title: Circling behavior developed in Dmp1 null mice is due to bone defects in the vestibular apparatus.
abstract: With age, there is a progressive loss of body balance function. Yet, the potential influence of osteoporosis on body balance is largely unknown. Dentin matrix protein 1 (DMP1) is highly expressed in bone and required for phosphate homeostasis and mineralization. Dmp1 null mice display striking defects in bone structure. In this study we reported circling behavior and hyper reaction to touching in Dmp1 null mice. Our histology, tartrate resistant acid phosphatase (TRAP) staining and µCT data showed dramatic changes, such as an expansion of poorly mineralized matrices, in the Dmp1 null porous bony structure in the vestibular apparatus. The targeted re-expression of DMP1 in the Dmp1 null bone fully rescued not only the bone phenotype, but also circling behavior and hyper reaction. Furthermore, X-gal stain and DMP1 immunohistochemistry assay showed that DMP1 was not expressed in neuron cells or balance related cells in the inner ear, suggesting that a defect in the bony labyrinth of the internal ear is indirectly responsible for the circling behavior and/or hyper reaction to touching. Finally, discovery of DMP1 lacZ signal in pericyte-like cells may suggest a new function of DMP1 in angiogenesis.
authors.affiliation: The State Key Laboratory Breeding Base of Basic Science of Stomatology Hubei-MOST & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Lv
authors.forename: Haiyang
authors.initials: H
authors.lastname: Huang
authors.forename: Yongbo
authors.initials: Y
authors.lastname: Lu
authors.forename: Chunlin
authors.initials: C
authors.lastname: Qin
authors.forename: Zubing
authors.initials: Z
authors.lastname: Li
authors.forename: Jian Q
authors.initials: JQ
authors.lastname: Feng
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D001847:Bone Diseases / Q000235:genetics* / Q000473:pathology* / Q000503:physiopathology; D016326:Extracellular Matrix Proteins / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D014722:Vestibule, Labyrinth / Q000378:metabolism* / Q000473:pathology* / Q000503:physiopathology; D055114:X-Ray Microtomography
chemical_list: C513308:Dmp1 protein, mouse; D016326:Extracellular Matrix Proteins