Activation of the hypoxia-inducible factor-1 in overloaded temporomandibular joint, and induction of osteoclastogenesis

摘要: 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 first time that hypoxia-inducible factor-1alpha (Hif-1alpha) is activated mature chondrocytes rat by mechanical overload, and Hif-1 can induce osteoclastogenesis via repression osteoprotegerin (Opg) expression. In TMJs, degeneration became prominent proportion duration overloading. Hif-1alpha expression observed hypertrophic chondrocytes, Hif-1alpha-positivity, level Vegf expression, tartrate-resistant acid phosphatase (TRAP)-positive cell numbers all increased same manner. When ATDC5 cells induced differentiation insulin were cultured under hypoxia, induction stage, but not immature stage. Inductions Hif-1-target genes showed a similar pattern. addition, Opg decreased played role, part, its regulation.