title: Rescue of odontogenesis in Dmp1-deficient mice by targeted re-expression of DMP1 reveals roles for DMP1 in early odontogenesis and dentin apposition in vivo.
abstract: Dentin matrix protein 1 (DMP1) is expressed in both pulp and odontoblast cells and deletion of the Dmp1 gene leads to defects in odontogenesis and mineralization. The goals of this study were to examine how DMP1 controls dentin mineralization and odontogenesis in vivo. Fluorochrome labeling of dentin in Dmp1-null mice showed a diffuse labeling pattern with a 3-fold reduction in dentin appositional rate compared to controls. Deletion of DMP1 was also associated with abnormalities in the dentinal tubule system and delayed formation of the third molar. Unlike the mineralization defect in Vitamin D receptor-null mice, the mineralization defect in Dmp1-null mice was not rescued by a high calcium and phosphate diet, suggesting a different effect of DMP1 on mineralization. Re-expression of Dmp1 in early and late odontoblasts under control of the Col1a1 promoter rescued the defects in mineralization as well as the defects in the dentinal tubules and third molar development. In contrast, re-expression of Dmp1 in mature odontoblasts, using the Dspp promoter, produced only a partial rescue of the mineralization defects. These data suggest that DMP1 is a key regulator of odontoblast differentiation, formation of the dentin tubular system and mineralization and its expression is required in both early and late odontoblasts for normal odontogenesis to proceed.
authors.affiliation: Department of Oral Biology, School of Dentistry, University of Missouri-Kansas City, 650 E. 25th Street, Kansas City, MO 64108, USA.
authors.forename: Yongbo
authors.initials: Y
authors.lastname: Lu
authors.forename: Ling
authors.initials: L
authors.lastname: Ye
authors.forename: Shibin
authors.initials: S
authors.lastname: Yu
authors.forename: Shubin
authors.initials: S
authors.lastname: Zhang
authors.forename: Yixia
authors.initials: Y
authors.lastname: Xie
authors.forename: Marc D
authors.initials: MD
authors.lastname: McKee
authors.forename: Yan Chun
authors.initials: YC
authors.lastname: Li
authors.forename: Juan
authors.initials: J
authors.lastname: Kong
authors.forename: J David
authors.initials: JD
authors.lastname: Eick
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Dallas
authors.forename: Jian Q
authors.initials: JQ
authors.lastname: Feng
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D017931:DNA Primers; D003804:Dentin / Q000378:metabolism*; D016326:Extracellular Matrix Proteins / Q000235:genetics* / Q000378:metabolism*; D005456:Fluorescent Dyes; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D051379:Mice; D008822:Mice, Transgenic; D008855:Microscopy, Electron, Scanning; D009804:Odontoblasts / Q000378:metabolism / Q000502:physiology; D009805:Odontogenesis / Q000235:genetics / Q000502:physiology*; D016133:Polymerase Chain Reaction; D011859:Radiography; D018167:Receptors, Calcitriol / Q000235:genetics; D014070:Tooth / Q000737:chemistry / Q000000981:diagnostic imaging / Q000648:ultrastructure
chemical_list: D017931:DNA Primers; C513308:Dmp1 protein, mouse; D016326:Extracellular Matrix Proteins; D005456:Fluorescent Dyes; D018167:Receptors, Calcitriol