title: Osterix regulates tooth root formation in a site-specific manner.
abstract: Bone and dentin share similar biochemical compositions and physiological properties. Dentin, a major tooth component, is formed by odontoblasts; in contrast, bone is produced by osteoblasts. Osterix (Osx), a zinc finger-containing transcription factor, has been identified as an essential regulator of osteoblast differentiation and bone formation. However, it has been difficult to establish whether Osx functions in odontoblast differentiation and dentin formation. To understand the role of Osx in dentin formation, we analyzed mice in which Osx was subjected to tissue-specific ablation under the control of either the Col1a1 or the OC promoter. Two independent Osx conditional knockout mice exhibited similar molar abnormalities. Although no phenotype was found in the crowns of these teeth, both mutant lines exhibited short molar roots due to impaired root elongation. Furthermore, the interradicular dentin in these mice showed severe hypoplastic features, which were likely caused by disruptions in odontoblast differentiation and dentin formation. These phenotypes were closely related to the temporospatial expression pattern of Osx during tooth development. These findings indicate that Osx is required for root formation by regulating odontoblast differentiation, maturation, and root elongation. Cumulatively, our data strongly indicate that Osx is a site-specific regulator in tooth root formation.
authors.affiliation: Cluster for Craniofacial Development and Regeneration Research, Institute of Oral Biosciences, Chonbuk National University School of Dentistry, Jeonju, South Korea.
authors.forename: T H
authors.initials: TH
authors.lastname: Kim
authors.affiliation: Cluster for Craniofacial Development and Regeneration Research, Institute of Oral Biosciences, Chonbuk National University School of Dentistry, Jeonju, South Korea.
authors.forename: C H
authors.initials: CH
authors.lastname: Bae
authors.affiliation: Cluster for Craniofacial Development and Regeneration Research, Institute of Oral Biosciences, Chonbuk National University School of Dentistry, Jeonju, South Korea.
authors.forename: J C
authors.initials: JC
authors.lastname: Lee
authors.affiliation: Department of Molecular Medicine, School of Medicine, Kyungpook National University, Daegu, South Korea.
authors.forename: J E
authors.initials: JE
authors.lastname: Kim
authors.affiliation: Genetic Laboratory of Development and Disease, Institute of Biotechnology, Beijing, China.
authors.forename: X
authors.initials: X
authors.lastname: Yang
authors.affiliation: Department of Molecular Genetics, The University of Texas M.D. Anderson Cancer Center, Houston, TX, USA.
authors.forename: B
authors.initials: B
authors.lastname: de Crombrugghe
authors.affiliation: Cluster for Craniofacial Development and Regeneration Research, Institute of Oral Biosciences, Chonbuk National University School of Dentistry, Jeonju, South Korea oasis@jbnu.ac.kr.
authors.forename: E S
authors.initials: ES
authors.lastname: Cho
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D049109:Cell Proliferation / Q000502:physiology; D024042:Collagen Type I / Q000502:physiology; D000090602:Collagen Type I, alpha 1 Chain; D003782:Dental Pulp / Q000166:cytology; D003804:Dentin / Q000002:abnormalities; D003810:Dentinogenesis / Q000502:physiology; D051379:Mice; D018345:Mice, Knockout; D008963:Molar / Q000002:abnormalities; D009804:Odontoblasts / Q000502:physiology; D009805:Odontogenesis / Q000502:physiology*; D015675:Osteocalcin / Q000502:physiology; D000076182:Sp7 Transcription Factor; D019228:Tooth Crown / Q000166:cytology; D014092:Tooth Root / Q000002:abnormalities / Q000254:growth & development*; D014157:Transcription Factors / Q000502:physiology*; D055114:X-Ray Microtomography / Q000379:methods; D016335:Zinc Fingers / Q000502:physiology*
chemical_list: D024042:Collagen Type I; D000090602:Collagen Type I, alpha 1 Chain; D000076182:Sp7 Transcription Factor; C479466:Sp7 protein, mouse; D014157:Transcription Factors; D015675:Osteocalcin
keywords: Osx; dentinogenesis; mice; odontoblasts; tooth development; tooth roots