and Hif-1alpha-positivity, level of Vegf expression, and tartrate-resistant acid phosphatase (TRAP)-positive cell numbers all increased in the same manner. When ATDC5 cells induced differentiation by insulin were cultured under hypoxia, Hif-1alpha induction was observed in mature stage, but not in immature stage. Inductions of Hif-1-target genes showed a similar expression pattern. In addition, expression of Opg decreased in hypoxia, and Hif-1alpha played a role, in part, in its regulation.
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Authors | Maya Shirakura, Keiji Tanimoto, Hidetaka Eguchi, Mutsumi Miyauchi, Hideaki Nakamura, Keiko Hiyama, Kotaro Tanimoto, Eiji Tanaka, Takashi Takata, Kazuo Tanne |
Journal | Biochemical and biophysical research communications
(Biochem Biophys Res Commun)
Vol. 393
Issue 4
Pg. 800-5
(Mar 19 2010)
ISSN: 1090-2104 [Electronic] United States |
PMID | 20171183
(Publication Type: Journal Article)
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Copyright | Copyright 2010 Elsevier Inc. All rights reserved. |
Chemical References |
- Hypoxia-Inducible Factor 1, alpha Subunit
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Topics |
- Animals
- Bone Resorption
(metabolism, pathology)
- Cartilage, Articular
(metabolism, pathology)
- Chondrocytes
(metabolism, pathology)
- Disease Models, Animal
- Hypoxia-Inducible Factor 1, alpha Subunit
(agonists, biosynthesis)
- Male
- Osteoarthritis
(metabolism, pathology)
- Osteoclasts
(metabolism, pathology)
- Rats
- Rats, Wistar
- Temporomandibular Joint Disorders
(metabolism, pathology)
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