title: Immunohistochemical and in-situ hybridization study of hypoxia inducible factor-1alpha and angiopoietin-1 in a rabbit model of mandibular distraction osteogenesis.
abstract: The endogenous release of angiogenic factors in a rabbit mandibular distraction osteogenesis model was investigated. The spatial and temporal expression of hypoxia inducible factor-1alpha (HIF-1alpha) and angiopoietin-1 (Ang-1) was compared at different phases. The lengthened calluses were harvested on post-osteotomy days 13, 20, 34 and 48, and then stained with haematoxylin & eosin. Immunohistochemical (IHC) and in-situ hybridization (ISH) examination of HIF-1alpha and Ang-1 staining was performed. The ossification in the distracted gap was predominantly intramembranous and slightly endochondral. Expression of HIF-1alpha and Ang-1 was mainly detected in the cytoplasm of fibroblast-like cells, osteoblasts and immature osteocytes on day 13 and 20, but declined with bone maturation. HIF-1alpha was also detected in the nuclei of some osteoblasts. These results suggest that the production of HIF-1alpha and Ang-1 in the distracted gap may contribute to new bone formation during gradual distraction of the mandible.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Hospital of Stomatology, School of Medicine, Zhejiang University, Zhejiang, PR China.
authors.forename: J F
authors.initials: JF
authors.lastname: He
authors.forename: Z J
authors.initials: ZJ
authors.lastname: Xie
authors.forename: H
authors.initials: H
authors.lastname: Zhao
authors.forename: W L
authors.initials: WL
authors.lastname: Ge
authors.forename: J A
authors.initials: JA
authors.lastname: Hu
authors.forename: Y N
authors.initials: YN
authors.lastname: Li
authors.forename: Z Y
authors.initials: ZY
authors.lastname: Gu
mesh_terms: D042683:Angiopoietin-1 / Q000032:analysis*; D000818:Animals; D002146:Bony Callus / Q000473:pathology; D002467:Cell Nucleus / Q000648:ultrastructure; D004396:Coloring Agents; D003593:Cytoplasm / Q000648:ultrastructure; D005347:Fibroblasts / Q000473:pathology; D005456:Fluorescent Dyes; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000032:analysis*; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008334:Mandible / Q000473:pathology / Q000601:surgery*; D023421:Models, Animal; D010006:Osteoblasts / Q000473:pathology; D010011:Osteocytes / Q000473:pathology; D010012:Osteogenesis / Q000502:physiology; D019857:Osteogenesis, Distraction; D011817:Rabbits; D011897:Random Allocation; D013997:Time Factors
chemical_list: D042683:Angiopoietin-1; D004396:Coloring Agents; D005456:Fluorescent Dyes; D051795:Hypoxia-Inducible Factor 1, alpha Subunit