To Study The Distribution And Significance Of Sibling Albumen During Tooth And Affiliated Periodontal Tissues

The extracellular matrix (ECM) of bone and dentin contains collagen and noncollagenous proteins (NCPs). The Small Integrin-Binding LIgand, N-linked Glycoprotein (SIBLING) family is one category of NCPs, which includes dentin matrix protein 1 (DMP1), dentin sialophosphoprotein (DSPP), bone sialoprotein (BSP) ,osteopontin (OPN) and MEPE. The SIBLING family members are expressed in the mineralized tissues of bone and dentin and they believed to play important roles in the mineralization.In the ECM of bone and dentin, DMP1 mainly occurs as the proteolytically processed 37 kDa (DMP1 N-terminal) and 57 kDa (DMP1 C-terminal) fragments, which originate from the N-terminal and C-terminal regions of the DMP1 amino acid sequence respectively. The distribution of DMP1 N- and DMP1 C-terminal fragments in dentin are different: the DMP1 N-terminal is located in the unmineralized predentin while the DMP1 C-terminal is mainly found in the mineralized dentin, which suggest that these two fragments may play different roles in dentinogenesis. DSPP in the dentin and bone is present as the proteolytically processed fragments: dentin sialoprotein (DSP) and dentin phosphoprotein (DPP). BSP is primarily found in bone, cementum and tertiary dentin. The biological functions of BSP in the mineralized tissues are complex. Studies showed that BSP acts as a nucleator for the formation of initial hydroxyapatite(HA) crystals, and then, as this mineral grows on the collagen matrix, it acts as an inhibitor in directing the growth of the crystals. In the mineralized tissues, OPN is mainly found in the bone, cementum, predentin, and tertiary dentin. Both in vitro and in vivo studies have shown that OPN is an effective inhibitor of HA formation and growth.The experiment objects are 30 human teeth and affiliated periodontal tissues specimens,. The expression of SIBLING proteins which contains C-DMP1,N-DMP1,DSP,BSP,OPN were examined in human teeth and affiliated periodontal tissues by immunohistochemical technique. Immunohistochemical staining procedure was performed according to PV method.In the result,we find that :1)C-DMP1 were mainly expressed in peritubular dentin, dentinal tubules ,odontoblast and cementum, while were negtively expressed in PDL tissue and predentin.2 ) N-DMP1 were positively expressed in predentine, odontoblast cell,and strong positively expressed in PDL cell and periodontal ligament which were negtively expressed in cementum.3)OPN were positively expressed in predentine, odontoblast, alveolar bone, cementum and periodontal ligament which were negtively expressed in dentin.4)BSP were positively expressed in periodontal ligament,and strongly positively expressed in cementum, osteoblast, osteoid and alveolar bone, and which were negtively expressed in predentine and dentin.5 ) DSP were mainly expressed in dentinal tubules,and weekly expressed in odontoblast.There was no expression of DSP in predentine, alveolar bone, cementum, periodontal ligament and gingiva.According to the observation of the results above all, we can conclude that:1.The distribution of DMP1 N- and DMP1 C-terminal fragments in dentin are different further comfirm their different functions.2.DMP1 and DSP play complementary and/or synergistic roles in the formation of human healthy teeth.3.BSP and OPN have different expression levels at different locations in human teeth and periodontal tissues, they may different play important roles in the mineralization of bone or dentin matrix..