title: Bone matrix hypermineralization in prolyl-3 hydroxylase 1 deficient mice.
abstract: Lack of prolyl 3-hydroxylase 1 (P3H1) due to mutations in P3H1 results in severe forms of recessive osteogenesis imperfecta. In the present study, we investigated the bone tissue characteristics of P3H1 null mice. Histomorphometric analyses of cancellous bone in the proximal tibia and lumbar vertebra in 1-month and 3-month old mice demonstrated that P3H1 deficient mice had low trabecular bone volume and low mineral apposition rate, but normal osteoid maturation time and normal osteoblast and osteoclast surfaces. Quantitative backscattered electron imaging revealed that the bone mineralization density distribution was shifted towards higher values, indicating hypermineralization of bone matrix. It thus appears that P3H1 deficiency leads to decreased deposition of extracellular matrix by osteoblasts and increased incorporation of mineral into the matrix.
authors.affiliation: Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of WGKK and AUVA Trauma Center Meidling, 1st Med. Dept., Hanusch Hospital, Vienna, Austria.
authors.forename: Nadja
authors.initials: N
authors.lastname: Fratzl-Zelman
authors.affiliation: Shriners Hospital for Children, Research Department, Portland, OR, USA.
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Bächinger
authors.affiliation: Oregon Health and Science University, Department of Ophtalmology, Portland, OR, USA.
authors.forename: Janice A
authors.initials: JA
authors.lastname: Vranka
authors.affiliation: Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of WGKK and AUVA Trauma Center Meidling, 1st Med. Dept., Hanusch Hospital, Vienna, Austria.
authors.forename: Paul
authors.initials: P
authors.lastname: Roschger
authors.affiliation: Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of WGKK and AUVA Trauma Center Meidling, 1st Med. Dept., Hanusch Hospital, Vienna, Austria.
authors.forename: Klaus
authors.initials: K
authors.lastname: Klaushofer
authors.affiliation: Shriners Hospital for Children and McGill University, Montreal, Quebec, Canada. Electronic address: frauch@shriners.mcgill.ca.
authors.forename: Frank
authors.initials: F
authors.lastname: Rauch
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D015519:Bone Density; D001857:Bone Matrix / Q000502:physiology*; D001842:Bone and Bones / Q000378:metabolism / Q000473:pathology; D002113:Calcification, Physiologic / Q000502:physiology*; D005838:Genotype; D051379:Mice; D011393:Procollagen-Proline Dioxygenase / Q000172:deficiency* / Q000378:metabolism
chemical_list: D011393:Procollagen-Proline Dioxygenase; C030606:proline, 2-oxoglutarate 3-dioxygenase
keywords: Bone histomorphometry; Bone mineralization density distribution; Murine bone; Prolyl-3 hydroxylase-1 deficiency; Quantitative backscattered electron imaging