title: Absence of bone sialoprotein (BSP) impairs cortical defect repair in mouse long bone.
abstract: Matrix proteins of the SIBLING family interact with bone cells and with bone mineral and are thus in a key position to regulate bone development, remodeling and repair. Within this family, bone sialoprotein (BSP) is highly expressed by osteoblasts, hypertrophic chondrocytes and osteoclasts. We recently reported that mice lacking BSP (BSP-/-) have very low trabecular bone turnover. In the present study, we set up an experimental model of bone repair by drilling a 1 mm diameter hole in the cortical bone of femurs in both BSP-/- and +/+ mice. A non-invasive MRI imaging and bone quantification procedure was designed to follow bone regeneration, and these data were extended by microCT imaging and histomorphometry on undecalcified sections for analysis at cellular level. These combined approaches revealed that the repair process as reflected in defect-refilling in the cortical area was significantly delayed in BSP-/- mice compared to +/+ mice. Concomitantly, histomorphometry showed that formation, mineralization and remodeling of repair (primary) bone in the medulla were delayed in BSP-/- mice, with lower osteoid and osteoclast surfaces at day 15. In conclusion, the absence of BSP delays bone repair at least in part by impairing both new bone formation and osteoclast activity.
authors.affiliation: Université de Lyon, Saint-Etienne, F42023, France. luc.malaval@univ-st-etienne.fr
authors.forename: Luc
authors.initials: L
authors.lastname: Malaval
authors.forename: Laurent
authors.initials: L
authors.lastname: Monfoulet
authors.forename: Thierry
authors.initials: T
authors.lastname: Fabre
authors.forename: Laurent
authors.initials: L
authors.lastname: Pothuaud
authors.forename: Reine
authors.initials: R
authors.lastname: Bareille
authors.forename: Sylvain
authors.initials: S
authors.lastname: Miraux
authors.forename: Eric
authors.initials: E
authors.lastname: Thiaudiere
authors.forename: Gerard
authors.initials: G
authors.lastname: Raffard
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Franconi
authors.forename: Marie-Hélène
authors.initials: MH
authors.lastname: Lafage-Proust
authors.forename: Jane E
authors.initials: JE
authors.lastname: Aubin
authors.forename: Laurence
authors.initials: L
authors.lastname: Vico
authors.forename: Joëlle
authors.initials: J
authors.lastname: Amédée
mesh_terms: D000818:Animals; D016723:Bone Remodeling; D001842:Bone and Bones / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D058574:Integrin-Binding Sialoprotein; D008279:Magnetic Resonance Imaging; D051379:Mice; D012795:Sialoglycoproteins / Q000172:deficiency* / Q000378:metabolism; D014945:Wound Healing; D055114:X-Ray Microtomography
chemical_list: C546872:Ibsp protein, mouse; D058574:Integrin-Binding Sialoprotein; D012795:Sialoglycoproteins