Mineralization defects in cementum and craniofacial bone from loss of bone sialoprotein.

摘要: Bone sialoprotein (BSP) is a multifunctional extracellular matrix protein found in mineralized tissues, including bone, cartilage, tooth root cementum (both acellular and cellular types), dentin. In order to define the role BSP plays process of biomineralization these we analyzed cementogenesis, dentinogenesis, osteogenesis (intramembranous endochondral) craniofacial bone Bsp null mice wild-type (WT) controls over developmental period (1-60 days post natal; dpn) by histology, immunohistochemistry, undecalcified histochemistry, microcomputed tomography (microCT), scanning electron microscopy (SEM), transmission (TEM), quantitative PCR (qPCR). Regions intramembranous ossification alveolus, mandible, calvaria presented delayed mineralization osteoid accumulation, assessed von Kossa Goldner's trichrome stains at 1 14 dpn. Moreover, Bsp(-/-) featured increased cranial suture size early time point, Immunostaining demonstrated that osteoblast markers, osterix, alkaline phosphatase, osteopontin were unchanged mandibles compared WT. mouse molars lack functional formation SEM, TEM, subsequent loss Sharpey's collagen fiber insertion into structure. alveolar mandibular equivalent or fewer osteoclasts ages (1 dpn), however, RANKL immunostaining mRNA, significantly number osteoclast-like cells (2-5 fold) later (26 60 corresponding periodontal breakdown severe resorption observed following molar teeth entering occlusion. Dentin was unperturbed molars, with no delay mineralization, alteration dentin dimensions, differences odontoblast markers analyzed. No defects identified endochondral base, morphology unaffected mice. These analyses confirm critical for processes cementogenesis whereas base minimally affected dentinogenesis normal teeth. Dissimilar effects on dental tissues suggest local and/or yet be defined interactions site-specific factors.